NEW FINDINGS IN AGRICULTURE
Year:2007 | Volume:2 | Issue:1|Papers Count:8

In order to quantify of dry matter accumulation in sunflower (Helianthus annus L.) at interference with redroot pigweed, a two years experiment based on additive design was performed factorially with sunflower cultivars (Azarghol, Hysun and Allstar), redroot pigweed densities (8.3, 25 and 41.7 plants m-2) at relative times of weed emergence (emerged with sunflower; 15 and 30 days after sunflower emergence) in Tabriz. Results showed that with increasing of 33.4 weeds/m2, biological yield of sunflower in three cultivars increased 40, 65 and 73 g/m2, when redroot pigweed emerged with sunflower.Effect of weed density unit on leaf dry matter in low densities was higher than high densities. Leaf to total dry matter ratio was not affected by studied treatments. The Azarghol can tolerate 8.3 weeds/m2 at 30 days after emergence without significant reduction in stem dry matter, while, reduction amount in two other cultivars were significant. In three cultivars, with increasing of weed density and earlier emergence times, anthodium dry matter reduced.

In order to study effects of planting date and cutting leaves on agronomic traits and yield of sunflower cultivars a field experiment was carried out in a split factorial experiment arranged in RCBD in 2005. Main plots consist of four planting date with ten days increment (from 30 march till 30 April 2005) and sub plots consist of three cultivars (Recor, Zarya, Azargol) with four level of cutting leaves treatment (first level as control, second level by cutting alternate leaves, third level by cutting on-third of top leaves and fourth levels by cutting of on-third of intermediate leaves). Treatments were donning at flowering stage (R5). Evaluated traits were plant yield per plant, hollow diameter, disk diameter, disk weight, stem diameter, and stem weight, filled grains number per disk, filled grains weight per disk, hollow grain number, 1000 kernel weight, harvest index, productivity effort and grain number per disk. Different treatment of cutting leaves on harvest index in (p<%1) and plant yield per plant and hollow grain number per disk in (p<%5) were significant. Effect of cultivars on plant yield per plant, disk diameter, disk weight, stem weight, filled grain number per disk, filled grain weight per disk, hollow grain number per disk, 1000 kernel weight, harvest index and productivity effort were significant in (p<%1). Means comparison showed that control treatment had maximum plant yield per plant with11.16 gr/m² and cutting one third of intermediate leaves had minimum plant yield per plant, second planting date had maximum plant per plant and Azargol had maximum plant yield per plant.

This experiment was done to evaluate the effect of planting date on agronomic characters of spring Rapeseed cultivars in Isfahan region during 2004-2005 in the research field of Islamic Azad University of Khoorasgan located in North East of Isfahan. The experiment was conducted as split plot on CRB with three replications. Four rapeseed cultivars consist of RGSOO3, PF7045-91, Option 500 and Hyola 401 as subplot and Four planting dates (Feb.27th and Mar.9, 19 and 28th ) were selected as main plot. Traits were considered as plant height‚ number of sub branch per plant, number of sub and main pods per plant, number of grain per sub and main pods, 1000 seeds weight, grain yield and oil seed content. Results showed that the effect of planting date on all traits, except plant height, was significant. Also, effect of cultivars on all traits, except number of sub branch per plant was significant. The interaction effects of year, planting date and cultivar on the number of sub branch per plant, number of sub and main pods per plant and 1000 seeds weight were significant. According to biannual results RGS003 cultivar at the first planting date recommended for Isfahan region.

Pathogenesis related proteins are compounds that produced by response to pathogens or environmental stress. Up to now numerous kind of b-1 and 3-Glucanase are identified in various plants and thein fungicide effect were tested. The aim of this research was isolation, over-expression and analysis of physiological activities of b-1 and 3-Glucanase (PR-2) from Medicago truncatula. In this case by Medicago sativa and Pisum sativum b-1 and 3-Glucanase gene alignment on Medicago truncatula genome three open reading frame with%50 similarity by having start and stop codon were identified and isolated that fragments were cloned in PET21c vector and expressed in E.coli BL21. SDS PAGE technique reveal that proteins were produce as an inclusion bodies. We also test their fungicide effect after folding them to achieve their natural structure on Alternaria alternaria and Fusarium graminearum. The result were significant (P<0.05) by SAS system analysis.

