Sehrawat, S.K.Tripathi, Anjali2019-01-092019-01-092018http://krishikosh.egranth.ac.in/handle/1/5810089463The present investigation entitled “Studies on canopy management in high density planting of guava (Psidium gujava L.)” was carried out at experimental orchard, Department of Horticulture, CCS Haryana Agricultural University, Hisar during the year 2016-2017. The experiment was laid out in a Randomized Block Design (RBD) with 18 treatments i.e. nine different plant spacings 6×2 m, 6×3 m, 6×4 m, 6×5 m, 5×2 m, 5×3 m, 5×4 m, 5×5 m, 6×6 m and two levels of pruning no pruning and 50 per cent shoot pruning of last season growth. The present investigation clearly revealed that 50 per cent shoot pruning of last season growth under high density planting was effective practice to manage the plant canopy, increased yield per unit area and better the fruit quality. Findings revealed that solar radiation interception significantly increased with increasing the plant spacings and pruning levels. Similarly, with increase in plant spacing and pruning level, canopy temperature and chlorophyll fluorescence were increased whereas relative humidity decreased during both the seasons. Solar radiation interception and microclimate parameters (canopy temperature and relative humidity) were significantly affected by the different parts of tree canopy. Upper part of canopy intercepted more solar radiation and canopy temperature and minimum relative humidity was found in upper part of canopy as compared to all other part of canopy. Plant growth parameters like tree trunk cross sectional area, tree spread, canopy volume and shoot length were also found maximum in wider spacing (6×6 m) plant and minimum was found in closer spacing (5×2 m) and pruned trees, while maximum tree height recorded in closed spacing and non pruned trees and minimum tree height was observed in wider spacing (6×6 m) and pruned trees. Chlorophyll ‘a’ and ‘b’ content of leaf were found maximum in wider spacing (6×6 m) and pruned trees while maximum leaf area and leaf area index was recorded in closer spacing (5× 2 m). Maximum fruit set, fruit retention percentage and minimum fruit drop were recorded in wider spacing (6× 6 m) and pruned trees. Maximum flower bud density, number of fruits/tree, fruit weight and fruit size, yield/tree were also observed maximum in wider spacing (6×6 m) while yield per hectare (tonnes) was recorded maximum in closer spacing (5×2 m). Pruning was proved effective practice to increase the productivity during winter season. Fruit firmness, TSS, total sugar and ascorbic acid content of fruits was observed maximum in wider spacing (6×6 m) and pruned trees during both the seasons, whereas acidity content found minimum in fruits harvested from wider spacing (6×6 m) and pruned trees. Fruit firmness, TSS, total sugar and ascorbic acid content of fruits were found significantly higher in upper part of canopy as compared to middle and lower part of canopy during both the seasons. NPK content of leaf was observed maximum in wider spacing (6×6 m) and pruned trees. Thus 50% shoot pruning during April was found most effective practice to manage the microclimate factors, plant growth and increased the productivity of closer spacing trees (5×2 m) during winter season and improved the quality of fruits during both the seasons.ennullThesis