Weed control with diclosulam in soybean

Abstract

The experiments were conducted in 2017-2018 on soybean (Glycine max L.) in three climatic regions of Russia (Altai Region, Krasnodar Region and Astrakhan Region) to evaluate efficacy of herbicide diclosulam (WG, 750 g/kg). Treatments included diclosulam: 1) applied preemergence (PRE) - 18.75 and 37.5 g i.a. ha-1; 2) applied postemergence (POST) at 1-3 leaves of soybeans (BBCH 11-13) - 11.25 and 22.5 g i.a. ha-1. Monocotyledonous weeds (Echinochloa crusgalli (L.) Beauv. and Panicum miliaceum ssp. ruderale (Kitagawa) Tzvelev) had low sensitivity to diclosulam. Diclosulam efficacy at minimum application rate against Fallоpia convolvulus (L.) A. Love and Solanum nigrum L. was 100%. Adjuvant ethoxylated isodecyl alcohol (EIAb) was added to diclosulam to increase treatment efficiency against Chenopodium album L., Amaranthus retroflexus L., Ambrosia artemisiifolia L., Persicaria maculosa S.F. Gray.  EIAb with diclosulam was the most effective at minimum application rate. Application of diclosulam did not cause phytotoxicity on 3 soybean cultivars Altom, Bara and Vilana. The maximum increase of soybean yield after herbicide treatment was observed in Krasnodar Region in 2018 at cultivar Bara (+ 9.2 centners per hectare).