High temperature is a major environmental stress that devastatingly affects wheat production. Thenceforth, developing heat-tolerant and high-yielding wheat genotypes has become more critical to sustaining wheat production particularly under abrupt climate change and fast-growing global population. The present study aimed to evaluate parental genotypes and their cross combinations under normal and heat stress conditions, exploring their diversity based on dehydration-responsive element-binding 2 gene (DREB, stress tolerance gene in response to abiotic stress) in parental genotypes, and determining gene action controlling yield traits through half-diallel analysis. Six diverse bread wheat genotypes (local and exotic) and their 15 F₁ hybrids were evaluated at two different locations under timely and late sowing dates. Sowing date, location, genotype, and their interactions significantly impacted the studied traits; days to heading, chlorophyll content, plant height, grain yield, and its attributes. Cluster analysis classified the parents and their crosses into four groups varying from heat-tolerant to heat-sensitive based on heat tolerance indices. The parental genotypes P₂ and P₄ were identified as an excellent source of beneficial alleles for earliness and high yielding under heat stress. This was corroborated by DNA sequence analysis of DREB transcription factors. They were the highest homologies for dehydrin gene sequence with heat-tolerant wheat species. The hybrid combinations of P₁ × P₅, P₁ × P₆, P₂ × P₄, and P₃ × P₅ were detected to be good specific combiners for grain yield and its attributes under heat stress conditions. These designated genotypes could be used in wheat breeding for developing heat-tolerant and climate-resilient cultivars. The non-additive genetic variances were preponderant over additive genetic variances for grain yield and most traits under both sowing dates. The narrow-sense heritability ranged from low to moderate for most traits. Strong positive associations were detected between grain yield and each of chlorophyll content, plant height, number of grains/spike, and thousand-grain weights, which suggest their importance for indirect selection under heat stress, especially in early generations, due to the effortlessness of their measurement.

The present study was conducted to evaluate the genetic diversity and relationships of 5 Saudi native chicken populations and a White Leghorn (L) str

Potatoes require high amounts of potassium (K) and nitrogen (N) fertilizers for optimum growth, production and tuber quality. Farmers and farming industries under the arid conditions and sandy soils of Saudi Arabia are applying K and N fertilizers to potatoes without attention to plant requirements. Therefore, five levels of potassium fertilizer were studied on agronomic performance, tuber quality and total yield of potatoes grown on a sandy soil in the arid environment of Central Saudi Arabia. Also, the effect of four levels of nitrogen fertilizer with different splitting methods on vegetative and tuber yields of potato were studied. The field experiments were carried out during 2002 and 2003 autumn seasons at the Experimental Farm of College of Agric. &Vet. Med., Al-Qassim University. Results reveled that increasing potassium sulfate rates resulted in a significant increase (p>0.05) in plant height, leaf area, chlorophyll concentration, specific gravity, K concentration and carbohydrate content. Marketable tuber yield was also significantly improved with increasing K rates. Also, the application of 300 kg Nha-1 split in three equal doses gave the highest percentage of soil coverage and marketable tuber yield. Under the conditions of this experiment, it is concluded that K and N is needed by potatoes for economic yield. The recommended rate for Al-Qassim and similar regions is 450 kg ha-1 potassium sulfate and 300 kg Nha-1 split in three equal doses which resulted in the highest potatoes yield.

Red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier) (Coleoptera, Curculionidae), is a devastating invasive pest, that invaded Saudi Arabia's date palms in 1987. Evaluation of the infestations and the efficacy of both preventative and control treatments have been studied from 2015- 2020 in Qassim. The results indicated that the number of infested date palms varied according to the years and locations. The infested date palm trees percentage was relatively high in 2016 (2.24%) and 2017 (3.19%), then gradually decreased to reach its lowest in 2020 (0.73%) due to the management protocol applied by the Ministry of Environment, Water, and Agriculture. Furthermore, the infested palm trees' percentage varied among the eight study locations, reaching the highest percentage in location G (SA7) with a general average of 4.31%. While in the other locations, the general infested percentage average was very low when compared to location G (SA7) with 1.21 and 0.47% in locations A (SA1) and H (SA8), respectively. The effectiveness of control methods increased sharply from 52.141% in 2015 to 90.0% in 2020 with a general average of 72.73%. The quarantine and management protocols of R. ferruginous applied in Qassim decreased the number of palm infestations. Contrary, the intensive use of insecticide in the last two decades promoted genetic mutations within the Rhynchophorus, which led to the emergence of a new species R. bilineatus. This leads to increase pesticide pollution, and control costs and the insect becomes more resistant to pesticides.

Salinity is a limiting factor for forage productivity in irrigated areas. The aim of this study was to evaluate the salt tolerance index (STI), the K/Na ratio, and the forage quality of several introduced cool season grass species in irrigated agriculture. Four irrigated water salinity concentrations were used (control, 4000, 8000, and 12000 ppm sodium chloride (NaCl)), and four grass cultivars belonging to three species were established under greenhouse conditions at the Qassim University Agricultural Research and Experimental Station during the 2012 and 2013 growing seasons (perennial ryegrass (Lolium perenne L., cvs. Aries and Quartet), endophyte-free tall fescue (Festuca arundinacea Schreb., cv. Fawn), and orchardgrass (Dactylis glomerata L., cv. Tekapo)). A randomized complete block design (RCBD) using three replications was used. Cultivars were evaluated based on their dry weights (g m⁻²) and forage quality. Additionally, the STI and potassium (K⁺) and sodium (Na⁺) concentrations in the studied grass cultivars were evaluated. The dry weights of the grasses decreased significantly as the salinity level of the irrigation water increased. At a salinity of 4000 ppm, the Aries perennial ryegrass had the highest dry weight at both sample cuttings. The Aries, Fawn, and Quartet grasses had the highest STI values. The percent of K⁺ and the K/Na ratio increased as the salinity of the irrigation water increased for the Fawn tall fescue and Quartet perennial ryegrass. In the previously cultivars, the percentage of Na⁺ decreased as the salinity level of the irrigation water increased, which was in contrast with the results observed for the Tekapo orchardgrass.