Determination of Weeding Frequency to Increase Production and Productivity of Sorghum
Sorghum (sorghum bicolor) is primarily a rain fed crop with low input management. Sorghum production has so many constraints, insect pest, disease and weed infestation are the most known among of them. Farmers in Ethiopia commonly lose up to 40% of their crops due to weed infestations. Because it is not normally planted in rows, weeding is a time-consuming task, taking up to 140 hr./ha. Most farmers in Ethiopia as well as in Amhara Region do not weed their fields at the right time because of labor bottlenecks. Weeds are therefore one of the most important crop production constraints in the country and the region. Heavy infestations of grassy weeds may cause up to a 20 percent yield reduction in the first two weeks after sorghum germination (International Journal of Agronomy Volume 2012)). The most troublesome weeds in sorghum include Striga (Striga hermonthica), Nut-grass (Cyperusrotundus), and other common narrow and broad leaved weeds. Farmers in the watershed have no a weeding habit of their sorghum at the right time and frequency, because they believe that weed free crops at the early stage of the crop will got stalk borer damage. And after at the beginning of September they start to weed their land and used the weed as a feed for their animal. Therefore, the objective of this study is to determine better weeding frequency of sorghum in Gumara-Maksegnit watershed.