Effects of Accel and Carbaryl on Apple Tree Nutrition and Fruit Yield

Abstract

Experiments were carried out in 1995 and 1996 to investigate the effect of accel (N-(Phenylmethy)-(H-purine 6-amine (6-BA) and carbaryl (1-Naphthyl methyl carbamate) sprayed two weeks postbloom on fruit set yield and plant nutrition of three apple (Malus pumila Mill.) cultivars; Empire; \'Jon-A-Red\' and \'Braeburn\'. The treatments consisted of accel (25, 50 and 75ppm), carbaryl (0.05, 0.1 and 0.2%) and unsprayed controls. Thinning trials conducted over two years indicated that accel and carbaryl consistently thinned the apple cultivars and significantly (P< 0.05) increased the yields. The leaf mineral concentrations were increased, decreased or not affected by the treatments. In 1995 the treatments significantly (P< 0.05) affected the leaf contents of N, Ca and Mg while in 1996 the treatments affected the leaf contents of N, P, K, Ca, Mg, Fe, Mn and Zn but not Cu. The treatments increased the fruit-flesh K, P and Mg contents in 1996. These results indicate that depending on apple cultivar, N content was reduced by the treatments while Ca and Mg were generally increased. Similarly the fruit-flesh contents of P, K and Mg were also increased. Carbaryl and Accel therefore thin apples, increase yields and affect the fruit quality.


Journal of Agriculture, Science and Technology Vol. 2 (1) 1999: 8-21