تاثير تنش رطوبتي بر شاخص هاي رشد و عملكرد هاي كمي و كيفي چغندر قند

چكيده انگليسي :

Abstract Water stress may be imposed in sugar beet to increase some qualitative traits and water useefficiency and to prevent excessive top plant portion growth without significant decrease in yield This study was conducted to determine the appropriate irrigation interval on the basis cumulativewater evaporation from standard evaporation pan class A and to find out the effects of theseirrigation treatments on growth indices and qualitative and quantitative yields of sugar beet Theexperiment was conducted in 2005 at the Lavark Agricultural Field station Isfahan University ofTechnology located near Nejaf abad using a randomized complete block design with split plot layout with four replications The study included four irrigation treatments irrigation after 70 85 100and 115 mm cumulative pan evaporation as the main plot and two monogerm cultivars zarghanand shirin as subplots The effects of irrigation treatments on top dry weight was non significant in79 100 and 224 day after planting samplings DAPS but was significant in 121 corresponding tothe maximum top dry weight occurrence up to 203 DAPS In these sampling top dry weightdecreased by about 30 24 as irrigation was delayed from 70 to 115 mm pan evaporation Theeffect of cumulative top dry weight was only significant at 5 level of probability in 121 and 203DAPS In these sampling Zarghan produced 15 79 higher top dry weight than shirin The effectsof irrigation treatments on root dry weight was significant in all sampling but the effect of cultivarwas non significant Delay in irrigation reduced root dry weight The effects of irrigationtreatments on leaf area index LAI was significant at 5 level of probability in 79 DAPS and at1 level of probability in other sampling LAI was reduced as irrigation was delayed The effect ofcultivar in LAI was significant in 79 100 and 121 DAPS The LAI of Zarghan was about 0 5 unitshigher than that of Shirin in these sampling Crop growth rate decreased as irrigation was delayedfrom 70 to 115 mm pan evaporation However irrigation delay more than 85 mm pan evaporationhad negligible effect on net assimilation rate and relative growth rate Irrigation treatmentsignificantly reduced root yield The maximum root yield 77 5 t ha 1 was obtained with 70 mmtreatment and the minimum root yield 54 37 t ha 1 was obtained with 115 mm treatment Cultivarsdid not differ significantly for root yield The maximum 17 19 and minimum 15 02 sugarcontent was obtained with 100 mm and 85 mm irrigation treatments respectively The highest andlowest sodium potassium and harmful nitrogen contents were found in 70 mm and 115 mmirrigation treatments The highest extractable sugar content 13 47 was obtained with 100 mmirrigation treatment The highest 8 45 t ha 1 and lowest 6 99 t ha 1 white sugar yield wereobtained with 100mm and 115 mm irrigation treatments respectively From the results of theseexperiments it might be concluded that Zarghan is more drought resistant than Shirin In addition in order to save irrigation water and to obtain the highest yield sugar beet might be irrigation after85 mm up to 100 mm pan evaporation during Farvardin and Ordibehsht and after that with 70 mmpan evaporation

ماهرخ، علي

تاثير تنش رطوبتي بر شاخص هاي رشد و عملكرد هاي كمي و كيفي چغندر قند

رشد نسبي RGR , قند ملاس