Agro-Physiological Traits of Kaffir Lime in Response to Pruning and Nitrogen Fertilizer under Mild Shading

Plants (Basel). 2023 Mar 3;12(5):1155. doi: 10.3390/plants12051155.

Abstract

Mild shading has been reported to increase leaf production in kaffir lime (Citrus hystrix) through the improvement of agro-physiological variables, such as growth, photosynthesis, and water-use efficiency; however, there is still a knowledge gap concerning its growth and yield after experiencing severe pruning in harvest season. Additionally, a specific nitrogen (N) recommendation for leaf-oriented kaffir lime is still unavailable due to its lesser popularity compared to fruit-oriented citrus. The present study determined the best pruning level and N dose based on agronomy and the physiology of kaffir lime under mild shading. Nine-month-old kaffir lime seedlings grafted to rangpur lime (C. limonia) were arranged in a split-plot design, i.e., N dose as a main plot and pruning as a subplot. Comparative analysis resulted in 20% higher growth and a 22% higher yield in the high-pruned plants by leaving 30 cm of main stem above the ground rather than short ones with a 10 cm main stem. Both correlation and regression analysis strongly highlighted the importance of N for leaf numbers. Plants treated with 0 and 10 g N plant-1 experienced severe leaf chlorosis due to N deficiency, while those treated with 20 and 40 g N plant-1 showed N sufficiency; thus, the efficient recommendation for kaffir lime leaf production is 20 g N plant-1.

Keywords: Citrus hystrix; chlorosis; leaf production; photosynthesis; shading.