Visual symptoms of micronutrients, boron and iron deficiency and mineral composition of blackberry tree

Abstract

The areas planted with blackberry trees have expanded in Brazilian subtropical regions, but is still necessary to improve the crop management, especially regarding its nutritional needs, as well as establishing parameters of visual diagnosis of deficiency, what would allow to achieve higher yields. This study aimed to evaluate the visual deficiency and mineral composition of blackberry tree under omission effect of nutrients. The experimental design was completely randomized blocks, with nine treatments and three replications, corresponding to the cultivation in a complete Hoagland & Arnon’s nutritive solution and in a solution with individual omission of N, P, K, Ca, Mg, S, Fe and B. The dry matter and chemical composition of shoot and root were evaluated, as well as the visual diagnosis. The nutrient deficiencies in seedlings of blackberry trees were pointed out by typical symptoms, while in the treatment with no nutrients restriction the nutritional contents found respectively in the leaves and roots were N = 11.4 g kg^-1 and 16.1 g kg^-1; P = 1.3 g kg^-1 and 4.2 g kg^-1; K = 9.8 g kg^-1 and 13.2 g kg^-1; Ca = 5.7 g kg^-1 and 9.8 g kg^-1; Mg = 2.3 g kg^-1 and 2.6 g kg^-1; S = 1.4 g kg^-1 and 2.7 g kg^-1; B = 37.8 mg kg^-1 and 18.9 mg kg^-1; Fe = 119.9 mg kg^-1 and 1,603.9 mg kg^-1. Individual omissions of N, Ca and B were the most limiting ones for the vegetative growth of this species.