A influência da adubação orgânica na preferência alimentar de Brevicoryne brassicae (Homoptera: Aphididae) em Brassica oleracea var. acephala (Brassicaceae)

Abstract

To search for organic fertilizers that target the trophobiotic balance in the culture of interest and of extreme importance in the search for more sustainable food production systems. The objective of this work was to analyze the influence of different organic fertilizers on the Brevicoryne brassicae food preference in Brassica oleracea var. acephala, establishing interrelations between the vegetable metabolism of the cabbage, the sources of fertilization tested and the resistance and / or susceptibility to the aphids. For this, the host was cultivated in a greenhouse, where it was cultivated in pots with organic fertilization added or not of phytoprotectants, following the following treatments: T1) commercial organic substrate at 70% + 30% humus (SO + H) as control; T2) (SO + H) + biofertilizer Vairo via soil; T3) (SO + H) + biofertilizer Supermagro via soil T4) (SO + H) + cow urine via soil; T5) (SO + H) + pulverized liquid humus; T6) (SO + H) + powdered whey and, T7) (SO + H) + pulverized biodynamic. The experimental design was completely randomized with 10 replicates, each replicate (plot) being one plant. For the bioassays of multiple choice food preference in the laboratory was created the aphid, and the evaluations were performed at 24 and 48 hours by counting individuals on all leaves (halos) representing all treatments. Chemical analysis of the substrates and cabbage was carried out, besides the phyto-constituents of the same ones after receiving the different treatments. The data were submitted to the Kruskal-Wallis hypothesis test (p <0.05), with a comparison of groups by the Simes-Hochberg method, after which they were submitted to principal components analysis. The application of the treatments influenced the food preference of B. brassicae in B. oleracea var. acephala. These provided different nutrient sources to the substrate and host plant, thus affecting its plant metabolism and consequently the resistance and/or susceptibility to aphids. Plants treated with liquid humus and Vairo showed less preference for aphids. These induced resistance, involving the accumulation of ascorbic acid that correlated with manganese. The treatments of cow urine, Supermagro and, to a lesser extent, whey were the ones that presented leaves with a higher preference for aphids, being these rich in nitrates and soluble sugars, these compounds being related respectively to nutrients nitrogen, iron and calcium. The control and biodynamic treatments presented intermediate results of preference and of correlation to nutrients and phytochemicals.