THE SCIENTIFIC JOURNAL OF AGRICULTURE (SJA)
Year:2006 | Volume:29 | Issue:1|Papers Count:12

This experiment was conducted to investigate the relationship between storing condition of potato seed and application of Gibberellic acid (GA3) on quantitative traits, apical dominance and total yield of potato crop. The research cites was Tajarak Station of Hamadan Agricultural and Natural Research Center. In this research we have treated three cultivars of potato with two methods of storing and three levels of GA3 containing 0, 5, 10 PPm. These treatments have been accomplished in factorial design with randomized complet blocks. Characters measured were: Number of constructed- main stems, number and mean weight of large tubers, number and mean weight of potato seed (average tubers), and number and mean weight of microtubers (minitubers). Data of this research showed significant differences at %1 level with Doncan's multiple range test for all traits. Five parts per millions of GA3 with two storage conditions and all three cultivars had the most effect on potato seed production. Hormone treatments had the highest effect on producing potato seed in tubers that had younger point on physidogical age."Draga" had the uppermost level of main stems in comparison with two other cultivars The effect of storage conditions in 5 and 10 ppm of GA3 on producing the amount of main stem did not show any significant difference at %1 level. In total, "Marfona" had the highest yield in most treatment and 3.71kg/m2 on mean weight of tubers from this cultivar was obtained.

In order to investigate the effects of single irrigation treatments on bread rainfed wheat (Triticum aestivum L.) a field experiment was conducted as split block arranged in a randomized complete block design (RCBD) with three replications in 1997-99 at Dryland Agricultural Research Institute (Maragheh Station). Total seasonal rainfalls were 351 and 210 mm, respectively. The treatments included three levels of irrigation (rainfed, one time irrigation at planting time (50mm), one time irrigation at flowering stage (50mm» and four rainfed wheat varieties (Cross Sabalan (V1), Cross Anza (V2), Azar2 (V3) and Sabalan (V4). The 1997-98 season was normal, while in 1998-99 the rainfall amount and its distribution was not suitable. Results showed that the single irrigation was effective in increasing yield. Irrigation at planting time caused early germination and increased 500-900kg.ha-1 grain yield. Grain, straw yields, height and TKW were determined from the middle of each plot and biological yield and harvest index were calculated There were positive significant correlations between grain yield with other yield components except TKW. Results of path analysis showed that increase in grain yield was due to increase seed number per spike, spike number per square meter and TKW respectively. Optimum level of single irrigation was at planting time combined with Azar2 wheat variety obtained maximum water use efficiency (19 which kg.mm-1) and maximum yield. Thus, when limited water use is combined with appropriate management, grain wheat production can be substantially and consistently increased in this semi arid zone. Single irrigation at planting time is useful when total costs of water and irrigation are 2095 Rial.m-3 water.

In order to study the effect of moisture stress related to irrigation period on grain yield of corn, an experiment was conducted in 2002 cropping season in Safiabad Agricultural Research Center of Dezful. The design was split plot in completely randomized block with four replications. The main plot consisted of three irrigation levels after 70, 120 and 170mm cumulative evaporation from the class A pan (optimal, mild and severe moisture stress respectively) and the sub plot also consisted of four corn hybrids including TWC600, SC 647, SC 704 and S.C720. Increasing the distance between irrigations and the stress decreased the grain yield from 11363 kg/ha (irrigation after 70 mm of evaporation) to 7810 kg/ha (irrigation after 170 mm of evaporation). A significant difference in 1% level of probability was observed among moisture stress treatments, hybrids and their interaction for the number of seed rows per ear and the number of seeds per row. The interaction effect between treatments showed that the highest grain yield was obtained with hybrid SC704 and optimum conditions of irrigation (12646.3kg/ha) and the lowest was obtained with SC647 and severe water stress (8143.23kg/ha). Considering the fact that there was no significant difference between irrigation treatments after 70 and 120mm of evaporation irrigation treatments, it seems that corn hybrids can tolerate irrigation delays up to 120mm of evaporation.

