Year:2004 | Volume:17 | Issue:(62 IN AGRONOMY AND HORTICULTURE)|Papers Count:16

There are many factors that they are unsuitable for walnut kernel storage such as not or bad packaging. In order to effect of walnut kernel packaging on the its quality and shelf life, after walnut dehulling , they dried in expose of sun and by using an air-dryer machine till its moisture content was reduced to 6%. Walnut kernels packaged in plastic films including PVC, LDPE/PA/LDPE and PA/PP. Packaged samples were storage in ambient temperature. The quality characteristics such as acidity content, peroxide value, iodine value, kreis test and presence of microorganisms especially fungi were studied in storage time. The results of our analysis showed that: LDPE/PA/LDPE and PA/PP films were better than PVC film and control. LDPE/PA/LDPE was better than PA/PP with little difference. Use of machine drying was better than sun drying with little difference. vacuum packaging was better than control. Use of machine drying was better than sun drying with little difference.

General and specific combining abilities of 5 inbred lines of maize with their crosses (Direct - crosses) were evaluated in randomized completely blocks design with four replications. Variance analysis showed genetical variation for all traits. GCA effects for all traits except for kernel depth were significant and SCA effects for all traits except for 1000kernel weight and ear wood percentage were significant. Thus genes with nonadditive effects were important in the kernel depth while additive effects were important in 1000 kernel weight and ear wood percentage. The importance of genes with additive and nonadditive effects were similar for different traits such as; days to silking, days to pollening, plant height, ear height, days to physiological maturity, ear length, No. of kernel /row, yield, days to full maturity and ear diameter. Genes with additive effects were more important with regard to nonadditive effects for No. of leaves above ear and No of kernel rows. The results indicated that K1515 , MO 17 lines for increasing yield, Kl515 and K1254/2 for early maturity, MOl7 for increasing 1000-kernel weight and No .of kernel/rows, K1263/8 and k1254/2 for increasing No .of kernel rows and ear diameter were suitable for breeding program.

Braconid Cotesia rufricus (Haliday) wasp is a gregarious endoparasitoid of lepidopterous larvae that attack rice armyworm larvae, M unipuncta and some other noctuid species. This parasitoid was reported for first time by author as a natural control agent in the rice fields of west em Mazandaran.Morphological studies showed that characteristics of this species is similar to exotic species which is also scientifically named Apanteles rufricus in the references. Biological studies showed that C. rufricus female wasp usually lay its eggs into young larval instars (first instars to third instars) of rice armyworm. After 3 to 4 days they hatched. Larvae usually feed 8-12 days from the host body contents and after full development, they emerged from the host and immediately made their pupal cocoons. After 5-10 days adult parasitoid emerged from the top of the cocoon.

Tropane alkaloids play vital roles in pharmaceutical industries. The researcher conducted the research in order to show the importance of these contents in industrial and semindustrial production of D. stramonium from solanaceae. The optimize situation for growth and production of tropane alkaloids via physicochemical factors were studied previously. Cell suspension from semi clear celli of leave explants in MS medium was obtained. MS medium contained kinetin (0.5 mg/lit) and NAA (2mg / lit) hormones .The results obtained from the different concentrations of glucose specified that the highest level of most alkaloids production obtained by 30 g/ lit glucose. In 40 g/Iit glucose, the most biomass was produced. In different concentrations of sucrose study it was specified that the most rate of alkaloids production obtained by 20 g/Iit and the most rate of biomass production obtained by 40 g/lit .The results showed that the concentration increased of nitrate led to the production decrease of tropane alkaloids .The best concentration of potassium nitrate for the production of tropane alkaloids was 9. 4 m M, and that of potassium nitrate for the production of biomass was 37.6 mM . Also it was evinced that the optimized concentration of ammonium nitrate for alkaloids production was 10 . 3 m M , and for the biomass was 41.22mM . The study of calcium chloride indicated that the best concentration for the growth and production of alkaloids was7.92 mm. The results obtained from the temperature study specified that the best condition for the most production of alkaloids was at 200°c and that of the most biomass production was at 250°c

Improving water productivity is vital to sustain and improve crop production in Iran. A split plot trail (RCBD) was conducted in Maragheh agricultural research institute (DARI) over three seasons in 1999-2002 to examine the effect of applying different levels of supplemental irrigation and nitrogen rates on grain yield of Sabalan rain fed wheat variety. The treatments included four levels of supplemental irrigation (rain fed, 1/3, 2/3 and Full Supplemental Irrigation) and five N rates (0, 30, 60, 90 and 120 kg. N. ha .I). Yields of rain fed conditions varied with seasonal rainfall and its distribution, with two factors having significant effects. With irrigation, crop response was generally significant up to 60 kg. N. ha-l, while optimum response for rain fed conditions was until 30 kg.N.ha-1. Optimum level of supplemental irrigation was with 1/3 of full supplemental irrigation was obtained maximum water productivity (WPI) and good yields. The WPI+P and WPI for this treatments (IBF.ST, N60) averaged over the three seasons were 7.4 and 30 kg. mm-I.

