Influence of Silicon Fertilization on Nutrient Accumulation, Yield and Fruit Quality of Melon Grown in Northeastern Brazil

The northeast region is the main producer of melons in Brazil. Soils under melon cultivation in this region are mainly pH-neutral and sandy, and hence prone to respond to Si fertilization, but there are no studies investigating Si application and melon responses in such an important producing area. To address this, here we carried out a field experiment to evaluate the effects of applying a diatomaceous earth-based fertilizer to melon grown on a Si-depleted soil from northeastern Brazil. The yield, weight, number, and quality of fruits, as well as the accumulation of Si and nutrients in melon leaves were evaluated. We found that Si fertilizer application increased the number, weight, and tonnage of melon fruits. This improvement in yield was related to an enhanced Si and nutrient uptake (N, P, K, Ca, Mg, Fe, Mn and Zn) by melon plants with the addition of silicon. Applying Si to soil did not significantly improve the pulp thickness, pulp firmness or soluble solids of melon fruits, despite a trend towards increased pulp thickness and soluble solids. The benefits of Si application were clearly observed to melon grown in sandy soils of northeast Brazil, but careful dose recommendation must be observed to make the practice cost-efficient and sustainable.