Vol. 6 Issue 3
Nuri Sabir Mohamed
Vickers microhardness indentations on steel cause deformations in only a small volume of the material. As a result, the values obtained greatly depend on the surface finish in the vicinity of the indentation.
This study investigates the dependence of microhardness test results on the test loads and surface conditions of a BS 970 steel in three heat treatment conditions.
Extensive measurements of the universally accepted roughness average were carried out on different grounds and polished metallographic surfaces. Profile graphs were recorded and microhardness measurements carried out under loads o 10, 20, 50 and 100 grams. At low loads, 10g, the measured hardness increased with the degree of polish (e.g. with the decreased in roughness average), whilst in hard steel, this effect persists up to 50g load. The shapes of indentations are affected by the directional characteristics of the grinding pattern.
Nuri Osman Mukhtar and Abdallah H. Nourai
The effect of starter N and P were studied on seed inoculated faba bean at three different locations in the Sudan namely Wad Medani and Turabi in the Gezira (new area) and Abu Hasheem (traditional faba bean growing area) in the Northern Province.
Starter N (20 kg N/ha) dose seemed to inhibit nodulation in the warmer area of Wad Medani while at the relatively cooler area of Abu Hasheem, the depressing starter N effect on nodule formulation was not evident.
Inoculation resulted in increased nodulation and plant dry matter production up to 6-8 weeks from sowing. Increased nodulation, however, was not reflected in shoot N uptake or seed yield.
Phosphorus enhanced nodulation, nitrogen fixation and seed yield. The enhancement was greater when a starter dose of N was applied. It seemed to have increase biological N2 fixation and/or the N use efficiency by faba beans. It is worth mentioning that P application though resulted in significantly higher seed yields, but it at the same time reduced the 1000 seed weight.
On the other hand, faba bean seed yield did not respond to seed inoculation or even fertilizer N in both areas in the absence of P. This indicated efficient N-fixation by the indigenous rhizobia in both areas.
Mohammad Saeed
Simple equations, based on easily available climatic data, were developed for the reference evapotranspiration (ET) in an arid climate of Saudi Arabia, taking 20 cm-tall alfalfa as a reference crop. These equations could be used in conjunction with crop coefficients to estimate the crop water requirements in irrigation practice, research work and computerized irrigation systems. The study was carried out with four non-weighing, freely drained, steel lysimeters having an actively growing dense cover of alfalfa, and surrounded on all sides by an alfalfa belt. The crop was frequently irrigated and the evapotranspiration was obtained by balancing the water inputs and outputs to the lysimeters. Equations based on the most important climatic variables were then fitted to the data.
M.O.A. Warrag
Pot and field trials were conducted during 1986 and 1987 growing seasons, respectively, to examine the factors responsible for the reduction in seed yield of cowpea which usually occurs for late planting dates in Qassim, Saudi Arabia. Cowpea cv CBS was used in this study. The highest seed yield was attained from March planting date and decreased progressively with late planting. This reduction was the result of low number of flowers and low pod set. Reductions in number of seeds per pod and set was attributed to lack of fertilization which resulted from male sterility. Male sterility was caused by anther in dehiscence and low pollen viability. These adverse effects appeared to be associated with the higher temperatures which were found at later planning dates.
U.G. Bokhari, Faisal Alyaeesh and Mahmood Al Noori
A number of warm season grasses imported from the United States, Australia and Kenya were tried at different locations in the Kingdom to evaluate their production potentials and nutritive values and to compare these with other forage crops. Among these, Blue panic (Panicum antidotale), Klein grass (Panicum coloratum), love grass (Eragrostis superba) and signal grass (Brachiaria decumbens) were found successful at many locations, however Blue panic surpassed all other species producing 150 to 180 tons of green material per hectare per year with 15 to 18% protein. Blue panic was also highly tolerant to high level of salinity (15000 ppm) and drought, using almost 50% less water than alfalfa. Comparison with other forage crops indicate that Blue panic is certainly more productive and nutritionally more acceptable than Rhodes grass (Chloris gayana).
M.S. Salah, S.M. Basmaeil and H.H. Mogawer
Growth of Aardi goat kids was studied by examining growth curves expressing the relationships between weight and age of the animals. Out of 14 weight-age regression equations for each group of single- and twin-born males and females, one equation was chosen in each group to describe growth best. Means of least squares of adjusted biweekly body weights were used in this estimation. During the 1st year of life, males followed quadratic and females quadratic-cum-log type functions for growth. During the 1st two years, which studied only in males, an incomplete-gamma-type function was found to be the best. Type of birth did not change the growth pattern of either male or female kids. Actual and estimated growth rates were closely comparable, and decreased with advancing age. Males reached maturity later than females.
M.M. Al-Farraj, Ali A. Al-Helal, R.A. El-Desoki and I. Al-Hubshi
Water absorbed as percentage of original weight of seeds of Citrullus colocynthis and Cucumis prophetarum increased markedly during the first experimental four hours and reached constancy thereafter. Percentage water absorbed after 24 hr was 20 and 34 for freshly harvested seeds and seeds stored for one year of Citrullus compared to 92% for Cucumis seeds.
Seed germination percentage of Cucumis at different temperatures increased rapidly during the first four days, the highest being 68% on the fifth day at 25°C.
Freshly harvested seeds of Citrullus as well as seeds stored for one year are dormant, while seeds stored for eight years reached their highest germination (50%) at 25°C on the 10th day. However chiling for one month at 4°C or treatment with 500 ppm kinetin (K) stimulated germination of seeds stored for one year where germination was 37 and 23% respectively. Neither gibberellin A3 (GA) nor mixture of GA and K stimulated the germination of these seeds. Sulphuric acid failed stimulate germination of freshly harvested seeds.
Jaber S. Mosa, Ibrahim A. Al-Meshal, Mohammed A. Al-Yahya and Mohamed S. Hifnawy
The steam distilled oil of the aerial parts of Triumfetta flacescens Hochst. ex. A. Rich was analyzed by the coupled technique GC/MS. By the aid of the electronic data system and the study of the mass spectra, up to 63 components could be identified and the chemical classes of another 28 constituents were deduced. These ingredients amounted for about 96% of the total oil content. The oil is rich in sesquiterpene hydrocarbons and their oxygenated derivatives, most of which belong to the azulene series. Terpene alcohols viz. linalool, 4-terpineol, cis-piperitol and cuminol together with other volatile oil constituents were found to be present in the investigated sample
H.A. Abulfatih and A.K. Nasher
The status of endangered succulent plants was evaluated according to their range of distribution in the Southwestern region of Saudi Arabia . Forty seven rare succulent plants are threatened as a result of overgrazing, trampling, road construction, and lack of concern for their conservation. Immediate action is required for the protection of these plants.
Ziad A. Shraideh
An acellular slime mold identified as Physarum polycephalum was isolated from surface soil collected at the Dibbin National Park forest in the north of Jordan. The myxomycete, the first to be isolated in Jordan, was isolated from dead organic matter incubated at room temperature in a moist chamber. It was characterized by small stalked gyrose sporangia, peridial lime deposits, branched capillitium and ornamented spores. It had a large yellowish phaneroplasmodium which showed rhythmic shuttle streaming with a periodicity of approximately 1.3 min