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Two U.S. outbreaks of salmonellosis in 2020 and 2021 were epidemiologically linked to red onions. The 2020 outbreak investigation implicated the production of agricultural water as a likely contamination source. Field trials were designed to investigate the prevalence and survival of Escherichia coli (surrogate for Salmonella) on dry bulb onions after the application of contaminated irrigation water at the end of the growing period. Irrigation water was inoculated at 3 log most probable number (MPN)/100 mL (2022 and 2023) or 5 log MPN/100 mL (2023, drip only) with a cocktail of rifampin-resistant E. coli and applied with the final irrigation (0.4 acre-inch/0.4 ha-cm) to onions. Onion bulbs (40 or 80) were sampled immediately after irrigation and throughout field curing (4 weeks) and E. coli was enumerated using an MPN method. For drip irrigation, at 3 log MPN/100 mL E. coli was detected on 13% of onions at 24 h but not detected at 0 h; at 5 log MPN/100 mL for drip irrigation applied to saturated soil, E. coli was detected in 63% of onions at 0 h. Prevalence significantly (P

Onion thrips, Thrips tabaci (Lindeman), is a major pest of dry bulb onion throughout the US and across the world. Yield and quality damage from thrips feeding and the expense of insecticides used for thrips management have jeopardized profitable and sustainable onion production. To improve approaches to thrips management, researchers in multiple US onion-producing regions developed novel, integrated pest management (IPM)-based strategies employing threshold-based insecticide treatments and reduced fertilization practices. The purpose of this study was to estimate the benefits from public investment in research to develop IPM-based onion thrips management techniques using a cost–benefit analysis. Benefits were extended over a 20-year timespan and were measured by reduced insecticide and fertilizer costs. The estimated net present value of benefits from improved pest management tactics will depend on the adoption and use of novel approaches to management. Using a scenario that assumes a maximum adoption rate of 58%, the estimated net present value of the research is $15.91 million, the benefit–cost ratio is 4.00, and the internal rate of return is 32%. Assuming a scenario with a maximum adoption rate of 29%, the estimated net present value of the research is $8.3 million, the benefit–cost ratio is 3.34, and the internal rate of return is 24%. Even when estimated assuming conservative adoption scenarios, results indicate a healthy return on investment in research to develop and refine new approaches to manage onion thrips and optimize dry bulb onion production.

The entomopathogen Beauveria bassiana (Bals.) Vuill. (Ascomycota: Hypocreales) can colonize plants endophytically and stimulate the production of secondary plant metabolites with anti-herbivore activities. We assayed the topical virulence of B. bassiana to Aphis gossypii Glover (Hemiptera: Aphididae), the effects of cucumber inoculation with this fungus on plant metabolites, and the physiological consequences for aphids that fed on these plants. Assays were conducted with both the commercial formulation of B. bassiana, 'Naturalis®-L', at the recommended concentration of 1.5 ml / L (yielding a spore concentration of 2.3 × 107 CFU per ml), and with a similar concentration of the isolated fungal strain. Topical application of 0.03 ml of solution per cm2, or 1 × 103 CFU, caused 100% mortality to A. gossypii adults after seven days, whether Naturalis®-L or the isolate alone was used. The fungus grew endophytically into foliage when sprayed on cucumbers at the 2-leaf stage and concentrations of alkaloids, flavonoids, phenols, hydrogen peroxide, and total chlorophyll were higher than in control plants 28 days after inoculation. Malondialdehyde content, plant growth, and total yield were unaffected by B. bassiana inoculation. Aphids fed on B. bassiana-inoculated plants for 24 h had reduced activities of detoxifying enzymes (glutathione-S-transferase, carboxylesterase, and acetylcholinesterase) compared to controls. Activities of digestive enzymes, (lipase, α-amylase, α-glucosidase, and aminopeptidase) were reduced in aphids from inoculated plants, which exhibited higher activities of superoxide dismutase, ascorbate peroxidase, and phenoloxidase, but lower catalase activity. Energy reserves (lipids, protein, and glycogen) were lower in aphids from inoculated plants, and they exhibited reduced fecundity, longevity, and reproductive periods, and a 50% reduction in the LC50 of pirimicarb. Thus, in addition to causing direct pathogenicity, inoculation of plants with B. bassiana negatively impacted A. gossypii physiology and reproductive performance and could usefully complement other strategies for managing cotton aphids on greenhouse cucumber.

Despite the identification of the potato tuber moth Phthorimaea operculella (Zeller) sex pheromone, no effective application based on this pheromone has yet been developed and evaluated. This study investigated the effect of pheromone lures, trap densities, heights of trap deployment, and pheromone doses in Yunnan, China, for the purpose of increasing the control efficiency of P. operculella and improving the application of pheromone technology in the field. The results showed that lures made of corn oil and red PVC pipes attracted the highest number of moths (11.73±1.90 per trap per day). Sex pheromone loading of 100 µg was optimal for trapping moths, but higher doses of pheromone inhibited attraction. The density of traps did not affect capture rates; therefore, the optimum trap density was 30–40 traps ha–1. The optimum height of trap deployment was not above the height of the plant canopy. This study provides technical details necessary for the monitoring and control of potato tuber moth using sex pheromones.

