Agronomy and chemical composition of sunflower (Helianthus annuus L.), as a forage option in a hot and humid intertropical environment Sunflower as a tropical forage

Abstract

The study was carried out at Colegio de Posgraduados Campus Tabasco, to know the sunflower phenology and its potential as a forage for ruminants in a hot and humid environment. During the 2016 dry season, six treatments were evaluated corresponding to cutting days after sowing (DDS): 65 (T₁), 72 (T₂), 79 (T₃), 86 (T₄), 93 (T₅) y 100 (T₆). The sunflower hybrid SYN3950HO was planted in a 5 x 40 m plot, under a randomized complete block design, and three replicates. The traits evaluated were: days to reproductive stages (R_i), plant height (AP) in cm, stem perimeter (PMT) in cm, flower diameter (DF) in cm, dry mass production in stem (PT), leaf (PH), petiole (PP), flower (PF), and total dry mass (MS t ha^-1), and the content of dry mass (MS), crude protein (PC), ash (CEN), neutral detergent fiber (FDN), and acidic detergent fiber (FDA). Analysis of variance were carried out for every trait, means comparison tests (Tukey P<0.05), correlation analyses among traits, and regression analysis of traits on DDS. Significant differences were found (P< 0.05) in AP, DF, PMT, PP, PF, and MS t ha^-1, as well as in MS, PC, FDN y FDA. The highest biomass yield, 16 t ha^-1, was reached by 100 DDS with nutritive values of 26 % MS, 12.7 % PC, 21.9 CEN, 44.2 % FDN, and 30.9 % FDA. It is concluded that sunflower is a suitable plant species to be grown and used in the ruminants feeding systems in the study area.