Journal of Agricultural Science and Technology
Volume:2 Issue: 1, Jan 2000

This experiment was carried out to study the effect of sodium chloride fromdrinking water and feed intake on the quality of egs from laying hens. Four hundredand twenty native and white leghorn laying hens ranging from 36 to 43 weeks of agewere used. Seven experimental treatments containing different levels of salt suppliedby feed and/or drinking water were compared. Increasing salt intake by the addition ofNaCI to drinking water or feed intake reduced shell thickness, shell ash and increased,the number of damaged eggs. Shell calcium was not affected hy added salt, however,the addition of salt to the food reduced shell-breaking strength. Breed differencesinfluenced the traits studied, except for shell percentage and shell calcium. Sodiumchloride intake from drinking water was more effective in reducing shell quality thansalt from food.

Floodwater spreading (FWS) for the artificial recharge of groundwater (ARG),is an easy and economical method of desertification control. An integratedapproach to desertification control based on FWS for the ARG was adopted in theGareh Bygone Plain in southern Iran. Deposition of the suspended load (SL),carried by floodwater into the sedimentation hasins and infiltration ponds,stabilizes the drifting sand and reclaims the eroded rangeland on which the ARGprojects are executed. Results of some of the physical and chemical analysesperformed on the one to four-year-old sediment samples obtained from the firstthree sedimentation basins at the Gareh Bygone Plain ARG scheme show that ofthe 19 factors analyzed, only two changed significantly due to the settlement of theSL in the basins: sand content decreased by 7.9 and 3.8% at the 0-10 and 0-30cm depth respectively; and the ESP increased by 17.2% at the 0-30 cm depth.Regression equations were developed correlating soil content of organic matter,total N,P, saturation percentage and CEC with silt + clay content. Theserelationships indicate the geological origin of N and perhaps P and the importanceof SL in the fertility status of the drifting sand.

The total nitrogen content of three barley cultivars: Cehada Capa (resistant at25aC), Cl 1243 (resistant at 5°C) and Rika 1 (susceptible at all temperatures) toPuccinia hordei 26°C. The results indicate that the total nitrogen content of cv. Cehada Capa leaveswas greater than that of Cl 1243 and Rika 1 and that of Cl 1243 was greater than thatof Rika 1 when plants were grown at 26°C. When plants were grown at 5°C, thepercentage of total nitrogen content of leaves of cv. Cebada Capa was significantlygreater than that of Cl 1243 and Rika 1, but no differences were found between Rika1 and Cl 1243. It was concluded that the total nitrogen content has no role in thetemperature sensitivity of barley cultivars. In most cases, especially in susceptiblecultivars, the nitrogen content of infected leaves was greater than that of healthyplants when plants were incubated at 26°C, but there were no significant differencesbetween total nitrogen content of infected leaves and that of their healthy controlwhen plants were incubated at 5°C.was determined and compared in healthy and infected plants at 5° and

A study was carried out to determine whether naturally-occurring weeds and othercultivated plants in tomato growing regions could act as symptomless reservoirs ofinfection to from weeds and oubergines were used in this investigation. A susceptible tomatocultivar was used for comparison. The plants were artificially inoculated at the five tosix leaf stage by root dip method. Only tomato showed wilt symptoms and died threeweeks after inoculation. These isolates were identified as F. o. f. sp. lycopersici. Weedsincluding were colonized to various degrees and determined as symptomless carriers. Therefore,in infested areas, aubergines should not be rotated consecutively with tomatoes andproper measures should be adopted to control the weeds.Fusarium oxysporum f. sp. lycopersici. A numher of F. oxysporum isolatesAmaranthus retroflexus, Amaranthus. sp., Chenopodium album, and aubergines

Eight wheat varieties some of which were earlier reported to be resistant to arrhennmanes, placing 2-day-old seedlings on the edge of a Pythiumwere inoculated with P. arrhenomanes. Inoculation was performed byP. arrhenomanes culture on corn mealagar dia.) containing glass beads and 1 ml of sterile water, and incubated for 4 days at25°O Non-inoculated seedlings were exposed to the toxic metabolite(s) from arrhenomanes filtrate of sterile water served as controls. Measurements were taken on root and shoot length,as well as fresh and dry root and shoot weights. There was an indication that it maybe possible to use the toxic metabolite(s) in screening for resistance to arrhenomanes. some differences among them in their reaction to fungal infection or exposure to thetoxic metabolite(s).for 3 h at 25°C. Infected seedlings were then transferred to test tubes (9 mmP.by placing them in test tubes containing 1 ml of a 25-day-old cultureP. arrhenomanes. Non-inoculated seedlings grown in test tubes containingP.Although all of the varieties appeared to be susceptible, there were