In order to study yield variation of the most tolerate genotypes of bread wheat (Triticum aestivum) against drought stress an experiment was conducted using RCB design with three replications. That was done on rain fed and irrigated land in agricultural research field of Salehabad in Ilam province (2005-2006). The most common genotypes consist of five varieties; Chamran, Atrak, Zagros, Koohdasht and Chenab were studied. Considering yield in the stress and non-stress conditions drought tolerance indices including MP (mean of productivity), SSI (stress susceptibility Index), TOL (tolerance), GMP (geometric mean of productivity) and STI (stress tolerance index) were calculated. High significant positively correlated indices were determined as selection factors of high yield potential and resistant varieties. According to drought tolerance indices Zagross and Chamran variety were found as the most tolerate and Atrak and Chanab were the most susceptible varieties examined.

In search of alternatives agents for conventional pesticides, the fumigat activity of essential oils from Artemisia haussknechtii, Mentha longifolia and Thymus daenensis were tested against adults of Callosobruchus maculatus. The experiment was conducted using a completely randomized design of factorial experiment. The essential oils were prepared by water distillation method. Experiment was carried out at 30±2 oC and 60±5% R.H. under dark condition. At a concentration of 18.518 ml/l essential oils of A. haussknechtii, M. longifolia and T. daenensis caused 100, 100 and 92% mortality of adults, respectively. LC50 values of essential oil of A. haussknechtii, M. longifolia and T. daenensis were found to be 1.204, 3.624 and 4.754 ml/l, respectively. It was found that plant essential oils could be used as a safe pesticide or model for new synthetic pesticides to control of storage pest.

Low Input Sustainable Agriculture (LISA) is an approach that reduces the dependence of farmer to certaian agricultural input and results in an increase in farm profitability, expansion of sustainability in farming and interaction amoung generations. The present study is an applied research which has been conducted by descriptive-correlative method using field implementation and questionnaire. The population of this study consists of wheat farmer's Sistan-o-Baloochestan province (N=15500) which were selected with stratified random sampling (n=187) and participate in this research. Content and face validity of the questionnaire were, established by faculty members and specialists in the field of agricultural extension and development. Questionnaire reliability was estimated by calculating Cronbach's alpha coefficient by SPSS/win. Reliabilities of the questionnaire were %79.8. There was negative correlation between levels of wheat production, income from wheat, educational level with acceptance of LISA. Also, significance differences were found in relation with the kind of wheat cultivation and participation in educational courses.

This study was done in descriptive, surveying and correlative method. The investigated population was 371 general specialists of Forestry, Range and Watershed Organization. Sample volume has been determined by Kookran formula. Relative simple random sampling method has been used in this research. Library-imputative and field study as two common methods have been used in order for collecting data. Content and face validity of the questionnaire were established by faculty members and specialists in the field of agricultural extension and development. Approving of questionnaire was done by using Kernbach Alpha Index. It was calculated as 0.93 for questions related to collaborative management and 0.91 for questions related to effectiveness of managers’ organizational behavior. Study of correlation index among the variant of the study have shown that the relation among collaborative management variant and following was positive, organizational behavior effectiveness variant, increase in profession skills, rapid accomplishment of organization goals, increase in the quantity and quality of activities, creating professional knowledge among experts improvement in occupational attitude of experts, creating innovation in experts, flexibility, human relationships and creating occupational groups. Results of progressive methods implies the following variants have a positive effect on managers’ organizational behavior effectiveness, creating ways in order for experts’ active attendance in meetings, managers acceptance of experts’ viewpoints in evaluation of staff, holding meetings with experts which is done by manager, manager’s attempt in problem solving by means of group activities and manager’s emphasis on group performance in evaluation and supervision of staff.