Alfano, Flora, Maria Cammareri, Angela Errico, Luigi Frusciante and Clara
Conicella. (1999) "2n Gametes in Solanum Tuberosum Dihaploids." [Vol.
76, No. 5, 281-285]
Pollen stainability over two years and microsporogenesis were investigated in seven dihaploids extracted
from Solanum tuberosum tetraploids (AVRDC1287.19, Conchita, Merrimack and W231). Two dihaploids proved to be male-sterile
and male gamete abortion is likely to be post-meiotic because a regular meiosis occurred. The other dihaploids proved to be partially
male-fertile and 2n pollen producers, as well. Almost all clones showed predominantly the formation of parallel spindles. Correlations
estimated between the observed abnormalities in spindle orientation and the meiotic products evidenced a high correlation between
parallel/fused spindles and dyads. The dihaploids were also used as parents in crosses with tetraploids. One berry with 44 seeds was
obtained from dihaploid AVI 24 used as pollen parent in 4x x 2x crosses. After 2x x 4x crosses, three dihaploids Including the two
male-sterile were found to be 2n egg producers. The formation of 2n gametes in S. tuberosum dihaploids is discussed in relation to
a direct use of dihaploids in sexual polyploidization schemes to combine useful traits in a superior genotype at 4x level.
Arce, Patricio, Mauricio Moreno, Monica Gutierrez, Marlene Gebauer, Paola Dell'Orto, Hebert Torres,
Ivette Acuna, Pauline Oliger, Alejandro Venegas, Xavier Jordana, Julio Kalazich and Loreto Holugue. "Enhanced Resistance to
Bacterial Infection by Erwinia Carotovora Subsp. Atroseptica in Transgenic Potato Plants Expressing the Attacin or the Cecropin SB-37
Genes."
[Vol. 76, No. 3, 169-177]
Blackleg and soft rot diseases, caused by the bacterium Erwinia carotovora, are among the diseases that cause important
losses in culture and storage of potato. In this paper, we introduced bacterial resistance into potato, via genes encoding for proteins with
antibacterial activity. For this purpose, potato clones were transformed either with the gene encoding the acidic attacin protein from
Hyalophora cecropia, or with the gene encoding the cecropin analog peptide SB-37. These clones were evaluated for soft rot and
blackleg resistance, after inoculation with the bacterial strain Erwinia carotovora subsp. atroseptica T7. Results reported in
this paper indicate that a considerable percentage of the potato clones (15-22%) showed increased resistance to bacterial infection,
revealed by reduced severity of blackleg or soft rot symptoms. Expression of the transgenes was demonstrated in some of the clones by
Northern blot analysis. This is the first report indicating that expression of the gene encoding for an attacin protein and for the cecropin
SB-37 peptide in transgenic potato confers increased resistance to bacterial infection.
Arsenault, WJ and A Malone. "Effects of Nitrogen Fertilization and In-row Seedpiece Spacing
on Yield of Three Potato Cultivars in Prince Edward Island." [Vol. 76, No. 4, 227-229]
AC Novachip and NorWis were recently introduced as new potato (Solanum tuberosum L.) chip cultivars on Prince Edward Island
(P.E.I.), Canada. Variability of nitrogen application and in-row seedpiece spacing, required for maximum yield, exist among cultivars presently
grown in P.E.I. This study was conducted to determine the N rate and in-row seedpiece spacing required for optimum production of AC
Novachip and NorWis compared to the standard cultivar Norchip, and also, to determine the effects of treatments and harvest dates on AC
Novachip. Treatments included N applied at 90, 134, and 179 kg/ha with in-row seedpiece spacings at 20.3, 25.4 and 30.5 cm. In addition to
the 120 day harvest for all three cultivars, treatments for AC Novachip were also harvested at 80 and 100 days after planting. For the 120
day harvest, yield of Canada No. 1 size tubers was higher for NorWis compared to Norchip while yields for AC Novachip and Norchip were
similar. Nitrogen application had no effect on yields of AC Novachip. Similar to Norchip, increasing the rate of applied N more than 134 kg/ha
resulted in little or no Increase in yields of NorWis. Yields of Canada No. 1 size tubers decreased as in-row spacing increased for AC
Novachip and were greater at 25.4 compared to 30.5 cm spacing for Norchip. In-row seed-piece spacing had no affect on Canada No. 1
size tuber yields of NorWis. Increasing the days to harvest increased the yields of AC Novachip. Nitrogen rate or in-row spacing had no
effect on Canada No. 1 yields of AC Novachip at the 80 and 100 day harvests. The results of this study suggest that little gain in yield of
Canada No. 1 size tubers for NorWis, similar to the standard cultivar Norchip, can be obtained with N application more than 134 kg/ha
or for AC Novachip by increasing the rate of N from 90 to 179 kg/ha. Unlike NorWis yields of AC Novachip and NorWis are reduced
when in-row seedpiece spacing is increased from 25.4 to 30.5 cm.
Aziz, A Naseer, Janet EA Seabrook, George CC Tai and Hielke De Jong. "Screening Diploid Solanum
Genotypes Responsive to Different Anther Culture Conditions and Ploidy Assessment of Anther-Derived Roots and Plantlets."
[Vol. 78, No. 1, 9-16]
Twenty-three diploid (2n-2x-24) potato clones were screened for response to four different anther culture media. Anther derived tissues
(calli/embryos) were obtained from seven of the clones in liquid culture media. Anther culture response of these seven clones was further
quantified on five additional media. Since clonal responses are specific to culture conditions (Tiainen, 1992), the seven genotypes
somewhat differed from each other in the magnitude of the response to each of the media. In agreement with Heberle-Bors (1985) a more
realistic assessment of the responsiveness was possible when pollen counts per anther were used to express the yield of anther-derived
material. A relatively higher level of exogenous cytokinin (6-benzyladenine) to that of auxin (3-indoleacetic acid) proved to be favorable for the
induction of calli/embryos. Use of a semi-solid medium saved space and was convenient for culture observations therefore it was found
more conducive for the genotypic screening. Anther derived tissues that regenerated to produce root tissue and/or plantlets were further
multiplied on a root culture medium and a plantlet medium. Liquid culture conditions on orbital shakers were conducive for the growth of root
explants. Anther derived material (roots and plantlets) originating from clone 9507-04 revealed differences in growth vigor. Flow
cytometric estimation of ploidy in regenerated roots and plantlets, revealed that clone 9507-04 revealed differences in growth vigor. Flow
cytometric estimation of ploidy in regenerated roots and plantlets, revealed that clone 9507-04 produced 44% monoploid roots and 77%
monoploid plantlets. Seventy three percent anther-derived plantlets from clone 6028-02 were monoploids.
Aziz, A Naseer, Janet EA Seabrook and George CC Tai. "Amplification of RAPD Markers From
Single Pollen Grains of Diploid (2N=2X-24) Potato." [Vol. 76, No. 4, 179-182]
Pollen grains from a diploid Solanum clone 9507-04 were used for RAPD analysis. Single pollen grains were isolated from
pollen in liquid suspension, or from dry pollen spread on a glass slide, and collected in individual PCR tubes. Dry pollen isolation was
found advantageous due to the convenience of handling and reduction in DNA cross-contamination. Primers UBC291 and UBC504 were
selected for the RAPD analysis of both the pollen samples and the pollen donor. Solanum clone 9507-04 produced three RAPD
markers UBC291-1.4, UBC291-0.8 and UBC291-0.4, under the selected PCR conditions. UBC504-1.17, UBC504-0.96, and UBC504-0.78
was also tested in a selected pollen sample. RAPD products were discernible from single pollen grains without requiring any DNA extraction
procedures. The three UBC291 amplified RAPD markers of the parent segregated in the selected sample of 60 pollen grains. Potential
applications of the RAPD analysis of single pollen grains are described.
Bains, Piara S, Vikram S Bisht, Dermot R Lynch, Lawrence M Kawchuk and John P Helgeson.
"Identification of Stem Soft Rot Erwinia Carotovora Subspecies Atroseptica) Resistance in Potato."
[Vol. 76, No. 3, 137-141]
Development of potato cultivars resistant to Erwinia species (Erwinia carotovora subspecies atroseptica, E. carotovora
subspecies carotovora, and Erwinia chrysanthemi) causing soft rot of stems and tubers involves identification and transfer
of the resistance to breeding lines possessing desirable agronomic traits. In total, 363 accessions of six wild Solanum species,
three somatic hybrids and nine sexual progeny of somatic hybrids were screened for stem soft rot resistance. Thirty-one, 50, and 67 percent
of accessions of Solanum boliviense, Solanum chacoense, and Solanum sancta-rosae, respectively, were resistant or
highly resistant, whereas, 100, 97, and 95 percent of accessions of Solanum canasense, Solanum tarijense, and Solanum
spegazzinli were susceptible or highly susceptible, respectively. Two tuber soft-rot resistant somatic hybrids, A937 and T355-11
produced earlier by the fusion of Solanum brevidens (P1 218228) and Solanum tuberosum (P1203900) or S.
tuberosum cv. Russet Burbank, respectively, and the sexual progeny of A937 and S. tuberosum cv. Katahdin were also highly
resistant. Transfer of resistance from S. brevidens to somatic hybrid (A937) and subsequently to the progeny suggests that the
resistance is simply inherited. In addition to the identification of 65 resistant or highly resistant clones of wild Solanum species, this
study has identified three tuber soft rot-resistant clones that are also resistant to stem soft rot. Potato cultivars showed a range of responses
to the pathogen.
