Mix cropping of legume (Vigna Radiata) and non-legume (Zea Mays) crops alleviates water stress as revealed by growth and biochemical parameters

Abstract

Drought stress is one of the most detrimental factors reducing crops yield throughout the world. The present study was conducted to assess the role of legume and non-legume mix cropping (maize and mung bean) in alleviation of water stress. The experiments were conducted both in Petri plates in the laboratory and in pots in the green house. Laboratory experiment was used for the determination of the effect of mix cropping on germination and growth parameters, while pot experiment was used for the determination of the effect on biochemical characteristics of both the crops. Water stress was induced as mannitol solution. Five treatments, i.e., control (0 M), 0.2, 0.4, 0.6, and 0.8 M mannitol, were used. Germination in both maize and mung bean was completely inhibited at 0.8 M of mannitol in both sole and mixed sown seeds. Germination in maize seeds sown as mix cropping was significantly lower than in maize seeds sown alone. No significance difference was observed in the germination of mung bean seeds sown alone or in mix cropping. The length and fresh and dry biomass of both root and shoot of maize seedlings grown in mix cropping were significantly higher than maize grown alone at various levels of water stress. In mung bean, length and fresh and dry biomass of root and fresh biomass of shoot were significantly higher in seedlings grown in mix cropping than in seedlings grown as sole cropping. Protein and moisture contents of maize grown as mix cropping were significantly higher than seedlings grown as sole cropping. There was a significance difference in protein content between seedlings of mung bean grown alone and mixed with maize at 0.6 M, while there was a significant difference in fat contents at 0.8 M. The moisture and ash contents of mung bean grown as sole and mix cropping showed no significant difference. The overall results showed that mix-cropping alleviated water stress up to 0.6 M of mannitol but did not show any promising effect above this level of water stress. It is concluded that mix cropping can be helpful in alleviation of low-level water stress, but under high water stress, mix cropping may not have any significant role.