Two experiments were carried out in a greenhouse to evaluate the variability in macronutrient contents in relation to growth regulator sprays on ‘Thompson Seedless’ and ‘Italia’ grapevines. The treatments were: chlormequat - 1,500mg L-1; daminozide - 3,000mg L-1; uniconazole - 30mg L-1; mepiquat chloride - 300mg .L-1 and control. The cuttings were grafted on the ‘Tropical’ rootstock and were rooted in sand. After 105 days of growth they were transplanted to 35L pots with a mixture of 1:1:1 volume of sand, soil and organic matter. Grapevines were pruned each 150 days, leaving two canes with six buds each for the ‘Italia’ cultivar and with fifteen buds for the ‘Thompson Seedless’ cultivar. Water was supplied through drip irrigation (1L/plant/day). Grapevines were fertilized with 1L of manure and micronutrient solution at each pruning. Macronutrients (MAP-1.45g, Ca2NO3-3.42g, urea-1.61g de , KCl-3.53g and MgSO4-1.94g) were suplied each 15 days during the plant growth. The petioles and the shoots were sampled each growth season (150 days) and dry matter was evaluated for yield and macronutrient contents (N, P, K, Ca and Mg). Results show that the spray of growth regulators induced alteration in the macronutrient patterns due to the decrease of shoot rate growth and increase in fruitfull shoots.
Vitis sp.; growth regulator; mineral nutrition