Bamberg, John B. "Screening for Gibberellin Deficiency Mutants in Solanum tuberosum
ssp. Andigena" {Vol. 76, No. 5, 321-322]
A GA deficiency mutant was previously described in a single population of Solanum tuberosum ssp. andigena (adg).
A representative sample of 120 adg populations in the US Potato Genebank was screened for the dwarfing mutant. Up to 500 seedlings of
each adg population were evaluated. Dwarfs were detected in 14 populations from a minimum of 0.2% to a maximum of 27.7%, indicating
that the allele is not particularly rare or at risk of loss from the Genebank.
Bamberg, JB. "Dependence on Exogenous Gibberellin for Seed Germination in Solanum
acaule Bitter and Other Solanum (Potato) Species." [Vol. 76, No. 6, 351-355]
Certain seed populations of the wild potato species Solanum acaule Bitter were identified as having consistent qualitative
dependence on GA to germinate. This was true for both germination in petri plates and in greenhouse conditions. The effect could be
transmitted across sexual generations. Progeny from crosses with GA-independent populations were intermediate, with no consistent
reciprocal effect. A broad survey of 2,580 populations including 60 potato species indicated that significant dependence on GA also exists
in other species. This trait may have physiological and evolutionary implications worth further investigation. Recognizing that populations
of some species are highly dependent on GA allows genebank managers and other potato scientists to accurately assess seed viability
and avoid inadvertent selection against useful traits which may be linked.
Bartz, Jerry A. "Suppression of Bacterial Soft Rot in Potato Tubers by Application of
Kasugamycin." [Vol. 76, No. 3, 127-136]
An immersion in aqueous solutions of KasuminR, containing kasugamycin at 10 to 320 mg/L
(ppm) for 1 to 320 sec delayed or prevented the development of soft rot on inoculated (Erwinia carotovora subsp. carotovora)
tuber disks incubated over wet filter paper at 24C for 24 to 72 hr. Treatment efficacy decreased as inoculum level and incubation period
increased. Short immersion periods were not as effective as longer ones. When stored tubers were inoculated from E. c. carotovora
and incubated up to 5 days in fog chamber at 20 C, immersion treatments in 20 to 400 ppm kasugamycin either had no effect or increased
soft rot development. By contrast, when the stored tubers were cut into sections before inoculation and treatment, immersion in 300 ppm
reduced soft rot development on the cut surfaces from 83% (inoculated controls) to 3.2%. With non-inoculated sections, treatment with 25
ppm reduced the SAD from 13.3 to 0.6%. Wash or rinse treatment of freshly harvested tubers in 40 to 160 ppm produced a significant
reduction in the severity of bacterial soft rot among tubers incubated for 72 to 96-hr. The 160-ppm treatment delayed disease onset by at
least 24 hr. Pre-washing freshly harvested tubers with clean or chlorinated water prior to antibiotic treatment did not consistently improve the
efficacy of the kasugamycin treatment.
Boiteau, Gilles and RP Singh. "Field assessment of Imidacloprid to Reduce the Spready of
PVYo and PLRV in Potato." [Vol. 76, No. 1, 31-36]
A three year field study conducted at the Potato Research Centre in Fredericton, New Brunswick, showed that imidacloprid applied in
furrow at planting or twice to the foliage in mid July could result in a limited reduction of PLRV spread in the potato crop. Tests did not
determine any significant effect on the reduction of the spread of PVY. The aphicidal property of imidacloprid was confirmed.
Brown, CR, M McNabnay and B Dean. "Genetic Characterization of Reduced Melanin Formation
in Tuber ‘flssue of Solanum hjertingii and Hybrids With Cultivated Diploids" [Vol. 76, No. 1, 37-43]
The degree of enzymatic browning in tubers was examined quantitatively in five plant introduction (P1) accessions of Solanum
hjertingii and in hybrids of this species with cultivated diploids that had high enzymatic browning. Polyphenol oxidase activity and
melanin formation in S. hjertingii accessions was subjected to an analysis of variance. There was significant variation in melanin
formation within accessions but the between accession component was not significant. This indicates that it would be most advantageous
to select low melanin formation by evaluating individual genotypes within an accession. Significant variation for PPO activity existed between
accessions, indicating that selection on the basis of accession means would be the best means of selecting for lower PPO activity. Both
parameters were much lower in all S. hjertingii genotypes compared to tetraploid cultivars known for their susceptibility to internal
blackspot when mechanically damaged. The reduced browning in S. hjertingii was due to a lack of PPO activity and not the shortage
of substrate. Progenies, and parents of four crosses between selected S. hjertingii genotypes and cultivated diploids were
measured for PPO activity and melanin formation. The mean performance of the progenies was closest to the S. hjertingii parent in
all cases. Degree of dominance indicated nearly complete dominance or overdominance In the direction of the S. hjertingii parent.
These results are discussed in light of other work which indicates that protein antigenic to PPO antibody is present in S. hjertingii.
It appears that inactive PPO is present in the tubers. The pronounced dominance of low PPO activity and suppression of melanin formation
in the hybrids with S. hjertingii is promising for the utility of this wild species as a source of genetic factors that, upon introgression
into the cultivated potato gene pool, would suppress browning.
Chacon, MG, RL Plaisted and BB Brodie. "Inheritance of the Resistance to Globodera
Rostochiensis Pathotype Ro2 in Potato." [Vol. 76, No. 6, 345-349]
Nine advanced tetraploid potato clones with S. tuberosum ssp. tuberosum, S. tuberosum ssp. andigena, and
S. vernei were found to be highly resistant to Globodera rostochiensis pathotype Ro2. In order to characterize the inheritance
of the resistance to Ro2 and determine the genotype of these Ro2-resistant clones, a series of test crosses to susceptible S.
tuberosum cultivars, as well as crosses between the resistant clones, were made. A total of 1081 seedlings corresponding to
18 families were grown, inoculated with 3000 G. rostochiensis juveniles (J2), and evaluated by the root-ball method. To determine
which genetic model best fit the data, goodness-of-fit-tests were performed. The analysis assumed tetrasomic inheritance under the
hypothesis that resistance is due to one locus with complete dominance. From the analysis of the data it is concluded that there is no
consistent evidence against the hypothesis that a single dominant gene is associated with the resistance to Ro2 and that the Ro2-
resistant clones are simplex. In general, the number of cysts observed on the root balls was low compared with the results of other studies,
the results of the different inoculations were variable, and there was an excess of resistant plants. Possible explanations for these
observations are discussed.
Connell, Timothy R, Larry K Binning and William G Schmitt. "A Canopy Development Model for
Potatoes." [Vol. 76, No. 3, 153-159]
Potatoes (Solanum tuberosum) in Wisconsin are predominately grown on soils that have a high potential for agrichemical
leaching. Weed control strategies are not designed for season long control from a single high rate herbicide application but for reduced
rates combined with mechanical and cultural strategies. The current recommended herbicide rates provide 7-9 weeks of efficacy.
Mechanical measures provide effective early season control, but development of crop canopy prevents cultivation after about four weeks.
Past studies have shown that shade levels comparable to those in a potato canopy can significantly reduce weed biomass. This study
was initiated to develop a canopy development model and evaluate the difference between Superior and Russet Burbank potatoes. Plots
were established in 1988-1992 at the Hancock Agricultural Research Station on Plainfield loamy sand (mixed, typic Upsidaments).
Light readings were taken both under the crop canopy and in full sunlight to determine the amount of shading provided by the crop.
Physiological Degree Days (P-day) were used to monitor the development of the potato varieties. Regression analysis was used to
determine if P-days could be used as a predictor for canopy development. Superior reached maximum canopy (88% shade) at seven
weeks after emergence (WAE) and maintained it until 9 WAE. Russet Burbank reaches maximum canopy at 8 WAE (98% shade) and
maintains shading above 80% until 13 WAE. The canopy model is an empirical relationships estimated using regression techniques,
and is currently being utilized in a weed management module for the WISDONc software program.
Corsini, D, J Pavek, C Brown, D Inglis, M Martin, M Powelson, A Dorrance and H Lozoya-Saldana.
