INTERACTIVE EFFECTS MODEL OF NITROGEN AND SILICON IN MAIZE QUALITY INDICES

Abstract

The purpose of the study was to evaluate the influence of nitrogen (N) and silicon (Si) on quality indices in maize grains, the Lovrin 400 hybrid. Nitrogen (ammonium nitrate) was applied in the range of 0-200 kg ha-1, with the 40 kg variation unit (N0, N40, N80, N120, N160, N200). Silicon (silicic acid) was applied foliar (0, 0.5%, 1.0%, 1.5%, 2.0%) in the main growth stage I: Leaf development BBCH Code, at 4 leaves, 6-8 leaves and 10 leaves, respectively.The combination of the two treatments resulted in 30 variants, in three repetitions. Corn grain quality indices such as starch (ST), protein (PRO), fat (FAT), fiber (FIB), ash (ASH) and moisture (MSTR) have been evaluated. Determinations were made using non-destructive NIR methods. Based on a general model of the type f = (N, Si), the PRO index indicated the strongest correlation (R2=0.800, with p<0.001), and the FAT index strongly correlation (R2=0.763 with p<0.001), with the two independent variable (N, Si). The ASH and FIB indices correlation had a average intensity (0.4-1, and for Si=1.26%. In the case of the FAT index, the contribution of N was negligible, and for Si was found the optimal Si=1.46%. The PCA analysis identified the association of some N × Si fertilization variants with the PRO index, and other N × Si variants with ST and FAT quality indices, which facilitates decisions in fertilization practice. PC1 (ST) explained 76.136% of variance, and PC2 (PRO) explained 21.798% of the variance. Clustering analysis has led to the formation of three distinct clusters in relation to afinity of respons expressed through PRO index values determined by N and Si treatments. This has practical importance in the management of fertilization in maize with the two fertilizers.