American Journal of Potato Research最新文献

In potato breeding, maturity class (MC) is a crucial selection criterion because this is a critical aspect of commercial potato production. Currently, the classification of potato genotypes into MCs is done visually, which is time- and labor-consuming. The objective of this research was to use vegetation indices (VIs) derived from unmanned aerial vehicle (UAV) imagery to remotely assign MCs to potato plants grown in trials, representing three different early stages within a multi-year breeding program. The relationships between VIs (GOSAVI – Green Optimized Soil Adjusted Vegetation Index, MCARI2 – Modified Chlorophyll Absorption Index-Improved, NDRE – Normalized Difference Red Edge, NDVI – Normalized Difference Vegetation Index, and OSAVI – Optimized Soil Adjusted Vegetation Index and WDVI – Weighted Difference Vegetation Index) and visual potato canopy status were determined. Further, this study aimed to identify factors that could improve the accuracy (decrease Mean Absolute Error – MAE) of potato MC estimation remotely. Results show that VIs derived from UAV imagery can be effectively used to remotely assign MCs to potato breeding lines, with higher accuracy for the potato B-clones (20 plants per plot) than the A-clones (6 plants per plot). Among the tested VIs, the NDRE allowed for potato MC evaluation with the lowest MAE. Applying NDRE for remote MC estimation using a validation dataset of potato B-clones (100 plants per plot), resulted in an MC estimate with a 0.81 MAE. However, the accuracy of potato MC estimation using UAV image-based methods should be improved by reducing the potato canopy’s variability (increasing uniformity) within the plot. This could be achieved by minimizing 1) potato vines bending over the neighboring row, causing vine overlap between plots, and 2) plants damaged by tractor wheels during field operations.

Accurate real-time estimation of nutrient concentrations in potato (Solanum tuberosum L.) canopies is crucial for advanced decision support systems in site-specific nutrient management. This study investigated the effectiveness of unmanned aerial vehicle (UAV) based hyperspectral imaging in predicting nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) concentrations in potato plants comparing two sampling types such as petiole/leaves and above-ground biomass (AGB) sampling. Furthermore, this study also investigates the prediction of AGB, total, and marketable yield of two potato cultivars, 'Atlantic' (chipping) and 'Red La Soda' (tablestock). Four UAV flights over experimental sites were made, and hyperspectral imaging sensors (393–995 nm, 273 bands) were conducted, which coincided with the in-field sample collection as ground truth. Data were analyzed using the partial least square regression model after preprocessing and extracting spectra from images. The model showed high accuracy in estimating plant N concentration from petiole/leaf samples (external validation R² = 0.58; [external validation RMSE = 0.31 × 10⁴ mg kg⁻¹]), as well as for P (0.75 [0.05 × 10⁴ mg kg⁻¹]) and S (0.58 [0.03 × 10⁴ mg kg⁻¹]). Potassium estimation accuracy improved with biomass sampling (0.47 [1.19 × 10⁴ mg kg⁻¹]). Above-ground biomass estimation had higher accuracy for 'Atlantic' (0.75 [1.29 Mg ha⁻¹]) than for 'Red La Soda' (0.57 [1.38 Mg ha⁻¹]). The model accurately estimated total and marketable tuber yields for both cultivars, with variations noted based on flight timing related to the crop stage. Cultivar ‘Red La Soda’ achieved the highest total yield accuracy on the first (0.76 [3.31 Mg ha⁻¹]) and fourth flights (0.76 [3.31]), while the ‘Atlantic’ had the highest accuracy on the third flight (0.50 [4.11]). Model outputs, including standardized coefficients and variable importance in prediction, visualizing band contributions to measured parameter predictions are presented. This study concludes that hyperspectral imaging successfully estimates the potato nutrient concentration and predicts the in-season potato yield, which can contribute significantly to the potato management decision support system. However, it underscores the importance of multiyear high temporal data acquisition with variable potato varieties to establish a reliable AGB and yield estimation model to improve performance.

