Impact of Plant Population and Weed Control Methods on the Growth, Yield and Economic Potential of Sugarcane (Saccharum officinarum L.) Cultivation

ABSTRACT: Sugarcane industries are faced with the challenges of reduced cane yield due to inability to ascertain an appropriate sugarcane planting density. Field trials were conducted at Bacita, southern Guinea savanna of Nigeria to examine appropriate planting density and weed control method that can minimize weed infestation in sugarcane field and give an optimum cane yield to improve the economic status of the sugarcane farming community. The experiment was established as a randomized complete block design in a split-plot arrangement with three replications. The main plot constituted four planting populations (43,200, 64,800, 86,400 and 108,800) plants ha-1 while the sub-plot consisted of six weed control practices (weedy check, pre-emergence application of terbuthylazine at 2.0 kg a.i. ha-1 + three supplementary hoe weeding (SHW), post emergence application of ametryn at 3.0 kg a.i. ha-1 + two SHW., post emergence application of dicamba at 0.5 kg a.i. ha-1 + two SHW., pre emergence application of terbuthylazine at 2.0 kg a.i. ha-1 + post emergence application of 2.4-D at 3.0 kg a.e. ha-1 and monthly hoe weeding). The study revealed that fifteen weed species were encountered as the most prevalent weed species in sugarcane ecology. Plant population of 108,800 plants ha-1 had the lowest weed seedlings population with highest cane yield (216.03 tons ha-1), production efficiency of 9.20% and benefit cost ratio of US$ 9.86 on every US$ 1 spent. This study concludes that, the adoption of 86,400-108,800 plants ha-1 of sugarcane and pre emergence application of terbuthylazine at 2.0 kg a.i. ha-1 + three SHW (for small scale growers) or pre emergence application of Terbuthylazine at 2.0 kg a.i. ha-1 + post emergence application of 2.4-D at 3.0 kg a.e. ha-1 for the commercial estates will minimize weed infestation and make sugarcane cultivation a profitable venture.

摘要：甘蔗产业面临着因无法确定适宜种植密度而导致甘蔗单产下降的严峻挑战。为探究既能有效减轻甘蔗田杂草为害、又可获得最优甘蔗产量，进而改善蔗农经济状况的适宜种植密度与杂草防控方案，本研究在尼日利亚南部几内亚稀树草原的巴奇塔地区开展了田间试验。本试验采用裂区排布的随机完全区组设计，设置3次重复。主区处理包含4个种植密度梯度：43200、64800、86400及108800株·公顷⁻¹；副区处理则涵盖6种杂草防控措施：杂草放任对照、播前喷施特丁津（terbuthylazine）2.0 kg a.i.·ha⁻¹+3次辅助人工中耕除草、播后苗前喷施莠去津（ametryn）3.0 kg a.i.·ha⁻¹+2次辅助人工中耕除草、播后苗前喷施麦草畏（dicamba）0.5 kg a.i.·ha⁻¹+2次辅助人工中耕除草、播前喷施特丁津2.0 kg a.i.·ha⁻¹+播后喷施2,4-滴（2.4-D）3.0 kg a.e.·ha⁻¹，以及每月人工中耕除草。本研究共检出15种在甘蔗种植生态系统中占优势的杂草物种。其中，种植密度为108800株·公顷⁻¹的处理杂草幼苗种群密度最低，甘蔗单产最高（216.03吨·公顷⁻¹），生产效率达9.20%，每投入1美元可获得9.86美元的收益成本比。本研究最终得出结论：对于小规模种植户，推荐采用86400~108800株·公顷⁻¹的甘蔗种植密度，配合播前喷施特丁津2.0 kg a.i.·ha⁻¹+3次辅助人工中耕除草方案；对于商业种植园区，则推荐采用播前喷施特丁津2.0 kg a.i.·ha⁻¹+播后喷施2,4-滴3.0 kg a.e.·ha⁻¹的防控措施。上述方案可有效减轻杂草为害，使甘蔗种植成为一项具备盈利性的产业。