EFFECT OF NITROGEN LEVELS, SOWING DATES AND SPACINGS ON INFESTATION WITH THE THE LEAFMINER AGROMYZA NIGRIPES (MEIGEN) (DIPTERA: AGROMYZIDAE). | ||
| Egyptian Journal of Agricultural Research | ||
| Article 11, Volume 76, Issue 4, December 1998, Pages 1485-1497 PDF (3.75 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejar.1998.361700 | ||
| Author | ||
| SAMIR A. EL-SERWY | ||
| Plant Protection Research Institute, Agricultural Research Centre, Dokki, Giza, Egypt | ||
| Abstract | ||
| The effect of 4 nitrogenous fertilization levels, 3 sowing dates and row spacing on infestation with the leafminer Agromyza nigripes (Diptera : Argomyzidae) on wheat grain yield was investigated at ElGemmeiza Agric. Gharbia Governorate, during the wheat growing seasons 1993-1994 and 1994-1995. Results indicated that percentage infested leaves and number of mines and alive larvae significantly increased by increasing nitrogen levels, except up to a rate of 80 kg/fed. Further increase of N fertilization insignificantly affected insect infestation or population. All considered parameters and grain yield were significantly decreased by delaying sowing dates.Row spacing had no discernable effect although grain yield was significantly increased at 20 cm spacing. Interactions between N level x sowing date, N level x row spacing and sowing date x row spacing expressed a significant effect on percentage infestation number of mines and alive larvae as well as grain yield. Interactions of N level x sowing date x row spacing on numbers of mines and alive larvae were significant in 1993-94 and 1994-95 seasons and on infestation and grain yield in 1994-95 seasons only. With the application of nitrogen rates of 40,50, 60, 70, 80 and 90 kg/fed. to wheat plants sown on Dec.10 at 20 cm row spacing emphasized that, all considered parameters were significantly reduced. Also, plants gave grain yields at a rate of 60 kg N/fed. compared to those receiving up to 80 and 90 kg N/fed. in 1995-96 and 1996-97 seasons. It is, thus, recommended that application of N at a rate of 60 kg/fed. to wheat plants sown by early December at 20 cm row spacing significantly reduced infestation and produced the highest grain yield. | ||
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