Enhancing rice yields through foliar application of essential micronutrients: A study on zinc, copper, and boron nutrition in context of Nepal

Abstract

Quantitative data on the effects of essential micronutrients—boron, zinc, and copper—on rice (Oryza sativa L.) are limited, which hampers optimized crop management strategies. This study aimed to enhance rice yields through the foliar application of these micronutrients. Conducted in 2022 at Gokuleshwor Agriculture and Animal Science College using a randomized complete block design with three replications, the research tested different combinations of these elements on the local rice variety Kaljade. The treatments included: T1 (control), T2 (zinc), T3 (copper), T4 (boron), T5 (Zn + Cu + B), T6 (Zn + Cu), and T7 (Zn + B), with doses of 5 kg/ha for zinc and 2 kg/ha each for boron and copper. The results demonstrated significant effects of the micronutrient treatments on all parameters studied. Notably, the combination of zinc, copper, and boron (Zn + Cu + B) led to the most favorable outcomes. This treatment resulted in the shortest maturity duration (116.3 days after transplanting), the highest number of tillers (22.5), and the tallest plant height (107.7 cm). Additionally, Zn + Cu + B produced the greatest leaf area index (0.0724), the highest number of grains per panicle (22.6), and the heaviest thousand-grain weight (21.83 g). Furthermore, Zn + Cu + B achieved the highest biological yield (12.35 t/ha) and grain yield (5.9 t/ha), markedly higher than the control treatment (4.12 t/ha). These findings highlight the significant role of zinc, copper, and boron in rice cultivation. The study underscores the potential of foliar application techniques to optimize micronutrient availability, thereby enhancing rice yields. For future agricultural practices in the study area, focusing on zinc, copper, and boron nutrition is crucial to further augment crop productivity and ensure food security.