The percentage of urediniospore germination of two isolates of yellow rust striiformis f. sp. tritici) |Race 41E 139 (4)], was studied at various temperatues between 5-20°C on agar andthe adaxial surface of detached leaves on a layer of benzimidazole agar. Fourreplicates for five temperature treatments were arranged as a preliminaryinvestigation to find the most appropriate temperature for the subsequent comparisonof spore germination on the host material under investigation. Mean percentagevalues were analysed separately and the levels of urediniospore germination atdifferent temperatures were compared using analysis of variance and Student-Newman-Keuls techniques. Spore germination of both isolates was high over thetemperature range 5-10°C, but dropped significantly at 15-20°C. At the coolertemperatures 5°, 7.5° and 10°C, isolate WYR 69/10 consistently germinated at ahigher level than isolate WYR 79/4, whereas at 20°C, the latter isolate gave thehighest figures. This observation indicates that both isolates germinated mosteffectively at 10°C on agar and detached leaves.{Puccinianamely, WYR 69/10 |Race 104E 137(1)] and isolate WYR 79/4

The ovipositiomil behaviour and success of encyrtid endoparasitoid of mealybugs, affinis oviposition starting from the searching for the host to the post-oviposition activitieswere described. Once encountered, the mealybug host was examined and probed by theovipositor of the parasitoid. Oviposition success was influenced by the defence activityof the host. parasitism than important role in increasing the efficacy of subsequent oviposition.Anagyrus pseudococci (Girault), anPlanococcus citri (Risso) and Pseudococcus(Mask.) were studied in the laboratory. Behavioural sequences duringP. citri was less able to defend itself and was more susceptible toP. affinis. Oviposition experience of the parasitoid played an

There is undoubtedly general agreement that the efficiency of educational investmentsshould he maximized through the managerial process as far as possible.Agricultural extension is one of the crucial tasks in developing agricultural societiescalling for considerable consumption of intellectual investment. The management ofagricultural extension projects (AEPs) however, needs careful planning in utilizingthis investment specially in terms of meeting the right clientele. This paper reports onthe use of a statistical device which can be applied for planning the social modeling ofagricultural extension programs. This statistical device, the so-called DichotomousDistribution of the Extension Clientele (DDEC) was designed and used by the authorto determine the social modeling of agricultural extension projects in Iran and thedegree to which the extension projects have been successful in reaching their targetclientele. The procedure consisted of four major criteria: farmers, educational needs,participation in AEP: access to utilities needed for adoption and utilization of theinnovation (advice given by the extension agents). As a result of using this methodand interviewing 912 farmers throught 57 randomly selected AEPs, it was found that66 percent of the projects in 1988 and 60 percent in 1989 were thoroughly efficient,and 16 percent in 1988 and 12 percent in 1989 were efficient. Four projects in eachyear were found to have a very low efficiency rate while one project in 1988 and fourprojects in 1989 were inefficient in terms of their social modeling. This procedur hasbeen applied to study the social modeling along with the efficiency of the extensionprojects dealing with the biological control of rice stenborer in eastern part ofMazandaran province where rice is the dominant cash crop. Acording to this resultobtained from the recent research projects, it was shown that the less differencesamong the number of trained farmers and the target groups the more efficient werethe extension project In addition, there was statistically significant difference amongthose of target groups and none target groups in term of applying the extensionboicontrol guidlines in rice production practices. The related extension projects werealso efficient (r=0.73) in term of their social modelings.

Electrical conductivity (EC) has been evaluated as a possible method for measuringviability and seedling vigour in wheat and other crops. A study was conducted usingdormant, stock, naturally-aged (5 years) and artificially-aged (10 and 15 days) wheatseeds (Triticum aestivum cv. Omid) to evaluate the effect of different seed lots onelectrical conductivity. All seed lots were subjected to the following tests: standardgermination; speed of germination; germination rate; time to reach 50% germination;electrical conductivity and seedling growth rates. C.K.I), experimental design wasused. Solute leakage from imbibed wheat seeds increased with treated or acceleratedaging in a linear manner in the range over which vigour was depressed. Significantdifferences were observed among selected seed lots in most of the parameters of seedquality.