Abstract

A study was conducted to determine the suitable herbicide(s) for effective weed management in finger millet, in order to address the major biotic stress of weeds infestation and attain optimal productivity of finger millet. Field experiments were conducted in Baringo and Kericho counties in Kenya for two growing seasons, using a randomized complete block design (RCBD) and replicated three times. Three pre-emergence herbicides were used: Mesotrine + Metolachlor + Terbuthylazine, Atrazine + S-metolachlor, and S-Metolachlor. The abundance of weed species was affected by the environment, herbicides used, and types of weed species present. The herbicides used were 2, 4-D amine salts, Atrazine, Metribuzin, and Fluroxypyr + Chlorpyrlid + MCPA, while a control of no weeding was also included. A high weed species abundance was observed in Baringo (20.4%) as compared to Kericho (19.4%). The lowest weed species abundance (WSA) of 0.11% was observed with Mesotrine + Metolachlor + Terbuthylazine. Weeds from the Poaceae family had the highest WSA of 34%. At Kericho, a weed density of 6.47 weeds/m2 was recorded, and a higher weed control efficiency of 90.56% and 88.88% was observed with Fluroxypyr + Chlorpyrlid +MCPA and 2, 4-D amine salts, respectively, with no phototoxicity observed. However, Metribuzin, Atrazine + S-Metolachlor, and Atrazine had higher weed control efficiency of 89.92, 90.13, and 88.34%, respectively, but caused high crop phytotoxicity, lower yields, and reduced crop biomass.  Application of 2, 4-D amine salts and Fluroxypyr +Chlorpyrlid+ MCPA recorded higher yields of 5.04 t/ha and 5.4 t/ha respectively, with a higher crop biomass of 2.6 t/ha and 2.7 t/ha respectively, which was not significantly different. Positive correlation was observed between crop biomass and yield (r=0.98), suggesting that the use of 2, 4-D amine salts and Fluroxypyr + Chlorpyrlid + MCPA will ensure effective weed management and contribute to increased finger millet productivity.

Key words: Crop phytotoxicity, post-emergence, pre-emergence and weed management.