Lâminas de irrigação e polímero hidroretentor no crescimento e fisiologia de abacaxizeiro cv. Imperial

Abstract

Pineapple is one of the most cultivated fruit in the world, where Brazil stands out in the international scenario of pineapple production. One of the most important steps in the cultivation of pineapple is the production of seedlings, requiring research on water management at this stage and ways to optimize water consumption, something sought in all agricultural activity in the current scenario, and hydrogel can be a form. to achieve this goal. Given the above, the objective of this study was to evaluate the growth and physiological aspects of pineapple seedlings obtained by stem sectioning submitted to irrigation depths and hydrogel volumes in the substrate. The experiment was conducted in a screened environment in the fruit nursery of the Department of Phytotechnics and Environmental Sciences of the Federal University of Paraíba. The treatments were obtained from the 4x4 factorial arrangement between irrigation depths (10, 40, 70 and 100% of evaporation) and hydrogel volumes (0, 10, 25 and 35 ml), and for the variables plant height, rosette diameter. and number of leaves the arrangement was 4x4x4, because in addition to the factors previously mentioned, there were evaluations at 30, 60, 90 and 120 days after transplantation (DAT). The experimental design was a randomized block design with three replications and two plants per plot. The growth variables evaluated were: plant height, rosette diameter, number of leaves, leaf area, root and shoot dry mass and the relationship between them, except for the first three that were repeated in time. Evaluations were made at 120 DAT. Physiological aspects: chlorophyll a, b and total indices, initial fluorescence, maximum and quantum efficiency of photosystem II, internal carbon dioxide concentration, stomatal conductance, transpiration and liquid carbon dioxide assimilation. The increase of the irrigation depth favored the growth variables, except for root dry mass, because the 66% depth allowed the highest values for this variable. The increase in hydrogel volume favored chlorophyll a, while b and total chlorophylls were not influenced, but had an increase of 40% with the depth. Regarding fluorescence, only the maximum fluorescence was favored by the 70% depth and the other variables were not significant. Both the hydrogel and the depth did not influence the gas exchange of pineapple seedlings.