JOURNAL OF CROP ECOPHYSIOLOGY (AGRICULTURE SCIENCE)
Year:2009 | Volume:3 | Issue:9|Papers Count:8

In order to detect genetic diversity and effective traits on forage yield of 49 accessions of alfalfa (Medicago sativa), an experiment was used in a simple lattice design with two replications at the Research Center for Agricultural Resources of East Azarbaijan, Tabriz, Iran during 2006. Traits evaluated in this study were: fresh forage yield, dry forage yield, days to %50 flowering, plant height, number of stem, number of nods, internode length, growth rate and leaf to stem ratio. Analysis of variance revealed that there were significant differences among ecnotypes for the most of the traits under investigation. Mean comparisons indicated that the ecotypes Nos. 37 (France), 13 (Tabriz local), 25 (Gorgan), 12 (Sabzevar) and 46 (Heris) were higher producers both for forage yield and quality under irrigation. They can be recommended as early maturing high forage producing and high growth rate ecotypes. Using WARD cluster analysis method, the 49 ecotypes of alfalfa were classified into 5 groups. Based on forage yield and quality, groups 5 and 2 were promising, respectively. Principal components analysis indicated that first PC and second PC significantly affected high yield and quality, respectively.

To evaluate agronomic potential of grass-pea vine (Lathyrus sativus L.) under arid and semi-arid conditions, 14 lines selected from preliminary comparisons were investigated in a randomized complete block design with three replications at Gachsaran Rainfed Research Station Center (GRRSC) during 2005-2007. The combined analysis of variance reaveled that the effect of genotype, year and interaction of genotype by year were significant for most traits under investigation. Because of low rainfall in 2007 year, the values of traits measured were lower than those of two previous years. Three year means showed that green forage yields were between 13719 and 21294 kg ha-1, biological yields ranged between 4670 and 6789 kg ha-1, grain yield between 1257 and 1616 kg ha-1, straw yield between 3297 and 5067 kg ha-1, 100-grain weight between 9.2 and 13 g and harvest index between 23.9 and 30.3%. It can be concluded that, line Sel.736 for green forage and dry forage yield and line Sel.1307 for grain yield were high producers.

To compare the grain yield of medium maturing corn hybrids and study the effects of traits on yield, an experiment carried was out in 2007 at Agricultural Research Center of Moghan, Parsabad, Iran. In this research 14 medium maturing hybrids of seed corn were studied in a complete randomized blocks design with 4 replications. Several traits like grain yield and its components, morphological and phonological characteristics were measured and analysed. Analysis of variance showed that the differences among the traits measured, except ear leaf area and stem diameter, were significant. Mean comparison of hybrids also revealed that the maximum yield belonged to hybrid number 3 (11870 kg ha-1) and the minimum yield to hybrid number 12 (5720 kg ha-1). The result, of experiment also showed that seed yield had significantly positive correlation with ear leaf area and the number of days to physiological maturity. The results of path analysis showed that number of days to physiological maturity, ear leaf area and 1000 seeds weight had significant positive direct effect on seed yield, in such a way that their increase resulted in higher seed yield. On the other hand, ear cob weight had direct and negative effect on yield; that is to say, increasing ear cob weight decreased seed yield. Consequently, it can be said that number of days to physiological maturity, ear leaf area and 1000 seeds weight were very important and effective on seed yield of the hybrids studied. Thus, we can use these traits in selection of high grain producing corn hybrids.

In order to investigate genetic diversity in sainfoin (Onobrychis vicifolia) for seed yield and related traits in 36 foreign and Iranian ecotypes, an experiment was conducted using a square lattice design with two replications. Analysis of variance revealed significant genetic diversity among ecotypes as to some of the traits. Significant and positive correlation was observed between seed yield and biomass. Plant height, biomass and thousand seed weight explained about 64 percent of seed yield variation. Direct effect of biomass on seed yield and indirect effect of plant height through biomass was high. Therefore, biomass could be used as an effective variable for selection of high seed yielding ecotypes in plant breeding programs.

