Crescimento de mudas de mamoeiro em função de lâminas de irrigação e de polímero hidroabsorvente

Abstract

Papaya (Carica papaya L.) is a plant widely cultivated in Brazil and to guarantee high yields, orchards should be renewed for 2 to 4 years, so the production of quality seedlings is extremely important. The objective of this research was to evaluate the initial growth of papaya seedlings as a function of doses of water-retaining polymer and irrigation depths. The experiment was carried out in a greenhouse, conducted in a Central Box Compound with four blocks, on irrigation depths corresponding to 30%; 40%; 65%; 90% and 100% of field capacity, and five volumes of hydro-absorbent polymer added to the soil (0; 1.45; 5; 8.55 and 10 g dm-3. The plant height, stem diameter, number of leaves and dry mass of the aerial part were evaluated. The data were submitted to analysis of variance and regression. It was found that the absorbent polymer doses showed a linear effect for the average height of the plants (cm), in periods of 15, 30 and 45 days. A quadratic effect was observed for hydrogel doses on the average height (cm) of papaya plants at 60 days after emergence. For the number of leaves, there was a quadratic effect at 15 and 30 days evaluated for hydrogel doses administered, the dose of 5 g.dm-3 being the one that showed the greatest result. For the dry mass of the aerial part, a linear effect was observed for the irrigation depths, with the largest one being the best. The application of hydro-absorbent polymer contributed to improve the height and number of leaves of papaya seedlings, demonstrating the efficiency of their use. The largest irrigation depths provided better performance in the production of seedlings.