Year:2004 | Volume:17 | Issue:2 (63 IN AGRONOMY AND HORTICULTURE)|Papers Count:14

Sustainability has included socio-economic and bio-ecological dimensions or attributes. This paper presents a conceptual framework for quantifying sustainability in water on the basis of economic theory. The conceptual model is implemented using fractional programming, which is a nonlinear programming method. Fractional programming enables multi attribute performance to be assessed without having to specify any prior weights for the various attributes; it has many advantages for the measurement of sustainability. The paper demonstrates theoretically and empirically that nonlinear programming methods allow the potential for improvements in sustainability to be accurately assessed and can provide normative guidance for management.

Biology of the predatory ladybeetle Scymnus syriacus was studied at 25°C, %65±5 RH , and 16L: 8D in laboratory.Population fluctuation was also studied during 1995-1996 in Rasht area. The coccinellid has four instar larvae and one prepupa and one pupa. Its developmental time from egg to adult takes 22.7 days under studied condition. Females longevity is shorter than males. Mean number of eggs laid per day and realized fecundity of females are 15.8and 597.5, respectively. The rate of daily oviposition decrease as the female age. S.syriacus pass the Winter as adult stage under fallen leaves and other plant debris. In the middle of Spring they become active and their reproduction continue until mid Autumn. Adults and larvae feed on aphids, especially citrus green aphid, Aphis spiraecola. The predator had six generations in a year in Rasht area.

In order to study the effect of manure application and irrigation interval on water use efficiency (WUE) and grain yield of maize (Zea mays L.) using KSC704 maize hybrid, an experiment was conducted in Khorram Abad region using split plot in randomized complete blocks design with three replication in two years (2000 and 2001). Irrigation treatments (traditional irrigation, 50, 75 and 100mm evaporated from A class evaporation plate) were assigned to main plots and four levels of manure application were assigned to subplots (0, 20, 40, 60 ton/hec). The Seed used in the experiment was single cross 704 hybrid. In each irrigation, water amount needed was measured on the basis of FC depleting percent formula and then pumped through water pipes and water meter. Result is from first and second years indicated that the effect of irrigation treatment on the grain yields and was significant at  a=1%, but the effect of manure application was non-significant. Significant increase in weight of thousand seed (gr) was created by depletion in irrigation period or decreasing of applied water, and application of 60 ton/hec of manure resulted significant in decrease of seed protein (%) at a=1%. Also Seed protein percent significantly increased in water stressed treatment. Applied water volume had decreased in all levels of applied manure. WUE was recorded optimum in 150 and 175 treatments and in the first year WUE in these treatment significantly differed from other treatments at a =5%. Canopy dry matter at a =5% significantly increased with manure application and rising applied water and decreasing irrigation period. It is suggested for acquiring optimum irrigation management and crop yield and increasing WUE irrigation period must be 6 days in last vegetation growth stage and initial teaseling and 8 day in other growth stage. Also this period may be changed in initial growth stage as irrigation period and applied water decreased, so that this stage root development is less than other stages.

In order to assess of substitution of different planting patterns in silage corn production, determine of consumption of inputs, correlation between yield and agronomic traits and comparison of average yield in planting patterns 50, 60 and 75 cm. This study carried out in experimental farm of Slamshahr and Karaj in Tehran province for two years (2000- 2001), by using a randomized complete block design in split plot arrangement with three replication. Methodology was partial budgeting technique and marginal rate of return. In order to estimate correlation between yield and agronomic treatment and also for comparison of yield in planting patterns, by using T-test, Pearson correlation coefficient and ANOVA. According to the results, there are significant difference between the mean yield of 50cm row space and 75cm row space. The highest correlation coefficient was between yield and agronomic traits of plant height (0.88) and head lengths (0.89). In planting pattern 50cm, economy of water, Fuel and land was estimated 36200 rials, 816 rials and %33.3, respectively. Increasing yield and net profit in planting pattern of 50cm was estimated %14.6 and 1.4 million rials, respectively. Marginal rate of return in planting pattern of 50cm to other planting patterns was more than interest rate. Marginal investment rate of return in planting pattern of 50cm to planting pattern of 75cm was estimated %752.3. So, according to economical analysis, 50cm row space is recommended as the best treatment.

