An Evaluation of Efficacy and Cost Effectiveness of Weed Control Options in Sugarcane Production at Mafambisse Estate in Mozambique

Abstract

Field trials were conducted at Mafambisse Sugar Estate in Sofala Province of Mozambique to evaluate the efficacy and cost effectiveness of weed control options in sugarcane production. Two sites were set up one under flood irrigation and the other under sprinkler irrigation. Four sugarcane varieties were planted in June 2012 at each site with plots placed in a completely randomised design with four treatments and four replicates of each treatment in a specific variety. The seed rate of 10 tons/ha was used in plant cane and basal fertilizer Monoammonium Phosphate (MAP) at a rate of 318 kgs/ha (N11-P22-K00) was applied. Top dressing using Urea fertilizer was applied at 12 WAP at a rate of 250 kgs/ha (N115 kgs/ha). Pre-emergent herbicides were applied to the plots that were supposed to be applied. For plant cane, Pendimethalin 500 EC at 3.5 l/ha, Extreme plus at 1.2kg/ha and MCPA 750 SL at 3 l/ha using manually. Post emergent herbicide was applied using Harness Extra at 2.8 l/ha, Ametryn 500 SC at 4 l/ha and Gramoxone 30 EC at 1 l/ha. Pre-emergent herbicides were applied to the ratoon cane, Pendimethalin 500 EC at 3.5 l/ha, Extreme Plus at 1.2 kgs/ha and Hexazinone 240 SL at 1.5 l/ha and post emergent herbicide application Tebusan 500 SC at 1.5 l/ha, Diuron 80 at 2.5 l/ha and Foliwet 900 at 0.6 l/ha. The best yield of 72 t/ha was obtained in N21 variety in sprinkler irrigated plant cane in the combination treatment. Hoeing treatment of N21 in furrow irrigation plant cane obtained the highest yield of 80.28 t/ha. In ratoon cane, best yields and profit margins were obtained in the N21 variety in the herbicide treatment. In conclusion, N21 variety is well adapted to Mafambisse conditions and a combination of herbicide and hand weeding to be recommended.