Effect of soil-applied CaC2 on gas exchange characters, nitrogen metabolism and fruit yield in cucumber (Cucumis sativus)

Ethylene is a potent phytohormone that influences a number of physiological and morphological characters in plants, and its biosynthesis is regulated by several factors, including nutrient availability. This study investigated the effect of using paint-coated calcium carbide (PCC) as a source of ethylene on nitrogen metabolism, photosynthesis and yield in cucumber (Cucumis sativus L.). The application of PCC significantly enhanced plant ethylene production regardless of the addition of nitrogen and there was a concurrent improvement in the morphophysiological attributes of cucumber. PCC application (30mgkg(-1)) in combination with N (60mgkg(-1)) significantly improved the leaf area, number of primary branches, nitrate reductase activity, nitrogen contents, photosynthetic rate, stomatal conductance, carboxylation efficiency, water use efficiency and fruit yield in cucumber. Therefore, the addition of soil-applied PCC and N could potentially be used to achieve a higher fruit yield in cucumber by improving nitrogen assimilation and photosynthetic characteristics.