Field use of a chlorophyll meter for nitrogen diagnostic pruposes in cotton /
The field use of a chlorophyll meter, SPAD-SOZ, for crofilm Inc. diagnosing N needs in cotton seems promising. This research was developed to define field sampling procedures, sampling stages, and the influence of cotton management practices such as irrigation that may affect field measurements of c...
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1998.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=733039051&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The field use of a chlorophyll meter, SPAD-SOZ, for crofilm Inc. diagnosing N needs in cotton seems promising. This research was developed to define field sampling procedures, sampling stages, and the influence of cotton management practices such as irrigation that may affect field measurements of chlorophyll with the SPAD meter. Two field experiments were conducted in 1995 and 1996. In 1997, an experiment was conducted with cotton plants grown in containers. The evaluation period was from 10 days before early square growth stage to the mature boll growth stage. The factors under study were N and irrigation regimes. The SPAD meter was capable of detecting soil applied N differences. The amplitude of response of the SPAD meter varied from 7 to 12 units when N rates from 0 to 150 kg [] were applied. The effect of irrigation treatments on SPAD meter readings was not clearly detected in field experiments, but this effect was significant in the container experiment at three sampling dates. Important associations were detected between SPAD readings and seed cotton yield, soil applied N, petiole [], leaf N, and leaf blade chlorophyll concentration determined in the laboratory. Significant differences between the regression models from different sampling dates, experiments, and growing seasons were observed. For this reason the possibility of prediction of tissue N estimates by chlorophyll meter readings for diverse cotton growing conditions appears limited. |
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| Item Description: | Vita. "Major Subject: Soil Science". |
| Physical Description: | xix, 138 leaves : illustrations ; 28 cm. |
| Bibliography: | Includes bibliographical references (leaves 130-137). |