In order to study the effect of nitrogen and potassium on yield and yield components on four bread wheat cultivars; Gemmiza 11, Sids 12, Sids 13 and Shandaweel 1, the treatments included three levels of nitrogen: 50, 75 and 100 kg N/fad accompanied by tow levels of potassium: 24 and 48 kg Ko2/fed. Field experiment was conducted at Sakha Agricultural Research Station, Agricultural Research Center, during the two growing seasons of 2008-2009 and 2009-2010. The treatments were arranged in a spilt-spilt plot design with four replications. The main plots were devoted to nitrogen levels and the sub-plots were allocated to potassium levels, while the sub-sub plots were designed to cultivars. Increasing nitrogen levels up to 100 kg N/fad. Resulted in significant gradual increase in days to heading and maturity, plant height, number of spikes/ m2 , number of kernels/spike, and grain yield/fad. On the hand, there was no significant effect for potassium fertilization levels on the tested agronomic characters. The results indicated that Gemmiza 11 was the earliest in heading and maturity in the two seasons. Shandaweel 1 gave the highest grain yield/fed in the first season while it was the latest one in days to maturity.Sids12 cultivars gave more spikes/ m2 in the both seasons.While,Sids 13cultivars gave the highest values of 1000grain weight. The interaction between nitrogen and potassium, nitrogen and cultivars, potassium and cultivars and cultivars, nitrogen and potassium rates did not show any significant effect on grain, straw yield/fed and harvest index in the two seasons. However, the interaction between nitrogen rates and cultivars and potassium and cultivars was significant for number grains/spike in the two seasons. The interaction between nitrogen levels and cultivars was significant for no. of spikes/ m2 in the second season. Also, the interaction between nitrogen and potassium levels was significant for no. of spikes/ m2 in the first season. It could be concluded that Shandaweel 1 can be cultivated under fertilization at 100kgN/fed to produce the highest yields of grains and straw per Fadden.

SummaryA study of the solitary parasitoid Microplitis rufiventris on larvae of Spodoptera littoralis showed that the age of the host at parasitization influenced the rate of development of the parasite, the percentage of parasitized hosts giving rise to mature parasite larvae, the number of moults subsequent to stinging, duration of larval instars, and the fecundity and longevity of the resulting adult parasites.

Three cultivars of bread wheat; Sakha 69, Sakha 93 and Sakha 94 were crossed in all six generations. P1, P2, F1, F2, BC1 and BC2 were obtained for two crosses;(Sakha 69 × Sakha 93) and (Sakha 93 × Sakha 94) to determine genetic parameters for number of days to heading and maturity, plant height, number of spikes per plant, number of kernels per spike, 100-kernel weight and grain yield per plant. The experiment was conducted at Sakha Agricultural Research Station during the growing seasons 2005/06, 2006/07 and 2007/08. Data revealed the presence of highly significant differences among crosses, among populations within crosses as well as among populations within each cross for all studied characters. The calculated values of A, B and C scaling tests for all studied characters in the two crosses were significant except for plant height in the second cross. The additive effect was more important and greater than the dominance effect for 100-kernels weight and grain yield per plant for the two crosses, while the dominance effect was more important and greater than the additive effect for days to heading and maturity for the two crosses and also for number of spikes per plant in the first cross. Heritability in broad and narrow sense indicated the importance of the non-additive variance components in the inheritance of the all studied characters except 100-kernel weight in the first cross. Heritability estimates in narrow sense were low to moderate for all the studied traits in the two crosses, ranged from 22.88% for grain yield per plant in the second cross to 69.10% for 100 kernels weight in the first cross. The expected genetic advance estimates in the F2 were low for number of days to heading, number of days to maturity, number of spikes per plant and 100-kernel weight in two crosses. The same trend were found for, plant height, number of kernels per spike and grain yield per plant in the second cross. While, indicated high for plant height, number of kernels per spike and grain yield per plant in the first cross.

When S. littoralis parasitized larvae with M. rufiventris were fed on different plant leaf hosts, the bionomics of this parasitoid, in its different stages, were affected. Castor‐oil leaves were, then, most suitable food to the parasitized host larvae of S. littoralis, than other host plants. Adults of M. rufiventris were affected by the food plant of its host. Adults life of M. rufiventris prolonged, when reared on S. littoralis host larvae fed on castor oil longer than when other plants were used. Moreover, percentages of parasitism with M. rufiventris in its hosts, i. e. the biological or integrated control, were higher, when they offered 50% honey solution as parasitoid supplementary food, than in case of starvation or other types of supplementary food, referring to the direct while that were the indirect role of nutrition in M. rufiventris. The data of the present work should be considered during the use of M. rufiventris in the biological and integrated control trials against the cotton leaf‐worm, i. e. S. littoralis larvae. Zusammenfassung Über die Abhängigkeit von Microplitis rufiventris Kok. (Hym., Braconidae), ein Parasit von Spodoptera littoralis (Boisd.), von der eigenen Nahrung und der Nahrung seines Wirtes Durch Fütterung von Spodoptera littoralis‐Raupen, die durch M. rufiventris parasitiert waren, mit verschiedenen Pflanzenarten wurde die Lebensweise des Parasiten in seinen verschiedenen Stadien beeinflußt. Rizinus‐Blätter erwiesen sich dabei für den Endoparasiten als günstigste Wirtsnahrung. Auch die Adulten von M. rufiventris wurden indirekt von der Fraßpflanze ihres Wirtes beeinflußt. Ihre Lebensdauer war nach Fütterung der Spodoptera‐Raupen mit Rizinus am längsten. Weiterhin wurde die Parasitierungsquote durch M. rufiventris mittels Darbietung einer 50prozentigen Honiglösung als Schlupfwespen‐Nahrung wesentlich erhöht. Diese Ergebnisse über die Abhängigkeit der Parasitierung von Spodoptera von der Raupen‐ und Schlupfwespen‐Nahrung sollte bei künftigen Versuchen zur biologischen und integrierten Bekämpfung beachtet werden.

Two field experiments were carried out under the Egyptian conditions during each of 1971–1972 and 1972–1973 to survey the most common pests which attack sugarbeet plants in six planting dates (11/14, 11/21, 11/28, 12/4, 12/11 and 12/18). The different species of insects and mites infesting the sugarbeet plants were counted and recorded. The main root properties (weight of roots, polarization percentage, total weight of roots/feddan1 and total weight of raw sugar/feddan) were found to be highly affected with the infestation degree of different pests. It was also found that the second, third (11/28) and fourth (12/4) planting dates were the best ones for sugarbeet growth and yield and the least for sugarbeet infestation. Zusammenfassung Über die Markmale der Zuckerrübe zu verschiedenen Pflanzzeiten in Beziehung zum Schädlingsbefall in Ägypten In Freilandexperimenten wurde 1971/72 und 1972/73 in Ägypten der Schädlingsbefall von Zuckerrüben, die zu verschiedenen Daten zwischen dem 14. 11. und 18. 12. gepflanzt waren, untersucht. Die an Zuckerrüben auftretenden Milben und Insektenarten werden aufgezählt. Die wichtigsten Wurzeleigenschaften (Gewicht, Gewicht/Fed., Polarisationsquote, Totalgewicht, Rohzucker/Fed.) korrelierten mit dem Grad des Befalls durch die verschiedenen Schädlinge. Es zeigte sich, daß das 2., 3. und 4. Pflanzdatum (21. 11.‐4. 12.) zum optimalen Zuckerrübenwachstum, zur Höchsternte und zum geringsten Schädlingsbefall führte.