Analysis of Principal Components for the Assessment of Silage Corn Hybrid Performance under Water Deficit

Abstract

Corn is an important crop for animal production systems. Owing to climate change, it is important to understand the behavior of commercial corn hybrids under low soil water availability. The objective of this study was to evaluate the morphogenic characteristics and yields of silage corn hybrids subjected to different water conditions using univariate and multivariate analyses. The experimental design was randomized blocks in a 5 × 2 factorial scheme with four replications. Corn hybrids (AGRI104, AGRI320, AGRI330, AGRI340, and AGRI360) and water replacement levels (50% and 100% replacement of crop evapotranspiration—ETc) were considered as factors. A water replacement level of 50% ETc was defined as a severe water deficit that persisted for 46 days from V7 until harvesting (R3). Plant height, stem diameter, leaf area, chlorophyll index, water productivity, fresh and dry mass, and dry matter of the shoot and root systems were evaluated. An analysis of variance and a mean test of isolated variables were carried out, and a multivariate perspective, through principal components was performed. In general, the replacement of 50% ETc changed the morphophysiological characteristics of the plants; however, it was only possible to classify the hybrids through a principal components analysis. The best performing hybrids, regardless of the water replacement levels, were AGRI340 and AGRI360.