Saleh M. Ismail

Wheat Phenological Development and Growth Studies As Affected by Drought and Late Season High Temperature Stress under Arid Environment

This study evaluates the potential for adaptability and tolerance of wheat genotypes (G) to an arid environment. We examined the influence of drought stress (DS) (100, 75, and 50% field capacity), planting times (PT) (16-November, 01-December, 16-December and 01-January), and G (Yocoro Rojo, FKAU-10, Faisalabad-08, and Galaxy L-7096) on phenological development, growth indices, grain yield, and water use efficiency of drip-irrigated wheat. Development measured at five phenological growth stages (GS) (tillering, jointing, booting, heading, and maturity) and growth indices 30, 45, 60, and 75 days after sowing (DAS) were also correlated with final grain yield. Tillering occurred earlier in DS plots, to a maximum of 31 days. Days to complete 50% heading and physiological crop maturity were the most susceptible GS that denoted 31–72% reduction in number of days to complete these GS at severe DS. Wheat G grown with severe DS had the shortest grain filling duration. Genotype Fsd-08 presented greater adaptability to studied arid climate and recorded 31, 35, and 38% longer grain filling period as compared with rest of the G at 100–50% field capacity respectively. December sowing mitigated the drought and delayed planting effects by producing superior growth and yield (2162 kg ha−1) at severe DS. Genotypes Fsd-08 and L-7096 attained the minimum plant height (36 cm) and the shortest growth cycle (76 days) for January planting with 50% field capacity. At severe DS leaf area index, dry matter accumulation, crop growth rate and net assimilation rate were decreased by 67, 57, 34, and 38% as compared to non-stressed plots. Genotypes Fsd-08 and F-10 were the superior ones and secured 14–17% higher grain yield than genotype YR for severely stressed plots. The correlation between crop growth indices and grain yield depicted the highest value (0.58–0.71) at 60–75 DAS. So the major contribution of these growth indices toward grain yield was at the start of reproductive phase. Its clear that booting and grain filling are the most sensitive GS that are severely affected by both drought and delay in planting.

Optimizing productivity and irrigation water use efficiency of pearl millet as a forage crop in arid regions under different irrigation methods and stress

A field experiment was carried-out at the Agriculture Experimental Station of King Abdulaziz University located at Hada Alsham, 110 km north east of Jeddah, to optimize the productivity and irrigation water use efficiency of pearl millets (Pennisetum glaucum L.), as green fodder under different irrigation methods and stress. Five treatments were investigated in this study: three with full irrigation requirements including sprinkler irrigation (SPI), drip irrigation (DI) and sub-surface drip irrigation (SDI), the remaining two treatments were stress treatment namely: sub-surface drip kept at 85% of field capacity (SDI 1) and sub-surface drip kept at 70% of field capacity (SDI 2). Irrigation water for all treatments was precisely supplied using water electronics module (WEM). Results indicated that SDI treatment gave the highest fresh and dry biomass, followed by SDI 1 compared to other treatments. Increasing number of cuts sharply decreased biomass production. Increasing water stress decreased biomass production but SDI with water stress increased biomass production compared to SPI with full irrigation requirement. Irrigation water use efficiency (IWUE) was decreased by increasing water stress and number of cuts. Results also proved that WEM is a practical tool to precisely supply irrigation water when needed, and can be effectively used to precisely control water stress.

WATER USE EFFICIENCY, GROWTH AND YIELD OF WHEAT CULTIVATED UNDER COMPETITION WITH Setaria

Understanding the critical period of weed competition is indispensable in the development of an effective weed management program in field crops. Current experiment was planned to evaluate the critical growth period ofSetaria and level of yield losses associated with delay in weeding in rain-fed drip irrigated wheat production system of Saudi Arabia. Field experiment was conducted to evaluate the effect of weeding interval (07-21, 14-28, 21-35, 28-42 and 35-49 days after sowing) and drought stress (75% and 50% of field capacity) on Setaria growth, wheat yield and water use efficiency. Season long weedy check and wellwatered (100% FC) plots were also maintained for comparison. Weeding interval and drought stress significantly (p ≤ 0.05) affected the growth and yield of Setaria and wheat. Drought stress from 75% to 50% FC resulted in reductions of 29-40% in Setaria height, 14-27% in Setaria density and 11-26% in Setaria dry biomass. All weeding intervals except 35-49 DAS significantly suppressedSetaria growth as compared with control. Delay in weeding increased weed-crop competition interval and reduced wheat yield and yield contributors. Therefore, the lowest yield of 1836 kg ha-1 was attained for weeding interval of 35-49 DAS at 50% FC. Water use efficiency and harvest index increased with decreasing FC levels but reduced with delay in weeding. Correlation analysis predicted negative association ofSetariadensity with wheat yield and yield contributors and the highest negative association was for harvest index (-0.913) and water use efficiency (-0.614). Early management of Setaria is imperative for successful wheat production otherwise yield losses are beyond economical limits.

Yield, fruit quality and nutrient uptake of ‘Nabbut-Ahmar’ date palm grown in sandy loam soil as affected by NPK fertigation

ABSTRACT A field experiment was conducted in 2011 and 2012 to study the effect of fertigation on yield, fruit quality and nutrient uptake of ‘Nabbut-Ahmar’ date palm cultivar grown in sandy loam soil. Three fertigation treatments were compared with traditional application. In traditional treatment (CT), the recommended dose [2300 g nitrogen (N), 1200 g phosphorus (P) and 1400 g/tree] was applied as a soil broadcast in three equal doses. The fertigation treatments, (T2), (T3) and (T4), represent all nitrogen, phosphorus and potassium (NPK) amounts of CT, 2/3 CT and 1/3 CT, respectively that were injected in twelve equal doses. The results showed that compared to CT, the fertigation treatments increased yield/palm by 41%, 31% and 18% for T3, T2 and T4, respectively. Beside the increase in yield, 33% and 66% of the applied fertilizers were saved by T3 and T4, respectively, compared with CT. Feritgation treatments had no negative impact on the overall fruit quality characteristics and even increased total soluble solids (TSS), soluble tannins and total phenols concentrations compared to the conventional fertilization. Availability of NPK increased by fertigation but without further increase in leaves and fruit. In conclusion applying 2/3 of the recommended dose of NPK fertilizers under dry land condition through fertigation maximize yield, quality and fertilizer use efficiency.

