Harvesting Interval Changes Yield and Nutritive Value of Kenaf in a Dry Tropical Climate

Abstract

Kenaf (Hibiscus cannabinus L.) could be a forage alternative to the cattle production in the dry tropics of Mexico. The objective of this study was to evaluate harvest intervals on yield and nutritive value of kenaf ‘Everglades 41’. Intervals evaluated were 20, 40, and 60 d, and a single harvest in October when growth ceased. Since rainfall varied between 1998 and 1999, there was a year effect (P < 0.05) for yield and plant height. Total dry matter (DM) was lowest from the 20‐d harvest interval and highest from the October‐only harvest (P < 0.05) both years. Multiple harvest treatments resulted in greater leaf:stem ratios. The October‐only harvest had the lowest (P < 0.05) crude protein (CP) with 189 g kg−1 and the multiple harvest ranged from 237 to 286 g kg−1. Leaf neutral detergent fiber (NDF) increased, as harvest interval increased, from 148 g kg−1 DM in the 20‐d treatment up to 175 g kg−1 DM in the October‐only treatment. Stems harvested in October‐only had the greatest NDF. The lowest acid detergent fiber (ADF) concentration (P < 0.05) resulted from regrowth of 20‐d harvests, with 131 g kg−1 DM. October plant density was 27% lower (P < 0.05) at the 20‐d harvest interval than in October‐only harvest. A harvest interval of at least 40 d is required for kenaf persistence and vigorous recovery.