Potato (Solanum tuberosum L.) as a strategic crop in agriculture sector, due to high production potential and food value, has an important role in feeding needs of human.Pathogen-free and sufficient seed production is main subjects for potato production, which can be resolved by using rapid multiplication methods. Stern cutting and leaf-bud cutting are most popular among these methods. This investigation was conducted in 2002 to assess response of potato cultivars to rapid multiplication methods. 18 different cultivars were grown in a greenhouse located at Hamedan Agricultural Research Center (west of Iran). The experimental design was 18x12 factorial in completely randomized design with three replications. According to the ANOVA, results, a significant difference between leaf-bud cutting method and stern cutting method on minituber length and weight were detected (P<0.05). The effects of both methods on post-harvest germination percent and number of rninituber buds were not significant, but highly significant differences between cultivars were observed (P<0.01). Interactions of cultivar cutting method type had significant effect on all traits. In conclusion, cultivars showed different responses to the types of cutting method. Results suggest that Fresco and Marfona genotypes by using leaf-bud cutting could be used for potato seed production, also Picaso by stern cutting.

Organic material is one of the main soil components and has a big role in the improvement of soil cultivation. To determine the effect of wheat residue on seed yield and its components, this experiment was carried out as split-split plots under a complete blocks design with three factors and four replications at Research Field, Department of Agronomy and Plant Breeding, College of Agriculture, Shahid Chamran University in Ahvaz. This experiment was done with the same treatments as the last year, but with a few changes. In this study, treatments were: I-Planting methods of wheat by ordinary method after mixing plant residues with soil, including: a1-Wheat straw+canola. a2- wheat residue+barley, a3-wheat straw, a4-wheat residue, a5-wheat straw+barley, a6- burning wheat residue, a7-wheat residue+canola, an8-removing the whole residues of previous crop. II- The second factor was chemical fertilizers in sub-plots including: b1- Chemical fertilizers for high yielding (120 kg/ha P205, 125 kglha K20 and 137 kg/ha N), b2-chemical fertilizers for medium yielding (72 kglha P205, 100 kglha K20 and 107 kg/ha N), b3-minimum chemical fertilizer applications based on current wheat seed production (40 kg/ha P205, 70 kglha K20 and 28 kglha N). The third factor that placed in sub-sub plots were varieties, including: cl-Chamran and c2-Atrac. In this experiment, barley and canola were planted as green manure. Also wheat straw and residue were mixture of whole straw produced in previous wheat plantation and mixing one-third of it with soil (removing the other two-thirds) respectively. The result showed that the highest seed yield was obtained for a7bl, a17b2,a6bl, a6b2 and a4b2 treatments. Also, the highest (0.824%) and the lowest (0.681) organic material were produced in a1 (wheat straw+canola) and a6 (burning wheat residues) treatments, respectively. Combination of plant residues before planting with medium and high fertilizer levels increased the grain yield production and soil organic matter, but a4 (removing a part straw and mixing the plant residue) resulted in increasing of soil fertility and is recommended as a treatment of straw management to get higher grain yield.

Grape (CV. Soltani) is one of the main crops grown in Uromieh region with an average of 20,000 ha. A study was carried out during 2000-2001 to determine composition, abundance and distribution of weeds. This study was carried out at Uromieh Agricultural Research Station. Type of design was randomized completed block with six treatments and three replications. Herbicides used in these experiments included: atrazine (WP80%), at 3 kg/ha, chlortal dimethyl (WP75%) at 15 kg/ha, diuron (WP80%) at 2 kglha as preemergence, and paraquate (SL20%) at 3lit/ha as post-emergence herbicide. The number of weeds was counted one, two and four month after application and fresh weights of weeds and grape yield were determined. Besides the results obtained from the experiments, no phytotoxy appeared on leaves and stem by using these herbicides.Plowing of the garden caused yield increasing %54-59. The results indicated that atrazine and chlothal-dimethyl were more effective in controlling Chenopodium album L., Descurinia sophia (L) Webb and Lactuca serriola L. than the other herbicides. Grape yield increased by the above mentioned treatments by 46 and 47 percent in 2001, and 29 and 42 percent in 2002 compared to the weedy check, respectively. None of the treatments caused phytotoxicity on leaf and stem of grape. According to this experiment, application of chlothal-dimethyl at15 Kg/ha (WP75%) as pre-emergence is recommended for weed control in vineyards.