"Late Blight Resistant Potato Germplasm Release AWN86514-2." [Vol. 76, No. 1, 45-49]
Potato breeding selection AWN86514-2, Solanum tuberosum gp tuberosum, is being released as germplasm
that is highly resistant to prevalent North American strains of Phytophthora infestans. This selection has been tested under field
conditions in Mount Vernon, Washington (P. infestans US11 and US8 with complex virulence pathotypes), as well as Corvallis,
Oregon, and eight other locations in North America. (predominately P. infestans US8) between 1994 and 1997. Both foliage and
tubers show partial resistance. Although AWN86514-2 is pollen sterile, it can be successfully used as a female parent. An average of
34% of the progeny from crosses between AWN 86514-2 and four susceptible clones were resistant to late blight when tested at Toluca,
Mexico in 1996. AWN86514-2 also has high resistance to Verticillium wilt and potato virus Y. AWN86514-2 is late maturing, with medium
yields of smooth, long-oblong, buff-skinned tubers. Specific gravity is high and french fry color from 7 C (45 F) storage is excellent. The
male parent of AWN86514-2 was Ranger Russet, a dual purpose french fry and fresh market variety, and the female parent was
KSA195-96, a selection made at Aberdeen, Idaho, from Polish germplasm received as true seed from the Polish Plant Breeding and
Acclimatization Institute. Possible sources of the late blight resistance in this clone include S. acaule, S. demissum, S. phureja, S.
simiplicifolium, S. stoloniferum, and S. tuberosum gp andigena which are in the lineage of KSA195-96. This
germplasm was developed and released by USDA-ARS in cooperation with the Agricultural Experiment Stations in Idaho, Oregon, and
Washington.
Corsini, Dennis Corsini, Jeff Stark and Mike Thornton. "Factors Contributing to the Blackspot
Bruise Potential of Idaho Potato Fields." [Vol. 76, No. 4, 221-226]
Blackspot bruise is a major problem in the fresh market and frozen french fry industry. The blackspot bruise potential of Russet Burbank
and Ranger Russet in Idaho potato fields was determined by surveying commercial fields during 1993 and 1994. Management factors were
monitored to determine what practices were contributing to blackspot susceptibility in addition to mechanical damage. The survey included
17 Russet Burbank and 3 Ranger Russet fields in 1993, and 28 Russet Burbank and 8 Ranger Russet fields in 1994. The 1993 season
was unusually cool and wet whereas 1994 was warmer than normal, resulting in a wide range of environmental conditions for the 2 year
study. Blackspot bruise potential was determined at different stages of tuber physiological maturity by collecting samples several weeks
prior to normal harvest, immediately before harvest, and after storing sub-sam-pies for several months. The blackspot bruise potential was
measured by both impact and abrasive peel tests.
Field maturity was the factor most consistently related to blackspot potential both years. In 1994 a multiple regression of 3 independent
variables - field maturity index, specific gravity, and percent available soil water at tuber sampling, compared with the blackspot potential as
the dependent variable gave a correlation coefficient of r = 0.73 (p = 0.001). Due to the cool, wet growing season in 1993, there was not
enough variability in specific gravity and available soil water among the fields sampled for these factors to correlate with the blackspot
potential. The available fertility data, although not complete for all fields, indicated no direct relationship between N, P, or K fertilization and
blackspot potential. Preharvest samples in late August had lower blackspot potential than harvest samples in mid September, and storage
samples in February had the highest susceptibility. There was a consistent increase in blackspot severity when tubers were equilibrated at
4 C compared with 10 C prior to bruising.
Creamer, NG, CR Crozier and MA Cubeta. "Influence of Seedpiece Spacing and Population on
Yield, Internal Quality and Economic Performance of Atlantic, Superior, and Snowden Potato Varieties in Eastern North Carolina."
[Vol. 76, No. 5, 257-261]
In recent stand assessment surveys on North Carolina farms, potato plant stands averaged only 67% of target populations. In
response to these findings, this study was designed to determine the effects of seedpiece spacing and varying seedpiece populations on
yield, internal quality, and economics of three potato varieties commonly grown in North Carolina: Atlantic, Snowden, and Superior. The
three varieties responded differently to changes in spacing and population. Atlantic was sensitive to differences in spacing and populations
with reduced yields of grade A tubers as spacing increased above 23 cm. Atlantic was not able to compensate for wide (46 cm) spacing,
even when seedpiece populations were high (double planted every 46 cm). Yield of B tubers was greater for 15 cm spacing and decreased
significantly as spacing was increased. Yield of Superior was affected less by increases in spacing than decreases in population. Superior
was able to compensate for wide gaps in spacing if seedpiece populations were high. Superior produced more B tubers at the 15 cm
spacing, and less at the 46 cm spacing. Yield of grade A Snowden tubers did not differ with spacing or population; however, there were
more B tubers in the 15 cm, 23 cm, and 46 cm (doubles) treatments than the wider spacing treatments. Incidence of hollow heart and heat
necrosis increased in Atlantic in treatments that tended to have larger tubers. Economic analyses of data suggest that growers can
significantly increase profit/hectare by optimizing spacing and populations with Atlantic and seedpiece populations in Superior.
Crosslin, James M, Peter E Thomas and Charles R Brown. "Distribution of Tobacco Rattle
Virus in Tubers of Resistant and Susceptible Potatoes and Systemic Movement of Virus into Daughter Plants."
[Vol. 76, No. 4, 191-197]
Fifty-nine potato cultivars or breeding clones were planted near Umatilla, OR and/or Pasco, WA, in fields known to be infested with
tobacco rattle virus (TRV) and vector nematodes, Paratrichodorus allius Jen. (Sid.). Tubers from these field plots were cut and
examined for corky ringspot (CRS) symptoms. Reverse transcription-polymerase chain reaction (RT-PCR) for TRV was conducted on
tissue samples from symptomatic and asymptomatic tubers. Sixty-five percent of the symptomatic and 42% of the asymptomatic tissue
samples from CRS symptomatic tubers contained detectable TRV. Approximately 2% of plants grown from either symptomatic or
asymptomatic tubers contained TRV when tested by ELISA, whereas 20% and 12% of plants grown from symptomatic and asymptomatic
tubers, respectively, were positive for TRV by RT-PCR. These results suggest that RT-PCR is a more sensitive assay for detection of TRV.
Systemic infections by TRV were detected more often in foliage of CRS-susceptible genotypes. Daughter tubers exhibiting symptoms of
CRS, and which contained RT-PCR detectable TRV, were produced on plants of three genotypes, including one from an asymptomatic
parent tuber.
CURWIN, DAVID. "News and Reviews-Memoriam" [Vol. 76, No. 1, 51]
David Curwen died at his home on August 23, 1998 at the age of 63. He was born on May 25, 1935 in Ridgewood, New Jersey, the son
of the late William and Joan Curwen. He attended schools in Ridgewood, and then attended the University of Vermont, receiving a B.S. in
Agriculture. He then completed his M.S. and Ph.D. at Penn State University in Horticulture. While completing his Ph.D. requirements, Dave
came to Wisconsin and began work in extension for the University of Wisconsin as Vegetable Crop Specialist, Horticulture, Serving the
expanding vegetable growing area of Central Wisconsin. His office was located at the University of Wisconsin Hancock Agricultural Experiment
Station in the center of the rapidly growing potato and vegetable area. Dave, as a diligent team worker in potato extension and research,
published over 100 formal publications and over 70 Extension Bulletins during his 30 year career with the University of Wisconsin. Dave as
the leader in developing the first Integrated Pest Management (IPM) program in Wisconsin. This idea was well received by potato and
vegetable growers, and it is still be implemented in newer programs. He also lead in the development of the Wisconsin Irrigation
Scheduling Program (WISP), the Potato Crop Management Program (PCM), and also contributed to the development of the new Integrated
Pest Management WISDOM program.
Dave was awarded the Wisconsin Potato & Vegetable Growers Association's Research and Education Award in 1984. In 1989 he
received a citation from the Wisconsin Legislature for his Wind Control work. He also received research awards from the Stevens
Point-Plover area Chamber of Commerce and Ore-Ida Foods in 1993 and 1994. On March 26, 1998, he was inducted into the Wisconsin
Potato and Vegetable Growers Association Hall of Fame. He served as chairman of the PAA Extension Section for several years and also
as am ember of the Editorial Board. Most significant and appreciated by all the PAA members was his dedicated service as Secretary of the
PAA for 10 years. Dave retired from the University of Wisconsin in 1994 and had a few years to enjoy some time of his own with his family.
He is survived by his wife Barbara and six children, 17 grandchildren and one brother, Peter Curwen.
