The effect of the forward speed of a potato harvester on tubers damage was in-vestigated. The potato harvester type is a two-row potato digger with riddle chain. The experiments were conducted in a potato field of Haradh Project of the National Agricultural Development Company (NADEC) east of Riyadh, in a sandy loam soil, and for a potato crop planted during the spring season of 2004. The potato type was Hermes (oval graded tubers). The degging depth was set to 22 cm, and the ampli-tudes of riddle chain of the implement were 17 and 25 mm. Results showed that the average values of tubers lifting percentage were in close agreement for all forward speed values (1.5, 1.7, and 2 km/h) of the potato harvester. However, it ranged be-tween 96% and 99%. It was found that there is no significant effect of the forward speed on both total damaged tubers percentage and damage index. However, there was a significant difference for the damaged tubers percentage when the amplitude of riddle chain was changed from 17 to 25 mm, where it decreased as the amplitude was increased. The values of potato damage index for all forward speeds were with-in acceptable limits of damage index. Minimum value of damage index was 0.04 at the speed of 2 km/h and amplitude of 25 mm.

A field strain of pink bollworm Pectinophora gossypiella (Saund.) collected from Sharquia Governorate, Egypt was exposed to the selection pressure of the for-mulation of Bacillus thuringiensis subsp. Kurstaki, Dipel 2x under laboratory condi-tions. Resistance ratio attained 16-fold based on the susceptible strain after 14 gen-erations of selection. Study the response of Dipel 2x resistant strain to some insecti-cides indicated that there is no cross resistance to the conventional insecticides, es-fenvalerate, chlorpyriphos and thiodicarb or the bioinsecticides Ecotech and Agerin. These data may be emphasizing the possibility of rotation the Dipel 2x with these insecticides in pest control program of pink bollworm to manage resistance to Bt products.

Microbiological assay of 150 samples of dairy products for the incidence of Co-liforms, E. coli, E. coli 0157:H7 and non-0157 E.coli, show the recovery of the Coli-forms and E.coli from the tested products with different incidence percentage. Strains of E. coli 0157:H7 and non-0157 E .coli were recovered from 9 (6%) and 13(8.6%) of the total samples, respectively. The behaviour of these isolates were tested when exposing to low pH, salt, low holding temperature and heat treatment. The results indicate obvious survival of E. coli 0157:H7 and non-0157serotype with pH as low as 3.8 pH for 5 days. Also, survival or even multiplication in TSB con-taining <6% salt. Moreover, the strains remained viable at low holding temperature (5oC). So, the product which contaminated with this pathogens remain hazardous even under such stress condition. Decimal reduction times (D-values) of cells sus-pended in saline solution, TSB medium, reconctituted dry milk and chocolate milk were determined. The greatest survival as evidenced by highest D and Z values oc-curred with chocolate milk. Product composition and type of strain affected the heat lethality rates.

A blend Juice prepared from apple juice and kiwifruit juice (60:40 v/v), was pas-teurized and stored for 3 and 6 months at 4o and 25oC untill analysis. Sensory evalu-ation showed significant differences between the fresh and pasteurized blend juice in all sensory attributes. The headspace volatiles of fresh apple, fresh kiwifruit, fresh and stored pasteurized blend juice at different temperatures were collected and sub-jected to GC and GC-MS analysis. A total of 33 volatile components were identi-fied, 18 esters (17 aliphatic and one aromatic), 6 alcohols, 3 aldehydes, 3 terpenic hydrocarbons, 2 ketones and 1 carboxylic acid. The volatile components in the pas-teurized blend juice showed considerable quantitative and qualitative variations dur-ing storage. By comparative study between the blend juice and fresh apple, fresh kiwifruit juices it was clear that the pasteurization process caused a remarkable in-crease in the total esters content due to the high increase in methyl propanoate, me-thyl butanoate and methyl benzoate. Pasteurization caused a sharp decrease in buta-nol which is the most abundant compound in fresh apple juice. All alcohols showed the same trend except ethanol. Pasteurization revealed a remarkable decrease in (E)–2-hexenal which is the most abundant compound in fresh kiwifruit juice. Regarding the effect of storage it was noted that the blend juice stored at 4oC showed high qual-ity after 3 months due to the remarkable increase in the contents of total ester, buta-nol, and (E) –2- hexenal with a decrease in limonene, but after 6 months the good quality was attributed to the high increase in ethyl butanoate concentration. While stroage at 25oC showed good quality after 3 months due to the very high increase in total esters content which attributed to a greate increase in ethyl butanoate concen-tration (which gave sweet and fruity aroma to juice), but storage for 6 months gave rise to a sharp decrease in ethyl butanoate which led to a high loss in aroma quality.

