رقابت براي منابع محيطي و ترميم عملكرد در آفتابگردان

چكيده انگليسي :

Abstract Plant density affects growth characteristics and yield of sunflower via changes in spaceavailable for growth of each plant As 100 of seeds planted never emerge the question is thathow far the planting distance could be reduced without considerable increase in competition andhow much the plants adjacent to an un emerged plant may compensate the reductions in yield dueto the lost plant To answer this in sunflower Hi Sun 36 hybrid an experiment was conducted atThe Agricultural Research Station Isfahan University of Technology using a split plot layoutwithin a randomized complete block design with three replications Row distance 60 and 75 cm was the main plot and plant distances over the row 12 14 16 and 18 cm were the sub plots Inaddition to evaluate the compensation power of this hybrid the conditions of no missing onemissing and two missing plants were studied The same row distances were the main plot andconditions of no missing one missing and two missing plants were the sub plots Under theconditions of no missing plant the effects of row and plant distances on all developmental stageswere not significant with the exception that days to physiological maturity was significantly lowerat 12 cm planting distance Plant height stem diameter and dry weights of stem leaves and headresidues head diameter and seed and biological yields were significantly increased but harvestindex decreased as row distance increased Increase in row distance also increased oil percentageand yield The effect of row distance on other traits was not significant Stem diameter dry weightsof stem leaves and head residues head diameter number of seeds per head 1000 kernel weight seed and biological yields and harvest index were significantly reduced and plant height increasedas planting distance decreased Also seed oil percentage and oil yields were reduced as plantingdistance decreased Under the conditions of missing plants and in all planting distances seed yieldincreased as row distance increased but this increase was only significant at 18 cm distance In allplanting distances stem diameter and dry weights of stem leaves and head residues head diameter number of seeds per head 1000 kernel weight and seed and biological yields were significantlyincreased as planting distance increased Harvest index only significantly increased as plantingdistance increased from 12 and 24 to 36 cm Seed oil percentage and oil yields were increased asplanting distance increased in all planting distances Plant height showed different responses tomissing plant conditions Assuming 85 emergence and under conditions of good soil structureand permeability the combination of 60 cm row distance and 14 cm between plants might besuitable for production of sunflower But the observed lodging growth trait responses andsensitivity of sunflower to soil structure and permeability may indicate that 18 cm plantingdistance with 75 cm between rows might be more suitable for production of sunflower Hi Sun 36hybrid under the conditions similar to this study where bad soil structure and compaction areproblematic

پورسخي، نازنين

رقابت براي منابع محيطي و ترميم عملكرد در آفتابگردان

لورك نجف آباد , 1386-1385 , دانشكده كشاورزي دانشگاه صنعتي اصفهان