Herbivory, seed priming, and tillage systems: Impacts on the growth response of Pisum sativum L.

Abstract

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 tillage treatment (moldboard and chisel plow), three levels of seed priming [Captan, PEG (polyethylene glycol) 8000, and Captan+PEG 8000], and four levels of herbivory by Sitona lineatus (L.) (caged controls, uncaged controls, 1 weevil/plant, and 8 weevils/plant). Pisum sativum stands at approximately 75% emergence were infested for 1 wk. Sitona lineatus infestations resulted in defoliation of approximately 5, 25, and 55% for the control, low, and high weevil densities, respectively. Conservation tillage led to increased surface residue but did not affect soil moisture, temperature, or compensatory growth response of P. sativum. Seed priming treatments, incorporating PEG, led to an undercompensatory growth response of P. sativum, as did high levels of S. lineatus defoliation. Improved seed priming methods that promote vigorous seedling growth may help minimize the impacts of S. lineatus and suboptimal soil conditions on P. sativum.