American Journal of Potato Research最新文献

To understand the effect of sclerotial density on tubers, and the method vis-a-vis timing of dehaulming on the development of black scurf, field studies were conducted under artificial epiphytotic conditions. Infection levels of up to 10% tuber coverage by scurf sclerotia (grades 0,1 or 2) did not affect yield, but tubers with more than 10% sclerotial coverage (grade 3 or higher) resulted in significantly lower yields compared to apparently healthy tubers (grade 0). The severity of the scurf was significantly higher when the tubers having up to 5% sclerotial coverage (grade 1) were used for sowing compared to sclerotia-free seeds. Seed tubers with more than 5% sclerotial coverage corresponding to grades 2, 3, and 4 of scurf severity were statistically at par with respect to scurf severity, but these had higher scurf intensity compared to grades 0 and 1 (sclerotial coverage 0–5%). The three test methods of dehaulming viz., cutting the tops, herbicide desiccation, and vine pulling didn’t impact the overall tuber yield, but the timing of dehaulming i.e., 7,14,21, and 28 days before harvesting did impact the yield. There was a significant effect of the time gap between vine kill and harvest on the development of black scurf. Dehaulming conducted at 7 days before harvesting produced significantly higher yields than 14, 21, and 28 days before harvesting. The longer the time gap, the more severe was scurf infection. Using herbicide as a method of dehaulming led to more sclerotial formation compared to cutting and pulling.

A survey of New Brunswick (NB) and Prince Edward Island (PEI) potato fields in crop rotation phase prior to potato production was conducted in fall (October and November) between 2017 and 2021. A total of 113 and 126 fields for NB and PEI, respectively, were surveyed with 20 to 35 fields each year tested in each province. Root lesion nematodes (RLN, Pratylenchus spp.) were detected in 99 and 98% of the fields for NB and PEI, respectively, and two root lesion nematode species, P. crenatus and P. penetrans, were identified in both provinces from 2017 to 2021. Based on 2019 and 2020 results, all surveyed fields in NB and PEI were detected with P. crenatus, while only 29 and 43% of the fields in NB and PEI were detected with P. penetrans, respectively. P. crenatus accounted for 96 and 89% of the populations for NB and PEI, respectively, while P. penetrans accounted for 4 and 11% in commercial fields, respectively. In a single in-depth sampled experimental field with a history of severe potato early dying complex in 2018 in NB, P. crenatus accounted for 88% and P. penetrans was 12%. Verticillium dahliae was detected in 94 and 92% of potato fields in NB and PEI, respectively. All isolates obtained from potato cv. “Russet Burbank” in a baiting trial were V. dahliae, belonging to two lineages. V. albo-atrum was detected in a few fields at very low level, except two fields in NB where V. albo-atrum was predominating over V. dahliae. Rotation crops did not affect V. dahliae population densities for NB and PEI, and did not affect RLN population in NB, but significantly affected RLN in PEI. Fall green cover crop did not affect the populations of RLN and V. dahliae in PEI. The present study revealed that the potato pathogenic root lesion nematode P. penetrans was present in less than 50% of surveyed fields and accounted for around 10% of root lesion nematode population in NB and PEI, and V. dahliae was the dominant species and was present in greater than 90% of surveyed fields in both provinces.

Colorado potato beetle (CPB) is an extraordinary example of pest resistance to insecticides. It is proved that increased activity of CPB’s ALiE / carboxylesterase is closely related to resistance to organophosphate insecticides. ALiE activity of different populations was tested, using spectrophotometry. The frequencies of ALiE activity of individual larvae were similar to the binomial distribution. For more resistant populations to organophosphates, the whole graph is shifted to the area with higher enzyme activity. Consequently, individuals with lower ALiE activity disappear from the population while individuals with higher activity appear more frequently. The analysis of single larvae ALiE activity showed a fairly high homogeneity of the examined populations, except for the population Kaona. Examination of single insect ALiE activity is viable and provides insight into the population, which is important for further genetic testing.

With a rising global population and looming water shortages in the U.S., there is a pressing need for water-efficient farming methods. The water needs of potato plants decrease in the late season due to foliage aging and tuber maturation. Therefore, proper late-season irrigation is vital in preventing water waste and maximizing potato profits. This study assessed the feasibility of reducing late-season irrigation to improve crop water productivity (WPc), tuber quality, and economic return. Field trials were planted near Othello, WA, across three years (2018–20). Treatments included five irrigation levels (ILs), 40%, 60%, 80%, 100%, and 120% of modeled evapotranspiration (ET), and five potato cultivars: Alturas, Clearwater Russet, Ranger Russet, Russet Burbank, and Umatilla Russet. Treatments started 100 to 105 days after planting (DAP), approximately 1500 day degrees (at or near peak canopy growth), and ended at vine kill, 150 to 155 DAP. Water from reduced ILs of 40% to 80% ET was more efficiently converted into yield (WPc) for Alturas than higher ILs; however, economic return for all cultivars typically peaked when irrigation was supplied at or above 80% ET. Tuber quality generally improved with a reduction in irrigation level, occasionally at the expense of yield and economic value.

