The insecticide malathion (57% E.C.) was applied at the rate of 712.5 gm active ingredient per feddan on dill, Anethum graveolens L. and coriander, Corianderum sativum L. for controlling aphids infesting these plants. An analytical method, using gas chromatography equipped with flame photometric detector was used for detecting the insecticide residues. A field trial was conducted to determine the rate of dissipation of malathion in dill and coriander plants and in the resulting oil. Residue analysis showed that the initial deposits determined one hour after application were 35.81 & 22.7 ppm in dill and coriander plants, respectively. Rates of dissipation of malathion were 4.72, 51.1, 68.39, 88.41 and 93.49% in dill plants and were 13.61, 43.22, 66.78, 86.26 and 91.85% in coriander plants at 1, 3, 7, 14 and 21 days post treatment, respectively. The pesticide was decayed quite rapidly in and on dill and coriander plants and detectable residues (1.62 and 0.93 ppm) were observed in these plants 28 days after treatment. At harvest 46 days for coriander and 70 days for dill after application malathion was found at average levels of 0.78 mg/kg and 0.54 mg/kg in dill and coriander dry seed, respectively. The volatile oil extracted from the seed by steam distillation process was contaminated with the insecticide at a higher levels than in the seed [about sevenfold in dill oil, 5.21 mg/kg and ninteenfold in coriander oil 10.16 mg/kg]. This means that malathion had tendency to co-distill with the dill and coriander oil throughout steam distillation process.

A comparison on the larvicidial activity of four commercial bacterial and viral bioagents, Profect®, Virotecto®, Viroset® and Protecto® were evaluated on the 2nd and 4th larval instars of Spodoptera littoralis (Biosd.). The LC50 values showed 1.35, 1.52, 1.57 and 1.61 mg/ ml against 2nd instar larvae, respectively. On the other hand, the LC50 values recorded 2.03, 2.5, 2.72 and 3.01 mg/L. on 4th instar larvae of S. littoralis using the above mentioned commercial bioagent products, respectively. The effect on four isozymes, i.e., ,  esterase (EST), glutamate oxaloacetate transaminase (GOT), malate dehydrogenase (MDH) and alcohol dehydrogenase (ADH) were evaluated. The obtained results indicated differences in the activity of the isozymes in treated 4th instar larvae as compared to untreated larvae.

Spiroplasma citri, the causal agent of stubborn disease, was isolated from leaves and fruits of diseased citrus plants and cultured on solid and liquid C3G medium. On the basis of mode of transmission, symptomatology, shape on solid medium, staining of infected plant tissues with Dienes’ stain and phase contrast microscopy, the isolated agent was identified as Spiroplasma citri. Identifiction was ensured by ELISA and PCR techniques. A fragment (1053 bp) from the spiralin gene of S. citri was amplified by PCR using two specific primers for the spiralin gene. The nucleic acid hybridization techniques (Southern and dot blots) were used for identification of the spiroplasmal genome using non-radioactive DNA probe specific for spiralin gene region. It was carried out as an alternative sensitive method for rapid detection of the Egyption isolate of S. citri   using non-radioactive DNA probe specific for spiralin gene region.

A numerical method was suggested for the identification of eight local halotolerant streptomycete isolates. Cultural, morphological, physiological and antagonistic characteristics of those isolates were determined. Arbitrary scoring of these characters for the eight unknown isolates and those of the more related known Streptomyces species in the keyof Pridham and Tresner (1974) was given and resulted 58 characteristic units. The degree of similarity was determined using the Dice coefficient method and clustering was achieved using the unweighted pair group method average (UPGMA) algorithm. Using this numerical method, six out of the eight Streptomyces isolates, i.e., ST08, ST09, ST11, ST13, ST14 and ST15 were identified as S. longisporus, S. janthinus, S. griseochromogenes, S. antibioticus S. baarnensis and S. albolongus with 100, 95.8, 95.0, 92.8, 95.0 and 91.1%, respectively. Isolates ST10 and ST12 were duplicate of S. echinatus with similarities of 93.3 and 94.6%, respectively. Application of the suggested numerical taxonomy on the 14 known Streptomyces species revealed that these species fell into three major clusters based on their color of aerial mycelia.

