تاثیر مدیریت توزیع نیتروژن برجذب وکارایی مصرف نور در ژنوتیپ های سورگوم علوفه ای

Abstract

Abstract One of the most important effective factors on yield potential difference on sorghum Genotypes is quality and quantity of absorbed photosynthetically active radiation(APAR) under influence of rate and quality distribution of nitrogen utilization. In order to investigation of cumulative photosynthetically active radiation (CPAR) and radiation use efficiency (RUE) under condition distributions of nitrogen side dressing and non-distribution, in forage sorghum Genotypes an experiment was conducted at Khorasan Razavei Agriculture and Natural Resources , Research Center Mashhad , Iran. The experiment was spilt plats base on randomized complete block design with three replications. The main plots were fifteen forage sorghum Genotypes (promising lines) and the subplots consisted of distribution of nitrogen side dressing and non-distribution. The sampling was done in 5 times for determination of some characters such as dry matter of whole plant (TDM), leaf area index (LAI) and photosynthetically active radiation(PAR).Then total dry matter(TDM), cumulative photosynthetically active radiation (CPAR) and Radiation use efficiency (RUE) were calculated by these traits. The variance analysis results showed that effect of Genotypes on total dry matter in first cutting was significant (p<0/05). The maximum and minimum were 20.17 t/ha and 13.56 t/ha which were belong to Genotypes (14) and (8), respectively. The fertilizer distribution method and interaction of nitrogen and Genotype on leaf area index were significant (p<0/05). Nitrogen distribution caused leaf area index and photosynthetically active radiation (PAR) to grow up to %9 and %2, respectively. The investigated Genotypes had significant difference on radiation use efficiency. The maximum and minimum were 4.18 g/mj2 and 3/06 g/mj2 which were owned to Genotypes 14 and 8, respectively. The results of investigation showed that differences on yield of forage Sorghum Genotypes were because of difference both of effective on yield dry matter namely radiation use efficiency and cumulative photosynthetically active radiation.