Daayf, Fouad and HW (Bud) Platt. "Assessment of Mating types and Resistance to Metalaxyl of
Canadian Populations of Phytophthora infestans in 1997." [Vol. 76, No. 5, 287-295]
The distribution of Al and A2 mating types, and of metalaxyl-sensitive (MS), metalaxyl-intermediate (MI), and metalaxyl-resistant (MR)
strains of Phytophthora infestans, the causal pathogen of late blight, were determined in Canada in 1997. Potato plants or tubers
and tomato plants or fruits, suspected to have late blight infection, were received from seven Canadian provinces in 1997, and were
assessed for the presence of P. infestans. Among 220 samples suspected to have late blight, P. infestans was recovered
from 132 samples (60%) received from British Columbia (BC), Manitoba, New Brunswick, Prince Edward Island, and Quebec. From the
132 samples, 364 isolates were obtained and tested for their mating type and response to metalaxyl. Populations of P. infestans
within Canadian provinces were homogeneous for mating types, except within BC, where populations comprised both Al and A2 mating
types both within fields and sometimes within samples. The A2 mating type was found in all provinces where late blight was present. The
Al mating type was found only in Manitoba (1 isolate) and hi BC (38 isolates). Unlike the old Al isolates, those found in BC in 1997 were
highly resistant to metalaxyl. These Al isolates are even more resistant than A2 isolates. Based on assays with 10 pg. mi’ of
metalaxyl, 14% of all tested isolates were MS, 69.8% were MI and 16.2% were MR. In addition, all provinces contained MS, MI, and MR
isolates. No specific mating type or metalaxyl sensitivity level were specific to tomato or potato.
de Souza-Dias, JAC, P Russo, L Miller and SA Slack. "Comparison of Nucleotid Seqiences
from Three Potato Leafroll Virus (PLRV) Isolates Collected in Brazil." [Vol. 76, No. 1, 17-24]
Polymerase chain reaction linked automated sequencing was used to compare the relatedness of Brazilian (BR) potato leafroll luteovirus
(PLRV) isolates. By comparing PLRV genomic sequences from Holland, Poland, Canada, Scotland, and Australia (GeneBank), three primer
pairs were designed and made that would hybridize to all give isolates, and amplifying three variable regions which display distinctive
nucleotide variations in each isolate. These primer pairs were used in the reverse-transcription polymerase chain reaction (RT-PCR) to
analyze analogous variable regions in three PLRV isolates from around Sao Paulo State, BR (two from field potatoes grown 500 km apart,
one from Datura stramonium). Each primer pair amplified a DNA product of predicted size from the CR isolates and a Wisconsin
(USA) isolate, and all PCR products were directly sequenced. Comparisons of the variable region sequences from the three Brazilian
isolates to the give isolates from GeneBank and the one from Wisconsin revealed that the BR isolates were approximately 99% homologous
with each other, 97% with the European and Canadian isolates, and 95% with the USA and Australian isolates. These results suggest that
the primer pairs utilized in this study can be used to detect PLRV (by RT-PCR) for diagnostic purposes, and can further be used to
differentiate between different PLRV isolates (when RT-PCR is linked to automated sequencing) for epidemiological purposes.
de Souza-Dias, JAC, P Russo, JA Betti, LMiller and SA Slack. "Simplified Extraction
Method for ELISA and PCR Detection of Potato Leafroll Luteovirus Primary Infection in Dormant Potato Tubers."
[Vol. 76, No. 4, 209-213]
This report describes a simple, rapid and inexpensive procedure for sampling large numbers of dormant tubers for analysis of potato
leafroll luteovirus (PLRV) infection. The procedure uses a common electric drill to simultaneously remove and macerate tuber-eye samples
for detection of PLRV by the enzyme-linked immunosorbant assay (ELISA) and the polymerase chain reaction (PCR). By using these
sampling and analysis approaches, 19 of 20 different PLRV isolates were detected in dormant tubers from plants with primary infections.
Results from the dormant tuber analysis, were verified by planting the tubers and testing leaf tissue by ELISA and PCR. Similar sampling
and testing done on healthy dormant tubers and sprouts from the tubers consistently gave negative results as expected.
DOUGLAS, DEXTER RICHARD..Memorandam, "News and Reviews.";
[Vol. 76, No. 4, 255]
[1937-1999] Dexter Richard Douglas, 61, plant pathologist and certified seed potato grower, died Friday, February 26, 1999 at Lost
Rivers Hospital in Arco, Idaho of cancer. He was born November 14, 1937 at Benton, Ohio, a son of Richard L. and Dorothy Phillabaurn
Douglas. He graduated from Fredericksburg, Ohio High School in 1955. He was employed by Rubbermaid for one year, then enrolled at
Kent State University. In 1962 he graduated with a B.S. degree. On May 26, 1962 he married Bernadine Bresson at Wooster, Ohio. He served
in the U.S. Army Veterinary Corps, at Fort Gordon, Georgia. After his discharge, he attended graduate school at the University of Wyoming,
receiving a master’s degree in plant pathology in 1965. He studied plant pathology at the University of Minnesota, receiving a doctorate
of philosophy in plant pathology in December 1968. Dr. Douglas accepted a position as Western States Plant Pathologist with the U.S.
Department of Agriculture at the University of Idaho Experiment Station in Aberdeen. They moved to Jerome in 1976, where he worked for
Chemical Supply Company. In 1978 they moved to Arco, where he owned and operated Hi Alta Seed Potato Farm in Moore, raising potato
farm varieties for seed and commercial use. He served as chairman of the Idaho Crop Improvement Association and also worked as a
private consultant nationally and internationally. He received the Eagle Scout Order of Arrow, enjoyed golfing, hunting, playing cards, was a
private pilot, participated in rodeo as a calf roper, and loved riding his horse in the hills of Idaho. Surviving is his wife, Bernadine Douglas,
Moore, Idaho; two daughters and spouses, Laura D. Waddoups (Jimmie K.), Moore, Idaho; and Syndy Douglas de Almonte (Ivan Julian),
Yuma, Arizona; and a granddaughter, Carsen C. Waddoups.
Errebhi, Mohamed, Carl J Rosen, Florian I Lauer, Max W Martin and John B Bamberg. "Evaluation
of Tuber-Bearing Solanum Species ~ for Nitrogen Use Efficiency and Biomass Partitioning." [Vol. 76, No. 3,
143-151>
Modern potato cultivars (Solanum tuberosum L.) require high rates of fertilizer nitrogen (N). This practice is costly and can pose
a serious threat to surface and groundwater. Previous evaluation of wild potato germplasm demonstrated the existence of species capable
of producing high total biomass under low N conditions, with the ability to make maximum use of added N. Therefore, a two-year field
experiment was conducted in 1994 and 1995 to investigate the response of selected wild potato accessions and their hybrids with the
haploid USW551 (USW) to low and high N environments. The haploid USW and cultivars Russet Burbank, Red Norland, and Russet
Norkotah were also included in the study. Uniform propagules and seedlings from the various Solanum species were
transplanted to a Hubbard loamy sand (Udic Haploboroll) at Becker, Minn. and were subjected to two N treatments: 0 and 225 kg N
ha-1. At harvest, total dry biomass of wild and hybrid potato germplasm was equal to or
higher than that of the cultivars. However, cultivar biomass partitioning was 1% to roots, 15% to shoots, 0% to fruits, and 84% to tubers,
whereas wild potato species partitioned 18% to roots plus nontuberized stolons, 52% to shoots, 23% to fruits, and only 7% to tubers.
Hybrids were intermediate, allocating 9% of their biomass to roots plus nontuberized stolons, 39% to shoots, 14% to fruits, and 38% to
tubers. Nitrogen use efficiencies for many of the species and crosses were comparable to that for Russet Burbank and greater than
those for Red Norland and Russet Norkotah. Of the wild species tested, S. chacoense accessions had the highest biomass
accumulation and N uptake efficiencies and may be the best source of germplasm for improving NUE in a potato breeding program.
Fick, Robert J and Roger C Brook. "Threshold Sugar Concentrations in Snowden Potatoes During
Storage." [Vol. 76, No. 6, 357-362]
The suitability of potatoes for processing into potato chips is dependent on chip color, and internal and external defects. Concentrations
of reducing sugars, and more specifically glucose, have been used as a quantitative indicator of acceptability of potato for chipping. The
research reported here investigated the correlation between sugar concentrations and chip color, and the variability of sugar concentrations
between samples and sample locations. Three potato storage research bins, each with an independent air handling and control system,
were located inside of commercial potato storage bins. Snowden potatoes were harvested in the fall of 1992 and stored at different
temperatures in the bins through late March, 1993. The potatoes were sampled bi-weekly during the storage period, and the samples
were analyzed for sugar concentrations (sucrose and glucose) using a YSI model 2700 sugar analyzer. The results indicated that a
Snowden potato sample with a glucose concentration of less than 0.0075% (fresh weight basis) will have a 90% probability of having an
acceptable Snack Food Association color score of 1.5 or lower. Lower numbers indicate whiter chips which are generally preferred by
chip producers. Similarly, a sample with a glucose concentration of 0.01% will have a90% probability of having a color of 2 or lower. Based
on tubers sampled from four heights within the storage bins, samples from the top of a potato bin will provide a representative
sample as long as recommended storage procedures are followed, and potato pulp temperatures are similar throughout the storage.