The current study was carried out at the Agricultural and Veterinary Research Station, Faculty of Agriculture and Veterinary Medicine, Qassim University, Kingdom of Saudi Arabia during the two seasons 2003/2004 and 2003/2004. The objectives of this study are to investigate the effect of irrigation scheduling methods with different amounts of applied water on date palme offshoot growth, Determination offshoot consumptive use, crop coefficient, actual water requirements and the suitable soil moisture tension in the root zone before irrigation. The irrigation was scheduling by three methods, evapotranspiration calculation method, soil moisture depletion  method and farmer method (control). The evapotranspiration  calculation method (ETo) included ten treatments as a percentage of evapotranspiration (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 ETo). The soil moisture depletion method included five treatments of soil moisture depletion as a percentage of field capacity (50%Fc, 60%Fc, 70% Fc, 80% Fc and 90% Fc). The results showed that scheduling irrigation of the offshoot by evapotranspiration calculation method (ETo) or by soil moisture depletion  method, the amount of applied water decreased and the offshoot growth and the water use efficiency increased; compared with the farmer scheduling method. The daily and seasonal gross irrigation requirements for date palm offshoots were 51.3 l/day and 2191 m3/hec.year, while the farmer applied 19960 m3/h.year. So, the farmer added seven times as much as the actual gross irrigation requirements. The maximum water use efficiency were 2.5 kg/m3 and 1.44 kg/m3 for the treatments 0.1 ETo and 50% Fc, respectively. The suitable soil  moisture tension in the root zone before irrigation were 21.5  to 22 C-bar and 22.5 to 23 C-bar for 60 cm and 90 cm depths, respectively.

This work aims at classifying the genus Tribulus which is represented in Egypt by 7 taxa (6 species & one variety) viz.: Tribulus terrestris, T.terrestris var. bicornu-tus, T.pentandrus, T.macropterus, T.megistopterus, T.mollis and T.kaiseri according to the current classical morphological features including those of flower which can lead to a correct taxonomic decision. The work includes detailed comparative vege-tative and reproductive morphology of the studied taxa, while drawings representing the extracted results are tried into cumulative plates. Also an artificial indented di-chotomous key for the studied taxa is constructed. The key easily differentiated the pentacyclic flowered taxa from the tetracyclic in 2 separated collections. The 1st is composed of 5 taxa in which; nature of pericarp (bony or herbaceous), leaflet pairs into large leaf (7 or 6), calyx (persistant or deciduous), anther connection (basi-or dorsifixed) and others are found effective in identification. On the other hand; calyx imbrication (quincuncial or ascending) and stigma (persistant or deciduous) are used in separating the 2 spp. within the 2nd collection.

Fractionation and acylation by ethyl alcohol and acetic anhydride were carried out to produce a modified corn germ and sunflower lecithins from their crude leci-thins. Emulsification activity and emulsion stability indices (EAI & ESI) were de-termined at different pH values (2, 4, 6, 8 and 10) for commercial and studied leci-thins. EAI was significantly improved in modified lecithins in comparison to crude lecithins with increasing rate of 52.9 and 58.6 % for corn germ and sunflower etha-nol soluble fraction lecithins and 15.6 and 20.5 % for acylated corn germ and sun-flower lecithins, respectively. The changes in ESI after times of 20, 40 and 60 min. showed a higher stability of emulsions prepared using modified lecithins which were closed to that prepared using commercial soy lecithin. Caramel was prepared using commercial soy, corn germ, sunflower lecithins and their modified forms. Hardness of tested samples was determined in the start of storage time while, acid value, per-oxide value, fatty acid pattern and sensory attributes were determined during storage period at room temperature for six months. Data revealed insignificant difference in caramels hardness. Samples contained crude sunflower; acylated corn germ and sun-flower lecithins were more sensitive to oxidation while, those prepared using com-mercial soy, crude corn germ, ethanol soluble fraction of corn germ and sunflower lecithins showed higher oxidative stability with significant differences (P<0.05). Concerning sensory evaluation, both ethanol soluble fractions and acylated lecithins produced high quality caramels not differed (P>0.05) to control one that contained commercial soy lecithin. The quality and quantity of lecithin that used in prepared of caramel samples played a major role in their characteristics. The modified corn germ and sunflower lecithin forms were preferred than the raw lecithins owing to their higher emulsifying activity and lesser quantity used. The ethanol soluble lecithins fraction, especially of corn germ can be competitive to the commercial soy lecithin in all emulsified food products.

