Helen Nocito
Major Professor: Dr. Stephen Meyers
MS DEFENSE SEMINAR
April 14th @ 8:00 a.m.
Room: HORT 222
“IMPROVED PUMPKIN WEED MANAGEMENT THROUGH MODIFIED HERBICIDE APPLICATION METHODS AND CEREAL RYE TERMINATION AND BURNDOWN”
Abstract: Indiana is a leading producer of fresh market pumpkins, but early season weed competition can greatly reduce pumpkin yield and fruit size. This thesis investigated novel weed management practices in pumpkins by 1) applying preemergence herbicides on granular fertilizer to improve crop safety and 2) determining optimal cereal rye cover crop termination method and preplant herbicide use. In the first experiment, four preemergence herbicides (flumioxazin, pyroxasulfone, dimethenamid-P, glyphosate) were applied as either a spray or an impregnated AMS fertilizer 14 days after direct-seeding pumpkins. When applying pyroxasulfone or glyphosate, the herbicide-coated fertilizer improved crop safety and total pumpkin number compared to sprayed plots. Additionally, herbicide-coated fertilizer significantly improved average pumpkin fruit weight for flumioxazin, pyroxasulfone, dimethenamid-P, and glyphosate when compared to a spray application. The results demonstrate that herbicide-coated fertilizer can increase pumpkin crop safety for herbicides not currently approved for postemergence use. In the second experiment, cereal rye cover crop was terminated by roller-crimping, mowing, or glyphosate herbicide and followed by a burndown application of either glyphosate, no herbicide prior to direct-seeding pumpkins. Weed control was significantly greater in plots where cereal rye was herbicide-terminated. Weed control was comparable in glyphosate and glyphosate burndown plots, which were both greater than plots without a burndown herbicide application. Pumpkin fruit number was significantly increased in roller-crimping and herbicide termination plots when compared to mowed plots, though termination method did not impact pumpkin weight. Glyphosate and glyphosate burndown significantly improved pumpkin fruit number as well as average pumpkin weight compared to no burndown treatment. This study shows that roller-crimping and herbicide termination of cereal rye, as well as the use of glyphosate or glyphosate use as a burndown treatment, improve weed suppression and pumpkin yield compared with mowing or the lack of a burndown herbicide.