HERBIVORY, SEED PRIMING, AND TILLAGE SYSTEMS - IMPACTS ON THE GROWTH-RESPONSE OF PISUM-SATIVUM L

Field experiments were conducted to determine the effects of herbivory , seed priming, and tillage practices on the growth response of Pisum sativum L. A factorial treatment design incorporated two levels of til lage treatment (moldboard and chisel plow), three levels of seed primi ng [Captan, PEG (polyethylene glycol) 8000, and Captan+PEG 8000], and four levels of herbivory by Sitona lineatus (L.) (caged controls, unca ged controls, 1 weevil/plant, and 8 weevils/plant). Pisum sativum stan ds at approximately 75% emergence were infested for 1 wk. Sitona linea tus infestations resulted in defoliation of approximately 5, 25, and 5 5% for the control, low, and high weevil densities, respectively. Cons ervation tillage led to increased surface residue but did not affect s oil moisture, temperature, or compensatory growth response of P. sativ um. Seed priming treatments, incorporating PEG, led to an undercompens atory growth response of P. sativum, as did high levels of S. lineatus defoliation. Improved seed priming methods that promote vigorous seed ling growth may help minimize the impacts of S. lineatus and suboptima l soil conditions on P. sativum.