African spider plant (Cleome gynandra L.) as biofumigant against weeds during Turfgrass (Paspalum notatum) establishment

Weeds are the most common pests, which interfere with turfgrass establishment and uniformity lowering functional and aesthetic quality of lawns. Killing weed seeds or suppressing their germination is necessary before establishing new lawn to prevent weeds from gaining a foothold hence, giving turfgrass a competitive advantage.  A field study was conducted at Bukura Agricultural College, Kenya, to explore the potential of biofumigation with African spider plant (Cleome gynandra) as an environmentally friendly alternative to use of synthetic herbicides for establishment of weed-free Paspalum notatum turfgrass. Biofumigation with chopped C. gynandra plants at flowering stage, incorporated into the soil at the rates of 4, 6 and 8 kg m-2, respectively, and was compared with Basamid® (97% Dazomet) at 0.029 kg m-2 and untreated negative control in a randomized complete block design experiment. C. gynandra at rates of 6 or 8 kg m-2 was as effective as Basamid® at 0.029 kg m-2 in significantly suppressing Galinsoga parviflora, Galinsoga ciliata and Bidens pilosa weed populations and reducing weed infestation. Other weed species occurred in the experimental plots in insignificant populations.  The results of this study demonstrated that C. gynandra has potential for use as a biofumigant against weeds during lawn establishment. Key words: Cleome gynandra, biofumigation, environmentally friendly, weeds, herbicides, lawn.