Effect of Foliar Application of Micronutrients on Tomato Yield in Plateau State

This study examines the effect of foliar application of micronutrients on the growth and fruit yield of tomato in Plateau State, North Central Nigeria. Micronutrient deficiencies, particularly iron, zinc, manganese, and boron, are increasingly recognised as yield-limiting factors in intensively managed tomato production systems. Foliar micronutrient application offers a rapid and efficient delivery method that bypasses soil fixation barriers common in Plateau State's volcanic and lateritic soils. This study establishes a randomised complete block design experiment at the National Horticultural Research Institute Vom substation, testing five foliar treatment combinations: no foliar application control, zinc sulphate alone, borax alone, iron chelate alone, and a combined zinc-boron-iron foliar micronutrient cocktail applied three times during the growing season at two-week intervals. Roma VF tomato variety is used. Fruit number per plant, average fruit weight, marketable fruit yield, fruit quality parameters including lycopene and ascorbic acid content, and blossom end rot incidence are measured. Findings reveal that the combined micronutrient cocktail achieves the highest marketable yield of 32.4 tonnes per hectare, a 41 percent improvement above the control, and reduces blossom end rot incidence from 18 to 4 percent. Zinc alone most strongly improves fruit quality scores. Iron application improves leaf chlorophyll content and plant vigour. The study concludes that foliar micronutrient application significantly improves tomato productivity and quality in Plateau State. It recommends the combined micronutrient cocktail application programme for commercial tomato producers.

Keywords: foliar micronutrients, tomato yield, blossom end rot, Plateau State, micronutrient deficiency.