Year:2002 | Volume:8 | Issue:2|Papers Count:10

Nitrogen limitation is on of the most important factors of yield production in the field crops. Application of nitrogen fertilizer in addition of reduction in economical output, induces environmental pollution. This investigation was carried out in research field of Karoun Agriculture and industrial Co. which is located at Shoushtar. Effects of planting pattern (0.9,1.2 and 1.5 m interrow), dat of planting (22 Aug, 20 Sep and 19 Oct) and application of nitrogen (0,100,200 and 300 kgNha -1 on nitrogen use efficiency, nitrogen uptake efficiency and nitrogen utilization efficiency in sugarcane (Saccharum spp) were studied in a strip split plot design with four replications. The final results indicated that relative nitrogen content were increased by high of fertilizer applications. Low plant density and nitrogen application decreased nitrogen uptake. Low plant density, late plantig and high fertilizer application resulted in low nitrogen use efficiency, also nitrogen uptake efficiency were decreased significantly in low density and high nitrogen application treatments. Nitrogen utilization efficiency on the basis of sugar yield were increased in low density, early planting and low nitrogen application treatments.

One of the bioassay aims is screening and introducing of the most effective insecticides for a especial pest. Deltamethrin and lambda - cyhalothrin were the most toxic insecticides and phosalone was the weakest toxic insecticide for life stages of sunnpest. Among three developmental stages (4th and 5th nymph over wintered adult) the 4th nymph was the most susceptible and the over wintered adult female was the most resistance life stages of sunn pest to insecticides. The sunn pest of over wintered adult was more susceptible than 4th and 5th nymphs to parathyroid insecticides. Fenestration was the most effective insecticide between the organophosphoric insecticides. Toxicity rate of deltametrin and lambda - cyhalotrin in comparision with Esfenvalerate and other group insecticides were very high. Data analysis was conductive by three methods, the result showed that RLD method was precise than RT.

Rice cultivation has been practiced in Iran since 2000 years ago. Now Gillan and Mazandaran provinces are the main producing regions of rice in the country. This crop is also produced in Khuzestan, Fars, Isfahan, Khorasan, Zanjan, Sistan and Baloochestan, Kordestan, Kermanshah, Eastern and Western Azerbaijan provinces.Two methods of rice cultivation are direct seeding and seedling planting. The latter is the more common method and produces higher yields. To prepare for seedling planting in the north of the country, two-wheel tractors, large and small plows and levelers are used. However, the advantages of active implements including direct application of power to the soil, hard-pan development and protection, and at the same time superior ability of smoothing the upper layer of the soil, has resulted in extensive utilization of rotary tiller in most rice-producing countries such as India, Japan, Thailand and other southeastern countries of Asia. In spite of the need, this machine has not been designed and manufactured in the country. Thus, the design and development of a rotary tiller for Ashtad 7.5 hp two-wheel tractor was undertaken in this study.First, major specifications of the two-wheel tractor mentioned above were obtained from measurements and manufacturer's data. The basic specifications of rotary tiller were derived from the available references regarding various rice-field tillers. Then the different parts of the machine were designed and selected and the machine was designed so that in addition to the working depth, the width can also be varied and adjusted conveniently. The machine width, forward velocity, maximum working depth, and rotor speed are 80 cm, 30 cm/s, 15 cm, and 200 rpm respectively. Field capacity of the machine is 0.11 ha/hr which was calculated from data obtained in field tests.

In order to study yield components of crop community and main stem of 6 triticale cultivars during 1995-96, an experiment was investigated in a frame work of statistical design of complete randomized blocks with 4 replications. The achieved results through variance analysis of yield components of crop community proved that there is a significant difference between cultivars from grain number per spikelet and the grain weight. The highest grain number per spikelet is for cultivar 36 (V4) with 1.77 grain per spikelet. This cultivar had the lowest grain weight with 33.7 mg. The study of yield components of crop community and the main stem with cultivar 36 (V4) indicates a balance between yield components. The Lowest grain number 4 per spikelet of cultivar Juallino- 92 is 1.33 grain per spikelet. This cultivar had the lowest grain yield. The highest grain weight is for cultivar 43 (V3) with 44mg. Because of holding the highest grain weight and relatively ideal grain number per spikelet, Cultivar 43 (V3) had the highest grain yield per hectare and of course it was considered along cultivar 49 (V5) in one group. karoon barley (V7) in comparison with triticale cultivars also had the lowest yield components and grain yield. F Concerning the study of yield components of main stem, similar results were appeared. But there was a difference. There was a difference not only between grain number per spikelet and grain weight hut also among cultivars concerning spikelet number per spike, and this difference was very significant, of course.

This research was conducted to investigate differences in ME value produced by different feedstuffs in different species of domestic birds including fowl, duck, Moscovy duck, goose and turkey. The used feedstuffs were corn, wheat, soybean meal, fish meal and alfalfa meal. The experiment used a completely randomized design by factorial arrengement (5x5), with feedstuffs and species of birds mentioned above. Each of the treatment was replicated 3 times with 3 adult birds in each. The ME values including AME, AMEn TME and TMEn of the feedstuffs in mentioned birds were evaluated using the force feeding method, then the data were- analyzed statistically. According to the results, significant differences were observed for two main factors as well as interaction between them (P<0.0001). The average of AME and AMEn value of feedstuffs in goose and turkey were significantly lower than the values for other species. The results also indicated that in regard to TMEn values of feedstuffs, fowl obtained the highest value for corn and fish meal and duck showed it for wheat, soybean and alfalfa meal. It is concluded that, the best method to express ME in poultry, is TMEn Furthermore, it is necessary to evaluate this variable for other species of poultry in future re searches.

Other than agro technical and climatically factors, a mirid bug.Creontiades pallid us affects withering and fall of blossoms and young boils of Varamin cotton in south of Khorassan. As it has heen confirmed by prof. Linnavouri this is the first record of this insect from Iran as a pest of cotton fields.Our studies on biology of C. pallidus during 1996-1998 showed that this insect has 4 generations/year on cotton Under natural conditions. it takes. 27-37 days/generation Duration of 5 nymphal instars at 28-30 0C, 50-60% and photoperiod 16:8 LD under laboratory conditions were 3-4 ,2-3 ,2-3 , 2-3 and 3-4 days respectively. Morphology (size, colour) of nymphs behavior, host plants, food preferences, fecundity, fertility, distribution and natural controlling factors of C.pallidus have been determined in this study. It was revealed that this bug lives on alfalfa fields and other host plants in early spring in south of Khorassan. When The blossoms appeared in mid June the insect population was low on cotton at the beginning of the season, but it increased at late season especially on late sown fields causing severe damages to such fields. Females lay eggs singly or in groups on line in plant tissues, apical buds or in medium size bolls. The most damage was caused by the 2nd generation because of flowering stage of cotton and by 3rd generation when the boils were still young during July-August.

Like any other materials the colour of the wood is the result of the reflection of light on the surface of the wood.The explanation is the wood absorbes some of the light visible spectra and as a result of the retlection of other light spectra its colour becomes observable.The colour of the wood has been considered as an important index of its beauty and usage and its determining is not less important than other characteristics.In this study the effects of steaming of Fagus Orientals wood discoloration was measured at deterrent time periods and temperatures and CIE Lab system was user for colour determination. The findings of this study suggest that steaming at 50 and 60°C is better than steaming at high temperatures like 80 and 90°C considering the lightness of the colour. Steaming at high temperatures causes the sapwood to have a severely two-colored appearance and makes the red heart colour more pronounced.