ABSTRACT Twenty-six genotypes of sunflower (16 F1-hybrids, four female lines, four restorer lines and two check varieties; Sakha 53 and Giza 102) were evaluated under two contrasting environments, i.e., loamy sand and clay soils in season 2016. Genotypes mean squares of the studied traits was significant (P0.01) either in the separate or in the combined analysis. The differences between the two environments were significant for all traits except head diameter (HD). The genotype x environment interaction was significant for all traits. Furthermore, most of the variability was for environment, except for husk %. Mean squares of the combined analysis of female and testers lines was significant (P0.01) for all traits. These results indicate the presence of additive variance. Mean squares of parents vs. crosses and lines x testers were significant for all traits, indicating the presence of non-additive in the inheritance of these traits. The combined analysis indicated that mean squares of lines x environment was significant for all traits, except for HD. Mean squares of testers x environment was significant except for days to 50% flowering and HD. The interaction mean squares of LxTxE were significant for all traits, indicating the interaction of non-additive gene effects with environment. The results of the combined analysis indicated that the ratio 2A/2D was less than unity for all traits, and the role of dominance was more important than that of additive effects. The results of GCA indicated that none of the female or male lines was the best combiner for all traits. Thirteen out of the 16 hybrids were significantly (P0.01to P0.05) earlier than the earliest check cultivar Giza 102. The performance of the F1-hybrids in days to 50% flowering were mostly related to the GCA of the parents rather than the SCA of the hybrids. The combined analysis of plant height showed that eight hybrids gave negative SCA effects. All the F1-hybrids were significantly (P0.01) shorter than the two check cultivars. Based on the combined analysis; eight hybrids had positive SCA for head diameter; but none exceeded the check variety in head diameter. Based on the combined analysis 8 hybrids showed negative SCA for husk%, the performance of all hybrids was significantly (P0.01) lower in husk % than the better check Sakha 53. The combined analysis of oil % indicated that five hybrids showed significant positive SCA, four of them exceeded significantly (P0.01 to P0.01) the better check cultivar Giza 102. The combined SCA effects of seed yield/head (SY/P) were positive and significant for three hybrids (A7 x RF1, A15 x RF3 and A21 x RF5). The performance of the first hybrid (46.45 g/head) was significantly (P0.01) better than the better check Giza 102 (41.21 g/head). The hybrids performance was not in accordance with sign and significance of SCA of SY/P. Furthermore, the GCA of the parents was far from yielding ability. The combined SCA of five hybrids for oil yield/head were positive and significant (P0.01). The performance of the first hybrid (A7 x Rf1) (18.18 g) exceeded significantly (P0.01) the better check Giza 102 in oil yield/head (15.43 g). It could be concluded that the performance of the hybrids was not in accordance with the sign and significance of the SCA effects. This could be due to that the ratio of 2A/2D was less than unity and the dominance effects were more important than additive in the inheritance of all traits, and evaluation of hybrids should be at a variety of environments. Key words: Line tester analysis, Helianthus annuus L., GCA, SCA.

NULL

NULL

NULL

NULL

NULL

Abstract

Al-Hassa oasis is considered as the biggest irrigated one in the World, being well known for its extensive date palm cultivation with an estimate of at least three million trees. The aim of this study is to evaluate the impact of soil fertilization practices on the productivity potential of date palm trees grown under the climatic conditions of Al-Hassa oasis, KSA. The opinions of 258 active farmers were randomly surveyed using specifically designed questioners that were also fortified with personal communications. The size of the samples was designated in accordance to Cocoran equation. The total samples were allocated into two major parts (193 for the old oasis and 65 for the new oasis). Results showed that the farm features (utilized agricultural area (UAA), ownership and labors) are different in both parts of the oasis. Fertilization practices (quantity applied per area or per tree) were diverse causing dissimilar productivity potentials (total or per area or tree). The average production of a tree in the old oasis is 81.4 kg, whilst it is 54.6 kg in the new oasis. Date palm production is significantly affected by total number of trees, applied fertilizer quantity, cultivated area and labor power. The impact of these factors is unlike between the two parts of the oasis. It is then concluded from the study that there are sincere needs for improving the soil fertilization practiced for the date palm trees grown in the Al-Hassa oasis, KSA in order to increase their productivity potential and hence improve the farmers' income.

This study was carried out to evaluate the effects of dry yeast (0.4 and 0.8%), salicylic acid (150 and 300 ppm) and ascorbic acid (150 and 300 ppm) as a spray application on black cumin plants to determine their effects on plant height, number of branches/plant, stem diameter, root length, capsule number/plant, capsules weight/plant, seed weights/plant, seed yield/fed, fixed oil percentage and oil yield/fed during both seasons. The highest concentration of each substance showed superiority in comparison with the lowest concentration of the same substance and the control. Salicylic acid at rate of 300 ppm showed significant increase in plant height, seed weight, seed yield and fixed oil yield. Meanwhile, Ascorbic acid at rate of 300 ppm presented significant increment in number of branches/plant, capsules number/plant, capsules weight and oil percentage. Dry yeast at rate 0.8% caused an increase in the root length which calculated at the first season as 17.15 cm and at the second season as 16.45 cm.

Globally, many crop production areas are threatened by drought and salinity. Potato (Solanum tuberosum L.) is susceptible to these challenging environmental conditions. In this study, an in vitro approach was employed to compare the tolerance of potato cultivars ‘BARI-401’ (red skin) and ‘Spunta’ (yellow skin). To simulate ionic and osmotic stress, MS media was supplemented with lithium chloride (LiCl 20 mM) and mannitol (150 mM). GC-MS and spectrophotometry techniques were used to determine metabolite accumulation. Other biochemical properties, such as total phenols concentration (TPC), total flavonoids concentration (TFC), antioxidant capacity (DPPH free radical scavenging capacity), polyphenol oxidase (PPO), and peroxidase (POD) activities, were also measured. The two cultivars respond differently to ionic and osmotic stress treatments, with Spunta accumulating more defensive metabolites in response, indicating a higher level of tolerance. While further investigation of the physiological and biochemical responses of these varieties to drought and salinity is required, the approach taken in this paper provides useful information prior to open field evaluation.

The potential toxicity of five selected herbicides i.e. bispyribac-sodium, penoxsulam, haloxyfop-p-ethyl, pinoxaden, and tralkoxydim, and a pyrethriod insecticide deltamethrin was determined on the early 4th instar larvae (after 24, 48 and 72-h exposure) and pupae (after 24 and 48-h exposure) of Culex pipiens L. in the laboratory. As a result, deltamethrin was count as the most toxic compound on the early 4th instar larvae and pupae of Cx. pip- iens compared with all tested herbicides after exposure times. For the tested herbicides, pinoxaden was the most potent herbicide against both tested developmental stages fol- lowed by bispyribac-sodium and penoxsulam, which exhibited a moderate toxicity; while haloxyfop-p-ethyl and tralkoxydim were deemed to be the lowest toxic compounds among all tested pesticides after exposure times. In addition, the toxicity of all pesticides against larval and pupal stages of mosquito was increased gradually as exposure time increased especially after 72-h exposure for larvae and 48-h exposure for pupae. In conclusion, this is the first report on the side toxicity effects of haloxyfop-p-ethyl, tralkoxydim, penoxsulam and bispyribac-sodium on immature stages (larvae and pupae) of Cx. pipiens mosquitos in Egypt.