Aroma inheritance was studied in a cross between Basmati 370 as aromatic rice and other Della as an aromatic F1, F2 and F3 progenies were analyzed. In this study, genotyping conducted was performed with a RAPD marker (primer OPAG-08) linked to aroma gene and AN-01 linked to nonaromatic gene using F2 generation and phenotype evaluation was performed with allelism test in F3 generation. Genotype evaluation with OPAG-08 marker showed that parent varieties, F1 and F2 populations have aroma band. On the other hand genotype evaluation with AN-01 marker showed that parent varieties, F1 and F2 populations have nonaroma band. Phenotype evaluation showed that Basmati 370, Della and F1 have strong aromatic. A number of 1100 single F3 seeds analyzed showed that 78 were nonaromatic, 309 were slightly aromatic, 420 moderately aromatic and 293 were strongly aromatic. Considering different aroma intensity in single seeds and genotype evaluation result, in case of single gene, or other than single gene this gene and multiallelism this gene cannot be suggested.

Drought stress as the most important abiotic stress plays an important role in the yield reduction of crops in arid and semi-arid worldwide. Therefore, considering physiological traits correlated drought tolerance criteria is of major importance. As ICARDA origin, 19 genotypes were studied for selection of drought tolerant in the field and laboratory at agricultural college, Razi University, Kermanshah, Iran. The genotypes under investigation showed significant differences for yield under stress (Rainfed condition) and non-stress (Irrigated at three stages: shooting, flowering and maturity) environments, indicating the presence of genetic variation and possibility of selection for drought tolerance. Based on the physiological traits, leaf water content (LWC%) and chlorophyll fluorescence (CHF), the genotypes BW/5, BW/48, BW/104, BW/34 and BW173 were superior. Stress tolerance index (STI) was high for the genotypes BW/5, BW/64 and BW/104. Screening under laboratory conditions, based on germination stress index (GSI), the genotypes BW/5, BW/67, BW/48, BW173 and BW/104 with check variety were selected as tolerant. Evaluation of genotypes under investigation based on multiple selection index (MSI) revealed that genotypes BW/5, BW/64 and BW/104 had the most drought tolerance. Consequently, study of overall physiological and agronomic characters showed that genotypes BW/5, BW/64 and BW/104 have high drought tolerance.

Because of uneven distribution of rain over the year and variable water supply either due to shortage of water or failure of the irrigation system, terminal drought is a major problem for wheat growth and yield stability in most regions of Iran. On the other hand, nitrogen deficiency is a major constraint to wheat production in this region. To evaluate the interaction between nitrogen and water supply, this experiment was conducted in year 2003/2004 at Ramin Agricultural Research and Education Center, Ahwaz, Iran. The experiment was a split- split plot in a completely randomized block design. Wheat was grown under three irrigation levels (50%, 75% and 100% full irrigation) and two wheat cultivars (Yawaroos and Chamran) and four nitrogen fertilization applications (0, 80, 120 and 180 kg ha-1). Results showed that grain yield increased with increasing N application. Grain yield at 0, 80, 120 and 180 kg N ha-1 was 341.04, 565.19, 625.66 and 651.52 g m-2 respectively. The difference between grain yield of 50% full irrigation treatment with 75% and 100% full irrigation was significant. Grain yield at 50%, 75% and 100% full irrigation was 523.11, 553.58 and 560.80 g m-2 respectively. Yawaroos grain yield (558.45 g m-2) was significantly higher than Chamran grain yield (533.21 g m-2).The interaction between nitrogen and water supply on grain yield was significant. At zero N level, increasing water supply did not increase grain yield, but at 80, 120 and 180 kg N ha-1 levels, grain yield was improved by increasing water supply. Also, by increasing N levels at any water supply levels, grain yield increased. In all treatments except variety treatment, grain yield increased and was controlled by biomass production and increasing the redistribution of carbon reserves. The difference between grain yield of varieties was due to the difference between their HI. It could be concluded that although reduced irrigation to 50% full irrigation may reduce the potential maximum yield of farmers receiving full irrigation, probably benefits a larger number of farmers and results in greater overall wheat production. In addition, increased nitrogen prior to terminal drought when there is not water limited may yield satisfactory results seen in all water supply treatments that has been imposed during terminal growth period.

