Effects of nitrogen on chlorophyll fluorescence and the relationship between chlorophyll content and spad values in sugar beet (Beta Vulgaris L) under drip-tape system

摘要

Determining Chlorophyll Content with Spectrophotometric Devices and Chlorophyll Extraction is a Time and Cost inefficient method so in the present Study finding a relation between Chlorophyll a, b, and Total content with Spad Values is one of the objectives. Moreover, Chlorophyll Fluorescence is a Photosynthetic activity index that is used in Biotic and Abiotic Stress studies. Nutrient deficiencies (i.e., nitrogen) as an abiotic stress can decrease yield, another aim of the current study is to determine relations between Nitrogen fertilizer rate and Chlorophyll Fluorescence and also Total Nitrogen accumulation in sugar beet organs. in order to it, an experiment carried out under tape-drip irrigation in 2013 and 2014 in Karaj, Iran, in Strip factorial plot with a randomized complete block arrangement with 2 levels of plant Spacing (14 and 20 cm), 2 levels of Planting Pattern (40-60 and 40-50) and Nitrogen Fertilizer treatment in four levels was: 0, 50, 75 and 100% of what had been recommended for furrow irrigation. The results showed nitrogen causes significant Changes on Chlorophyll A, Chlorophyll Total and SPAD Value (P 0.5). Means comparison indicated that using 75% and 100% of nitrogen recommended for furrow irrigation had the best impacts on these traits. Correlation between all this traits implies that Chlorophyll a, b and Total measured with Spectrophotometry and Spad Values had positive and significant relations with themselves and with Impure sugar Yield (P 0.01) the results also showed nitrogen causes significant Changes on Nitrogen accumulation in different Sugar beet Organs (P 0.01) in a way that the treatment with maximum and minimum fertilizer rate had the maximum and minimum nitrogen accumulated in their organs respectively. The minimum chlorophyll Fluorescence was measured in the treatments that had the minimum fertilizers rate.