To study some physiological characteristics affecting grain yield in 7 barley genotypes, a field experiment was conducted at Kaboutarabad Research Station, Esfahan, during 1998-2000 cropping seasons using a randomized complete block design with three replications. The results revealed that genotypes were significantly different in grain yield. Genotypes (Torsh/ 9cr.279- 07//BgsS ) no.6 (7300Kg/ha) and(Chat// Roho/ Alger- Ceres) no.7 (5400Kg/ha) produced highest and lowest grain yield, respectively. Genotypes no.6 (6.2) also developed the highest canopy. However, the smallest canopy belonged to genotype no.7. Dry matter accumulated with slow rate until 750°cd, however, it increased, there after and reached to its maximum at 1700 °cd. Total dry matter declined later. Walfajer (no.l) was the latest (1400 °cd) to reach to spike emergence and the 6 remaining genotypes were similar (1100°cd). Genotype, no.1 with the highest CGR (23.4 gm-2(10°cd)-1) at anthesis was the most efficient genotypes in dry matter production. This explains its high grain yield.

The important role of vesicular-arbuscular mycorrhizal VAM symbiosis in phosphorus nutrition of plants has been appreciated for a long time. Meanwhile, investigation in the role of mycorrhizal symbiosis on pistachio cultivars has been neglected. This study was carried out due to the economically importance of the tree and regarding to its various cultivars which are used as base plants in grafting after growing in different soils. In a randomized complete block design (RCBD) six cultivars of Pistachia vera were grown in pots at green house condition in seven soil types of pistachio cultivating areas of Kerman province. Physical characteristic of soils including their spore and phosphorus nitrogen, potassium, pH, EC were measured before cultivating plants. After growing the plants, their dry weight, shoot and root length, root infection of plants with mycorrhizal fungi and their total phosphorus amounts were measured. Different cultivars showed significant differences in total dry weights and total plant phosphorus, shoot and root length and root infection rates. Data analysis also showed significant differences between soils in case of spore count and phosphorus amounts before and after growing plants.

Thirty nine advanced breeding lines of wheat were inoculated at seedling stage with four pathotypes of wheat yellow rust 6E130A+, 6E134A+, 134E148A+ and 166E42A+ and then infection type and latent period were scored. A high correlation coefficient was found between infection type and latent period and the correlation increased with the increase of potentiality of the pathogen to cause the disease. Most of the lines appeared to be resistant to at least one of the pathotypes. Many lines showed incomplete resistance of which M-80-3, M-78-9 and M-78-16 demonstrated longer latent period. M-78-18 lacked seedling resistance and was susceptible to all four pathotypes, however, M-78-4 and M-80-4 appeared to be completely resistant to all four pathotypes. Cluster analysis was performed on the basis of the resistance reaction of the lines to all pathotypes. The lines were divided into five groups. The similarity of the individuals within each group was mostly based on their number of complete resistance in response to different pathotypes.

To study the inheritance of resistance to Fusarium graminearum in wheat the resistant cultivar Sumai 3 was crossed to the susceptible -cultivar Falat. The parents and F1 and F2 progeny were evaluated in the greenhouse for resistance to the spread of fusarium within a spike. Inoculations were performed by injecting a droplet of inoculums into a floret at one third to fourth of main spike at the time of an thesis. Infected plants kept in greenhouse with high humidity and suitable temperature. Twenty one-days after inoculation the proportion of infected spikelets was recorded and percents was calculated from these proportions. Means and variances of the percents of infected spikelets were used to fit genetic model, estimate the number of genes and the heritability of resistance. The simple additive-dominance model explained the inheritance of resistance in the cross. Dominance and epistatic effects were not significant. Two to three resistance genes depending on the used formula was estimated. Broad-sense heritability was 0.86. The frequency distribution of the percent of infected spikelets were continuous and within the limits of parents. The results indicate that it should be possible to select resistant individuals in F2 generation of this cross.

To investigate genetic diversity, evaluation of drought resistance and genetic polymorphism of chickpea lines in the field and molecular level using RAPD molecular marker, 21 lines of chickpea were tested in a randomized completely block design with three replications under two irrigated and rainfed conditions in the research station of Faculty of Agriculture; and research laboratory of Faculty of Science Razi University of Kermanshah. The results of analysis of variance exhibited high significant differences among the lines for yield potential (Yp), stress yield (Ys) and stress tolerance index (STI), indicating the existance of genetic variation and possibility of selection for drought resistance.Comparison of phenotypic coefficient of variation and genotypic coefficient of variation among Yp, Ys and STI showed that most of the variation was related to STI, Ys and Yp, respectively, displaying more variation in rainfed conditions. It was also observed that most of this variation was genetic. The results of mean comparison displayed that the highest potential and stress yield were belonged to the line number 11 (FLIP 92-60 C) and the most STI was related to the lines number11 and 20. Evaluation of three dimensional plot showed that the best drought resistant lines with suitable yield under rainfed and irrigated conditions were the lines 4, 7, 8, 11, 14 and 20 (group A). The results of RAPD analysis indicated the appropriateness of these techniques for determination of polymorphism among the samples. From the 5 primer used with RAPD-PCR technique, 69 polymorphic band was produced and the average band produced for each primer was 13.8 polymorphic band. According to the dendrogram resulted from the banding pattern the lines were classified into 3 groups and 8 sub-groups. According to the resulted dendrogram the farthest genetic distance was between the lines (10), and 14 with the lines 2 and 13. It is therefore suggested to get advantage of the crosses (1014), in a chickpea breeding program., 13) and (2, 14), (2,13) Comparison between the obtained dendrogram resulted from molecular experiment and the dendrogram resulted from field experiment indicated that the results of these two experiments were 71.59 in agreement with each other, providing a good background for studying drought tolerance based on the molecular markers.

