VARIATION OF PHOTOSYNTHETIC PIGMENTS AND Chl/Car RATIO IN WHEAT IN RELATION TO FERTILIZATION RATE

Abstract

The study evaluated the content of photosynthetic pigments (Chl, Car) and the Chl/Car ratio in wheat leaves, Alex cultivar, in relation to fertilization rate. Mineral fertilizers with N (0-200 kg ha^-1) and P, respectively K (0-150 kg ha^-1) generated 11 experimental variants. The tests were performed on the flag leaf (BBCH 7 stage). The chlorophyll content (Chl) varied between 34.73 ± 1.14 units in the control variant (V1) and 60.52 ± 1.17 units in the V8 variant. The carotenoid content (Car) varied between 4.51 ± 0.18 units in the control variant (V1) and 11.41 ± 0.27 units in the V11 variant. The Chl/Car ratio was calculated, which recorded values between 7.70 ± 0.15 in the control variant (V1) and 5.27 ± 0.08 in the V11 variant. Different correlations were found between photosynthetic pigments and N, respectively P, K (eg. r = 0.832 between Chl and N; r = 0.828 between Car and N; r = 0.717 between Car and P, K; r = -0.770 Chl/Car and N; r = -0.728 between Chl/Car and P, K). The regression analysis facilitated the obtaining of some variation models of Chl, Car and the Chl/Car ratio in relation to N and P, respectively K, in statistical safety conditions.