Effect of Weed Management Methods on Yield and Physical Quality of Coffee at Gera, Jimma Zone, South West Ethiopia

Abstract

A field experiment was conducted to evaluate different single and integrated weed management methods on yield and physical quality of highland coffee from 2001-2005 at Gera, Jimma zone. Ten different weed management methods; one slashing/year ( farmers practice), crotalaria cover crop at 65kg/ha, coffee husk mulching at 15 tone/ha, roundup at  4Lt/ha, roundup 2ltollowed by crotalaria cover, roundup 2lt followed by coffee husk mulching , slashing  followed by crotalaria cover followed  by coffee husk mulching followed  by 2lt roundup,  slashing  followed by crotalaria cover followed  by coffee husk mulching followed  by lt roundup,  slashing  followed by crotalaria cover followed  by coffee husk mulching,  were compared in coffee berry disease resistant variety “7440” field using randomized complete block design with four replications. In the experimental field noxious weed species recorded among others were Digitaria abyssinica, Cynodon spp, Cyprus spp, Commelina benghalensis, Hydrocotyl Americana, Bidens pilosa and Ageratum conyzoides. The overall result showed that integration of different weed management methods as one treatment gave excellent control of the noxious perennial weeds when compared with individual weed control approaches. Five years mean yield of 1.2, 3.7, 6.4, and 4.3 Q/ha clean coffee was obtained from slashed, crolotaria cover cropped, un-decomposed coffee husk mulched and herbicide applied plots, respectively. However, integrated weed management in coffee using slashing+crolotaria cover cropping+un decomposed coffee husk mulching+herbicide application gave a highly significant mean yield of 15 Q/ha clean coffee. The result also demonstrated that physical quality of coffee; dry coffee bean seed length, width and depth were highly significantly affected by weeding methods. In addition, the result also showed possibility of reducing herbicide rates in coffee from 4 lit/ha as sole weed control approach to 1 lit/ha while integrating different weed management approaches with the tremendous yield increase;15 Q/ha clean coffee instead of less than 5 Q/ha.

Keywords: Coffee, physical quality, weed management method, yield