Vegetative performances, chemical composition and feeding value of soybean under impact of water deficit and spider mites

A pot experiment was conducted to investigate the vegetative performances, chemical composition and feeding value of soybean under impact of water deficit and spider mites as well as the possibility to their overcome through imidacloprid treatment. The development of aboveground mass, root mass and biochemical composition of soybeans were influenced by the water deficit and mites, but the sensitivity of these parameters to the action and interaction of these stress factors was different. The aboveground mass showed a greater sensitivity to mite attack while the root biomass – to water stress. The interaction water deficit × mites reduced the plant height, leaf weight, aboveground biomass and nodulation (respectively by 24.7, 45.7, 41.9 and 48.8%) and increased the root length and root weight (1.4 and 1.9 times). The crude protein and mineral content of soybean leaves was reduced under water stress × mites. The soybean leaves had also a higher content of plant cell walls and a lower in vitro digestibility as the negative consequences of mite feeding on these parameters were stronger pronounced than these of water stress. Positive and significant effect of the treatment with imidacloprid after the imposed stress in soybeans was established in terms of the parameters plant height and aboveground biomass.