Decrease in Imazamox Selectivity in Green Pea (Pisum sativum L.) Cultivation Under Irrigation

The selectivity of imazamox, in two commercial formulations, was tested on two green pea varieties at two locations in 2017. The field trials were conducted following the OEPP/EPPO standard methods for selectivity testing. Both herbicides were applied at two rates: the maximum recommended dose (1.2 l/ha) and twice the recommended dose (2.4 l/ha). Visual assessments were performed during the growing season and plant height was measured when growth was significantly reduced. At harvest, both quantitative and qualitative yield parameters were measured, including seed yield, tenderometer index and seed size. The results indicate that under irrigation, imazamox has increased residual activity, leading to significant phytotoxicity. This is reflected in reduced vegetative growth, delayed generative development (flowering) and postponed harvest, with negative effects on both quantitative and qualitative yield parameters.