An important export production of our country is pistachio which plays a great role in non-oil exporting, with almost over 400 million dollars annually foreign currency income. The shortage of water has been a serious problem in producing pistachio which can be solved by managing survey inputs and their optimum application. In this research through an empirical analysis and a two-stage-cluster sampling, 228 producers were interviewed. Then, based on two scenarios; profit maximization and cost minimization, optimum qualities of inputs were determined. The results show that optimum quantity of water is 7791 m3 per ha for profit maximization. With respect to the area of land under pistachio cultivation in Rafsanjan (100,000 ha), in case the farmers consume water based on optimum quantity, the problem of make over use of underground water source (nearly 154 million) can be solved. In this paper, water optimum quantity was investigated by using cost minimization and Data Envelopment Analysis (DEA).The results of this scenario show that if the farmers act based on cost minimization, water optimum quantity will be 7294/ha on the average. Focusing on the present water consumption average of9104.8 per producer, if the farmers act based on cost minimization, quantity of underground water used will be reduced to 181 million. Thus the problem of over using of underground sources will be removed if the farmers act on economic principles. The technical, allocative and cost efficiency of producers was calculated, and the results show that the producers" efficiency average is 0.721, 0.819, 0.6 1 3respectively. Difference of producers" efficiency show that we can increase yields by optimum use of inputs

Drought stress is one of the most important environmental factors in reduce of growth, development and production of plants. Alfalfa is a important forage plants in farms and rang lands. Suitable germination and drought tolerance alfalfa by selection of drought tolerant genotypes is very important .In order to this ,in the first experiment, influence of drought stress on percent and rate of germination, radicle and plumule growth of eight alfalfa accession namely, Baghdadi, Nikshahri, Ghareh,Yazdi, Siriver, Sequel, Ranger and Kodi have been measured. Stress was applied with PEG6000, and drought potentials were: Zero (control),-4,-8 and -12 bar. The data showed that intensity of reduction in different accision is was not the same in response to drought stress. There are the lowest change percentage in Yazdi and Nikshahri accessions and the highest in Ranger accession in the most of characters.In the second experiment, the selected accession namely,Yazdi, Nikshahri and Ranger were grown in hydroponics culture with different osmotic potentials (PEG6000).After 4 weeks, different parameters such as: Root length, shoot length, root length to shoot length ratio, number and surface of leaves, root, shoot and leaf dry weight were measured. Genotypes survived in high potential (-12 bar),were transferred to soil to set seeds.The result showed with increasing drought stress, above parameters decreased, while root length to shoot length ratio was increased. Yazdi alfalfa was the most tolerant and Ranger was the most sensitive accession in response to osmotic stress.

In order to develop Autumn sowing, introduce a new climate and investigate of sugar beet growth, an experiment was conducted using a randomized complete block design with four replications in Orzoieh, Kerman in 2000101 cropping season .Bolt tolerant cultivar (DEZ) was sawn in three different dates including Sep.1th, Sep.23th, Oct.12th .and trend of sugar beet growth was studied every two weeks. plants of the first sowing date with maximum CGR 20g/m2/day were significantly better than the latest with maximum CGR 11.9 glm2/day .The root CGR was low and then significantly increased. The root CGR was in highest after 165 days of germination at the first sowing date. RGR was decreased in all three sowing dates but it was the highest for the third sowing date. The first sowing date had the highest NAR (4.2 glm2/day) and LAI. Leaf Area Ratio (LAR) in the first sowing date was more than the others ,but it was the lowest at the end of the season.

In order to studying effects of planting dates and intra-row spacing on quantitative traits and germination of onion seed (Allium cepa L.cv. Texas Early Grano 502) an experiment was conducted in Kabootar Abad Research Station of Isfahan during two growing seasons (1998-1999 and 1999-2000).The experiment design was a split plot with a randomized complete block arrangement and four replications. Main factor included four planting dates (from the 22nd September every 15 days), and sub factor included three intra-row spacing (10,20 and 30 centimeters). The number of umbels/m2,capsules/umbel and seeds/capsule were increased significantly in first and second planting dates as compared with third and fourth .Among planting dates, the third planting date had the lowest 1000 seeds weight. Seed yield and umbels/m2 increased significantly as plant space decreased from 30 to 10 centimeters. The means of Capsules/ umbel and 1000 seed weight reduced in 10 cm plant spacing as compared with the others. Among yield components, umbels/m2 had the most contribution in the seed yield .Planting dates and plant spacing did not have significant effects on the seed germination percent. The seed germination rate in first and second planting dates was higher than the two others, but plant spacing didn’t have any significant effects on this trait.