Function of agricultural ecosystems is based on genetic resources, management practices and also on biotic and abiotic factors. Genetic pools are indicative of biodiversity in agro ecosystems and today this has a rather wider concept and includes all organisms of plat, animal, microorganisms and origins which contribute directly or indirectly to food products. Despite the ecological importance of biodiversity in agricultural sustainability, little attention has been given to this issue worldwide and particularly in Iran. For protection and utilization of agro biodiversity, extensive understanding of their criteria and temporal and spatial distribution at all levels is required. In this study an attempt was made to evaluate agricultural biodiversity in Iran at all levels. For this purpose necessary data was collected from 183 countries in 27 provinces of the country and proper statistical analysis and different relevant indices was calculated. Present article is based on the first part of the series of articles prepared. Based on the results, distribution of all field crops, cropping systems, cropping intensity, rotation index and rotation efficiency index was investigated. It is apparent that there are two main cropping systems in the country, namely wheat -based and rice -based. The former is more extensive than the latter. Average cropping intensity index in the country is less than that for Asian, but it is comparable with the world average. Conventional crop rotation is not much diverse and all with short periods. This has caused a low efficiency for rotation systems. Polyculture has no significant role in this context and in general agricultural biodiversity at the ecosystem level is relatively poor and management tendency is towards monoculture of irrigated crops in short rotation periods.

There are different phythophagous mites on pear trees in western Iran. Amongst them the pear leaf blister mite (Phytoptes pyri Pagenstecher) is the most serious pest. However, the influence of the prevailing climatologically conditions of western Iran on this species are unknown. Surveys were conducted during 2002 - 2003. It causes pinkish red pustules on young leaves during pring. They subsequently turn yellow, red or green, occurring on both sides of infested leaves. They can be scattered randomly over the leaves, or in bands on each side of the midrib. About 22% of the leave surfaces become chlorite and adult mites keep on migrating to new pastures. Eventually the blisters turn brown then black and then the leaves fall off the fruit of severally infested trees can be malformed and also fall off, especially in urban areas (gardens). The infestation reaches its peak in the middle of September (end of Summer). In some regions it can cause 100% defoliation and loss of fruit, in these cases it affects the fruit production of the following year. During late Summer, early fall (last half of September) adult mites seek cover under bud scales where they over winter to re-appear again during Spring. This mite has 1-3 generation in a year.

To study the trend of hard seed breakdown of annual medic (Medicago scutellata) cv. Robinson at different storage and natural systems, an experiment was conducted at climatic research station of Khoram-Abad during 2002 and 2003. The treatments consisted of I. Pods kept at natural pasture conditions (pods left in medic residues), 2. Pods separated from residues and exposed directly to climatic conditions and 3. Pods kept in storage room at constant temperature. Seed germination tests were carried out at harvest time (early July), September, October, November and December of each year and the percentage of hard seed breakdown was measured for each month separately. The data were arranged as split plot in time and were analyzed and compared using a complete block design with three replications. The percentage of hard seed breakdown increased with time from harvest and the highest percentage was observed in December across all storage systems. Exposing the pods directly to climatic conditions caused the highest hard seed breakdown compared to other storage systems while the lowest was seen in pods kept at store room with constant temperature. The interaction of time and storage conditions revealed that the highest rate of hard seed breakdown happened when seeds were directly exposed to climatic conditions up to December each year.

Fusarium wilt disease is one of the most effective factors of Chick-pea (Cicer arietinum) crop losses in the West and North-west of Iran which is caused by Fusarium oxysporum. Many phytopathogenic microorganisms, incuding Fusarium oxysporum, attack their host plant by secreting pectic enzymes which causes modification of cell-wall structure, increasing accessibility of cell-wall components for degradation by other enzymes. To study polygalacturonase enzymes from isolate F58 of Fusarium oxysporum, enzyme purification was achieved by cation exchange chromatography. Elution of the column was carried out with 1M NaCl gradient. The presence of PG enzymes was investigated by SDS-PAGE. The results showed two distinct bands, about 33 and 35 kDa in isolate F58. These two bands showed PG activity in enzyme activity staining technique. The optimum pH for enzyme activity before and after purification was determined to be about 4.5.