Effect of foliar spray of micronutrients in banana under high soil pH condition.

Abstract

Among the micronutrients required by banana, iron, zinc and boron are found to be major yield limiting factors in India. Nearly, 5.9, 4.7 and 1.27 kg of Fe, Zn and B, respectively are absorbed per hectare for optimum production of banana based on the total uptake of these micronutrients (Lahav, 5). Generally, the micronutrients are given to banana through either soil or foliar application. In soil, where pH is greater than 8.5, the availability of micronutrients to banana crop is not at sufficient level, even though the soil is rich or applied with sufficient quantities of micronutrients. Turner et al. (10) found that zinc deficiency was more common in high pH soils or on excessively limed soils because Zn ions in the chelated complex can be replaced by calcium ions. They also found that banana yield declined from more than 60 t/ ha at soil pH 4.5 to about 30 t/ha at pH 8.7. This was thought to be associated with changing supply of Zn to the plants and leaf analysis data supported this interpretation. Under such conditions, micronutrients can be given to banana through foliar sprays. In contrast, Hernandez and Lugo Lopez (3) found that foliar spray of trace elements gave a markedly lower response than soil applied mixtures. Absence of Fe and Zn depressed performance to the level of NPK only. Das and Mohan (2) proved that application of 6g B, 9g Zn, 6g Cu and 6g Mn per plant significantly increased bunch length, number of hands and fingers in banana cultivars, Jahaji (AAA), Brajahaji (AAA) and Chenichampa (AAB). Studies on soil and foliar applications of micronutrients in banana, and its evaluation and comparison in high pH soil are meagre. Hence, an attempt was made in the present study to compare the soil and foliar applications of micronutrients in banana in high pH soil.