Níveis críticos de boro no solo e na planta para cultivo de mudas de maracujazeiro-amarelo

摘要

It was objectified to evaluate the application of boron to the substratum of production of yellow passion fruit cuttings, for the establishment of the critical levels of the B in the soil and the plant. The experimental design used was randomized blocks with 5 treatments and 4 replications. The doses of boron were: 0; 0,25; 0,50; 0,75 and 1,00 mg dm-3 of B. All the plants received doses of N, P, K and Zn of 300; 100; 150 and 5,0 mg dm-3, respectively. The experiment was lead in vases with 2.0 dm3 of substratum of a Typic Haplorthox. After 70 days of the sowing were evaluated: height, leave numeric, dry matter, nutritional status of plants and soil nutrients. The passion fruit plant seedlings answered to the boron application in soil with low concentration of 0,06 mg dm-3 of B, extracted with hot water. The highest development of the plants was associated with the level of B 0,5 mg dm-3 and the content of 0,4 mg dm-3 of B in soil end content of 22 mg of B kg-1 in the aerial part.