VARIATION OF THE THOUSAND KERNEL WEIGHT IN WHEAT IN RELATION TO NPK MINERAL FERTILIZATION

Abstract

The study evaluated the variation of the thousand kernel weight (TKW), as an index of wheat quality, in relation to NPK mineral fertilization. The research took place at the Agricultural Research and Development Station Lovrin, Timis County, Romania. The Ciprian wheat variety was cultivated, on a chernozem type soil with medium fertility, under non-irrigated conditions. Nitrogen, phosphorus and potassium fertilizers were applied. Nitrogen (N) was applied in three fertilization levels 0, 60 and 120 kg ha-1; phosphorus (P) was applied in two fertilization levels, 0 and 60 kg ha-1; potassium was applied in four fertilization levels, 0, 40, 80 and 120 kg ha-1. From the combination of nutritional elements and applied doses, 16 experimental variants was evaluated, and the experiments were organized in four repetitions. The thousand kernel weight (TKW) was evaluated by measurement, with a laboratory balance with a precision of ±0.002 g. The ANOVA test confirmed the safety of the data and the presence of the variance in the data set (F=11.19783, Fcrit=2.80349, p<0.001), under conditions of Alpha=0.001. Strong correlations were identified between TKW and P (r=0.833) and weak correlations between TKW and N (r=0.672). The variation of TKW in relation to the nutritional elements applied was described by different equations, under statistical safety conditions, in relation to the elements taken into analysis. The direct and interaction effect of NPK on TKW variation was observed, under conditions of R2=0.898, p<0.001. 3D models and in the form of isoquants were generated, which graphically described the variation of TKW in relation to N (x-axis) and PK (y-axis). The cluster analysis facilitated the grouping of the experimental variants based on the Euclidean distances, in relation to the TKW values, under statistical safety conditions (Coph.corr.=0.806).