How bean fly, Rhizoctonia root rot, weed and productivity are affected by cultivar, herbicide application and planting date

Abstract

A 2-year research was conducted to evaluate the effects of bean cultivar, herbicide and planting date on a plot scale in Zanjan Province, Iran. Weeds across plots were identified as 26 species. Weed density was often lower for the fourth planting date (25–30 June) than the first date (10–15 May) of Imazethapyr, Trifluralin, hand-weeding and control at seedling, flowering and maturity stages of bean growth. At seedling and flowering, there was a greater Rhizoctonia root rot incidence on the first planting date than the fourth date. Postponing cultivation to the fourth planting date decreased mean disease incidence up to 93% at flowering in 2014 and 75% at maturity in 2015. There were greater mean fly infestation ratings at the third (2014) and fourth (2015) planting dates of treatments. Fly infestation was lacking in beans planted at the second date of cultivar and herbicide treatments examined in 2015. Postponing planting from the first date to the fourth one increased mean plant dry matter up to 162% at flowering in 2015. The highest number of pods per plant and seeds per pod were recorded for the third (2014) and first-second (2015) planting dates. This study recommends a postponed planting to minimize disease, herbicide use and weed threats, and thus produce beans in sustainable agriculture.