A kairomone from adult Cydia pomonella L. scales is an important factor in the host recognition and searching behaviour process of Trichogramma cacoeciae Mar-chal and Trichogramma dendrolimi Matsumura. The Trichogramma spp. used the chemicals from the host eggs for orientation to host and increased their parasitism. The females of T. cacoeciae*, T. dendrolimi** and T. dendrolimi*** contacted the unwashed host eggs significantly longer than the washed eggs. Washing the codling moth eggs with hexan significantly reduced the parasitism of all the tested Tricho-gramma strains compared to unwashed eggs. The treated apple trees with wing scales of C. pomonella had significant influence on the parasitism compared to un-treated trees. The percentage parasitism of codling moth eggs on the treated trees (31.6%) was significantly higher than on the untreated trees (19.3%).

Two field experiments were carried out at El-Khroub experimental station, east of Constantine, Algeria, to evaluate the effect of N, P, K fertilization and their interaction on growth characters and yield of wheat grown on calcareous soil. The design of each experiment was split-split plot. Urea was applied as folier application to one experiment to evaluate the supplementel application of nitrogen under dry farming conditions. The results showed that the main stem height, number and height  of tillers and number of leaves were varried according to the levels  of  N, P, K fertilization as well as to presence or absence of urea., Straw yield significantly increased due to increasing nitrogen level and potassium fertilization in absence or presence of urea. However, grain yield was significantly increased either with increasing nitrogen level in absence of urea or with increasing phosphorus levels in absence or presence of urea. Straw yield was significantly affected by N * P interaction in absence or presence of urea and N * P * K when urea was applied. However, grain yield was significantly affected by N * P and N * P * K interractions in absence of urea application.

Cotton in Egypt has an important economic situation. Thus the study aimed to evaluate the expected economic effects and productivity of environmental factors on Egyptian cotton production. This comes by predicting production yield value and evaluating its return due to cultural and environmental desired and undesired variables. So, convenient production pattern could be determined to obtain maximum yield under these variables effect. The study clarified that expected cotton yield under desired environmental variables will be ranges between 4169-4336 thousand quintar, with an average equal 4253 thousand quintar. This production will realize national net income ranges between 429.37- 474.68 million L.E., with an average equal 452.03 million L. E. Meanwhile, the expected cotton yield under undesired environmental variables ranges between 3171- 3338 thousand quintar with an average equals 3255 thousand quintar. This yield will realize national net income ranges between 33.37- 78.60 million L. E. with an average equals 55.99 million L.E. The study also indicated that cotton crop is one of the extremely affected crops by the environmental and cultural variables extended in its production zones due its long life period. This is detected by its decrease in the production value undesired environmental factors, where this decrease ranges between 23.02% to 23.94% of the

Flusilazole and triflumizole residues in apple fruits were chemically determined at different periods after spraying of these fungicides under field conditions. The obtained results indicated that, seven days after flusilazole application, unwashed apple fruits were found contained higher residues (0.322 ppm) than the allowed tolerance level (0.2 ppm), while washed and peeled fruits were contained lower residues (0.149 and 0.087 ppm, respectively) after the same period from experiment. These residues were rapidly decreased by elapse of time, so unwashed, washed and peeled apple fruits were contained levels below the allowed MRL i.e. 0.092, 0.008 and <0 ppm, respectively after fourteen days of flusilazole application Accordingly, unwashed apple fruits could be marketed safely 14 days after flusilazole application, while washed and peeled fruits could be used safely after seven days. In the case of triflumizole, unwashed apple fruits were contained 2.030 ppm after five days of application. Such residue is higher than the tolerance value (2.0 ppm), while washed and peeled fruits were contained residues below the tolerance permissive values i.e. 1.010 and 1.970 ppm after three and one days of application, respectively. These values were rapidly decreased by time prolongation, so, unwashed, washed, and peeled apple fruits were contained residues below the allowed tolerance of 1.280, 0.490 and 0.160 ppm at seven days after triflumizole application, respectively. Accordingly, unwashed apple fruits could be marketed safely seven days after triflumizole application, while washed and peeled fruits could used safely three and one days after application, respectively.

Two whitefly species, Aleurotuberculatus jasmini Takahashi and Dialeurodes kirkaldyi (Kotinsky) were found infesting Arabian jasmine shrubs, Jasminium sambac at the Botanic Garden of Faculty of Agriculture, Ain Shams University, Shoubra, Qalyubiya, Egypt. To obtain basic ecological data for both species, samples of Arabian jasmine leaves were conducted every ten-day intervals throughout one complete year (January to December 2004). Seasonal fluctuations of alive total population, nymphs and adults (empty exuviae) of the both species indicated that the D. kirkaldyi was more dominant one than A. jasmini throughout the tested year. Three periods of seasonal abundance for both species were established. Three annual field generations were estimated for D. kirkaldyi, which lasted 170, 90 and 100 days, respectively. While A. jasmini passed throughout five annual field generations, which lasted 80, 80, 70, 60 and 70 days, respectively. The effects of nine ecological factors (7 physical +2 biotic) on the population dynamics of alive nymphs population for both species were estimated. Each factor gave variable effects for both species while the combined effects of these nine factors were responsible as a group for about 74.2% and 95.5% of the changes in nymphal population densities of D. kirkaldyi and A. jasmini, respectively.