Guenthner, Joseph F, Maury V Wiese, Alexander D Pavlista, Joseph B Sieczka and Jeffrey Wyman.
"Assessment of Pesticide Use in The U.S. Potato Industry." [Vol. 76, No. 1, 25-29]
Pesticide use in US fall crop potato production was surveyed for the years 1990 to 1994. The purpose of the study was to provide
information about the relative important of each pesticide and potential alternatives. The objectives were to: (1) inventory pesticides used
on potatoes, (2) rank the target pests and (3) estimate the economic value of the major pesticides. Extension specialists working on
potatoes in twelve states provided the main source of survey data. The most commonly used pesticides in four categories: fungicide -
chlorothalonil; insecticide - methamidophos; herbicide: metribuzin, and "other" - diquat. The most frequent target pests
were: early blight (Alternaria solani), late blight (Phytophthora infestans), aphids (primarily Myzus persicae),
Colorado potato beetle (Leptinotarsa decemlineata), lambsquarter (Chenopodium album), and pigweed (Amaranthus
spp.). The pesticides that provided the most annual value to potato growers were methamidophos ($281 million), diquat ($86 million),
metribuzin ($81 million), CIPC ($56 million) and esfenvalerate ($52 million).
Hosaka, Kazuyoshi. "A Genetic Map of Solanum phureja Clone 1.22 Constructed Using RFLP
and RAPD Markers." [Vol. 76, No. 2, 97-102]
A genetic map of a widely used haploid inducer, Solanum phureja clone 1.22, was constructed. One hundred and twenty-two
RFLP and twenty RAPD marker bands were specific to S. phureja clone 1.22, and were mapped on 100 loci (five to eleven loci per
chromosome) in the span of 606 cM. These would be useful to monitor the chromosomes of the haploid inducer that may be eliminated
from triploid embryos of 4x x 2x during the process of haploid induction from potato.
Hoy, Casey W. "Colorado Potato Beetle Resistance Management Strategies for Transgenic
Potatoes." [Vol. 76, No. 4, 215-219]
NewLeaf potatoes could provide substantial ecological and economic benefits to potato growers. A concern with NewLeaf potatoes,
however, is that Colorado potato beetle may develop resistance to the Bt endotoxin because of the intense selection pressure imposed
by its constant presence in the transgenic crop. Before these cultivars were released, however, entomologists throughout North America
conducted biological research needed for a strategy to prevent or delay resistance in Colorado potato beetle. This paper describes the
considerations and research behind the proposed strategy. Because NewLeaf potatoes express a relatively constant and high concentration
of Bt endotoxin throughout the foliage of each plant, reducing selection for resistance must come from planting standard potatoes as a
refuge for susceptible beetles. Avoiding resistance through random mixtures of NewLeaf and standard potatoes was evaluated in laboratory
and field studies. The conclusion from this research was that the seed mixture would not provide an effective refuge. The most effective
alternative refuge was judged to be a block of standard potatoes planted in the same field as the NewLeaf potatoes. By allowing susceptible
beetles to survive in their fields, potato growers might sustain the benefits of very effective controls.
Kim, Soon Kim, Jae Heung Jeong, Kyung Hwa Choi, Young Hee Joung and Hyouk Joung. "Effects
of Rindite on Breaking Dormancy of Potato Microtubers." [Vol. 76, No. 1, 5-8]
Potato microtubers were treated with rindite to investigate the effect on dormancy breaking. Postharvest application of rindite by
fumigation with 2 ml rindite for 48 hr or 4ml for 24 hr significantly reduced the dormancy period of potato microtubers using a
32 x 15 x 17 cm tightly sealed plastic box. Approximately 2 weeks after the treatments microtubers of all cultivars, Atlantic, Superior,
Lemhi Russet, Red Dale and Kennebec started to sprout. The efficiency of the treatments were the greatest for the cv. Lemhi Russet
intermediate for cv. Superior and least for cv. Red Dale. In all cultivars of potato microtubers, more decay was observed, the earlier
rindite treatment occurred after harvesting, therefore potato microtubers should be treated with rindite at least 2 weeks after harvest when
the skin of microtubers is mature. The data indicates that the dormancy of potato microtubers with well-matured skin can be effectively
broken with an optimum treatment of rindite.
Kowalski, Stanley P, John M Domek, Kenneth L Deahl and Lind L Sanford. "Performance
of Colorado Potato Beetle Larvae, Leptinotarsa Decemlineata (Say), Reared on Synthetic Diets Supplemented with Solanum
Glycoalkaloids." [Vol. 76, No. 5, 305-312]
Glycoalkaloids are a class of secondary compounds (nitrogenous, steroidal glycosides), ubiquitously distributed throughout the
Solanaceae. Numerous studies (in planta) have shown that certain glycoalkaloids, e.g., a-tomatine, solanocardenine, and leptine,
have a negative impact on performance of the Colorado potato beetle, Leptinotarsa decemlineata (Say). However, the presence
of other secondary compounds, as well as the nutritional status of the plants used, are additional variables in such experiments. By rearing
Colorado potato beetle, from egg to prepupal stage, on a synthetic diet supplemented with the glycoalkaloids a-tomatine, a-chaconine,
a-solanine, leptine I and the steroidal aglycone solanidine, we have been able to further establish the effects (ex planta)
of these compounds on the Colorado potato beetle. Leptine I displayed a dose-dependent negative activity against the Colorado
potato beetle (as measured by larval weight gain and time to molt), when assayed at 0.31, 0.62 and 1.23 mM concentrations; however, by
the fourth stadium no effect was found. When Colorado potato beetle were fed a higher concentration of leptine 1(2.4 mM), there was a
sustained effect in all stadia. At 2.4 mM, leptine I displayed a greater negative impact on Colorado potato beetle growth and development
than did a-tomatine. a-Chaconine at 2.4 mM did not impair Colorado potato beetle performance relative to Colorado potato beetle
reared on control diets. a-Chaconine plus a-solanine, at concentrations commonly found in Solanum tuberosum
L. foliage (0.6 and 0.3 mM respectively), did not impair Colorado potato beetle performance. The steroidal aglycone solanidine (2.4 mM)
had a significant negative impact on Colorado potato beetle performance. Results are discussed In the context of host-plant resistance
and insect-plant interactions.
Kwon, M, YI Hahm, KY Shin and YJ Ahn. "Evaluation of Various Potato Cultivars for Resistance to
Wireworms (Coleoptera : Elateridae)" [Vol. 76, No. 5, 317-319]
Fifty potato cultivars, 11 early-maturing, 11 mid-maturing and 28 late-maturing cultivars, were evaluated in the field for resistance to
wireworms, using the equation injury rate (%) = (No. of damaged tubers/No. of total tubers) x 100. In preliminary field tests, four wireworm
species were found in the experimental site: Selatosomus puncticollis (Motschulsky), Melanotus legatus Candéze,
Agrypnus argillaceus (Solsky), and A. binodulus coreanus Kishii. Larvae of S. puncticollis were dominant (over 95%
occurrence). Significant differences for resistance were observed among the 50 cultivars. Of 11 early-maturing cultivars, high levels of
resistance to wireworms were obtained from cvs Anco and Irish Cobbler. Among the 11 mid-maturing cultivars, the American cultivar
Alamo and the Japanese cultivar Shinyuseo exhibited high resistance to wireworms. Of 28 late-maturing cultivars, cvs Whitu, Sieglinde,
Spunta, and Some Miore were very resistant to wireworms, whereas high levels of resistance were observed in the cvs Cardinal,
Norm No. 2, Ojiro and Rosa. These resistant cultivars should be useful in future breeding programs.
Lafond, J and RR Simard. "Effects of Cement Kiln Dust on Soil and Potato Crop Quality."
[Vol. 76, No. 2, 83-90]
Cement kiln dust is a potential source of K and Ca for crops on acidic soils in Eastern Canada. The objective of this study was to assess
the effect of cement kiln dust on soil chemical properties and potato (Solanum tuberosum L. cv. Superior) yield and quality on two
Spodosols. Four rates of cement kiln dust, commercial K fertilizers, and lime were yearly applied and arranged in a randomized complete
block design with four replicates. Soil extractable K and Ca increased rapidly after cement kiln dust applications and were comparable to
commercial fertilizers or lime treatments. Heavy metal soil contents and plant uptake were not influenced by treatments. Soil metal contents
decreased from to initial soil levels and were lower than recommended maximal norms. Tuber yields increased with rates of cement kiln
dust and commercial fertilizers but decreased with lime rates. Yields were positively correlated to soil extractable K and partially with
extractable Mg. The K and Mg plant uptake increased with cement kiln dust and commercial fertilizers rates but was significantly reduced
by liming. Tuber specific gravity decreased with the highest commercial fertilizers and cement kiln dust rates. These results showed
that cement kiln dust is an effective source of K and Ca for potato production without short term loss in tuber quality or soil contamination
by metals.
