Seasonal growth characteristics and shading ability of six sugarcane varieties were compared during the second production year. For each variety, trend analysis of data showed a significant linear trend. Differences in shoot emergence among the varieties were observed beginning in early April and as the season progressed, shoot production and shoot height increased for L 97-128, Ho 95-988, L 99-226, and L 99-233 but lagged for HoCP 96-540 and LCP 85-384. Beginning in mid-April ground cover increased most rapidly for L 99-233. In late May ground cover was around 60% for LCP 85-384 and HoCP 96-540; around 70% for L 97-128, Ho 95-988, and L 99-233; and was approaching 90% for L 99-226. Sugarcane canopy height across the growing season was consistently greater for L 97-128 and L 99-233 and averaged 21% more than for the other varieties in early June and 15% more in mid-July. Based on photosynthetically active radiation (PAR) data collected in the row middles, sunlight in the sugarcane canopy at ground level was reduced an average of 61% in early June for L 97-128 and L 99-226 compared with 29% for LCP 85-384 and HoCP 96-540. By late July PAR reduction was equal and averaged 90% for L 97-128, Ho 95-988, L 99-226 and L 99-233 compared with 78% for LCP 85-384 and HoCP 96-540. Shade studies were conducted in fields with natural infestations of bermudagrass and johnsongrass using enclosures (0.61 x 0.61 x 0.61m) covered with shade cloth providing 30, 50, 70 and 90% shade. At 55 days, bermudagrass ground cover under full sunlight was 88% compared with 10% for 90% shade; above ground biomass for 90% shade was reduced 95%. Exposure to 90% shade for 35 days decreased johnsongrass plant population 86% and above ground biomass 90%. With 30% shade, dry weight of bermudagrass was reduced 30% and johnsongrass biomass was reduced 45%. Based on this research the varieties L 97-128, L 99-226, and L 99-233 should be competitive with bermudagrass and johnsongrass. In contrast, the open canopy of HoCP 96-540 would be conducive to weed reinfestation.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-02252009-092709 |
| Date | 25 March 2009 |
| Creators | Bittencourt, Mariana Ferreira |
| Contributors | Kenneth Gravois, Benjamin L. Legendre, Eric P. Webster, James L. Griffin |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-02252009-092709/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
Page generated in 0.0167 seconds