Author
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Richard Jr, Edward |
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Dalley, Caleb |
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Submitted to: Sugar Cane International
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/14/2005 Publication Date: 7/20/2005 Citation: Richard Jr, E.P., Dalley, C.D. 2005. Bermudagrass (Cynodon dactylon) Interference in a Three-Year Sugarcane (saccharum spp.) Production Cycle. Sugar Cane International. 23(4):3-7. Interpretive Summary: In Louisiana, sugarcane is grown as a vegetatively-propagated perennial with at least three annual harvests following a single planting. During each production year the crop emerges from winter dormancy and begins a new infancy period on a row top that is not disturbed. This type of culture is especially conducive to the establishment of perennial weeds such as bermudagrass. Three sugarcane varieties having different spring emergence patterns and stalk populations at harvest were planted into a dense infestation of bermudagrass to determine the effects of season-long competition on sugarcane growth and yield as the varieties progressed through a normal plant-cane, first-ratoon, and second-ratoon production cycle. Bermudagrass competition reduced the number of harvestable stalks and gross cane yield by 6%, with an 8% reduction in sugar yield during the plant-cane production yr. In the first-ratoon season, stalk height was reduced by 5% for both durations of competition, and sugar yield was reduced by 13 and 8% in the plant-cane only, and plant-cane through first-ratoon durations of competition, respectively, with no differences in stalk height or sugar yield. In the second-ratoon season, number of harvestable stalks and stalk height were reduced by bermudagrass competition only where bermudagrass remained for the full production cycle. Gross cane and sugar yields in the second ratoon were reduced by all durations of competition compared to no bermudagrass competition, with sugar yield being reduced by 4, 5, and 10% in the plant-cane crop yr only, plant-cane and first-ratoon crop yr, and plant-cane, first- and second-ratoon crop yr durations of competition, respectively. Total loss of sugar yield for the three-yr production cycle, when bermudagrass was not controlled, was 1600 kg sugar/ha. This research found that if bermudagrass is allowed to compete within a prior crop season, its impact carries over to subsequent crops of the same planting even if it is completely controlled in those production years. Therefore, it is especially important to control this weed in the fallow season prior to planting and in the early stages of the sugarcane cycle in order to minimize bermudagrass’s impact on sugarcane production. Our findings did not reveal any varietal differences in competitiveness with bermudagrass. However, this is not meant to imply that varieties cannot be selected in the future that would have an increased or decreased competitiveness with bermudagrass. Varieties most likely to be more competitive with bermudagrass would be those that are early emerging, have high stalk populations, and form a dense canopy, as bermudagrass is not very tolerant of shade. Technical Abstract: Three sugarcane varieties having different spring emergence patterns and stalk populations at harvest were planted into a dense infestation of bermudagrass to determine the effects of season-long interference on sugarcane growth and yield as the varieties progress through a normal plant-cane, first-ratoon, and second-ratoon production cycle. To create four durations of interference, bermudagrass was removed in the spring following planting, following the plant-cane production yr, following the first-ratoon production yr, or allowed to remain during the entire three-yr crop production cycle. Though differences in degree of bermudagrass infestation occurred in the plant-cane production yr in both runs of the experiment, the differences were not evident in the first- or second-ratoon production yr and weed infestation did not appear to be affected by variety. Bermudagrass interference reduced the number of harvestable stalks and gross cane yield by 6%, with an 8% reduction in sugar yield during the plant-cane production yr, with each variety responding similarly to bermudagrass interference. In the first-ratoon season in 1992, stalk height was reduced by 5% for both durations of interference, and sugar yield was reduced by 13 and 8% in the plant-cane only, and plant-cane through first ratoon durations of interference, respectively, with no differences in stalk height or sugar yield for 1993. In the second-ratoon season, number of harvestable stalks and stalk height were reduced by bermudagrass interference only where bermudagrass remained for the full production cycle. Gross cane and sugar yields in the second ratoon were reduced by all durations of interference compared to no bermudagrass interference, with sugar yield being reduced by 4, 5, and 10% in the plant-cane crop yr only, plant-cane and first-ratoon crop yr, and plant-cane, first- and second-ratoon crop yr durations of interference, respectively. Total loss of sugar yield for the three-yr production cycle, when bermudagrass was not controlled, was 1600 kg sugar/ha. This research found that if bermudagrass is allowed to interfere within a prior crop season, its impact carries over to subsequent crops of the same planting even if it is completely controlled in those production years. Therefore, it is especially important to control this weed in the fallow season prior to planting and in the early stages of the sugarcane cycle in order to minimize the impact of bermudagrass interference on sugarcane production. |
