Optimizing flowering in the LSU AgCenterâs Sugarcane ( Sacchrum spp. hybrids) Breeding Program is an important step in the variety development program. The effect of nitrogen and ambient air temperature in pot cultured sugarcane were examined as a means of improving sugarcane flowering. The experiment was conducted on agronomic and reproductive traits of sugarcane at the Sugar Research Station, St. Gabriel, LA, on sugarcane genotypes subjected to artificial photoperiod regimes. The potting media consisted of equal parts of washed sand, Canadian peat moss, and a Commerce silt loam soil (fine-silty, mixed, nonacid, thermic aeric Fluvaquents). Early nitrogen (22.4-22.4-22.4 kg ha-1) in addition to a high nitrogen potting media (>200 mg kg-1) was necessary for adequate vegetative growth and stalk numbers for tasseling. Leaf macronutrient levels were examined at reproductive growth stages as affected by pre-photoperiod nitrogen fertilizers (22.4-22.4-22.4 kg ha-1 and 0-22.4-22.4 kg ha-1). Since tasseling in nitrogen and no-nitrogen treatments were 77% and 25%, respectively, the critical leaf nutrient level for nitrogen at the vegetative stage for sugarcane intended for tasseling should be 12.4 g kg-1. A chlorophyll meter was used to collect chlorophyll readings from the same leaves that were sampled for plant analysis. The initiation stage was the only stage that both leaf nitrogen (r = -0.34) and chlorophyll meter readings (r = 0.80) showed significant associations. A chlorophyll index level (34.53) was developed as a maximum threshold level for sugarcane breeding genotypes at the initiation stage. Average daily maximum temperature for specific time intervals can affect sugarcane tasseling. A reduced regression model (P=0.02) for the overall tasseling regime indicated that the percent tasseling is expected to increase 4.19 percent when the May 30 â June 14 temperatures increase by one degree above 31.9° C, decrease by 4.36 percent when the June 15- June 30 temperatures increase by one degree above 32.1° C, and decrease by 4.69 percent when the August 16 â September 10 temperatures increase by one degree above 33.1° C. These results help to explain the variation in tasseling percentages that have been encountered over the years when above average temperatures were experienced.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-11132007-101101 |
| Date | 14 November 2007 |
| Creators | LaBorde, Christopher Michael |
| Contributors | Benjamin Legendre, Kenneth A. Gravois, Collins Kimbeng, Steven D. Linscombe, 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-11132007-101101/ |
| 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. |
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