Two field experiments were conducted during the summer season of 2003 and 2004 to study the effect of organic and bio-organic fertilizers [esterna biofert, compost, biocompost and effective microorganisms (Em)] on vegetative growth, yield and physical and chemical components in tubers of local and fuseau Jerusalem artichoke cultivars. Results indicated that Em, biocompost and biofert significantly increased plant height, number of main and lateral shoots and dry weight as well as the concentrations of Chl (a+b), carotenoids and total carbohydrates in the leaves. Moreover, dry matter, inulin, nitrogen, phosphorus and potassium of tubers showed a significant increases. The highest vegetative growth and tuber yield were obtained when Em, biocompost and biofert were applied. The respective increase in lateral shoots, Chl (a + b), carotenoids, average tuber weight and size were higher in local cultivar. Whereas fuseau cultivar tubers showed greater dry matter than those of local variety. The application of Em, biocompost and biofert fertilizers in both local and fuseau cultivar gave the relatively higher yield with good quality.

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.

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.

The most important black table olive (Olea europaea L.) “Kalamata” cultivar, grafted onto three different vegetative olive rootstocks[Picual (Pic), Frantoio (Fra) and Koroneiki (Kor) cvs.] was evaluated with 2-year-old grafted plants grown in sand clay soil, and received concentrations of salt mixture (NaCl, Na2So4, CaCl2, MgSo4 and KCl) making 6000 and 8000 ppm with SAR 12 of salinity level, for two seasons. Morphological and chemical parameters were investigated to determine the relative salinity tolerance of these rootstocks and to define possible reasons for any observed differences in the salt tolerance. However, results indicated that differences in response to salinity among rootstocks were observed primarily in morphological traits. Increasing of salinity level in irrigation water decreased, all of scion height and its rate of increase, leaf area, number of leaves/plant and fresh & dry weight of leaves and roots. But different rootstocks can affect the degree to which these pa-rameters is reduced under salinity, where Kalamata growth on Picual and Frantoio was considerably better than on Koroneiki at 6000 and 8000 ppm treatments. In-versely in untreated grafted plants Kalamata on Kornaki exhibited the best growth vigor, comparing with Kal/Pic or Kal/Fra plants, suggesting that a decrease of scion growth in untreated grafted plants is a salt tolerance quality transmitted by tolerant rootstocks. Salinity significantly decreased leaf chlorophyll (a) and (b) content of all grafted plants, but different content among rootstocks were noted. On the contrary, proline content increased in leaves of all treated plants, however, insignificant dif-ference was noted between rootstocks, yet the interaction between the two factors show that Kalamata on Picual and on Frantoio rootstocks recorded higher values of leaf proline content than Kalamata on Koroneiki rootstock. Leaves and roots Na+ and Cl- content of treated grafted plants showed an increment but to a different de-gree, comparing with the untreated (control) plants. There were differences among the grafted plants where Kalamata grafted on Koroneiki (the least tolerant cv.) most-ly affected by saline treatment and accumulated the highest content of Na+ and Cl- in leaves comparing with Kalamata on Picual (the most tolerant cv.) or on Frantoio (the Sanaa LazArab Univ. J. Agric. Sci., 13(2), 2005400moderate tolerant cv.). Tolerant rootstocks contained more Na+ in roots than in leaves. This response become apparent as salinity increased. Leaf N, P and K con-tents decreased in Kalamata leaves as influenced by different rootstocks and increas-ing salinity in irrigation water comparing with the control. Kal/Pic and Kal/Fra plants had higher N% in leaves than Kal/Kor plants, whereas Kal/Pic accumulated K more than the other plants, while P content in leaves of all grafted plants were insig-nificant in the two seasons. Based on the overall growth parameters and chemical composition in response to salinity, Kalamata grafted on Picual exhibited the great-est salt tolerance followed by those grafted on Frantoio whereas, Kalamata on Koro-neiki showed the poorest plants pertaining salt tolerance.

The Saudi Arabian Ministry of Agriculture experimental station at Al-Maddina Al-Monwarah region, identified very few plantations of the most productive Vitis vinifera var. maddini with the highest fruit quality. This research was designed to optimize rooting effeciency in relation to cutting length and auxin treatment. Cutting length (long vs short) showed strong impact on rooting ability. Results showed that longer cuttings produce more and longer roots than shorter ones. IBA treatments up to the 500 ppm level showed significant increase in root number, but do not have significant impact on root length. Rooted cuttings were planted in an open field for further evaluations. These findings may facilitate the clonal propagation of this val-uable vines at Al-Maddina Al-Monwarah region, grapevine growers and Horticultur-ists in Saudi Arabia .

This study was carried out at the Strawberry Improvement Center Experimental Farm, Nobaria, Beheira Governorate and the Horticulture Research Station, Bar-rage, Kalubia Governorate during 2001/2002 and 2002/2003 seasons. The study aimed to investigate the effect of calcium nutrition (0, 13and 26 kg/fed. Ca) and modified atmosphere storage (10,20, 30 and 40% CO2) on the post harvest decay of cold stored strawberry transplants and their subsequent fruit production. The results indicated that increasing the rate of calcium application during the transplant growth period and carbon dioxide concentration around transplants during the cold storage resulted in significant decrements in transplant decay, infection percentage, disease severity of roots and crowns. There was a positive relationship between cal-cium nutrition and early yield. Moreover, the highest calcium rate gave the highest total yield while no significant difference was noticed between control and 13 kg/fed treatments. This study concluded that adding Ca++ at 26 Kg /fed as fertiga-tion of calcium nitrate (13% Ca) to the growing strawberry transplants followed by modified atmosphere storage (40% CO2) during the prolonged cold storage allowed maintenance of transplant quality and increased their yield while minimizing decay development.

Two filed experiments were carried out at the New Salheyia Region, Sharkia Governorate, during the two successive seasons 2001/2002 and 2002/2003 to study growth and productivity of wheat plants as affected by complete foliar fertilizer compounds under water stress conditions in newly cultivated sandy land.