Effect of foliar mineral fertilizer and plant growth regulator application on seed yield and yield components of soybean (Glycine max) cultivars

Abstract

Soybean is known for its high protein content, which is the reason why it is widely used as one of the main food sources for humans and animals. In order to increase soybean yield, farmers tend to use foliar mineral fertilizer and plant growth regulator to this crop. Furthermore, a starter fertilizer application into the soil without foliar application may cause low yield contents of soybean. The aim of this investigation was to estimate the effects of different foliar mineral fertilizers (MF) and plant growth regulator (RGR) application on quantitative traits (plant height (PH), lower pods attachment height (LPH), number of seed pods per plant (NSPP), number of seeds per plant (NSP), weight of seeds per plant (WSP) and 1000-seed weight (TSW) and soybean grain yield (SGY)) in three soybean cultivars (Lastochka, Akku and Galina) in Shymkent of the Turkestan region, Kazakhstan. Four treatments of fertilization were tested: control (starter fertilizer, Р60К45), Р60К45 + Mo+B, Р60К45 + Epin and Р60К45 +Vuksal. Mo+ B, Epin and Vuksal were foliar applied one-two times at growth stage. The field experiments were carried out in South-Western Research Institute of Animal Husbandry and Plant Growing, during the years 2019, 2020 and 2021. In both research years, Akku had higher values for all investigated traits than Lastochka and Galina. Results showed that foliar MF and PGR application significantly increased the values for PH, LPH, NSPP, NSP, WSP, TSW and SGY. Vuksal is more effective than Epin and Mo,B in soybean cultivars because Vuksal is a liquid fertilizer that contains has higher concentration of macronutrients (16%N, 16%P2O5, 12%K2O+me, w/v). Generally, cultivar Akku and treatment starter fertilizer (Р60К45) + Vuksal (2,5 L/ha) may be recommended in soybean production in localities with similar agro-ecological conditions.