Each year ≈24,000 acres of onions (Allium cepa) are produced in the Treasure Valley of eastern Oregon and southwestern Idaho, which accounts for 20% of U.S. dry-bulb onion acreage. Onions in this region are long-day onions and are irrigated by either furrow irrigation or drip irrigation, with drip irrigation having become the predominant system in the past 10 years. Onion production in the Treasure Valley faces many biotic pressures and changing market conditions that renders cultivar development and testing of critical importance to the onion industry. Direct-seeded yellow, white, and red onion cultivars have been evaluated yearly at the Malheur Experiment Station, Oregon State University, in Ontario, OR, USA, since 1975. From 2010 to 2020, 10 onion seed companies participated in the trials. There were 21 to 32 yellow cultivars, two to 10 red cultivars, and one to seven white cultivars entered in the trial each year. Only five cultivars were entered all 11 years. Total yields for the yellow cultivars ranged from an average of 680 cwt/acre in 2010 to 1277 cwt/acre in 2018, and averaged 961 cwt/acre over the 11 years. Yield of yellow bulbs larger than 4 inches (colossal and super colossal) ranged from 13% in 2010 to 61% in 2018, and averaged 34% over the 11 years. Single centered yellow bulbs ranged from 46% in 2013 to 70% in 2014. Total yields for the red cultivars averaged 520 cwt/acre and total yield of white cultivars averaged 988 cwt/acre over the 11 years. Over the 11 years, single-centered bulbs of red cultivars averaged 65% and single-centered bulbs of white cultivars averaged 45%. Some newer cultivars show improvements in single centeredness, resistance to Iris yellow spot virus, and yield of larger bulbs over cultivar Vaquero, which was released in 1993, indicating the success of breeding efforts. Yields of five yellow cultivars that were in the trials every year since 2010, increased over time. This increase can be partly attributed to improvements in cultural practices over the years: adoption of drip irrigation, more intensive nutrient management, refined onion thrips (Thrips tabaci) control, and higher plant population.

The entomopathogenic nematode, Steinernema carpocapsae, was evaluated for control of the potato tuber moth, Phthorimaea operculella, under laboratory conditions. We evaluated different concentrations of S. carpocapsae for control of 2nd, 3rd, and 4th instar P. operculella. The median lethal concentration (LC50) of S. carpocapsae infective juveniles (IJs) to 2nd, 3rd and 4th instar larvae of P. operculella was 200, 363, 181 IJs mL−1, respectively. With the extension of treatment time, the cumulative mortality increased for 2nd, 3rd, and 4th instar larvae and pupae of P. operculella. Fourth instars were the most susceptible for all observation periods. Therefore, our results suggest that S. carpocapsae could be an effective biological control agent for P. operculella.

The western flower thrips, Frankliniella occidentalis, is one of the most destructive sucking pests of vegetables, fruits and ornamental crops in China. Spinosad is one of the most commonly used insecticides to manage thrips. To assess the incidence of spinosad resistance in F. occidentalis field populations in eastern China, survival rates for 24 different populations were compared with those of a susceptible laboratory strain. All populations showed significantly higher resistance to spinosad compared with the control as determined by comparing median lethal concentrations. Two populations from Shouguang and Liaocheng in Shandong Province were classified as having moderate and high levels of resistance to spinosad with a mean resistance ratio of 17.0 and 89.2, respectively. Our research indicates a widespread reduction in spinosad efficacy for controlling F. occidentalis field populations, and that resistance management strategies should be implemented as soon as practicable, to reduce the potential of progressive resistance development and loss of efficacy.

Groundnut ringspot virus was recently identified in tomatoes in South Florida — the first report in the United States. It can infect tomato plants at all stages of growth and lead to unmarketable fruits or plant death. This 4-page fact sheet shares what is known about the symptoms, host range, disease transmission, and management. Written by Eugene McAvoy, Scott Adkins, Craig Webster, Charles Mellinger, Loren Horsman, Galen Frantz, Stuart Reitz, and Shouan Zhang, and published by the UF Department of Plant Pathology, July 2011.

Revised! ENY-658, a 10-page illustrated fact sheet by Joe Funderburk, Stuart Reitz, Phil Stansly, Dave Schuster, Greg Nuessly, and Norm Leppla, provides pepper and eggplant growers with management information for this serious pest of ornamental, vegetable, and fruit crops in the field and greenhouse — biology and ecology, tomato spotted wilt, and management programs. Includes references. Published by the UF Department of Entomology and Nematology, October 2009. ENY-658/IN401: Managing Thrips in Pepper and Eggplant (ufl.edu)