Evaluation of an improved Katambora grass cultivar G HR1 for root-knot nematode management in tobacco

Abstract

Increased environmental, human and animal health concern with nematicides use in controlling root-knot nematode (Meloidogyne spp.) in tobacco (Nicotiana tabacum L.) has fostered the need to find environmentally-friendly alternatives. Among these alternatives is the use of non-host crops in rotation with tobacco. Katambora Rhodes grass (Chloris gayana) is among the widely used rotation crops but, to achieve good nematode control, the grass has to be grown for at least three seasons preceeding the tobacco crop. After the government land reform program in Zimbabwe, the availability of land to accommodate long rotations became limiting because average farm sizes were reduced. Additionally, tobacco is increasingly grown by small-scale growers on small pieces of land where it is not practical to devote areas to the recommended 3–4 years of a grass ley. To alleviate this, the Tobacco Research Board, Zimbabwe developed a superior Katambora grass cultivar with a higher nematode suppression effect. Evaluation trials were carried out in a greenhouse at Kutsaga in a split plot design. Results showed that unlike the traditional Katambora grass that required 36–48 months to effectively suppress nematode populations and restore soil fertility, the new variety, G HR1 gives the same benefits in only 9–12 months.

Keywords:

• katambora
• root-knot nematode
• rotation