Effect of tillage systems and polyacrylamide on soil physical properties and wheat grain yield in arid regions differing in fine soil particles

ABSTRACT A field study was performed for two consecutive seasons to evaluate the effect of polyacrylamide (PAM), tillage systems and particle size on soil physical properties and wheat grain yield. The PAM rates were 0, 10 and 20 kg ha−1 while the tillage treatments included no-tillage (NT), moldboard plowing (CT1), and chisel plowing (CT2). Soil fine particles size of two locations were A (25.2 silt + clay) and B (38.5 silt + clay). Location B reported higher organic matter and total porosity while lower in bulk density. The CT1 and NT treatments denoted better soil organic matter percentage. The CT1 presented maximum infiltration rate compared to other tillage systems. No tillage showed better soil water contents while the minimum was in CT1 of location A and CT2 of location B. Increasing the PAM rate increased total porosity, infiltration rate and soil water content while decreased soil bulk density. Possibly, the presence of compacted layer in location A hindered the effect of PAM. At location B, the CT2 with PAM of 20 kg ha−1 had the highest grain yield compared to other tillage systems. The PAM is beneficial for soil and water conservation and can be used in agriculture.

Enhanced mungbean and water productivity under full irrigation and stress using humic acid in arid regions

A field experiment was conducted during 2016 and 2017 seasons at the Agriculture Research Station of King Abdulaziz University at Hada Al-Sham, Saudi Arabia in a split plot design to investigate the response of Mungbean [(Vigna radiate (L.)Wilczek] MN-96 cv. to three irrigation water regimes(100%, 80% and 60% of water requirements)and three humic acid (HA) rates (15, 30 and 45 kg/ha HA) was mixed with the soil surface. Seed yield and yield components were significantly similar under 30 and 45 kg HA/ha. No significantly differences were showed between seed yield/ha, yield components and IWUE under the 80% water regime with45 kg/ha HA and 100% water regime with 15 kg/ha HA.

Immobilization of Ni and Zn in Soil by Cow and Chicken Manure

This study was performed to evaluate the effect of both cow and chicken manures application on the immobilization of Ni and Zn in soils. Effect of cow and chicken manures on the bulk density, pH and the distribution of Ni and Zn in various chemical fractions of an alkaline, sandy loam soil was explored in a PVC columns study. Cow and chicken manures were mixed at rates of 10, 20 and 30 g/kg of soil. The soil-manure mixture was incubated for two months at room temperature. Sequential extraction procedure was performed on all samples from each column to determine Zn and Ni in different fractions (soluble-exchangeable, organic, carbonates and residual). Results obtained showed a decrease in soil bulk density with an increase of 0.3 units in soil pH as compared to the control. After 60 days of incubation, Ni concentrations were found to be 28 and 34% of inorganic fraction, while the residual reaction accounted for 58 and 53% for cow and chicken manure respectively as compared to the corresponding control. In case of Zn, soil organic matter fraction accounted for 53-57% of the total Zn. The soluble and exchangeable fraction which, although, slightly increased with time remained very low (2-4%) for the two metals. Therefore, the addition of the manures resulted in improved soil bulk density and showed a good potential in immobilizing both two metals in the studied soil.

TREATED WASTEWATER USE AND ITS EFFECT ON WATER CONSERVATION, VEGETATIVE YEILD,YIELD COMPONENTS AND WATER USE EFFICIENCY OF SOME VEGETABLE CROPS GROWN UNDER TWO DIFFERENT IRRIGATION SYSTEMS IN WESTERN REGION, SAUDI ARABIA

The conducted clinical and instrumental study revealed that the aggregate group of the patients with chronic diseases of throat differs by increased frequency of isolated and combined disorders of gastrointestinal tract. If a patient has such symptoms as hoarseness, tickling, scratching, burning, feeling of dryness in throat, frequent variant of gastro-intestinal tract disorders is gastroesophageal reflux disease with pharyngolaryneal reflux. There are such severe pathologies of throat as pachydermia of vocal cords and nodules of vocal cords among more frequently met disorders at gastro-intestinal tract diseases. High probability of accompanied pathology of throat in the form of pachydermia and nodules of vocal cords at patients with gastro-intestinal tract disorders stipulates for the necessity of conducting fibrorhynolaryngoscopy in combination with fibergastroscopy.Study presents short overview of drug situation’s indicators during the first, or heroin decade of drugs, and then during the second, soft and synthetic drugs decade of drugs in Slovakia. Then the results of series of nation-wide school surveys, mapping development of licit and illicit drugs use among children and youth during nineties are outlined. The results indicated constant growth of licit and illicit drugs consumption among primary school pupils, and secondary school students until the fourth wave of nation-wide school surveys in the years 2006 – 2007. However, the next wave after four years has detected profound change in the expected pattern of further growth in the case of illicit drugs. Instead of this decline of use or at least stabilization occurred among Slovak youth. At the same time we have found growth of use in the case of licit drugs – alcohol and tobacco, more profoundly among girls. Also the use of new synthetic drugs among young people was revealed via traditional school survey.