Agricultural pollutants are commonly detected in Wisconsin groundwater around potato production on coarse-textured, low organic matter soils and practical nitrate reduction strategies are needed to address groundwater quality. Soil column studies with loamy sand soil common to the potato production region were conducted to explore the ability of organic soil additives incorporated below the simulated potato root zone to capture nitrogen in leachate water. Soil additives included two biochar types (biochar 400 and biochar 700, both at 5% wt wt^− 1 concentrations) and two papermill residual lignocellulose products (papermill source 1 and papermill source 2, evaluated at 60,525 and 49,320 kg ha^− 1, respectively) injected in the soil amendment zone below the simulated potato root zone. Additionally, one humic acid treatment with 500 kg ha^− 1 dry lignite humic acid incorporated into the simulated potato root zone and 374 L ha^− 1 liquid humic acid incorporated below the simulated potato root zone was included. Nitrogen fertilizer was added at study initiation and midway through the study. Distilled water was added every 14 days during the 14-week study period to simulate high precipitation events and leachate volume was quantified and analyzed for nitrate-nitrite nitrogen content. Leachate volume varied slightly and inconsistently among treatments and compared to soil with no additives. Biochar and papermill lignocellulose products reduced the season flow-weighted nitrate-nitrite nitrogen concentration by up to 7.6 and 34%, respectively, but humic acid was ineffective. Treatment efficacy diminished over time. Further research is needed to investigate soil treatment longevity and response to plant biotic interactions, but the papermill residual products were particularly effective at reducing nitrate-nitrite nitrogen content in leachate in this study.

Given the increasing challenges of water scarcity and the stringent quality requirements of the frozen potato-processing industry, this multi-year research trial aimed to determine whether reduced late-season irrigation on potatoes could improve French fry color. The study was conducted near Othello, WA, and was comprised of five irrigation levels: 40%, 60%, 80%, 100%, and 120% of modeled evapotranspiration (ET), and five potato cultivars: Alturas, Clearwater Russet, Ranger Russet, Russet Burbank, and Umatilla Russet. Irrigation treatments started 100 to 105 days after planting (DAP), approximately 1500 day degrees (at or near peak canopy growth), and ended at vine kill, 150 to 155 DAP. Fry color was assessed following storage durations of 45 and 90 days after harvest from three storage temperatures of 4.4 °C, 6.7 °C, and 8.9 °C, using a photovolt reflectometer, measuring percent light reflectance, in which higher values represented lighter fries. The study found that reducing late-season irrigation generally improved overall fry color. Fry color improvements were observed in four potato cultivars grown with 20% to 40% less irrigation than the control (100% ET); Ranger Russet exhibited no improvement. Reducing late-season irrigation by more than 40% resulted in darker fries for Clearwater Russet, Russet Burbank, and Umatilla Russet when tubers were stored at 4.4 °C and 6.7 °C. Excess irrigation, greater than 100% ET, generally darkened fries in Alturas, Clearwater Russet, Russet Burbank, and Umatilla Russet. These findings provide valuable guidelines for potato growers, indicating that while reducing late-season irrigation can enhance fry color, the effects may depend on a combination of cultivar, irrigation level, and storage temperature.

Potato production is being affected by high temperature stresses worldwide due to global warming. The biological basis of carbohydrate metabolism and reactive oxygen species (ROS) activity in potato tubers under high temperature stress is yet to be clearly understood. We evaluated the activities of two of the most important primary ROS members: superoxide (O₂.⁻) and hydrogen peroxide (H₂O₂) and their scavengers to understand the effects of heat stress on the changes of carbohydrates in growing tubers of five potato varieties including heat-tolerant and heat‐susceptible check varieties. The enzymatic ROS-scavengers were found to be differentially activated in these genotypes. The detoxification mechanism was more efficient in dual-stress (heat and salt) tolerant variety compared to single-stress tolerant variety. The antioxidant activity was increased by several folds in the tolerant variety compared to the susceptible variety. Storage starch accumulation and its composition was affected by O₂.⁻ and H₂O₂ metabolisms in potato tuber. The findings will be helpful in understanding the biological basis of the effect of ROS-detoxification on starch accumulation in growing tubers under heat stress.

Potato virus Y (PVY) is a common and devastating pathogen of potato worldwide and insecticide control alone for aphid vectors is not effective due to the rapid transmission of the virus by aphids following probing. Three Ry genes for extreme resistance to PVY have been identified and are used in potato breeding programs for the development of PVY-resistant varieties. Tightly linked molecular markers have been developed for all three genes and are used for marker-assisted selection (MAS). However, some varieties with known extreme resistance to PVY do not amplify any molecular markers for these resistance genes. Sante and its progeny Bistra are examples of two varieties with extreme resistance to PVY and yet have no amplification of Ry associated molecular markers. The source of PVY resistance in Bistra was mapped using SNP genotyping of 190 of its progeny which had been characterized for response to PVY infection using a N-Wilga strain. A major QTL was found on the proximal end of chromosome 11, in close proximity to Ry_adg, one of the three known extreme resistance genes for PVY. However, no known markers which detect Ry_adg amplify in Sante or Bistra which indicates they may possess a currently unidentified resistance gene, or the genetic linkages of molecular markers typically associated with the presence of Ry_adg no longer exist due to recombination between the gene and its associated molecular marker primer annealing sites.