A faunstic survey of lacewings (Chrysopidae) was conducted in Khuzestan province during 2002-2004. Altogether 4 species belonging to 3 genera from one trible (Chrysopini) was collected and identified as follow in which those with one and two asteriskes belong to species that are new records from province and Iran respectively: Chrysoperla carnea Stephens, C. mutata* Mclachlan., Suarius nana Mc!., Anisochrysa venosa** Rbr. The dominant species in all province was c.carnea. Laboratory experiments were conducted to study the effects of 4 temperature (20°,25°,30° and 35°:I:IC) and prey on larval voracity of C. carnea at RH:65:I:5 and photoperiodism 16:8 (L:D) in a randomized complete design. The results show that the average aphid consumption of each C. carnea larva increased with temperature from 20-30°C. Altough the larval consumption increased slightly from 30-35°C, larval mortality was maximum (about 60-70%) in this temperature range. The average aphid consumption of Rhopalosiphum maidis Fitch of each larva to complete its developmental period at 20, 25, 30 and 35° C were 135.1, 173.6 , 205.2 and 211.5 aphids. The average aphid consumption of R. padi(L.) at first three temperature were 115.7, 121.1 and 155.6 aphids and consumption of Brevicoryne brassicae(L.) at this condition were 130, 135.9 and 226.8 aphids. The average aphid consumption of Aphis fabae(Scop) were 127.7, 159.9 and 163.1 aphids and consumption of A. nerii were 214.8, 258.3 and 334.9 at above temperature, respectively. Aphid species has significant effect on C.carnea larval voracity. Maximum and minimum consumption level of each 3 rd instar larva that fed 75-80 percent of total food in larval period was from A. nerii and R. padi respectively.

Rice as an important crop has significant role on the economy of our country. Aroma has a significant influence on rice price and marketing. In this study the genes controlling aroma was investigated. In the first year, a cross of Rashti to 008 was obtained and in the second year, F1 generation was grown and then F2 segregant population was obtained the next year. Then their seeds were used to allelic test. Phenotypic evaluation indicated that aroma is controlled by two recessive genes and aromatic: nonaromatic plants only matched to the 1:15 ratio (a=5%). So, according to this investigation, rice aroma is controlled by two recessive genes.

In this research, the data for the weights of 6, 9 and 12 months lambs with Sanjabi race were used in Mehrgan breeding sheep station (located in Kermanshah). To estimate the fixed environment effects and genetic and phenotypic parameters, the Least Square and Animal Model method were used. The mean for the weights of 6, 9 and 12 months was 32.5±5.2, 39.3±5.6 and 48.4±5.8 kilogram respectively. The fixed effects of birth year, lamb sex and birth type were significant in all traits (P<0.01) but dam age was not significant in any traits (p>0.5). The heritability coefficient for 6, 9 and 12 month weights were 0.31 ±0.02, 0.27±0.01 and 0.17±0.01 respectively. The correlation coefficients of genetic, phenotype and environment between 6 and 9 month, 6 and 12 month and 9 and 12 month weights were estimated (0.89, 0.89,0.93), (0.73, 0.75, 0.81) and (0.84, 0.87, 0.97) respectively.