Effect of foliar application of micronutrients on growth, fruit retention and yield parameters of acid lime (Citrus aurantifolia Swingle)

The deficiency of micronutrients is widespread in Nepal, which results in poor growth, fruit drop and lower yield. June drop and pre-harvest drop reduce fruit retention and yield of Citrus. A study on the effects of micronutrients on June drop and pre-harvest drop of Citrus has not been conducted in Nepal and few in the global range. So, the effects of foliar application of micronutrients (Zn, B and Cu) were studied on plant growth, fruit retention and yield parameters of acid lime (Citrus aurantifolia Swingle) var. Sun Kagati-1. The findings revealed the significant effect of Zn alone or in combination with plant canopy spread under growth parameters. Zn and B alone or in combination significantly affected fruit retention and yield parameters of acid lime. Zn and/or B resulted in significant minimization of June drop and pre-harvest drop of fruits with a greater reduction in combination type treatments. Cu enhanced fruit weight and thereby led to greater yield. Treatment Zn (0.1%)+Cu (0.05%)+B (0.05%) was best on which fruit set was 26.14% higher as compared to control. Similarly, the June and pre-harvest drops were 18.52% and 5.18% lower in the treatment, respectively. Moreover, yield due to the treatment was 1.6 times greater than that of control as a result of higher fruit number and fruit weight. Thus, the application of Zn, B and Cu can be beneficial in obtaining a greater fruit set. Further, their role in the minimization of June and preharvest drop augments the fruit yield of acid lime.