The toxicological effect of two pesticides, pyriproxyfen and abamectin were eva-luated on third instar larvae of the cotton leafworm, Spodoptera littoralis (Boisd.). According to the estimated toxicity values, i.e. LC50, LC90 and slope values, the chemical abamectin showed that it was slightly more toxic than pyriproxyfen. The effect of these two insecticides, at the determined LC50 and LC25 values on the di-gestive physiology of treated larvae, as indicated by some nutritional indices was conducted. Obtained results demonstrated that pyriproxyfen and abamectin caused a significance reduction in growth of treated larvae as depicted by larval weight gain Also, a significant decrease was found in the efficiency of ingested food to body matter and efficiency of conversion of digested food to body matter as compared to untreated insects. These effects were generally more evident when abemectin was used. The two tested compound also caused histological changes in the midgut of treated larvae, in form of disruption in the columnar epithelium cells and stretching leading to tearing in the peritrophic membrane. This observation might explain the impairment in nutritional indices in treated larvae as compared to the control.

North Carolina Design III was used to estimate gene effects in bread wheat crosses. Twelve Egyptian bread wheat genotypes i.e. Sakha 69, Sakha 8, Gemmeiza 1, Gemmeiza 3, Gemmeiza 7, Giza 160, , Giza 162, Giza 164, Giza 165, Sids 1, Sids 3 and Sids  4, each was crossed back to testers, high performing (Gemmeiza 9) and low performing parent (Sakha 92) during three winter successive seasons i.e. 2002/2003, 2003/2004 and 2004/2005, to study; heading date (days) plant height (cm), flag leaf length (cm) flag leaf width (cm), flag leaf area (cm)2, extrusion length (cm), number of spikelets/spike, spike grain weight (g.), number of spikes/plant, number of grains/spike, 1000-grain weight (g.) and grain yield/plant (g.) characters. Results indicated that epistasis played great role in the inheritance of all studied characters except number of spikes/plant. Additive(D)and dominance(H) genetic variances were significant in all studied characters except number of spikes/plant and number of grains/spike. The additive genetic variance was more than dominance for heading date, plant height, flag leaf length, flag leaf width, extrusion length, spike length and 1000- grain weight. The ratio of (H./D) 0.5 was less than one for these characters but for the remaining characters the dominance genetic variance was more than additive. The values of(F) indicated that dominance was unidirectional for flag leaf length and flag leaf area, whereas it was ambidirectional for the remaining characters Prediction results revealed that it could be possible to derive reasonable proportion of new recombinants which are falling out side parental range for heading date, flag leaf length, flag leaf width, spike length, number of spikelets/spike, number of spikes/plant, 1000- grain weight and grain yield/plant. Genetic correlation indicated that additive, dominance and epistasis gene effects controlling grain yield/plant and spike grain weight, number of spikes/plant, number of grains/spike, 1000- grain weight, were signifant, suggesting common genetic pool or pleiotropy. Thus, selection based on additive genetic correlation indicated that indirect selection via, spike grain weight, number of spikes/plant, number of grains/spike and 1000- grain weight would be effective and enhance its importance as selection criteria .

Twenty one mite species belonging to 3 suborders and 11 families were found in grain residues and mixed flour samples collected from warehouses and mills at Great Cairo. They were 12 pest species, 7 predatory and 2 parasitic species. Species commonly found in all inspected materials at all locations were Dermatophagoides farinae Hughes, Tyrophagous putrescentiae (Sch.) and Cheyletus malaccensis Oud. However Acrus siro (Lin), Acarophenax tribolii (New.) and Pyemotes herfsi (Oud.) were often abundant. The remaining species occurred sporadically in the collected materials. Actinedid and acaridid mites were “dominant” and “constant” in mixed flour and grain residues samples, the second group was the most abundant. Whereas gamasid mites was “recedent” and “accidental”. Mixed flour taken from Qaliobia Governorate harboured the highest number of mite species (15 species) followed by grain residues from Giza Governorate (13 species). While grain residues taken from Cairo Governorate harboured the lowest number (5 species).The highest infestation level with mites (2677.3 individuals) was recorded in mixed flour at Qaliobia Governorate, while the lowest one (1067 individuals) was found in grain residues at Cairo Governorate. Generally, mixed flour harboured more mite species than grain residues. Most of the collected mite species occurred during autumn and winter except P. herfsi and A. tribolii which were recorded during spring and summer, respectively. Dominance and frequency of occurrence, population fluctuations, effect of temperature and relative humidity on the population dynamics, also the relation between the predators and pests of mites were discussed in details.

