SUBSTRATES FOR THE PRODUCTION OF MACAÚBA SEEDLINGS

An experiment was carried out to evaluate the use of substrates for the production of macaúba seedlings that provide its rapid growth as a strategy to reduce the cost of acquisition and transportation. The experiment was installed at the Embrapa Cotton Experimental Field in Barbalha-CE. A randomized block design was used, in a 6 x 4 factorial scheme (substrates and simple superphosphate doses), with four replications. The treatments were composed of substrates formed by the mixture of vegetable soil (terriço) and cattle manure, in a proportion ranging from 0 to 80% + 20% of coarse sand, with the control 100% of coarse sand having been used as a control. To these substrates, the following doses of simple superphosphate were added: 0; 200; 800 and 3,200 g.m-3 of substrate. The experimental unit consisted of five plastic bags measuring 25 cm in height and 16 cm in diameter, with a capacity of 5.03 L of substrate, which was conducted for a period of 9 months. As cultural treatments, daily irrigation was carried out, with the other cultural treatments being carried out when necessary. Monthly top dressing was fertilized with nitrogen and potassium diluted in water, applying 50 mL of this solution to each plant. At the end of the experimental period, the plants were measured for their height, number of live leaves, diameter of the plant neck, dry matter production and economic analysis