Avaliação do crescimento e qualidade de mudas de jaqueira (Artocarpus heterophyllus Lam.) em função da adubação nitrogenada

Abstract

The fruticulture it's a sector that has been in the spotlight in the Brazilian agribusiness. Responsible for a great production volume of fruits that are consumed in and outside of the country, the Brazilian northeast region it's responsible for the majority of the production, mainly tropical fructiferous. Among the fructiferous adapted to the tropical climate there's one that has been little explored economically, which is the Jackfruit (Artocarpus heterophyllus Lam). To initiate the production it is necessary to obtain good quality seedlings, meaning, in the given testing, the main target was to evaluate the response of the seedling to the Urea doses (0, 1, 2, 3 e 4g dm-3). The experiment was made divided by blocks, each with 4 repetitions. There were two evaluation regarding growth, height, diameter of the base of the plants, leaf area and relative rate of height and diameter growing (TRCA) and (TRCD) respectively. The evaluation on the content of chlorophyll a, b and total were made with ClorofiLOG and the gaseous exchange, chlorophyll fluorescence through IRGA. To evaluate the quality of the seedlings, were performed dry leafing mass material, stalk, root and total, (MMSF),(MMSC),(MMSR) and (MMST) respectively, calculating previously with Dicksons quality index (IQD). The data were subjected to variation and regression. It is verified that the increased index of chlorophyll until 4g dm-3 of Urea, whereas the photosynthesis rate and photochemical dissipation increased linearly. To obtain the maximal growing of the jackfruit seedlings it is recommended to apply 2,2g dm-3 of ureia. The Dickson quality index has shown with the increased doses of urea with the estimated value on the application of 2,2g dm-3 of urea.