Onion Thrips Control, 1975

The test was to evaluate furrow or band applications of certain materials (such as is done for maggot control) for activity against onion thrips, and subsequent effects on yield and/or quality of onions at harvest. Granular formulations were applied at planting time either directly into the furrow with the seed, or by the “bow wave” method (surface band just ahead of seeder shoe). Plots were single row; 20 feet long; 36 inch row spacing separated by single guard rows; replicated 6 times in randomized block design. Planting was at the rate of 10 seeds/foot of row, using a V-belt hand seeder on April 17. Plots were fertilized prior to planting and were sprinkler irrigated during the season as needed. Soil was classified as a Chehalis sandy loam with pH of 5.9 to 6.1 and organic content of 2.5 to 2.9%. Seedling stand counts were made on June 2 and July 23. Adult thrips counts (5) were made at 10 day intervals between July 15 and August 25. On September 22 (158 days after seeding and treating) the onion bulbs were lifted for field drying. Topping, grading and weighing were accomplished by October 24.