الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Field experiments were undertaken during 2009 and 2010 seasons at Toukh Tanbisha village, Berket El-Sabae region, Minufiya Governorate. The obtained results indicated that cotton seeds treated with imidacloprid increased emergence of cotton seedlings, improved germination and increased stem length. The systemic insecticide (imidacloprid) was found to be the most effective treatment recording the least population of aphids, leafhopper, thrips, green bug and whitefly, succeeded to protect cotton plants from sucking insects. Imidacloprid is widely used in cotton integrated control but decreased the numbers of predators. Understanding the relationship between fertilization and the incidence of insect pests is essential for the management of chemical fertilization and insect pests in modern agroecosystem. Effects of combination of phosphorus, nitrogen and potassium fertilizers on population dynamics and density of cotton pests Aphis gossypii, Thrips tabaci and Empoasca spp. Results indicated that numbers of adult or immature stages of Tetranychus urticae showed that significant variations among nitrogen treatments and it’s population density. Increasing nitrogen level in the range of 60 to 90 kg /feddan enhanced mite population on cotton leaves. But, nitrogen fertilizer significantly reduced the population density of Empoasca spp. whereas; it enhanced the population densities of both A. gossypii and T. tabaci in the two seasons of study. Phosphorus fertilizer proved to be very effective in lowering the incidence of T. urticae on treated plants, but it caused significantly decrement in density of Empoasca spp. Increasing potassium fertilizer caused considerable reduction in aphids population, whereas the opposite case was true with mite numbers. Field persistence of the insect growth regulators lufenuron, chlorfluzuron and triflumuron were assessed in the laboratory using second and fourth larval instars of Spodoptera littoralis. Laboratory bioassays indicated that lufenuron and chlorfluzuron were more effective on both 2nd and 4th larval instars, as well as killing both larval instars faster than triflumuron. Field-laboratory experiments were conducted to show direct and residual effects of the tested IGR,s in terms of toxicity and stability. They indicated that all the tested insecticides were stable under field conditions and give high percentages of mortality. Overall, lufenuron was more efficient than the other tested insecticides. Using this insecticide for cotton leafworm control in cotton fields may give better results under field condition stage. Lufenuron was proven to be more rapid and effective against cotton leaf worm than triflumuron. Mean food consumed were decreased in treated larvae as compared with that of untreated ones. Laboratory study on the activity of the entomopathogenic nematode, Steinernema carpocapsae (Rhabditida: Steinernematidae) killed 25-37% cotton leafworm larvae within 48 and 96 h from treatment, prevent progress to pupation and adult insect. S. carpocapsae was quite tolerant to methomyl. Percent mortalities of infective juveniles varied from 11.11 to 66.66% within 96 hours. Pyrothroid insecticides exhibited better efficacy than chlorpyriphos on cotton bollworm. Moreover, significant lower infestation percentages were noticed when spraying with insecticides took place rapidly after low green boll infestation. Insecticides application as integrated control increased cotton yield.