Several nurseries of olives in Fayoum and Giza were surveyed for root rot incidence during early summer of 2003. In Fayoum, root rot incidence reached 53% while in Giza, disease incidence was 44%. Disease symptoms consist of partial wilting, leaves browning and twig dieback, which was associated with severe root rot and basal stem cankers and followed, in most cases, by plant decline and death. The most frequently isolated fungi from rotted roots were Fusarium oxysporum, F. solani, F. moniliforme, Rhizoctonia solani, Sclerotium rolfsii, Cylindrocarpon sp.  and Alternaria alternata. Isolation frequency of different fungi varied among olive cultivars. Generally, Fusarium spp. were the most frequently isolated  pathogens and Fusarium oxysporum was the most frequent (35.5%) on all cultivars followed by F. solani (19.3%) R. solani (16.1%). Meanwhile, S. rolfsii, F. moniliforme, Cylindrocarpon sp. and A. alternata occurred at lowfrequencies. Pathogenicity tests showed that all tested isolates caused varied degrees of root rot symptoms on olive transplants, cvs. Manzanillo and Picual. Fusarium oxysporum, F. solani and R. solani caused the highest root rot incidence and severity on both cultivars. There was a positive correlation between disease severity on roots and severity of foliar symptoms. All evaluated olive cultivars were susceptible or extremely susceptible to fungal pathogens. All cultivars showed high disease severity with root rots, especially in response to infection by F. solani, F. oxysporum and S.  rolfsii. However, the least foliar symptoms were recorded on cultivar Coratina. Application of two commercial biological control products (Rhizo-Plus and Trichoderma 2000) to soil, 24h before planting olive cuttings in the nursery, significantly reduced incidence of root rot on transplants of cultivars Manzanillo and Picual, up to 28 weeks after planting

The effect of both beekeeping processes (compressed bees Cb and traditional beekeeping Tb) and food diets (vitamins mixed with pollen grains, pollen grains only and plain sugar syrup) on the colony build up were studied during February – April, 2004, at the apiary belonging to Faculty of Agriculture, Ain Shams University. Feeding colonies with supplementary vitamins plus pollen grains resulted after four brood cycles significantly high daily rates of rearing brood (523 and 434 brood cells for Cb and Tb, respectively) and drawing combs (4.31 and 1.61 combs for Cb and Tb, respectively) compared to either unique pollen grains (432 and 338 brood cells and 3.2 and 1.19 combs for Cb and Tb, respectively) or plain sugar syrup (313 and 219 brood cells and 2.1 and 0.79 combs for Cb and Tb, respectively). On the other hand, the worker’s longevity recorded vice versa which were 21.2  26.2, 23.8 days for colonies fed on vitamins plus pollen grains, pollen grains and sugar syrup, respectively. The colonies which fed on vitamins plus pollen grains, pollen grains and plain sugar syrup, their workers were hoarded 236, 220 and 191 mg of sugar syrup / 3 days, respectively.

Biological studies on the Hawaiian beet webworm, Hymenia recurvalis were carried out under laboratory conditions of 18.6 ± 2°C and 70 ± 5% R. H. The incubation period ranged between 5 and 7 days with a mean of 6.0 ± 0.3 days. The mean durations of larval, prepupal and pupal stages were 26.29 ± 0.3, 5.04 ± 0.08 and 16.86 ± 0.18 days, respectively. Mean adult longevities were 28.42 ± 1.80 and 26.08 ± 1.83 days, ranging between 19-41 and 15-37 days for female and male, respectively. The sex ratio was about 1 : 1.3 (♀ : ♂ ). Accumulative thermal units needed for certain biological features of H. recuurvalis were calculated and the estimated thermal thresholds were 10.97, 12.14, 10.49 and 13.55°C for egg, larval, pre – pupal and pupal stages, respectively. The corresponding values for the thermal units needed for development of these stages were 51.49, 168.47, 47.88 and 102.59 day degree at 25°C for the respective stages.