Estimation of Chlorophyll Using SPAD meter

Abstract

A chlorophyll meter measures the greenness of leaves and can indicate the chlorophyll content and N status. Therefore, by using a chlorophyll meter, proxy information related to the leaf N content could be obtained and this would avoid the need of laborious laboratory analysis. Keeping in this view a field experiment was conducted during winter (Rabi) 2019 growing season at the experimental field of JNKVV, Jabalpur to estimate crop nitrogen (N) and chlorophyll content in wheat using SPAD. The treatment comprised of 3 sources of nutrient M1- Inorganic sources (NPK fertilizers), M2- organic sources (FYM, vermicompost, biofertilizers Azotobacter and PSB) and M3- Integrated sources (50% Inorganic + 50% organic) as main treatments and 5 NPK levels S1- control, S2- 100% RDF, S3- 150% RDF, S4- 200% RDF, S5- Based on soil test value for target yield of 6t ha-1 as sub treatments were replicated thrice in a split plot design. The results showed that the correlation (r = 0.94, 0.90, 0.92 and 0.94, respectively) and coefficient of determination (R2 = 0.96, 0.94, 0.83 and 0.94, respectively) was significantly and positively correlated with SPAD and nitrogen concentration in leaf. Similarly significant and positive correlation (r = 0.84, 0.76, 0.78 and 0.71, respectively) found with SPAD and total chlorophyll values. Coefficient of determination (R2) SPAD with chlorophyll and leaf N concentration proved to be significant (R2 = 0.75, 0.76, 0.54 and 0.85, respectively) at different growth stages. It was concluded that SPAD meter are useful for the determination of proxy chlorophyll and total nitrogen content of wheat plant.