Love, Stephen L. "Founding Clones, Major Contributing Ancestors, and Exotic Progenitors of
Prominent North American Potato Cultivars." [Vol. 76, No. 5, 263-272]
Neither founding clones nor major genetic contributors to modern North American potato cultivars have been systematically identified.
Available pedigrees, through 12 generations, were used to identify founding clones and major contributing ancestors (MCAs), to outline
relationships among these clones, to determine the genetic contribution of MCAS and exotic germplasm to prominent cultivars, and to
draw conclusions about the gene base of prominent North American cultivars. Based on 1996 certified seed acreage, 46 cultivars were
identified as prominent, of which 44 had published pedigrees. Using this pedigree data, 12 MCAs consisting of four types were identified:
land race types including Daber and Sutton’s Flourball; Immediate descendants of land race types including Busola, Early Rose,
Garnet Chili, Imperator, Richter’s Jubel, and Triumph; early USDA releases including Chippewa, Earlaine, and Katahdin; and
one derivative of a German Solanum demissum x S. tuberosum population designated Germ. No. 3895-13. These clones
appeared in the pedigrees of from 61 to 100% of the 44 most prominent North American cultivars. Some MCAs appeared numerous times
in the pedigrees of the cultivars with the maximum being Busola, which appeared in the pedigree of NorDonna 94 times. Across the 44
cultivars, the genetic contribution of MCAS averaged from 1.4% for Daber to 23.2% for Katahdin. A positive genetic contribution by exotic
germplasm was present in 34 of the 44 cultivars. Krantz, Russet Nugget, Conestoga, and Yukon Gold had exotic germplasm contributions
of 49.5, 34.1,32.3, and 31.3%, respectively.
McNabnay, Marcus, Bill B Dean, Rick W Bajema and Gary M Hyde. "The Effect of Potassium
Deficiency on Chemical, Biochemical and physical Factors Commonly Associated with Blackspot Development in Potato tubers."
[Vol. 76, No. 2, 53-60]
Blackspot bruise is a physiological disorder of potato tubers resulting from mechanical damage to tissues during handling. This
study examined the effect of potassium nutrition on biochemical and physical changes normally associated with blackspot bruise in
potato tubers. Four potato (Solanum tuberosum L.) genotypes (TXA 763-5 [very resistant], Ranger Russet [very susceptible], Russet
Burbank [susceptible], and Lemhi Russet [very susceptible]) differing in susceptibility to blackspot bruise were grown at three potassium
nutrition levels (100%, 10%, and 0% of the potassium in full strength Hoagland's solution). Tubers from the three treatments were tested
for their chemical, biochemical and physical characteristics commonly related to blackspot bruise susceptibility. The potential to develop
malanin pigments was measured as total oxidative potential (optical density, OD475 of clarified tuber
homogenates. Tuber tissue extracts were assayed for polyphenol oxidase (PPO) activity with catechol, measured as increase in
OD410 overtime. Specific gravity of tubers was determined with a brine solution series. Physical
property measurements were made by impacting cores of tuber tissue in a specially designed instrumented pendulum. Shock wave speed,
Young's modules, failure stress, and failure strain were all measured dynamically during impact. Tubers produced under both the 10% and
0% potassium regimens had almost 2x the free tyrosine of control tubers. The 0% potassium tubers had significantly higher PPO activity
than the control. Both of these factors likely contributed to the significantly higher total oxidative potential that was observed in tubers from
both the 10% and 0% potassium treatments. Tubers from both the 0% and 10% potassium treatments had a significantly lower Young's
modulus (a measure of stiffness), significantly lower failure stress and the shock wave of impact propagated through both of them
significantly different in their susceptibility to black pigment development, they all responded similarly to the treatment with regards
to the variable measured. The TXA-763-5 clone was much more susceptible to developing black pigments in these tests than expected.
The other three cultivars performed as they do in commerce.
Medina, Marco V and HW (Bud) Platt. "Comparison of Different Culture Media on the Mycelial
Growth, Sporangia and Oospore Production of Phytophthora Infestans" [Vol. 76, No. 3, 121-125]
The purpose of this study was to evaluate various culture media, with or with B-sitosterol, on mycelial growth, sporangia and oospore
production by isolates of Phytophthora infestans. Nine media were compared to rye agar (RA) which is frequently used to culture P.
infestans. Poor fungal growth across most isolates was observed on soybean agar, carrot agar and carrot agar with sterols relative to
RA. Only clarified V8 juice containing B-sitosterol (CLV8S) resulted in significantly more sporangia production compared to RA. All other
media performed similar to the RA. No significant differences were found in the sizes (length and width) of sporangia produced among the
isolates tested on various media. Oospore production was greatest when P. infestans was cultured on carrot agar with B-sitosterol
(CAS) or CLV8S when compared to RA. Responses of isolate matings varied somewhat with an A2 isolate from Nova Scotia consistently
producing fewer oospores in matings with A1 isolates compared to the other A1/A2 mating combinations. Rye agar and oat meal agar with
or without B-sitosterol as well as clarified V8 juice agar with B-sitosterol are useful for in vitro growth of mycelium.
Miller, Jr, J Creighton, Douglas C Scheuring, Jeannie P Miller and George CJ Fernandez.
"Selection, Evaluation, and Identification of Improved Russet Norkotah Strains."
[Vol. 76, No. 3, 161-167]
Strain (sub-clonal, line, or intraclonal) selection for certain characteristics within some potato varieties has been very successful,
e.g. improved skin type (Russet Burbank from Burbank), improved skin color (Red LaSoda from LaSoda; Red Norland and Dark Red
Norland from Norland), and improved vine vigor and yield (Norgold Russet M from Norgold Russet). In 1989, strain selection with Russet
Norkotah was initiated by the Texas Potato Variety Development Program. Some 192 giant hill and/or tall type plants were selected from
seedsmen and/or commercial Russet Norkotah fields in Colorado, while 183 were selected from commercial fields in Texas. Replicated
yield trials with the final 13 of the original strain selections and Russet Norkotah were conducted in 1992, 1993 and 1994 in both Colorado
and Texas. A mixed model analysis of variance was performed followed by disjoint cluster analysis in order to group strains into high,
medium, and low yielding classes or clusters. Canonical discriminant analysis was performed to confirm the three clusters and to
determine the extent to which various yield attributes are related and can be used to separate the three clusters. Several strains including
TXNS (Texas Norkotah Strain) 112, TXNS 134, and TXNS 278 were identified as superior in Colorado, while TXNS 223, TXNS 249, and
TXNS 296 were similarly identified for Texas growing conditions. These strains usually outyielded Russet Norkotah by 20-30%.
Mojtahedi, H and GS Santo. "Ecology of Paratrichodorus allius and its Relationship to the
Corky Ring-spot Disease of Potato in the Pacific Northwest." [Vol. 76, No. 5, 273-280]
Paratrichodorus allius, a vector of the tobacco rattle virus which causes the corky ringspot disease (CRS) in potato, was identified
in soil samples from Oregon and Washington. Two populations from potato fields in Pasco, WA and Umatilla, OR reproduced successfully
on alfalfa, wheat, and corn which are commonly rotated with potato, and most weeds associated with this crop in the Pacific Northwest.
Greenhouse studies showed that P. allius was sensitive to low soil moisture, and increased 10 and 100 fold on Samsun NN tobacco
in soil above field capacity compared to 1/2 and 1/3 field capacity, respectively. Population dynamic studies for 1996 and 1997 on a
potato-wheat cropping sequence showed that P. allius declined after the winter wheat cover crop was disked in the spring of 1996,
and remained low on potato at the 0-90 cm soil profile, with no evidence of downward migration. In 1997, P. allius declined early in
the season on wheat, and remained low until June-July when it peaked before declining again. In soil columns, P. allius placed
30 cm below a confined tobacco root system was able to reach and transmit tobacco rattle virus. The nematodes below 30 cm transmitted
the virus only when plant roots were allowed to grow to that depth.
Mundy, Charlotte, Nancy G Creamer, Carl R Crozier and L George Wilson. "Potato Production on
Wide Beds: Impact on Yield and Selected Soil Physical Characteristics." [Vol. 76, No. 6, 323-330]
Planting three rows of potatoes in a bed the width of two conventional rows offers an easily managed way to Increase seed piece
populations, with the potential of increasing tuber yield and enhancing tuber quality. A wide bed production system (3 rows of potatoes
planted on a 1.9 m flat-topped raised bed) was compared to a conventional-ridged system (1 row of potatoes in sharply sloped ridges
on 96 cm centers) in 1996 and 1997 on a Norfolk sandy loam soil and a Portsmouth fine sandy loam soil in eastern North Carolina.
