Post-flowering morpho-physiological behavior of Alphonso mango as influenced by plant growth regulators, polyamine and nutrients under rainfed conditions.
Burondkar M. M., Jadhav B. B., Chetti M. B.
Author Affiliation: Department of Agril. Botany, Dr. B.S. Konkan Krishi Vidyapeeth, Dapoli - 415 712, Dist: Ratnagiri, Maharashtra, India.
: 425-432
Abstract : The influence of plant growth regulators (NAA at 20 ppm, CPPU (forchlorfenuron) at 10 ppm and paclobutrazol at 10 and 25 ppm), polyamine (putrescine at 50 ppm), nutrients (1.0% KNO3, 1.0% K2SO4 and 0.1% Ca-EDTA), each sprayed at 3 stages (full bloom, marble and egg stages of fruit growth) and soil application of paclobutrazol (750 mg/m.c.d), irrigation along with absolute control, was investigated on 32-year-old mango cv. Alphonso, in South Africa, during the 2003/04 and 2004/05 cropping seasons. All the treatments significantly influenced the number of fruits retained at peanut, marble, egg and harvest stages of fruit growth. Among the treatments, paclobutrazol (25 ppm) and putrescine (50 ppm) had significant influence on all morpho-physiological characters and thereby recorded significantly higher yield (107.7 and 101.74 kg fruits/tree) over the control, which was 123.1 and 110.6% higher, respectively, for paclobutrazol (25 ppm) and putrescine (50 ppm) over the control (48.32 kg/tree). Fruit yield was significantly and positively correlated with higher number of fruits retained per panicle at marble, egg and at harvest stages. Among the treatments, paclobutrazol treatments had significantly higher leaf chlorophyll content, lower leaf transpiration rate and higher diffusive resistance over all the other treatments at all the 3 stage of fruit growth. The size of individual fruit was significantly higher with KNO3 (10.4%) and K2SO4 (11.8%) over the control. The maximum cost:benefit ratio was obtained with foliar application of paclobutrazol at 25 ppm (1:6.11), followed by paclobutrazol soil application (1:4.48), KNO3 (1:4.32) and K2SO4 (1:4.25). Although, the fruit yield was maximum with putrescine, due to its high cost, the cost:benefit ratio was lower compared to the other treatments.