Effects of Biofumigation of Spider Plant (Cleome gynandra L.) Against Root-Knot Nematodes (Meloidogyne Spp.) on Quality of Tuberose (Polianthes tuberosa L.)

Abstract

Tuberose (Polianthes tuberosa L.) is a perennial summer flower grown by smallholders in Kenya for export as it requires low technical and financial input. However, its production and export volumes in Kenya - have been declining drastically. This declining trend has been attributed to root-knot nematodes (Meloidogyne spp) infestation, leading to rejection of cut flowers. This study evaluated the effect of biofumigation of Cleome gynandra against root-knot nematodes. Two experiments were conducted at Egerton University, Njoro, Kenya, using a randomized complete block design with four replications. The treatments were: accessions of C. gynandra; ‘Egerton’ volunteer; ‘Taastrup’; ‘PS’ and ‘IP8’applied at 6 kg/m^-2 compared with fumigant (97% dazomet), Brassica napus, solarization and untreated control. Data was collected on nematode infestation and quality of tuberose in terms of stem length, number of leaves and stem diameter. Biofumigation with different C. gynandra accessions was as effective as the fumigant and Brassica napus in reducing nematode population by 34%, gall numbers by 83% and galling index by 96% when compared with the control. Biofumigation with different C. gynandra accessions enhanced the spike length by 32%, marketable spikes by 80%, and reduced non-marketable spikes by 95% when compared with the control. C. gynandra can be used as a biofumigant for management of root knot nematodes and improvement of yield and quality of tuberose.