الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
Field studies were carried out on cotton plants (Giza 85 variety ) for three successive years (1999-2001) in the farm of the Faculty of Agriculture at Moshtohor. Plants received application of three different treatments,i.e., Herculis. (a conventional insecticide). Neemazal (1% Azadirachtin) the active ingredient of neem plants extracts ) and Mikrosol (micro-nutrient fertilizer). The effect of these treatments on plant height. numbers of leaves, flowers and bolls /plant, number &% of opened bolls, percentages of infestation by E. insidana & P. gossypiella and seeded cotton yield were estimated . The effect of treatments on cotton fiber quality and some biochemical compnents in cotton bolls were also studied . For confirming the effect of the assayed agrochemicals on pink and spiny bollworms
a laboratory experiment was designed to find out the mortality percentages among I instar larvae of the two pest species when treated through the artificial diet offered for larval feeding . Another field study carried out during three cotton seasons (1999-2000) was conducted to find out the weekly counts of pink and spiny bollworm moths caught in sex —pheromone traps (Delta sticky board trap for P. gossypiella and funnel trap for E. insulana). The obtained results may he summarized as follows:-
I-Field studies :
l.1.Effect of tested agrochemicals on plant — growth parameters .
The obtained data indicated that the chemical insecticide and nemazal treatments were nearly of no effect on plant height (means of three years; 94.57& 94.9 cm., respectively opposed to 95.23 cm. For the control plants ). number of leaves / plant (51.46. 51.72&52.41, respectively ). number of flowers / plant (1.47, 1.5& 1.46 flowers ) and number of produced bolls / plant (11.87. 12.24& 12.15 bolls , respectively ). These parameters of cotton plants growth increased. significantly. in plants that received spraying by the foliar fertilizer, mikrosol, being. 104.62cm.. 58.3 leaves. 2.24 flowers and 14.76 boll. respectively. While, the least mean number of opened bolls plant (9.09: 3 years mean ) occurred on the control plants and this number increased to 9.86 and 9.56 for plants treated with Herculis, and neemazal. This number reached its highest value (11.87 opened bolls / plant ) an plants treated with the foliar fertilizer, mikrosol.
1.2. Effect of agrochemical treatments on % of infestation by bollworms :
The obtained results indicated that either of the used agrochemicals reduced. significantly, the percentage of infestation by spiny and pink bollworms than control , but the lowest percentage of infestation 3 years mean by E. insula►a and P. gossypiella was recorded by using the chemical insecticide. Herculis, (1.02 and 0.79% , respectively opposed to 25.7 and 27.55%. respectively in case of the control plants ). The three years mean percentages of infestation in cotton bolls after using Neemazal were 9.84 and 10.12 % and after using the foliar fertilizer Mikosol were 11.27 and 8.03% by E. i►sulana and P. gossypiella , respectively .
1.3. Effect of agrochemicals on seeded cotton yield production:
At the end of cotton seasons 2000 and 2001, the seeded cotton produced in each treatment was weighed, the highest seeded cotton yield produced from the treatment in which the chemical insecticide Herculis, was applied (1320&1178k.g/ feddan , in the two seasons respectively), indicating a two years mean increase of 87.61 % in the final yield than control). That
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was followed by the treatment in which 3 sprays of the foliar fertilizer, mikrosol were applied (1140 kg. / feddan in year 2000 & 1069.5 kg./ feddan in year 2001. showing 65.95 % as. a two years mean, in the weight of seeded cotton yield than control ). In tratment in which the plant extract agrochemical, Neemazal was applied, the two years, mean % increase in the results yield than control was 25.42 % (880 kg. / feddan in year 2000 and 790 kg. in the subsequent year, opposed to 665.8 kg cotton / feddan in case of the control ). It should be clarified that the percentages of’ increase in seeded cotton yield after using the chemical insecticide than in case of using mikrosol were 15.79and 10.14% in years 2000 and 2001, respectively with a mean of 13.1%. Concerning the problems of pollution which may be caused due to successive and intenssive use of insecticides, and the safety of using the foliar fertilizer, the latter treatment may be fairly recommended, as it led to 69.95% increase in the resultant seeded cotton yield than control.
