Condições nutricionais e aplicações de auxina e ureia via foliar na fixação e tamanho de frutos de lichieira (Litchi chinenses Sonn) cv. Bengal

Low productivity, associated to low fruit set of lychee and to its economic importance in Brazil, leads to a search for knowledge, in order to find out whether there is a relationship between the nutrients in the soil and/or in the leaves and the start in production. This work aimed to verify the nutritional availability in soil and the accumulation of macro and micronutrients in the leaves of ‘Bengal’ litchi. The trial was conducted between December 2012 and November 2013, in a commercial orchard in Paraíso Farm, Municipality of Rio Paranaíba-MG, at coordinates 19o25'33" South and 46o15'37" West. We selected 50 uniform plants, 25 for each area (I and II). They were identified and tagged in December 2012. Area I had a high production for the year of 2013/2014, while area II had a low one because it had shown a high production in the year of 2012/2013. The areas were fertilized in February and September of 2012 and 2013. Leaves were collected from reproductive branches monthly for samplings of macro and micronutrients, with the first gathering in December 2012 and the last in November 2013. Samples of soil were collected from under the plants for analyses. The leaves and the soil were packaged, properly identified, and then taken to the laboratory of soil analysis and plant material. The data was submitted to analysis of variance, and the effects of the treatments compared by the Tukey test at 5% probability. It is possible to observe in decreasing order in the soil: K> Ca> P> Mg> S and higher levels of the nutrients P, K and Mg in the soil of the area II compared to area I, with averages of 71.51; 351 and 22.44 mg.dm, respectively. The leaves followed the order N> K> Ca> Mg> P> S, and N,P, K and Ca macronutrients sampled in the area II had average percentages of 8.6; 7.69; 19.94 and 17.60%, respectively, higher than the averages in area I. It is not possible to conclude only by the contents of the means of the macro and micronutrients in the soil and the leaves when will the fruit set occur. The macronutrients in soil and leaves are present in greater quantities in area II while chemical attributes and micronutrients are higher in leaves in area I.