Agronomic and nutritional characteristics of sorghum hybrids (Sorghum bicolor L. Moench) cultivated for silage production

Abstract

The experiment was conceived to evaluate the agronomic and nutritional characteristics of the BR-700, AG-2005, MASSA-03, 699005, 699001, 698005, 698007, and 498111 sorghum hybrids cultivated in two different localities. The hybrids were sowed in November 1999 at 180.000 plants/ha. The study was conducted in accordance with a randomized block design with eight treatments, three replications, and the results were analyzed separately for each locality. The average data among localities were used to determine the main component and cluster analyses. The dry matter yields, stem, leaf and panicle proportion and percentage of crude protein and cell wall components were determined. The results showed highest percentages of whole plant crude protein in 698005 and AG-2005 hybrids. The 699005 hybrid presented highest(P<0.05) levels of neutral detergent fiber, acid detergent fiber, and cellulose. There were no differences in the whole plant lignin, hemicellulose, and acid detergent insoluble nitrogen content between different cities. The highest dry matter yield (P<0.05) was observed in the 698005 that presented the best proportion of plant components. The 498111 hybrid presented highest stem percentage in the dry matter and lowest levels of neutral detergent fiber and acid detergent fiber. The hybrids classification, according to a principal component and cluster analyses indicated two groups: the first one characterized by panicle proportion and crude protein content, whereas the other one was characterized by dry matter production, stem proportion and acid detergent fiber content. KEY-WORDS: Cluster analyses. Dry matter production. Morphological composition. Principal component.