Preliminary report on yield productivity and mineral composition of the fig tree as a function of boron and cattle manure fertilization in Brazil

Abstract

Introduction. Information correlating leaf nutrient contents to fig tree yield is still rare in Brazil. The objective of our research was to evaluate the effect of fertilization with boron and cattle manure on fig tree productivity and the leaf and fruit nutrient contents, and to estimate the extraction of nutrients by the crop. Materials and methods. The treatments consisted of five boric acid levels [(0, 20, 40, 60 and 100) g per plant] combined with two levels of cattle manure [(0 and 10) kg per plant]. The experimental design was in randomized blocks in a split-plot scheme with four replicates. The cattle manure levels constituted the plots, and the boron levels the subplots. We studied tree productivity, macronutrient and micronutrient leaf and fruit contents, amounts of nutrients extracted per ha and per crop yield, and fig tree leaf and fruit dry matter nutrient contents as a function of sampling dates. Results. Fruit yield productivity, average fruit weight and number of fruits per tree were not affected by B fertilization but they were by cattle manure levels, which increased the fig tree productivity. The macronutrient and micronutrient leaf and fruit contents obtained are discussed in relation to Brazilian results already published. The levels of cattle manure did not significantly affect the amount of nutrients extracted from green fig yield. The Mn, Zn and B leaf contents and the fruit extraction of Mn and B increased linearly with boric acid levels. The fig tree leaf nutrient contents varied with the plant physiological stages during its production cycle. Conclusion. These results should be taken into account for the development of fig tree fertilization programs in Brazil.