Crop Regulation Studies in guava (Psidium guajava L.) cv. L 49 under Ultra High Density Planting

A field experiment was carried out on 8 years old guava cv L 49 trees to assess the effect of pruning level and growth regulators with different combinations on vegetative growth and fruiting attributes in Ultra High Density Planting. The experiment consisted of 2 factors with 36 combinations viz., factor -1 (pruning level) P1- pruning of 25 cm of the shoot from the tip, P2- pruning of 50 cm of the shoot from the tip, P3- pruning of 75 cm of the shoot from the tip, P4 – control (without pruning). Factor -2(growth regulators) G1, G2- Potassium nitrate (1 ,2%), G3, G4- Thiourea (0.1 ,0.2%), G5, G6- Ethephon (250, 500 ppm), G7, G8- Cycocel (250, 500 ppm) and G9 – Control. Results showed that among different levels of pruning, 50cm pruning from the tip with potassium nitrate spray at 2 different concentrations was found to be the best for promoting early vegetative bud burst, fruit set and fruit yield. The increment in plant height and canopy spread in East-West and North-South were recorded more in 25 cm pruning from the tip. A greater number of shoots are visible in the P3G5 combination. When compared to other treatments, the P3G2 combination significantly increased the average index number of bud bursts and shoot length under Ultra High Density Planting.