Impact of Time of Weeding on Tobacco (Nicotiana tabacum) Growth and Yield

An experiment laid in a Randomized Complete Block Design with 4 blocks and 5 treatments, was done at Kutsaga Research Station in the 2012 / 2013 season to study the impact of time of weeding on tobacco production. The treatments comprised of different times of weed control with a weed free treatment as the control. The variables measured were stalk heights at 5, 6 and 7 weeks after planting and, leaf expansion measurements were also recorded at 9, 10 and 11 weeks. Leaf yield was measured at untying using a digital scale. Results showed that Tobacco stalk heights were affected at 5 W.A.P since significant differences () were noted among the treatments. Suppressive effects of weeds were shown at 6 and 7 W.A.P due to effective competition (RCI > 0) in all other treatments excluding the control. There were significant differences () among the treatments on leaf expansion at 9, 10 and 11 W.A.P. The treatment weeded at 4 W.A.P showed leaf yield that was significantly higher (L.S.S = 270.8) than the treatment weeded at 2 W.A.P. Basing on the 3 reaps recorded, time of weeding had an influence tobacco yield.