Assessment of weed species traits, germination to flowering duration and crops affected on farms in Kisii Central Sub County, Kisii County, Kenya

Abstract

Weed invasion is one of the greatest challenges affecting smallholder farming in Kenya. Timely and effective weed management needs knowledge on weed species traits and their nature of growth. This study aimed at assessment and documentation of weed species traits and time taken from germination to flowering for effective weed management. Ten plots were selected 1km equidistantly along a transect set across each of the eight randomly sampled sub-locations in the study area. In each plot, a 2m² portion was demarcated for monitoring weed species germination to flowering time. Botanical classification of weed species was carried out through examination of the foliage and reproductive regions with the aid of guide books. Weed species G. parviflora and E. brachycephala had the shortest duration to flowering of 4 weeks while T. minuta and D. stramonium, each had the longest flowering duration of 7 weeks. Majority (14) of the weed species were broadleaved while eight were narrow leaved weed species. Thirteen annual weed species were recorded while only nine species were perennial. Three weed species were grass, 2 sedges, 1 shrub and 16 herbs. Fourteen weed species were eudicot while only 8 were monocots. Four weed species were dispersed by insects while wind dispersal and animal dispersal had 9 weed species in each case. Most farms were infested by a variety of weed species which included Pennisetum clandestinum, Oxalis latifolia, Cyperus rotundus, Amaranthus hybridus and Datura stramonium. Weed species traits and interval from germination to flowering will aid forecast on successive weed invasions and thus guide farmers on the effective time of weed management measures such as adoption of integrated weed management practises to optimize crop production.