Potato plant stands, leaf area index at approximately 9 WAP, yield, and quality were measured. Soil temperature, soil moisture, and cone
index, as a measure of soil penetration resistance, were also measured,wide beds were more moist than conventional ridges early in the
season. Cone index was greater throughout the root profile in wide beds in two of three tests. The row on the west side of an individual
wide bed was most similar to conventional ridges in daily soil temperature fluctuations between minimum and maximum temperatures,
and had greater fluctuations than the middle and eastern rows of the wide bed. Total yield and yield of grade A potatoes were not
significantly different between wide beds and conventional ridges at either site. At one site, yield of grade B potatoes was significantly
less in the wide bed; among the three rows in the wide bed, the eastern row had significantly lower yield of grade B potatoes.
Conventional ridges had a higher percent of green grade A potatoes than the wide beds in one of three trials. Under North Carolina
conditions, changing production systems would be unadvisable for most growers because wide beds do not increase yield enough
to justify spending the money for more seed and to change equipment.
Nitithamyong, Anadi, Joachim H Vonelbe, Raymond M Wheeler and Theodore W Tibbitts.
"Glycoalkaloids in Potato Tubers Grown Under Controlled Environments." [Vol. 76, No. 5, 337-343]
Tuber content of a-solanine, a-chaconine, and total glycoalkaloids (TGA) was determined for the potato cultivars, Norland, Russet
Burbank, and Denali grown under different environmental conditions in growth chambers. The lowest TGA concentrations (0.30 to
0.35 mg g1dry tissue) were found in the cv. Norland with 400 umol
m-2 S-1> photosynthetic photon flux (PPF),
12 h day length, 16 C temperature, and 350 umol mol-1> carbon dioxide. The ratio of
a-chaconine to a-solanine was close to 60:40 under all growing conditions, except that it was 50:50 under the low
temperature of 12 C. Cultivars responded similarly to environmental conditions although TGA was about 20% greater in cv. Russet Burbank
and about 30% greater in Denali compared to Norland. The largest changes in TGA occurred with changes in temperature. In comparison
to 16 C, TGA were 40% greater at 12 C, 80% greater at 20 C, and 125% greater at 24 C
(0.70 mg g1. The TGA concentration increased from 10 to 25% with an Increase in light from
400 to 800 umol m-2S-1 PPF for all
three cultivars. TGA increased 20% with extension of the day length from 12 to 24 hr and also increased 20% when carbon dioxide was
increased from 350 to 1000 umol mo -l. TGA concentrations were not influenced by changes
in relative humidity from 50 to 80%. TGA concentrations decreased only slightly in harvests made from 9 to 21 weeks after planting.
Variations in TGA among the different growing conditions and cultivars were below 20 mg/100 g fresh weight (= 1.0 mg
g-1 dry weight) recognized as the upper concentration for food safety. However the results
suggest that TGA should be considered when potatoes are grown at temperatures above 20 C.
Plaisted, RL, DE Halseth, BB Brodie, SA Slack, JB Sieczka, BJ Christ, KM Paddock and MW Peck.
"A Mid to Late Season Golden Nematode Resistant Variety For Use As Tablestock or Chipstock."
[Vol. 76, No. 1, 1-4]
Reba has a bright clear skin, attractive shape and cooking qualities that make it suitable for tablestock. The chip color from 70 storage
has been equal to that of Monona. The specific gravity of Reba is .013 less than Atlantic and .007 greater than Monona. In upstate New
York and Pennsylvania trials, Reba has produced a marketable yield about 9% greater than Atlantic. On Long Island and New Jersey,
Reba has yielded about 14% greater than Superior. Reba is resistant to race Ro1 of the golden nematode, as resistant to scab as Monona,
and moderately resistant to Verticillium wilt.
Platt, H.W. (Bud), R.D. Peters, M. Medina, and W. Arsenault. "Impact of Seed Potatoes Infected with
Phytophthora Infestans (US-1 or US-8 Genotypes) on Crop Growth and Disease Risk."
[Vol. 76, No. 2, 67-73]
As the surface area with late blight symptoms of seed tubers increased, the incidence of plant emergence decreased. This relationship
was more dramatic with the US-8 genotype than the US-1 genotype of Phytophthora infestans, the causal agent of late blight.
However, when seed tubers were inoculated with both US-1 and US-8 isolates, the plant growth responses were generally intermediate
to those obtained with the two genotypes alone. More resistant cultivars (eg. Dorita, Island Sunshine, and Sebago) had greater plant
emergence and less seed rot than those susceptible cultivars (eg. Green Mountain and Shepody) but the response differences between
resistant and susceptible cultivars was less clear with US-8 as most cultivars had 100% seed rot. Seed handling treatments affected
crop growth and disease risk; as the inoculum levels and in some cases, the pre-planting storage period increased, plant emergency
decreased generally due to greater seed rot incidences. Of the one registered seed treatment fungicide and several non-registered
and/or experimental fungicides tested, only two significantly improved plant emergence. During three years of study, "diseased"
seed treatments generally led to seed rot except in 1996 when one plant in one experimental plot of infected seed had subsequent
spread of the disease to the foliage. Furthermore, within one week, a field epidemic development outwardly from the single infected
plant due to the occurrence of favorable weather conditions. Further research opportunities are discussed relative to the impact of
infected seed on crop growth and disease risk.
Reeves, AF, OM Olanya, JH Hunter and JM Wells. "Evaluation of Potato Varieties and Selections
for Resistance to Bacterial Soft Rot." [Vol. 76, No. 4, 183-189]
Potato varieties and selections were evaluated for resistance to bacterial soft rot caused by Erwinia carotovora subsp.
carotovora and Erwinia carotovora subsp. atroseptica in mist chamber. A randomized complete block design
was a single treatment and 3 replications was used in this study. Potato lines were inoculated with bacterial suspension (10 tubers /
line) using the puncture inoculation method and incubated for 4 days in a mist chamber at 21 C and 100% relative humidity in the dark.
Although there were differences in incidence of soft rot and in amount of weight reduction, most of the potato lines were susceptible to
tuber soft rot. Mean incidence (%) of soft rot ranged from 10 to 100%. Mean reduction of tuber weight (%) ranged from 0.13 to 16.43%.
Among the varieties and selections tested, AF 522-5 was the most resistant to tuber weight loss, while AF 1424-7 was most susceptible.
There were also significant differences between years, and a variety by year interaction. Testing over a period of years is recommended.
A significant correlation coefficient of soft rot incidence (%) and reduction of tuber weight (%) was obtained (r=0.65; P=0.05), indicating
that incidence was a fair measure of soft rot potential. However, the greater variability in results for incidence make weight loss a
better measure of soft rot reaction. There was a significant difference among varieties in the reduction of tuber weight when potato
lines were inoculated either 1 or 2 months after harvest, but the interaction of time by year prohibits a conclusion as to which time
gives a better test reaction. Late maturing varieties had slightly less weight loss than earlier maturing varieties.
Reeves, AF, GA Porter, TM Work, DH Lambert and AA Davis. "Quaggy Joe: A High-Yielding,
Round, White Potato Variety for Fresh Market." [Vol. 76, No. 6, 331-335]
The Quaggy Joe potato variety is high-yielding and medium to medium-late maturing with attractive, round-oval, white-skinned,
white-fleshed tubers with medium-shallow pink eyes. Its major use is expected to be as a maincrop tablestock variety. Quaggy Joe
is resistant to the potato leafroll virus, and is also moderately resistant to early blight (Alternaria solani), dry rot (Fusarium
sambucinum), and soft rot (Erwinia carotovora subsp. carotovora). Quaggy Joe tubers have shown very little shatter
or blacksport bruising, but sprout earlier than Atlantic. Young plants have shown sensitivity to the herbicide metribuzin.
Russo, P, L Miller, RP Singh and SA Slack. "Comparison of PLRV and PVY Detection in Potato
Seed Samples Tested by Florida Winter Field Inspection and RT-PCR." [Vol. 76, No. 5, 313-316]
Two sister-samples of 400 tubers each were taken from seed potato lots of cultivars Atlantic, Hampton, and Russet Norkotah, all of
which were grown In New York State during the summer of 1996. One sample of each cultivar was planted In Homestead, Florida in a
winter test plot where plants were inspected for disease symptoms. Tubers in the other sample were directly tested for the presence
of potato potyvirus Y (PVY) and potato leafroll luteovirus (PLRV) using reverse transcription polymerase chain reaction (RTPCR) methods.
Hampton tubers appeared to have similar PVY Infection rates in dormant tubers according to summer inspection, Florida winter inspection
and RTPCR, whereas Florida testing appeared to reveal a higher PVY Infection rate in Atlantic tubers compared to RT-PCR and summer
inspection. In contrast, higher rates of PVY infection in Russet Norkotah were observed by RT-PCR compared to Florida tests. In addition,
RT-PCR appeared to detect PLRV at higher rates in all three cultivars compared to Florida test results. All tubers positive for virus by
RT-PCR were sprouted In a greenhouse and ELISA results from leaves corroborated the PCR results in 85% of the positive cases, and
100% of the negative cases that were sprouted.
