International Journal of Agriculture and Agricultural Sciences ISSN 1712-3496 Vol. 4(2), pp. 082-089 September, 2017. © Advanced Scholars Journals

Full length Research Paper

Influence of nitrogen fertilizer rates on growth and yield of fibre hemp cultivars in South Africa

*Francois de Klerk, Matthews Makeba and Winnie Gabriel Barnard

Agricultural Research Council- Institute for Industrial Crops, Private Bag x 82075, Rustenburg 0300, South Africa.

Accepted 19 August, 2017

Abstract

Hemp (Cannabis sativa L.) has been grown in Southern Africa for medicinal purpose for many centuries, and in the past half century as an illegal drug crop marijuana, “dagga”. It was however, noted that hemp has high fibre which can be used in formation of particle boards, textile products, paper and clothing. Field experiments were conducted during 2006/2007 and 2007/2008 seasons at Addo of Eastern Cape Province. The objective of the study was to determine the influence of nitrogen fertilizer rates; thus, 0, 50, 100 and 150 kg ha^-1 on growth and yield of fibre hemp cultivars, Kompolti, Felina 35 and Novosadska. In 2007/2008, Novosadska was used to replace Felina 35, whose fibre was very short. Trials were laid out in complete randomised block design with four replications and four nitrogen levels and two hemp cultivars. The results revealed that there were significantly higher fresh biomass yields, dry biomass yield, and fibre yield in the fertilized units than in the unfertilized control unit. The highest plant height, fresh and dry biomass yield were obtained with 100 and 150 kg ha^-1 of N fertilization were applied at Addo during 2006/2007. Higher nitrogen levels tended to produce higher yield and quality in both seasons. Kompolti performed better than Felina 35 and Novosadska. Kompolti had a higher fibre percentage and quantity than other cultivars in both seasons. It was therefore concluded that nitrogen application had a positive effect on growth and yield studied, and the optimum fertilization rate of nitrogen will be 100 and 150 kg ha^-1.

Key words: Fibre hemp, cultivars, nitrogen fertilization, yield, quality.