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ARS Home » Midwest Area » Urbana, Illinois » Global Change and Photosynthesis Research » Research » Publications at this Location » Publication #311229
Title: Weeds and their effect on the performance of maize and fingermillet in the mid-hills of Nepal

Author
item KARKI, TIKA - Tribhuvan University
item SAH, S - Tribhuvan University
item THAPA, R - Tribhuvan University
item MCDONALD, ANDREW - International Maize & Wheat Improvement Center (CIMMYT)
item Davis, Adam
item KHADKA, Y - Nepal Agricultural Research Council

Submitted to: International Journal of Applied Sciences and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2014
Publication Date: 12/1/2014
Citation: Karki, T.B., Sah, S.K., Thapa, R.B., McDonald, A.J., Davis, A.S., Khadka, Y.G. 2014. Weeds and their effect on the performance of maize and fingermillet in the mid-hills of Nepal. International Journal of Applied Sciences and Biotechnology. 2:275-278.

Interpretive Summary: Food security in developing areas is often constrained by persistent yield gaps due to agronomic, environmental and social factors. In the mid-hills of Nepal, relay cropping of maize with fingermillet is the predominant cropping system, but crop yields can be severely reduced by weed pressure. Basic information on weed species composition, biomass production and their effect on crop yields and economics are lacking for this region. We conducted a field study in two representative mid hill districts of Parbat and Baglung during the summer season of 2010 and 2011 in Nepal. A total of 10 major weed species were observed, with weed communities dominated by Ageratum conyzoides and Polygonum chinensis. Weed infestation under typical farmer practices reduced the grain yield of maize by over 50% in all study areas. Similarly, the combined yield of both maize and fingermillet was also significantly reduced by over 60%. Weeds are having large negative impacts on crop performance in the region, indicating an urgent need for new agronomic practices, and possibly new cropping systems, in the mid-hills of Nepal.

Technical Abstract: Relay cropping of maize with fingermillet (maize/fingermillet) is the predominant cropping system for sustaining food security in the hilly regions of Nepal. In this region weed pressure severely reduces crop yields, yet basic information on weed species composition, biomass production and their effect on crop yields and economics are lacking. Such information will be necessary to develop effective weed management strategies for the future. We conducted a field study in two representative mid hill districts of Parbat and Baglung during the summer season of 2010 and 2011 in Nepal. A total of 10 major weed species with population densities of 172 per 0.25m2 in Parbat and 311 per 0.25m2 area in Baglung were observed. The highest percentage of both relative and absolute densities were recorded for Ageratum conyzoides in Parbat and Polygonum chinensis in Baglung. Compared with weed infested crops under typical farmer practices, weed-free maize had yield increases of 1.985 Mt ha-1 (117%) in Baglung and 1.760 Mt ha-1 (108%) in Parbat. Similarly, in finger millet, yield increases due to weed removal were 0.489 Mt ha-1 (63%) in Baglung and 0.403 Mt ha-1in Parbat. The combined yield of both crops was significantly increased by 79.3% and 61.7% in Baglung and Parbat, respectively, under weed-free compared to weedy conditions. Weeds are having large negative impacts on crop performance in the region, indicating an urgent need for new agronomic practices, and possibly new cropping systems, in the mid-hills of Nepal.