Zebra chip is an increasingly serious disease in commercial potato production globally. Resistance can be pursued by control of the insect vector, the tomato-potato psyllid, Bactericera cockerelli or the bacterial causal agent, Candidatus Liberibacter solanacearum (Lso). Some Lso-infected plants of the wild potato species S. microdontum (mcd) had been observed to have low symptom expression. Thus, we evaluated a representative core collection of 86 individuals from 50 mcd populations in the US Potato Genebank (USPG). Real-time quantitative PCR on tissue from infected leaves was used as a proxy for bacterial titer of Lso. Russet Burbank control had 56% of the MLT of the most susceptible mcd individual. The average for all mcd was 67%, and the lowest, most resistant six mcd individuals were 0%. Repeated testing of those six individuals identified two as most reliably resistant: mcd15B2 from PI 265575 and mcd62B1 from PI 498126. All of these mcd individuals are available from USPG. They should be useful for research and breeding aimed at better understanding and controlling Zebra chip disease.

Potato (Solanum tuberosum L.) dry rot due to fungal infections causes the loss of a significant amount of potatoes. In this study, the antifungal effects of sunflower (Helianthus annuus L.) extracts against Fusarium sulphureum were investigated. The results of in vitro antifungal tests showed that all four sunflower extracts significantly inhibited the growth of F. sulphureum. Notably, the optimal inhibitory concentrations of ethyl acetate extract from sunflower disk (EESD), ethyl acetate extract from sunflower stalk (EESS), petroleum ether extract from sunflower disk (PESD) and petroleum ether extract from sunflower stalk (PESS) against F. sulphureum were 160 mg/mL, 160 mg/mL, 240 mg/mL, and 240 mg/mL, respectively. In addition, these extracts significantly inhibited the activities of polygalacturonase (PG), polymethyl-galacturonase (PMG), carboxymethyl cellulase (Cx), and β-glucosidase (β-Glu) secreted by F. sulphureum in three potato varieties: Longshu No.7, Longshu No.10 and Xindaping. These results provide a theoretical foundation for the biological control of potato dry rot.

Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say) is a major insect pest of potato and development of resistant varieties is part of a strategy for management. Wild relatives of potato are resources for genetic improvement through breeding. Interspecies crosses to introgress CPB resistance will be facilitated with rapid and inexpensive selection methods. Solanum okadae is a novel source of feeding deterrence against the beetle and was associated with production of a naturally occurring leaf-specific lactone-containing metabolite in the foliage. The Baljet assay has been used for decades in pharmaceuticals for rapid screening of lactone-containing compounds. A modified Baljet assay was developed for potato foliar tissue to rapidly screen for lactone-containing compounds in plants from the field, greenhouse, and laboratory. Herein we report the screening of potato foliage for CPB resistance with a Baljet assay validated by CPB larval feeding studies. Foliage from wild accessions of S. okadae were tested using the Baljet assay and results showed that production of the leaf-specific lactones has a large range of variation in the species. In addition, tubers tested using the Baljet assay had negligible levels of lactone-containing metabolites, confirming leaf-specific production of lactones. This inexpensive method using leaf disk screening will allow potato breeders to quickly select for potential CPB resistant germplasms and advance the breeding of sustainable crops.

Potato (Solanum tuberosum L.) production often requires intensive tillage with the moldboard plow (MP), which involves deeper soil tillage and turning of the soil to provide enough loose soil for proper tuberization. Although tillage with the MP allows better potato seedbed preparation and lower weed pressure, it is also associated with increased soil compaction, soil aggregate destruction, and increased soil organic matter (SOM) mineralization. The objective of this four-year (2019–2022) study conducted in 14 commercial fields was to compare the use of MP with primary non-inversion shallow tillage (ST) in terms of their effect on selected soil health indicators, soil moisture, potato petiole nitrate concentration, potato yield, and specific gravity. Commercial fields ranged from 1.5 ha to 19 ha where the main field was split in half, with one side tilled using MP (22.5–30 cm plowing depth) and the other half using ST (15–30 cm plowing depth). Soil and plant tissue samples were taken within four sub-replicates (91 m²) created per each treatment per each site and three to four sites were used as replicates per each year. Compared to MP, ST increased active carbon by an average of 9%, soil respiration by an average of 26%, and aggregate stability by an average of 8%. Biological N availability (BNA) increased by an average of 20% with ST, and the effect was statistically significant in three out of four years. Soil moisture at 20 cm depth tended to be higher with MP than ST in three out of four years. Although not statistically significant, when averaged across four years, potato petiole nitrate concentrations were 5% and 12% higher with ST than MP in samples collected at the flowering and post-potato flowering stages, respectively. Total and marketable potato yields, along with specific gravity, were comparable for the two tillage regimes. Signs of soil improvement were observed at the early stages of ST adoption. Marketable yield was negatively correlated with the soil nitrate levels measured during the growing season but was positively correlated with active carbon, aggregate stability, and soil moisture. Future studies could compare both tillage regimes over multiple growing seasons to assess their impacts over a full cycle of rotation. The novelty of the present study was that it was conducted in real-life conditions across large growers’ fields with different conditions and across four years.

