Do fungal endophytes and acephate have interactive or additive effects on early season thrips damage and yield in cotton?

Thrips are considered a major pest of early season cotton, and can have significant impacts on the success and health of young cotton. However, early season damage to cotton by thrips has produced variable responses in terms of final yield. This study will look at the long term impacts (yield) of early season thrips damage, as well as explore the use of potentially beneficial fungal endophytes as a treatment option for early season thrips problems. Interactions between fungal endophytes and a common insecticide commonly used to prevent thrips, acephate, will also be explored for both seed treatments and foliar sprays. Prior to planting, cotton seeds were treated with either one of two candidate fungal endophytes, an acephate seed treatment, or both. Additional treatments received all combinations plus a foliar spray of acephate when thrips levels reached the thrips action threshold (1 thrips per true leaf). Control plants were also planted that received no action, seed treatment, foliar spray, or a combination. Seedlings were scouted twice a week starting at 50% stand emergence until 5^th true leaf, where adult and immature thrips counts were taken, as well as plant damage ratings on a scale of 1 to 5. At the presence of the 5^th true leaf, foliar treatments stopped, and plants were sampled for the presence of the candidate endophyte. Whole plant dry weight measurements were also taken. Yield per treatment was assessed at the end of the season.