EFFECT OF COTTON PLANTING DATES AND WEATHER FACTORS ON SOME SUCKING PESTS | ||||
| Egyptian Journal of Agricultural Research | ||||
| Article 4, Volume 74, Issue 3, September 1996, Page 611-625 PDF (3.75 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/ejar.1996.428731 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
| MOHAMED A. NASSEF; RAMADAN M. SALEM; WATSON M. WATSON | ||||
| Plant Protection Research Institute, Agricultural Research Centre, Dokki, Giza, Egypt. | ||||
| Abstract | ||||
| The present study was carried out at Sakha Agric. Res. Station to evaluate the effect of 4 cotton planting dates (March 17, April 2, April 16, and May 1 during 1990 season and March 11, March 26, April 8 and April 22 during 1991 season) on the population density of thrips, Thrips tabaci (Lind), cotton jassid, Emposaca decipiens (Paoli) and common red spider mites, Tetranychus spp., as well as the effect of three climatic weather factors (temperature, relative humidity and wind speed) on such pests. Results could be summarized in the following points 1-In both seasons, the population of cotton thrips has two to three peaks of abundance during April and May. The prevailing weather factors were responsible collectively for 77.4% (1990 season) and 71.6% (1991 season) of thrips population changes. In this respect, the effect of temperature was negatively highly significant . 2-Only one peak occurred of cotton Jassid on each planting date in early-season period (from April to May) in both seasons. Then, the population fluctuated during mid to late-season recording four to five peaks (from May to October). The three weather factors were responsible for 75.6% and 31.6% (1990 season); 92.1% and 35.1% (1991 season) of the changes of early and mid to late-season populations, respectively. 3-Three peaks were observed for mite population on the second half of July, mid of August and the first half of September for the four planting dates in both seasons except for the fourth date of 1990, where it had two peaks only. Relative humidity was the main weather factor which affected positively mite population as it was responsible for 44.5% and 63.1% of mite population changes during 1990 and 1991 seasons. | ||||
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