Determine relationship of leaf chlorophyll concentration and yeild using chlorophyll meter in sugar beet

In order to determine relationship of leaf chlorophyll concentration and yield and quality using chlorophyll meter in sugar beet research was conducted using various levels of nitrogen fertilizer during different growth stages of sugar beet plants on research farm of Sugar beet Institute located in Karaj Kamal- Abad during 2007، design based on Randomized Complete Blocks in four replications. Five level pre-sowing nitrogen from the source of urea was applied in amounts of 0 (as control)، 120، 160، 200 and 240 kg/h. Chlorophyll concentration leaf blade number 5 was measured by chlorophyll meter (SPAD) at 12-15 leaf stage. In the same leaves، concentrations of nitrogen (by Kjeldahl method) was measured. The results showed that moreover 50% of the variability in yield is explained by the SPAD reading in the growth stages 12-15 leaf in sugar beet. SPAD value was، also related whit N concentration and α- amino N in root. The highest SPAD reading showed maximum α- amino N in root. Nitrogen fertilizer had significant effect on the chlorophyll meter reading. The least number read from SPAD was 38، which associated with no-applied nitrogen treatment. highest yield of root (ton / hac) in this experiment was related to with N160، which the number read from the chlorophyll meter in levele was equal with 41/2. According to the obtained results، therefore، whit further research chlorophyll meter (SPAD) can be used as a simple rapid and non- destructive and may be useful to predict yield and may be a useful tool determine which field to harvest late in season.