Forage production from fine branches and sprouts of native maniçoba

Abstract

The growth and forage production of Manihot glaziovii were evaluated in plants growing in Itapetim-PE, Brazil via a complete block experimental design with four treatments (0, 33, 50, and 100% branch cutting intensity) to analyze increases in height and diameter. Furthermore, 3×2 factorial treatments (three branch cutting intensities: 33, 50, and 100% as well as two types of collected forage material: Branches with diameter < 10 mm and corresponding sprouts on the same branches 1 year after being cut) were analyzed for improvement in forage quantity and quality parameters. Height increase was affected (P < 0.05) by branch cutting intensity (0.29, 0.11, 0.43, and -0.04 m plant-1, respectively, for 0, 33, 50, and 100% branch cutting intensities), while the increase in diameter was not affected (P > 0.05) (3.97 mm plant-1 was the overall mean increase). Cutting intensity×type of collected material, in combination, affected (P < 0.05) the quantity of the collected forage: means were considered similar (P > 0.05) in the first (branches) and second (sprouts) forage collection events for 33% (0.66 and 0.75 kg dry matter plant-1, respectively) and 50% (1.40 and 1.73 kg dry matter plant-1, respectively) cutting intensities; it decreased (P < 0.05) from the first to the second collection events, when 100% of branches and sprouts were harvested (3.37 and 2.06 kg dry matter plant-1, respectively). The combined effects of aforementioned parameters were observed (P < 0.05) as interactions for some forage quality variables. Neutral detergent fiber content remained constant (P > 0.05) between 50.57 and 54.41% in forage containing branch and sprouts from 33 and 50% cutting intensities. It increased (P < 0.05) to 62.20% in sprouts from 100% cutting intensity. Acid detergent fiber content increased (P < 0.05) from around 38.4% to 46.63% in sprouts from plants subjected to 100% cutting intensity. The crude protein (between 8.72 and 10.08%) and ether extract (between 2.74 and 4.35%) contents were unaffected (P > 0.05) by these factors. Mineral matter content was higher (P < 0.05) in sprouts from all cutting intensities with 5.9% being the highest. Up to 50% of Manihot glaziovii branches with Ø < 10 mm and corresponding 1-year-old sprouts can be pruned with no negative effect on the quality and quantity (up to 1.73 kg dry matter plant-1) of the collected forage.