DETERMINATION OF CRITICAL PERIOD OF WEED CONTROL ON GINGER (Zingiber officinale Roscoe) AT SELAM, SOUTH WEST ETHIOPIA

Abstract

Ginger is an important spice and cash crop in Ethiopia. However, its production is constrained by different abiotic and biotic factors; weed is one of the most important biotic factors which reduces yield of ginger. Therefore, this study was conducted in 2023 main cropping season at Yeki, South Western Ethiopia to determine the critical period of weed competition and yield loss. The trial had twenty treatments in two sets, namely weedy set and weed-free set, each sets comprising weed competition durations of 15, 30, 45, 60, 75, 90, 105, 120 and 135 days after crop emergence and weedy control as well as weed-free plot throughout crop life cycle. The trial was laid out as a randomized complete block design with three replications and the treatments were assigned randomly to experimental units within a block. The weed and crop data were collected and subjected to analysis of variance by using SAS software. The most dominant species was Bidens pilosa L. (Asteraceae family) with density and relative density of 73 m -2 and 18.4%, respectively. Weed density, weed dry biomass, yield components and yield of ginger were significantly affected by weed competition durations. Uncontrolled weed growth reduced the yield of ginger by 93%. The beginning of CPWC (Critical period of weed control) based on 10% AYL (acceptable yield loss level) occurred at 180 GDD (Growth degree days), which was corresponded to 26 DAE (Days after emergence). The end of the CPWC at 10% AYL occurred by 1150 GDD or 143 DAE. To prevent more than 10% yield loss, the efficient weed contr ol period for ginger at Selam area could be accomplished by keeping the crop weed free between 26 to 143 DAE. Further research in different physiographic, edaphic and climatic conditions is recommended.