Advancing onion thrips management and production in onion in the Northeast by improving soil fertility programs

View the project final report

• 2016 annual report

Commodities

• Vegetables: onions

Practices

• Pest Management: chemical control, cultural control, integrated pest management

Onion thrips (Thrips tabaci Lindeman) is a significant pest of onion in the Northeast. Growers often rely on weekly insecticide applications to control onion thrips. However, these insecticides are frequently over-used and which can lead to environmental contamination and insecticide resistance. Therefore, there is a need to supply onion growers with other options that will reduce insecticide applications, while still providing effective onion thrips control. Nitrogen and phosphorus have both been demonstrated to impact thrips densities. I propose a non-chemical approach to reducing onion thrips in onion through the manipulation of fertilizer applications. I will compare the effects of standard and reduced rates of nitrogen and phosphorous as well as an adjusted application timing of nitrogen on thrips populations and bulb yield. Results from this study will be used to develop a fertility program that reduces nitrogen and phosphorous and also reduces thrips densities and damage without compromising bulb yield. Anticipated benefits will be lower costs of production including saving growers’ time in making pesticide applications, reducing undesirable environmental effects, and mitigating resistance development to current insecticides. In order to disseminate the results of this study, I will present these findings at grower and scientific meetings and create publicly accessible extension materials.

The long-term goal of this project is to decrease insecticide and fertilizer inputs without compromising bulb yield, and supply growers with complementary agricultural practices that will decrease onion thrips infestations in onion. To achieve this long-term goal I propose the following objectives:

1) Develop a nitrogen fertility plan that reduces onion thrips densities in onion.

a) Evaluate reduced rates of nitrogen fertilizer and different application timings of nitrogen fertilizer on onion thrips densities, damage, and bulb yield in onion in a field study.

b) Evaluate reduced rates of nitrogen fertilizer and different application timings of nitrogen fertilizer on onion thrips reproduction and feeding levels in onion in a controlled no-choice experiment in the greenhouse.

2) Develop a phosphorus fertility plan that reduces onion thrips densities in onion.

a) Evaluate reduced rates of phosphorus fertilizer on onion thrips densities, damage, and bulb yield in onion in a field study.

b) Evaluate reduced rates of phosphorus fertilizer on onion thrips reproduction and feeding levels in onion in a controlled no-choice experiment in the greenhouse.

3) Disseminate research results to Northeastern onion growers.