Productivity and Nutritive Quality of Three Kenaf Cultivars (Hibiscus Cannabinus L.) As Influenced by Growing Day with Different Planting Density.

This study was conducted to evaluate the dry matter (DM) yield and forage quality of three Kenaf cultivars in relation to planting density (10 x 10 and 10 x 20 cm²) and growing days (Day 53, Day 62, Day 73, day 84, Day 93, Day 104 and Day 115) in the northern area of South Korea from May 20 to September 12. The experiment was laid out in a split plot design with three replications. The main plots consisted of planting density and growing days with three cultivars of Kenaf as sub-plots; Dowling, Everglade and Tainung. The DM yield increased with maturity in all three cultivars, especially Dowling showed the highest DM yield at each harvest time. The crude protein (CP) contents of all three cultivars decreased with maturity. Especially, the decrease in the CP contents was greater in the early stage than in the late stage. The planting density did not affect the CP contents, even though they are little higher in 10 x 20 cm² compared to 10 x 10cm². Among cultivars, the higher CP contents ware observed in Dowling at each growing day. No difference in the neutral detergent fiber and acid detergent fiber contents was observed in the planting density and cultivars, although the increasing tendency was found with maturity. These results suggest that Kenaf can be a good potential forage crop in the northern area of South Korea, especially Dowling which had the greatest DM yield (29.5 ton/ha) and best forage quality (67.1% NDF and 55.8% ADF) when harvested on Day 104 at 10 x 20 cm² planting density.