Impact of metribuzin dose and water stress on chickpea plant health

Abstract

Chickpea is an important rotational pulse crop for Saskatchewan field crops. Since 2019, Saskatchewan chickpea production has suffered from a plant health issue following rainfall events around flowering to early podding resulting in apical wilting and eventual branch death. Post-emergence broadleaf weed management in chickpea relies on metribuzin, which can result in variable injury in chickpea. The study objective was to evaluate the effect of metribuzin dose and water stress on chickpea health in the greenhouse. At two weeks after treatment (WAT), chickpea mortality reached 25% for 206 g ai ha−1 (label rate) metribuzin dose and 56% for 413 g ha−1 dose, respectively. Maximum chickpea vegetative chlorosis and necrosis was 81% for the 413 g ha−1 metribuzin treatment and 65% for the 206 g ha−1 treatment. Chickpea longest branch length was reduced from 34 to 26 cm at 8 WAT with the 206 g ha−1 metribuzin treatment. Three weeks of permitting the soil to reach the wilting point and induce symptoms reduced chickpea longest branch length from 38 to 24 cm by 8 WAT. Chickpea pod production was reduced by 75% with the 206 g ha−1 metribuzin treatment and 90% with the water stress regime. Metribuzin at labeled dosing in Saskatchewan induced plant death and considerable vegetative necrosis when evaluated in the greenhouse.