Rykbost, KA and KA Locke. "Effect of Seed Piece Size on Performance of Three Potato Varieties
in the Klamath Basin of Oregon." [Vol. 76, No. 2, 75-82]
A survey of cut seed lots from Klamath Basin commercial potato operations showed poor uniformity of seed piece size and numerous
undersize seed pieces in most of the 18 seed lots examined over two years. Experiments were conducted in 1995, 1996, and 1997 to
evaluate effects of seed piece size on the performance of Russet Burbank, Russet Norkotah, and Century Russet cultivars. Weighed
seed tubers were cut into four pieces to obtain seed piece sizes of 21, 35, 50, 64, and 78 g (+/= 2 g). Seed pieces less than 50 g resulted
in delayed emergence and reduced stem numbers in all varieties. Effects of seed piece size on yield and tuber size distribution were
greatest for Century Russet and lease for Russet Norkotah, but were significant for all varieties over the three-year study. Increasing
seed piece size increased yield of U.S. No. 1 and total yield, while reducing tuber size. An economic analysis, based on crop values for
fresh market use and seed costs, found optimum seed piece sizes of 64 g for Russet Burbank and Century Russet and 50 g for Russet
Norkotah.
Rykbost, KA, DC Hane, PB Hamm, R Voss and D Kirby. "Effects of Seedborne Potato Virus
Y on Russet Norkotah Performance." [Vol. 76, No. 2, 91-96]
Research plots were established in 1996 and 1997 at Klamath Falls and Hermiston, Oregon and Tulelake, California to determine:
1) the extent of seedborne PVY spread during the growing season; 2) effects of seedborn PVY on yield and grade of Russet Norkotah;
and 3) the economic consequences of varying levels of seedborne PVY infections. A series of 5 treatments evaluated initial PVY infection
levels of 1 to 60% in 1996 and 1 to 98% in 1997. Virus spread occurred earlier and was more extensive at Hermiston than at Klamath Falls
or Tulelake. Plants derived from PVY-free seed were nearly 100% PVY infected at early senescence at Hermiston. Comparisons of potatoes
grown from PVY-free seed versus potatoes grown from seed where initial PVY infection levels were 60% in 1996 and 100% in 1997 showed
seedborne PVY infection at these levels reduced U.S. No. 1 yields by an average of 40% at Hermiston, 20% at Tulelake, and 12% at Klamath
Falls. Predicted total yield losses were 0.19, 0.12, and 0.08 Mg ha-1 for each percent of PVY
infection at HAREC, IREC, and KES, respectively. Reductions in gross crop value were estimated at 39, 26, and 14%, respectively, based
on regression analyses.
Singh, M, RP Sing and L Moore. "Evaluation of NASH and RT-PCR for the Detection of PVY in
Dormant Tubers and Its Comparison with Visual Symptoms and ELISA in Plants."
[Vol. 76, No. 2, 61-66]
Detection of the common strain of PVY (PVY0) in field-grown dormant potato tubers, by nucleic
acid spot hybridization (NASH) and reverse-transcription polymerase chain reaction (RT-PCR) was compared with diagnosis by visual
symptoms and enzyme linked immunosorbent assay (ELISA) on leaves of eight potato cultivars, differing in their symptom expression and
virus content. NASH and RT-PCR readily detected PVY0 in dormant tubers. The percent
agreement between NASH and RT-PCR ranged from 77.6 to 100 for cvs. included in this study (AC Novachip, Atlantic, Norchip, Red Pontiac,
Russet Burbank, Russet Norkotah, Shepody and Superior). ELISA on leaves was almost as good as NASH and RT-PCR on dormant tubers,
but required dormancy break. Only two cultivars, namely Red Pontiac and Russet Burbank, could accurately be assessed, based on the
visual symptoms. A very high degree of discrepancy was observed for PVY0 diagnosis
between visual symptoms and other detection procedures for varieties like Russet Norkotah and Shepody, which are known to be latent
carriers of PVY0. The use of NASH and RT-PCR in large-scale post-harvest testing is feasible.
Spooner, David M, Alberto Salas Lopez, Zósimo Huamán and Robert J Humans. "Wild Potato
Collecting Expedition in Southern Peru (Departments of Apurimac, Arequipa, Cusco, Moquegua Puno, Tacna) in 1998: Taxonomy and New
Genetic Resources" [Vol. 76, No. 3, 103-119]
Peru has 103 taxa of wild potatoes (species, subspecies, varieties, and forms) according to Hawkes (1990; modified by us by a
reduction of species in the Solanum brevicaule complex) and including taxa described by C. Ochoa since 1989. Sixty-nine of these
103 taxa (67%) were unavailable from any of the world’s genebanks and 85 of them (83%) had less than three germplasm
accessions. We conducted a collaborative Peru (INIA), United States (NRSP-6), and International Potato Center (CIP) wild potato
(Solanum sect. Petota) collecting expedition in Peru to collect germplasm and gather taxonomic data. This is the first of a
series of planned expeditions from 1998-2002. We collected from February 18 to April 18, 1998, in the southern departments of Apurimac,
Arequipa, Cusco, Moquegua, Puno, and Tacna. We made 57 germplasm collections, including 14 taxa that are the first available as
germplasm for any country (Solanum aymaraesense, S. chillonanum, S. incasicum, S. megistacrolobum subsp. megistacrolobum
f. purpureum, S. longiusculus, S. multiflorum, S. pillahuatense, S. sawyeri, S. sandemanii, S. tacnaense, S. tarapatanum, S. urubambae,
S. velardei, S. villuspetalum), and two additional taxa that are the first available for Peru but with germplasm from Bolivia (S.
megistacrolobum subsp. toralapanum, S. yungasense). Collections also were made for the rare taxa S. acroscopicum, S.
buesii, S. limbaniense, and S. santolallae. Our collections suggest the following minimum synonymy may be needed for
Peruvian potatoes: S. sawyeri as a synonym of S. tuberosum; S. hawkesii and S. incasicum as synonyms of S.
raphanifolium; S. multiflorum and S. villuspetalum as synonyms of S. urubambae.
Zhang, L, JF Guenthner, RB Dwelle and JC Foltz. "U.S. Opportunities in China’s Frozen
French Fry Market." [Vol. 76, No. 5, 297-304]
International trade of processed potatoes, especially frozen french fry exports, has become an important part of the US potato Industry.
In China, one of the world’s biggest potato producing countries, consumption of US frozen french fries has significantly increased
since the late 1980’s. By employing economic theory and econometric techniques, this study evaluates China’s current frozen
french fry market and predicts its future development. Export demand models are developed for US frozen french fries in Greater China
(Mainland China, Hong Kong, and Taiwan). The study finds that US foreign direct investment and fast food restaurants in China have
great influence on the market demand for US frozen french fries. Other variables in the model include price of US frozen french fry exports,
consumer income, population, price of substitutes, and trade barriers. The study forecasts that Mainland China’s frozen fry imports
will exceed Taiwan and Hong Kong after year 2000. In 2005, US frozen french fry exports will increase to 227,000 tons to China, and
454,000 tons to Greater China. Although there may be some challenges, China’s market provides opportunities for the US potato
industry.
Zimnoch-Guzowska, Ewa, Renata Lebecka, and Jadwiga Pietrak. "Soft Rot and Blackleg
Reactions in Diploid Potato Hybrids Inoculated with Erwinia spp." [Vol. 76, No. 5, 199-207]
From 1993 to 1996 three groups of potato genotypes were evaluated for resistance to Erwinia spp.:(1) 31 interspecific diploid
hybrids (28 resistant and three susceptible), (2) five hexaploid or pentaploid somatic hybrids of Solanum tuberosum (tbr) x S.
brevidens (brd), and (3) eight cultivars. Two evaluation methods were applied: tuber point inoculation with either Erwinia carotovora
ssp. atroseptica (Eca) or E. chrysanthemi (Ech) to test tuber soft rot resistance and stem base inoculation with Eca to test
blackleg resistance. Some resistant diploid hybrids and somatic hybrids of tbr x brd were superior to cultivars for both tuber and
stem resistance. Tuber and stem resistance to Erwinia spp. in the most resistant diploid hybrids were equal to the highly resistant
somatic hybrids of tbr x brd. Tuber resistance to Eca was highly correlated to tuber resistance to Ech
(r=O.815***). In two years of evaluation for stem resistance, three diploid hybrids and a derivative of one
of the somatic hybrids (USA M 264) failed to develop symptoms of blackleg following inoculation with Eca. Analyses of variance for tuber
and stem resistance indicated significant effects of genotype, year and genotype x year interaction. A positive relationship between tuber
and stem resistance to Erwinia spp. has been found, however the genetic control of resistance in tuber and stem is partially
independent. In the case of Eca the correlation coefficient was r = O.725***>. Therefore it should be
possible to obtain resistant genotypes to both blackleg and tuber soft rot. Several resistant diploid hybrids were selected from among
those tested, which also have several other characters desirable for potato breeders.