Title: کاربرد کلروفیل فلوئورسانس برای ارزیابی دقیق میزان نیتروژن گیاه گندم و ذرت
Author: 12345

The effect of nitrogen fertilizer on yield and chlorophyll meter reading at profile leaves of three forage sorghum cultivars
Majid Majidian^*, Gilva Ahmadi, Gholamreza Mohsenabadi and Ali Aalami
Department of Crop Production and Plant Breeding, College of Agriculture, University of Guilan, Rasht, Iran
E-mail:ma_majidian@guilan.ac.ir

Abstract
Sorghum is one of the cereals grown in the marginal areas of the world. Fertilizers have not been commonly utilized in the cultivation of sorghum in many of the marginal parts of Iran. This study was conducted in order to investigate effect of nitrogen fertilizer on yield and chlorophyll meter reading at profile leaves of three forage sorghum cultivars, a field study was conducted in 2010 cropping season in Agriculture Experiment Station College of agriculture, University of Guilan. A randomized complete block design with factorial arrangement with three replications was used. Treatment consisted of four levels of nitrogen fertilizer (0, 50, 100 and 150 kg N ha^-1) along with three sorghum cultivars (Pagha, Esphidfid, KSF2). Results showed that Maximum forage yield was obtained in KSF2 with an average forage yield of 40517 kg N ha^-1and also maximum forage yield in sorghum was obtained with 150 kg N ha^-1 with an average yield of was 27064 kg ha^-1 but yield difference among 50,100 and 150 kg N ha^-1 were not significantly different. Thus, it can be suggested that KSF2 cultivar should be applied with 50 kg N ha^-1 in condition Rasht reign. Based on the results obtained from this study nitrogen has similar trend at chlorophyll meter reading in sorghum profile leaves, but among cultivars has not similar trend, that could see different in leaves and tillering characteristics cultivars. For chlorophyll meter reading at profile leaves of sorghum, we should measure total leaves which this work is hard and pass ones time, so suggest that instead of chlorophyll meter reading at profile leaves of sorghum, for mean chlorophyll meter reading, 8th leaves, and for maximum chlorophyll meter reading measure 5th leaf that and if our objective is minimum chlorophyll meter reading, leaves in down plant measurement.
 
Keywords: Chlorophyll meter reading; Cultivar; Nitrogen; Sorghum; Yield