The application of phyto-nanotechnology in horticulture is a sustainable tool for agriculture due to its cost-effectiveness and eco-friendly properties. Essential micro-elements have been used as nano-fertilizer to enhance crop production. Fine-tuning of the nanoparticle dose is also recognized as the critical factor determining their impact on plant growth. Therefore, this study aimed to investigate the effects of iron (Fe) and manganese (Mn) oxide nanoparticles (NPs) on potato plants physiological and biochemical changes under the hydroponic conditions. Observations revealed that the plant growing in the adapted hydroponics media (supplemented with 4.0 mg L^− 1 Fe₃O₄ NPs and 1.0 mg L^− 1 MnO₂ NPs instead of original Fe and Mn salt respectively) improved various physiological and biochemical parameters, total biomass, and tuber yield compared to the untreated control. The growth-promoting impact of metal oxide NPs (hereafter refers as MONPs) simultaneously induced the activity of various antioxidant enzymes (SOD, CAT, POD) and contributed to the adequate reduction in malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) content relative to the untreated control plants. This indicated that the application of MONPs could improve the potato yield per plant via modulating the plant antioxidant machinery. In addition, the application of MONPs as nano-nutrient appreciably improved the photosynthetic efficiency of plants via modulating the photosynthetic pigment content like Chl a, Chl b, total Chl, ratio Chl a/b, carotenoids as well as soluble sugar. The SEM-EDX elemental mapping also showed a slightly higher content of metals ions (Fe, Mn, and Ca) in the root and shoot tissues, however, the TEM analysis also confirmed absorption as well as transportation of MONPs in the root tissues growing in the presence of MONPs. This study opened the opportunity of utilizing MONPs as nano-nutrient in a hydroponic condition for development of pathogen-free potato tuber.

The ability to initiate sprouting soon after harvest to enable direct tuber testing for potato virus Y (PVY) could aid in acquiring more rapid results compared to the traditional winter grow out tests currently used. Methods to break dormancy for PVY detection using laboratory direct tuber testing by ELISA in commercially produced Ranger Russet, Clearwater Russet, and Umatilla Russet seed lots were tested over two years and compared to leaf testing results obtained from the winter grow out and spring grow out. At harvest, three 400 tuber samples from each cultivar were obtained for the trial and included (1) untreated control (UTC), (2) application of cold aerosol smoke, or (3) application of Rindite. Tuber samples were held at 18.3 C and sprout development was monitored weekly. Treatments were direct tuber tested for PVY when one treatment of that cultivar achieved three sprouts elongating to six millimeters. A fourth 400 tuber sample was collected, treated with Rindite, and included in the Idaho winter grow out plots in Waialua, Hawaii and leaves were sampled and evaluated for PVY using ELISA. Laboratory tested seed was stored and planted in a spring grow out (Kimberly, Idaho) and leaf samples were analyzed for PVY by ELISA. Rindite treated tubers had greater sprout rating and number of sprouts elongating compared to UTC tubers and tubers receiving the smoke treatment at time of PVY testing. Smoke had a greater sprout rating but did not always significantly differ in the number of sprouts elongating compared to the untreated tubers. Overall, estimates of PVY prevalence from direct tuber testing showed limited significant differences to those obtained in the winter grow out for each cultivar, year, and PVY incidence. However, in year two, the incidence of PVY in the winter grow out (7% PVY) significantly differed from direct tuber testing (16% PVY) in Ranger Russet. In both years, the spring grow out PVY results for all cultivars were not significantly different than the direct tuber testing, except in year one the Ranger Russet direct tuber tested UTC showed 10% lower PVY detection compared to the spring grow out. This study identified a novel dormancy breaking treatment to promote earlier and accurate PVY detection by direct tuber testing using ELISA and provided data to support direct tuber testing for post-harvest evaluation of PVY in seed certification.

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.