Silício no crescimento, fotossíntese, anatomia e bioquímica do maracujazeiro, e indução de resistência a Dione juno juno (Lepidoptera: Nymphalidae)

Abstract

Brazil is one of the main origin center of species of the genus Passiflora, besides being the largest world production of passion fruit, however this crop is severely attacked by the Dione juno juno leafhopper caterpillar, and the need for new control methods, such as silicon fertilization. Silicon is not considered an essential element for plants, but is an agronomically beneficial element because of the various positive effects it provides, such as in development, photosynthetic capacity, anatomy and even increasing resistance to pests and diseases. The objective was to evaluate phytotechnical, morphological and biochemical aspects in Passiflora edulis f. flavicarpa Deg. under doses of calcium silicate (Ca2SiO4) (Experiment 1) and AgriSil® (SiO2) (Experiment 2), and the effect on the key pest D. juno juno. The experimental design was a completely randomized design with 5 treatments for each experiment (calcium silicate via soil at doses of 0; 2,5; 5; 7,5 and 10 g Si.pot-1 and Agrisil foliar with 0, 2, 4, 8 and 16 g L-1) and 8 replicates, each portion consisting of a pot. Phytotechnical variables, chlorophyll content, silicon content, anatomical measurements, total phenolics and enzymatic activity were evaluated. In relation to the insect, consumption and food preference were evaluated, besides variables in the development of individuals. The doses of 5,0 and 7,5 g Si.pot-1 by the soil and 8 g.L-1 leaf spray provided the best effects in relation to the plant. In relation to the entomological variables, doses of 5,0; 7,5 and 10 g Si.pot-1 by the soil provided the best results in pest control. It is concluded that the intake form of the element is preponderant for the analyzed variables, both sources provide beneficial effects to the passion fruit, while in the insect combat only the fertilization by the soil was efficient.