In this study, both the methanol extraction of sage leaves and clove buds were added as natural antioxidant at concentraction 100, 200 and 300 ppm from butter weight using in cake production. The cake produced was storage at room tempera-ture for 8 weeks. Butter stability was measured by Rancimat apparatus. Also, perox-ide value, acid value and thiobarbituric acid value were measured. Sensory evalua-tion was measured directly after baking (before storage) and at the end of storage pe-riod. Rancimat results showed that increasing natural antioxidant concentration led to longer butter stability and retarded rancidity than control. At the same time sage leaves extraction was much effectiveness for period long butter stability compared to clove buds extraction. Also the results revealed that the more concentration of natural antioxidants increased the peroxide value, acid value and thiobarbituric aicd value decreased compared to control. Sensory evaluation in zero time indicated im-provement in taste, flavor, texture and tenderness while color values were decreased with increasing sage and clove extraction compared to control. After 8 weeks of storage sensory evaluation scores were generally decreased.

Soils of Egypt characterize with raising pH values, CaCO3 content, clay and Fe & Al oxides. These factors contribute, to a large extent, in P-fixation in soil and its transformation into unavailable forms. This reflect, in turn, on plant growth and the resultant crop. So, the main target of this investigation is raising the use efficiency of P-fertilization, decreasing P-fixation, increasing its availability in soil and promoting its uptake by plant through testing new methods for P-application compared with the traditional one (P-application before sowing). Therefore, two field experiments were designed in sandy soils during the two winter seasons 2002/2003 and 2003/2004 at South Tahrir Res. Station, Ali Moubark village, El-Bustan region, Behira gover-norate under drip irrigation system. For the two experiments, P was applied as soil or seed coating. Soil application treatments were added at a rate of 30 kg P2O5/fed., once before sowing, twice: before sowing and during the vegetative growth stages or in three portions, before sowing and during the vegetative and flowering growth stages. In seed coating method, seed were coated before sowing with P at rates of 0.1, 0.2 and 0.3 kg P2O5/kg seed. Data obtained revealed that the treatments of P-soil application generally surpassed the P-seed coating ones. In this respect, P-soil appli-cation in three portions (at sowing and during the vegetative and flowering growth stages) gave the highest increments in seed, straw and seed protein yields as well as macro- and micronutrients contents in both seed and straw compared with the tradi-tional method of soil P-application. Moreover, seed coated with 0.2 kg P2O5/kg seeds attained the highest increases in all abovementioned yield components and nu-tritive contents among the treatments of seed coating method, whereas, coating of seeds with 0.3 kg P2O5/kg seeds caused the least ones. Therefore, it can be conclud-ed that the addition of P to sandy soil at a rate of 30 kg P2O5/fed., in three portions, i.e. at sowing and during the vegetative and flowering growth stages reduce P-fixation by soil factors, increase its availability, promote its uptake by plant, achieve the highest productivity of faba bean seed, straw and seed protein yields and im-prove the nutritive contents of both seeds and straw.

Six population’s seeds of four yellow maize crosses were formed during 2001 and 2002 growing seasons. Their plants were evaluated during 2003 growing season under two planting dates (14th May and 29th June) for six agronomic traits at the Agric. Res. Stat. of Fac. of Agric., Ain Shams Univ., Shalakan, Kalubia Gover-norate, Egypt. The present work aimed to determine the genetic parameters and their interactions with planting dates for grain yield per plant, 100-kernel weight, number of kernels per row, ear length, ear diameter, and days to silking in the six popula-tions (P1, P2, F1, F2, BC1 and BC2). Mean values of the six populations for all studied traits in all crosses were higher under normal planting date than those under late one. Therefore, normal planting date seemed to be non-stress environment. The potence ratio for all traits in the four crosses exceeded (+1) except days to silking where it was less (-1). The highest heterosis percentage relative to mid and better parent reached 192.06% and 152.01% in cross 1 for grain yield per plant under late plant-ing date. Inbreeding depression values were not-significant in all studied traits ex-cept ear diameter and 100-kernel weight in crosses 1 and 3 as well as grain yield per plant in all crosses also, it was positive for most studied characters in the four cross-es except days to silking trait. Dominance occupied the first rank, additive or domi-nance type of epistasis occupied the second or the third contributor to the genetic ef-fects in order of importance according to cross with exception of days to silking, where additive and additive occupied the first and the second ranks. Narrow sense heritability was relatively high for yield attributes whereas it was low for grain yield per plant. Meantime, expected genetic advance was relatively moderate or low for all traits. Therefore, it could be suggested that selection for most studied traits in the subsequent generations will be relatively more effective than in the early genera-tions.