The total phenol content of two wheat cultivars Mvl7 (as resistant) and Bolani (as susceptible) were determined at different times after inoculation with race 134EI50 of Puccini a striiformis. Samples were taken at 24,48,72,100, I 44,and 216 hours after inoculation. The result showed a rapid increase in total phenol content of inoculated leaves of resistant cultivar. It was 3 times higher than that in susceptible cultivar at 100 hour after inoculation. There was no significant difference in total phenol content between inoculated susceptible cultivar and control. In general it was concluded that there was a relationship between resistance in M v 17 and accumulation of phenolic compounds

In order to study allelophtic effects Haloxylon ammodenderon extract ,an experiment was Contacted in a completely randomized desing with factorial combination in three replications. For studying nematodicide effects, an experiment was randomly designed with four treatments and three replications. The Factors taken into consideration for allelopatice effect were the concentration of Haloxylon extract at 4 levels (0,25,50,100%) and two crops species (wheat and alfalfa),and the nematocide effects were investigated at 4 levels (0,10,25,100%). The result of this study showed that the Haloxylon extract has the allelopathic and nematodicid effect. The maximum allelopathic effects was at in the 100% concentration. In this concentration, germination and the length of the shoot was decreased under effect of Haloxylon extract as compared with control condition. In the 50% concentration of Haloxylon extract, except germination all of the attributes were decreased compared with control treatment. In the 25% concentration of extract only length of root was decreased compared with control treatment. In this study, showed wheat and alfalfa have two diffemet responses. The alfalfa was more effective than wheat due to allelopathic effect. The results of analysis showed that experiment treatment on living and dead total and also parasite dead saprophyte nematodes was influenced the numbers of dead and living parasite and on 1 % level. Althogh these experiments was not influence on living saprophyte nematods . This result also showed that Haloxylon extract at 25% concentration in addition could be killed about 64% parasite nematodes. While has had a little effect on free and saprophyte nematodes, the nematodicid poison could be killed total of the nematodes in the soil contain parasites and saprophyte nematodes. On the other hand 25% concentration of Haloxylon extract has minimum in hibitatory on charactristics growth of alfalfa and wheat.

Khavari Nejad , Department of Biology, University of Teachers Education, Tehran , Iran. H. Fahimi, Department of Biology, University of Teachers Education, Tehran, Iran. Effects of long term soil salinity was studied in cotton (Gossypium hirsutum L.) cultivars , Siokra (resistant) and Sahel (semi- resistant ) under four level of salinity [ EC=O.6 (control) EC=6.3, EC=12.3 and EC=16 dsm-l]. Salinity stress decreased stem and root length, organic material and chlorophylls (a, b, a+b) contents in both cultivars. Salinity induced increase in the content of proline, soluble sugars, and soluble proteins and also decrease in peroxides activity were higher in siokra leaves significantly. In both cultivars Na+, Cl-, K+ concentration increased significantly in the leaves, indicating that salinity resistance was not associated with the ability of the plants restrict of ions uptake and accumulation. Na+ accumulation in Sahel was higher than Siokra.

Investigation of inheritance, mode of gene action and determination of effective breeding strategy for improvement of physiological and morpho-physiological traits specifically in drought stress conditions is very important. Therefore, this study was conducted using two drought susceptible and tolerant wheat cultivars. Cultivars Sakha8 (tolerant) and Pishtaz (susceptible) as parents along with FI, F2, BCI and BC2 generations were sown in a randomized complete block design with three replications in drought stress conditions. Results of analysis of variance indicated significant difference between generations for all the traits. Degree of dominance revealed over-dominance for all the traits. Positive value of parameter F indicated that dominance genes mainly have placed in parent Sakha8 having higher value of mentioned traits. Fitting simple additive-dominance model designated that the model accounted for genetic changes of harvest index and biological yield. Additive-dominance model were not able to account for changes of traits flag leaf relative water content and mean of grain filling rate. It was revealed that m-d-h-i-j model for flag leaf relative water content and m-d-h-i model for mean of grain filling rate are the best models. Estimation of heritability and mode of gene action indicated that selection for improvement of traits studied in stress condition and specifically in early generations have medium genetic gain. Therefore, it is concluded from the present study that can propose use of traits mean of grain filling rate and harvest index as indirect selection criteria for improvement plant grain yield in drought stress condition.

Twenty eight native alfalfa populations and two improved cultivars were used to estabilish a polycross nursery. Leaf number per seedling, length of longest stem, cotyledon length and width, unifoliate internode length, and leaf blade length and width were measured on over 2000 individual 30-days old seedlings. The seedlings were transplanted to the field, and individual plant’s fresh and dry weight (IPFW, IPDW), number of shoots per plant (NS) and plant height (PH) were measured on 900 plants in four harvests. Days until 50% flowering, percentage of ground cover, fresh and dry weight of leaves/plant ratio, and size of trifoliate leaves were also measured in experimental plots. Narrow sense heritability values based on individual plant measurement(HI) and on plot mean basis(H2) were calculated. For each trait, HI was usually lower than the corresponding values of H2, and these differences were more obvious for mature plant heritabilities. The heritability values for the seedling traits were higher than mature plant traits. Among mature plant traits PH and NS had the highest and lowest heritability values, respectively. Among seedling traits the highest heritability belonged to cotyledon length.