Comportamento fisiológico e agronômico de plantas de pimenta-do-reino (Piper nigrum) cultivadas em gliricídia (Gliricídia sepium L.) sob doses de NPK.

Abstract

In the conventional cultivation of black pepper (Piper nigrum) hardwood stakes are used as a tutor for plant growth. However, for the implantation of one hectare of black pepper it is necessary to remove 25 to 30 trees from the native forest to produce stakes. In this context, the cultivation of black pepper in a live tutor of gliricidia (Gliricidia sepium L.) stands out, which has been the object of investigation as it is a sustainable alternative to produce the culture. However, there is a lack of technical information about the effects of this type of tutor on the physiology and growth of black pepper, given the hypothesis of competition between these two species for water, light or nutrients. Thus, the objective of the present research was to evaluate the physiological behavior, vegetative growth and productivity of black pepper in the first year of cultivation with a live tutor of gliricidia subjected to doses of potassium (K), nitrogen (N) and phosphorus (P). For that, three experiments were carried out in the municipality of Castanhal-PA, under field conditions, in a randomized block design, with treatments arranged in split plots, with 3 replications. Experiment 1: plot - two types of tutors (hardwood season and Gliricidia sepium L.), subplot - K doses (15, 30, 60 and 90g K2O plant-1 of); Experiment 2: plot - two types of tutors (hardwood season and Gliricídia sepium L.), subplot - N doses (10, 20, 40 and 60g N plant-1); Experiment 3: plot - two types of tutors (hardwood season and Gliricídia sepium L.), subplot - P doses (20, 40, 80 and 120g P2O5 plant-1). The results obtained indicate that G. sepium has an important role in the maintenance of gas exchange, in particular the positive influence on photosynthetic rate and stomatal conductance, in summer. Pepper plants in hardwood season stand out initially in terms of growth, however, with time and at the end of the first year of cultivation, black pepper in a live tutor of G. sepium tends to show vegetative growth like cultivation with a season of G. sepium. hardwood, especially with the supply of lower amounts of N and K and higher amounts of P. In the study with doses of N, the production of green pepper was higher in cultivation with G. sepium and dry pepper regardless of the type of tutor adopted, on the other hand with K and P the production of green and dry pepper was higher in cultivation with season of hardwood.