Supplying Zinc Salt Tablets Increased Zinc Concentration and Yield of Coffee Trees

In Brazil there are two usual forms of supplying zinc (Zn) to coffee plants, in the soil with macronutrient fertilizers or by means of foliar sprayings. Both have limitations that compromise the Zn availability to the plant. This study examined the plant responses to the foliar sprays with ZnSO₄ and insertion of Zn salt tablets, made with a mix of Zn sources, into the orthotropic branches of Coffea arabica L. Zinc supplied by foliar sprays or tablets inserted into the trunk both increased leaf Zn content, although the tablets provided more consistent Zn supply. Coffee production was higher with Zn treatments, regardless of the method of supply. The supply of Zn by the insertion of tablets into coffee tree trunks thus proved to be a promising way to supply Zn.