Effects of foliar applied thiourea on maize physiology, growth and yield (Zea mays L.) under shaded conditions

Adverse climatic conditions lead toward reduction in agricultural crop production that is a serious threat for global food security. Reduced irradiance in crop season affects plant physiology, growth and yield. To alleviate shade stress, foliar application of thiourea (TU) has not been comprehensively tested on maize. In this regard, a greenhouse study on maize crop was established with different TU application (as foliar) rates; CK (0 mg L−1), T4 (400 mg L−1), T8 (800 mg L−1) and T16 (1600 mg L−1) under shaded and non-shaded conditions. The results indicated that TU increased physiologically photosynthetic rate (Pn), biochemically chlorophyll a, chlorophyll b and leaf water content. In term of nutrient concentration, stem and leaf nitrogen contents were increased by 18.30% and 23.55% respectively in T16 as compared to CK. Overall, higher amount of TU (T16) increased plant height (5.10%), stem diameter (11.90%), stem fresh weight (5.16%), stem dry weight (5.22%), 100-kernel weight (23.58%) and grain yield (9.08%) than that of CK. However, TU application under shaded environment could not produce similar yield as that of non-shaded plants. Overall, non-shaded plant had 9.71% higher grain yield than that of shaded conditions. But it can be concluded that foliar application of TU at higher concentration could be a promising option to maintain maize productivity under shaded conditions. Furthermore, combination of TU with other plant nutrients should be tested to improve maize growth under shaded conditions.