Canopy architecture for higher productivity (mango and grapes) (Ongoing)

MANGO

• In an integrated trial of high density planting, vegetative growth parameters were lower for Paclobutrazol applied trees and those on Vellaikulumaban rootstock.
• FAI was lower and DIFN was higher for wider spacing compared to closer spacing on Vellaikulumban and for Paclobutrazol treatments.
• There were no significant differences in light interception by total canopy among spacing, rootstock and Paclobutrazol treatments.
• Flowering was more at wider spacing and on tree that received Paclobutrazol treatments the trend being more pronounced with Olour rootstock.
• The highest fruit yield of 7.72 tons/ha. during the 13th orchard year was obtained with 3 m x 3m spacing using Vellaikulumabn rootstock compared to control at 10 x 10 m yielding 1.61 t/ha.  The treatment combinations did not affect fruit quality attributes.
• All the fruit samples were free from Paclobutrazol residues, however Paclobutrazol @ 0.125 g and 0.25 g a.i/year/plant were noticed in the soil at the time of harvest. Vellailkulumban rootstock found to contain higher amount of residue compared to that of Olour rootstock.
• The light regimes available at different canopy levels and corresponding photosynthesis rates of mango leaves was quantified at flowering stage.
• The periphery of the canopy received photosynthetically active radiation (PAR) of 1455 to 1671 µ E m-2 s-1 and the photosynthesis rate was in the range of 8.21 to 9.86 µ mol m-2 s-1.
• The middle of the canopy which normally receives sunflecs received PAR in the range of 550-750 µ E m-2 s-1. The photosynthesis rate of leaves located at this canopy level ranged from 4.65 to 5.44 µ mol m-2 s-1.
• The lower portions of the canopy receiving diffused light received PAR in the range of only 80 to 125 µ E m-2 s-1. Correspondingly the photosynthesis rate of leaves located at the lower portions of the canopy ranged from 1.12 to 2.27 µ mol m-2 s-1.
• When the photosynthetic efficiency of the leaves positioned at the middle and lower levels of the canopy was compared to the fully exposed peripheral leaves, the efficiency reduced by 43-45 % at middle of the canopy and 77-86% at bottom level of the canopy.

GRAPES

• Five Spatial pruning (Forward) was effected in Flame And Sharad Seedless at 15 days intervals starting from 1st September to 1st November 2012.
• Crop yield and quality was poor in September pruned vines and most of the crop was lost due to heavy rains during peak flowering stage.
• Vines pruned during first week of October were harvested after 102 days. The mean bunch weight was 220 g, 50 berry weight 140 g, TSS ranged from 17 – 17.4OB and acidity 0.72%. Colour development was not up to the mark.
• The third date of pruning resulted in harvest after 110 days. Mean bunch weight was 255g, 50berry weight ranged from 176 -198 g, TSS varied from 18.8 – 19.0OB and acidity 0.60 – 0.57%.
• Vines pruned on second week of October resulted in harvesting after 116 days. Mean bunch weight was 314-336 g, 50 berry weight 200–252 g, TSS ranged from 19.0 – 20.4OB and acidity 0.56 - 0.46%.
• Raised 650 grafts of ArkaMridula meant for meadow orcharding of guava at a spacing of 2.0 x 1.5m and planting will be done in the ensuing monsoon.
• About 50 plants each of grafts, tissue cultured plants, air layers and plants raised by cuttings are procured and planting will be done in the ensuing season.
• In situ grafting of new grape cv. Saritha Krishna, Black Seedless, was done to conduct further experimentation of Y trellis.
• About 100 plants of Flame seedless were removed to establish new scions viz., Red Globe and Crimson Seedless in their place to conduct further studies.
• Eight new grape rootstocks viz., 1103-P, St. George, 110-R, 1613-C, Salt Creek, Talaki-5-A, 1616-C and SO4.