Recently, the potential economical importance of the methylotrophic bacteria encouraged the isolation of this group. In the present study five Egyptian isolates were obtained from green leaves surface of legume plants named PPFM.C (ChickPea), PPFM.Ph (Common bean), PPFM.F (Faba bean), PPFM.P (Peanut) and PPFM.S (Soybean) ,to study their general characters which belonging to  methylotrophic bacteria. Morphological studies indicate that all isolates were short rods, gram negative and motile. All Physiological studies to the isolates gave the same results except PPFM.F which could not grow in peptone medium. All isolates were sensitive to Kanamycin but they were resistant to Erythromycin. There was a great range in the ability of the isolates to grow on different sodium chloride concentrations indicating that PPFM.Ph grew well in 5 % sodium chloride, and they were able to excrete and produce cytokinin. Molecular biology studies indicated that there was a great similarity between PPFM.C and PPFM.Ph (99.34%). Identification was carried out to the5 isolates, PPFM.F may be related to Methylobacterium mesophilicum, PPFM.P may be related to M. fujisawaense and PPFM.Ph, PPFM.C and PPFM.S were related to M. radiotolerans.

Four olive cultivars namely Manzanello, Picual, Coratina and Arbicon grown at Wadi El-Natroon area, Egypt under drip irrigation system in sandy soil were compared for optimizing their own yield as well as fruit quality parameters during 2001 (off-year) and 2002 (on-year), by application of an integrated and balanced fertigaion program including macro and micro-nutrients. Results showed that remarkable and significant differences in leaf mineral contents, yield and yield quality parameters were detected by using well distributed fertilizer program during the growing season of olive trees. The treated four cultivars attained higher yield in the “on” and “off” year than the control. The most outstanding olive cultivars having greater yield were Picual, Manzanello, Coratina and Arbicon in a descending order. Oil percentage was maximized with Picual olive while, Arbicon olive had the lowest value. Free fatty acids (%), Iodine number as well as Acidity (%) were minimized in Coratina olive and the lowest peroxide number as was in Picual olive. It is apparent that for planting Picual olive variety proved to be the promising one due to its greatest yield and best fruit quality specially when the actual requirements of macro and micro nutrients were used through the drip irrigation system.

Degradation aspects in terms of kinetics of the tested samples namely  dates, oranges and olive residues by the dromedary ruminal microflora is comparatively studied with vetch-oat hay as a standard. The results indicate greater hydrolytic ac-tivity of the dromedary ruminal microflora towards dates and orange residues than both olive residues and hay.  Fermentation of dates and orange residues reaches their stationary phase after 24 hours and olive wastes after 48 hours. However, fermentation process was marked by two phase; namely the degradation of soluble fraction and that of cellulosic one. The results showed also that types of substrate is a determining factor for in vitro gas production. In fact, substrate rich in cellular content (dates and orange residues) is characterised by a fast fermentation that moves towards CO2 production, and it is marked by a long latency phase. On contrary,  the fibrous substrate degradation (olive residues and hay) is tributary of less long latency period and generates CH4. The degradation level observed indicates that the dates and oranges residues might represent an acceptable source of energy for dromedary. On the other hand, the olive residues, in spite of being rich in organic matter, cannot be used in animal feeding.

Seven cotton genotypes involving cvs. Giza 70, Giza, 77, Giza 86 and Giza 83 and the exotic varieties; Pima S7 and SeaIsland, as well as, the American Upland variety Tamcot C.E., were crossed in a diallel pattern, excluding reciprocals, in 2000 season to produce 21 F1 hybrids. Parents and F1­­'swere evaluated in 2001 season for eight economic traits. Mean squares due to genotypes were highly significant for all traits, revealing the presence of sufficient variability in the population. Significant desired negative mid and better parent heterosis were found for fiber-to-seed attachment force and days to flowering. Significant positive heterosis was also observed for yield and its components. The variances due to general combining ability (GCA) and specific combining ability, (SCA) were significant for all studied traits, indicating the importance of both additive and non additive gene action in the inheritance of these characters. The GCA/SCA ratio was found to be greater than unity, indicating predominance of additive and additive x additive types of gene action in the inheritance of these traits. Based on GCA effects, the Upland variety Tamcot C.E. proved to be the best general combiner for earliness, boll weight, seed index, seed cotton yield and lint cotton yield/ plant. Giza 83 seemed to be good combiner for fiber-to-seed attachment force, Giza 86 for lint percentage and Pima S7 for number of bolls per plant.

and 2003 to investigate the interactive effect of Zn and different nitrogen sources, i.e., mineral nitrogen (ammonium sulfate) and organic nitrogen (poultry manure) on the growth and productivity of onion (Allium cepa) cv. Giza 20. Four levels of Zn application (0, 1, 2 and 3 ppm) in a sulfate form were foliar sprayed at 30 and 60 days after planting. Within each Zn application, three treatments of nitrogen dose were applied in different combination forms (mineral and organic sources). Nitrogen treatments were 100% mineral N; 75% mineral + 25% organic and 50% mineral + 50% organic. Organic-N source was poultry manure. All poultry manure treatments were applied during soil preparation. Data showed that all growth parameters of onion plants increased as the fraction of poultry manure increased. Zn had also a positive effect on all plant parameters except of plant length, and leaf dry weight. The interactive effect of Zn and poultry manure increased yield and quality of onion bulbs. The most effective treatments on bulb fresh weight, total yield and quality were the spraying with 1 or 2 ppm zinc and the application of N as 75% mineral and 25% organic, in both seasons