To measure the effects of late season drought stress on agronomic traits of 20 barley genotypes, two different experiments in completely randomized block designs with three replications, one under drought stress and other non-stress conditions, were conducted at Mashhad during 2007-2008 growing season. The purpose of this study was to find genotypes tolerant to stress and non–stress conditions. The results showed significant difference among genotypes for grain yield, number of spike per m2, grains per spikel, 1000 grain weight, grain filling period, plant height, biological yield, harvest index for both under stress and non stress conditions. Drought stress caused significant reduction on whole agronomic traits. The highest average grain yield under two experimental conditions belonged to the genotypes No.20 (6478 kgh-1) and 8 (5393 kgh-1). While the lowest grain yield produced of the genotypes Nos.14 and 4, with 2250 and 2661 kg/ha respectively. The highest correlation of grain yield under stress condition was attributed to 1000 grain weight (r=0.55 **) and non stress condition to harvest index (r=0.66**).The results indicated that three indices of MP , GMP and STI had highest positive and significant correlation with yield at both conditions. Comparison of their values (STI, GMP, and MP) showed that genotype No.20 (M-82-14) to be highest producer at both conditions. It can thus be recommended to drought stress condition. This genotype is promising line in temperate region of Iran with highest grain yield (7729 kgh-1) and (5245 kgh-1) at non stress and stress conditions respectively. The genotypes No. 8 (D5) and No 18 (M-80-16) were the other suitable genotypes. Based on these indices genotype No 4 (fassih) was un-suitable to drought condition. Its MP, GMP and STI, values were 2661, 1920 and 0.11 respectively.

Beekeepers use Kandovan region as an apiary to collect nectar and produce marketable honey. This study was conducted to determine medicinal plants visited by honeybees in this area. If these plants were determined, their time of flowering and locations could be recommended to the bee keepers for the emplacement of honeybee colonies to produce high quality and quantity honey in the beehives. In this project collection of nectar, pollen and both pollen and nectar by honeybees surveyed for two years in every 7-10 days intervals, within the radius of 3 Km. from the apiary. Plants collected (256 spp) were determined in the herbarium of the Agricultural and Natural Research Center of Tabriz and medicinal plants were then separated by using scientific reference books and also by native rural people. From all of the plants species collected and determined in Kandovan region, 98 species were found to be visited by bees. These species belonged to 66 genera and 22 families. Fifty two species out of 98 were determined to be medicinal plants in this region. These species did belong to the following genera: Lamiaceae (7 species), Fabaceae (8 species), Rosaceae (7 species), Asteraceae (6 species) and Apiaceae (3 species). Nine species of these plants produced nectar, 18 species pollen and 23 species both pollen and nectar.

New methods, like simultaneous use of carbon dioxide and phosphine, are used in integrated pest management programs. These procedures will reduce adverse effects of phosphine and improve rapidity of stored product pest control. The efficiency, penetrating ability of these two fumigants and different concentrations of phosphine in 50% carbon dioxide of atmosphere on developmental stages of the Indian meal moth, Plodia interpunctella Hbner. were studied. This species was reared at 27±1oC temperature, 70±5% relative humidity and 12:8 h (D:L) photoperiod. Then they were put three depths in to galvanized reservoirs of wheat with 30 cm distances, then filled with wheat and added different amounts of phosphine in the form of ammonium phosphide to reservoirs. 50% of reservoir volume was injected by Carbon dioxide. Based on data recording after three days LC50s for adults, eggs, larvae and pupae of P. interpunctella were calculated to be 85.14, 171.75, 160.1 and 123.99 ppm, respectively, and in empty reservoirs were 69.74, 151.90, 123.30 and 106.02 ppm, respectively. Differences of mortalities in bottom, middle and top of reservoirs were not significant (P<0.01). In other words, phosphines associated with 50% of carbon dioxide have appropriate distribution and penetration ability in reservoirs.

The purpose of this study was to determine the effect factors on adoption of new technologies by wheat farmers in Isfahan. Data were collected by randomization method and completion of 381 questionnaires. The methodological approach of this study was descriptive-correlative. Validity of the instrument was established using a panel of experts consisting of senior faculty members in agriculture extension and education at Tarbiat Modarres University. Further, the agricultural officer of Isfahan Province validated the questionnaire. A reliability analysis was conducted and Cronbach alpha value was found to be 87 percent. The results of multiple regression analysis (stepwise method) revealed that the variables of mechanization level, the size of the wheat cultivated land holding, the level of education and the wheat farming antecedents predict a variation of 59% of their adoption of new technologies. The results of the multiple regression analysis (stepwise method) also revealed that the wheat farmers’ social status, the extend of their use of communication channels and the wheat farmers’ attitude in consideration with the on-farm demonstration predict a variation of 50.3% of their adoption of new technologies. Significant differences were found among the mean scores of the wheat farmers’ adoption of new technologies in relation with the type of agricultural system, the type of seeds used and methods of wheat cultivation used. The results obtained from the factors analysis revealed that the three following factors, social, agricultural and personal characteristics explain 68.072% of the variation of the wheat farmers’ adoption of new technologies.