Sobrevivência e crescimento inicial de pinhão-manso em função da época de plantio e do uso de hidrogel

Abstract

The practice of the watering in forest seedlings during the planting and after the first weeks it is of having recognized importance in commercial plantings, mainly in times whose climatic conditions are not favorable to the establishment and the development. Alternatively, the job of polymeric hydroretainer (hydrogeis) in the sylvicultural treatments of forest species, it is based him capacity to keep and gradually availability water to the plants during drought periods that happen the planting. The present work aimed at to compare the effect of the use of gel hygroscopic (hydrogel) and of the planting times on the establishment and the initial growth of seedlings Jatropha curcas L. in the conditions of the west of Paraná. The treatments understood the planting of seedlings of three provenances of oil seed plant (Don J. Caballero, Nova Porteirinha and Janaúba) submitted or not to the immersion of the root system in the action of the planting in hydrogel moisturized previously, in the concentration of 5g L-1. The implantation of the settlement happened in the different times (spring, summer, autumn and winter) in blocks randomized blocks design, arranged in outline of subdivided portions, with five repetitions, for each station-seasonal one. After the period of 90 days, the effect of the polymeric was quantified on the establishment of the seedlings through the survival percentage and the initial growth through the variables morphometrics of the increment of the height and diameter of the collar, H/D relation, number of leaves, number of primary ramifications, area of the leaf, leaf area, specific leaf area, and of the leaf area index. The results indicated the largest survival (p<0,05) with use of the polymeric hidroretainer just in the planting of the spring. The provenances Pedro J. Caballero and Nova Porteirinha presented larger answer capacity to the development for the different planting times, with larger growth values in the planting of the spring