1.4. Effect of tested agrochemicals on cotton fiber quality :
All of the applied treatments (Herculis. Nemazal and Mikrosol ) increased and improved the cotton fibers quality (% of fiber, smoothing maturity and fiber length ) than control. Highest increasing percentage than control in these three
prameters occurred in treament that received 3 sprays of Herculis, (12, 30.8 and 2.5 % . respectively ). That was. followed by Mikrosol treatment for % fiber and smoothing maturity (9.3& 23.1 %. respectively ), and by Neemazal treatment for the fibers length (1.8 % increase than control ). Also . the most strength of fibers (29.7 gm/tex.) was recorded from treatment by the chemical insecticide opposed to 24.8. 24.3 and 25.8 gm. / tex. for Mikrosol, Neemazal and control, respectively .
1.5. Moths population assessments by using sex- pheromones:
Sex-phermone of E. insulana and that of P. gossypiella were used in traps to find out the weekly counts of both species in cotton fields throughout three successive seasons (1999-2000)- Numbers of male moths caught varied between the two species, different seasons, time of catch and environmental temperature and R.H.
The obtained data showed that , generaly P. gossypiella moths population was higher than that E. insulana in the three seasons of study means of seasons total no. of moths: 1056,1018&803 for P. gossypiella opposed to 666.5 819.5 & 465.5 moths for E. insulana in 1999, 2000 & 2001, respectively. It could be also deduced from results that the whole populations
of moths of both species were higher in 1999 and 2000 cotton seasons than that of season 2001. Generally . data showed that moths of P. gossypiela began to appear in the field during the first or second week of May. While. E. insulana moths started to be caught in the pheromone trap during the first to the third week of May. The numbers of moths caught in the pheromone traps increased in the subsequent months after that. The maximum mean cath of P. gosspiella male moths caught in the sex pheromone trap was 86.2moth. recorded on July. 13th 1999. 85.5 moths on August, 3’11 2000 and 75 moths / trap on August. 17th 2001. While those of E. insulana were 63 moths on August 17’h 1999, 89 moths on Agust 17’h 2000 and 45 moths / trap on June 22nd 2001. Two peaks of moths population abundance could be detected for each species . For P. gosspiella , those occurred on July, 13th ( 86.2 moths ) & August I O’h 1999 (81 moths ); July. 6’11 (76.5 moths ) & August, 3’12000 (85.5 moths ) and June, 22”(1 (60.5 moths ) & August, 17’1’ 2001 (75 moths ). While. for E. insulana, those were counted on June, 22” (58.5 moths )& August 7’1’ 1999 (63 moths ); July. 13’1’ (64.5 moths ) & August. 17’h 2000 (89 moths ), and June 22” (45 moths ) & July. 22” (37 moths ).
H . Laboratory studies :-
I1.1. Insecticdal activities of tested agrochemicals on lst instar larvae of pink and spiny bollworms:-
The tested agrochemicals were mixed, at the desired concentration to artificial diet, then offered tothe freshly hatched larvae of both species. Mortality data were recorded after 24. 48 and 72 hours. The highest 3 days mean mortality percentage among the treated larvae, was obtained from the Herculis. treatment ( 98.33& 92.42 % for P. gosspiella and E. insualna. respectively ). Neemazal came the next in case of E. insulana (72.17 % mortality opposed to 61.17 % mean mortality by using the foliar fertilizer, Mikrosol ). While, on P. gossypiella 1’` instar larvae, Mikrosol came after the chemical insecticide as it caused 62.83 % mortality, opposed to 56.5 % mean mortality by using Neemazal.