فصلنامه اکوفیزیولوژی گیاهان زراعی
پیاپی 16 (زمستان 1389)

In this research potato cultivars including Savalan, Agria and Kaiser and its promising clones (397009-3, 397008-10 and 397009-7) were examined in three irrigation regimes in a split plot design based on randomized complete blok design with three replications in Ardabil Agriculture and Natural Resources Research Station during 2008 and 2009. Irrigation treatments (irrigation rate of 50, 75 and 100 percent of water required) were assigned to main plots and promising clones and cultivars to sub-plot. Analysis of variance showed that there were significant differences among irrigation levels and cultivars in for total and marketable tuber yield, tuber number, tuber weight per plant, years and years × cultivars interaction of total tuber yield, irrigation levels × cultivars interaction in all traits except total tuber weight per plant and main stem number per plant. All of the clones and cultivars at 100 percent required water, 397009-3, 397008-10 and 397009-7 clones, Savalan and Kaiser cultivars at 75 percent required water and 397009-3, 397008-10 clones and Savalan cultivar at 50 percent required water produced higher marketable tuber yields. Clone No. 397008-10 produced high marketable tuber number and tuber weight per plant in all of irrigation levels. Clones 397008-10 and 397009-3 and Savalan were selected under mild and severe water deficit conditions, and Agria as susceptible to water deficit.

Investigating assimilate contribution and grain filling pattern in winter wheat is importance under drought stress condition. This study was conducted to evaluate the relationship between drought stress on grain filling and yield of 4 cultivars including MV17 (dwarf), Alvand, Shahryar (semi-dwarf) and Toos (tall). Experimental design was randomized complete block with three replications. Drought stress assigned to main plots and cultivars to sub plots. Growth curve sampling started at 7 days after anthesis with 4 days interval. In pre-anthesis drought stress Alvand produced highest yield, while it was 29.14% less than control treatment. The yield of Toos cultivar was lowest at pre-anthesis drought stress. Rate of grain filling of Toos cultivar did not change at pre-anthesis drought stress. Drought stress treatment at post-anthesis decreased rate of grain filling in all cultivars as compared to control, but it was significant only Toos c.v. In pre-anthesis drought stress grain filling duration increased in Alvand but decreased in Toos. Alvand with higher rate of grain filling produced highest grain yield (3850 kg/ha). It can be concluded that, drought stress decreases grain filling duration and rate of grain filling.

In order to evaluate the effects of plant density and nitrogen on quantity and quality of forage corn an experiment was conducted in Daregaz region in cropping season 2008 – 2009. The experimental design was a split – plot based on randomized complete block with three replications. The main plots were four levels of nitrogen (0 , 75, 150 and 225 kg/ha) and sub plots were three levels of plant density (75000, 100000 and 125000 plant/ha). The results showed that increasing nitrogen levels and plant density, plant height, percentage crude protein and total protein production (ton/ha) were increased. By increasing plant density, stem diameter, leaf and ear weight decreased while they increased with increased nitrogen levels. The highest forage yield obtained at nitrogen level 150 kg/ha (46 ton/ha) and 100000 plant per hectare (40.27 ton/ha). The highest total protein production (7 ton/ha) obtained at nitrogen level of 150 kg/ha and plant density of 125000 plant/ha.

This present study has been carried out in order to evaluate the effect of culture medium and genotype on callus induction and regeneration of two onion varieties through root tip culture. For callus induction, micro samples from 1-3 mm root tip of 2 day old in vitro germinated plants laied on four culture media (1mg/l 2, 4-D, 0/5mg/l 2, 4-D, 0/5mg/l 2, 4-D with 0/5mg/l kinetin, 1mg/l 2,4-D with 1mg/l kinetin) in darkness conditions. Subculture of samples was done after four weeks. The produced calluses were laied in embryogenic culture medium for 4 weeks and after formation of embryoes, they were put in plant regeneration culture medium for eight weeks. Result showed that callus induction percentage is affected significantly by cultivar and culture medium, but reciprocal effect of both factors was not meaningful on callus induction percentage. Plant regeneration percentage and number of embryo per callus is affected meaningfully by cultivar, but type of culture medium and reciprocal effect of both factors was not meaningful on plant regeneration percentage and number of embryoes per callus. Embryogenic callus percentage is affected meaningfully by cultivar, but type of culture medium had not meaningful effect on embryogenic callus percentage. Callus induction percentage, plant regeneration percentage, number of embryo per callus and embryogenic callus percentage, are higher in white Kashan cultivar in relation to red Rey one and in culture medium involving hormonal combination of 2,4-D and kinetin, application of 0/5mg/l 2, 4-D can be usful. Considering the callus induction percentage, embryogenic and plant regeneration percentage, white Kashan cultivar and culture medium containing 0/5mg/l 2, 4-D is appropriate as compared with other cultures.

Fenugreek is an annual plant belonging to Legominosae family with a long history of farming in Iran. There exists various accessions of this plant in Iran; however, no comprehensive study to fully understand it has ever been carried out. Twenty populations of fenugreek native to Iran were collected from different parts of the country to asses the genetic variability of the plant and study some of their features. The results suggest that there are significant differences in most of traits under study. The wet weight ranged between 23.93 and 44.41 grams of the wet weight per plant. Moreover, the accessions, were classified with regard to the flowering features into 3 categories of early blooming, inter blooming, and late blooming. The results also showed that the accessions started to produce flower within 39 to 76 days of plantation. The index of one thousand seed weight also showed meaningful differences ranging from a low of 5.56 grams in Semnan mass to a high of 19.44 grams in Kermanshah accession. The analysis of ploid level of the accessions native to Iran revealed that all the masses under study were diploid (2n=2x=16). Finally the results show that the native masses of Iranian Fenugreek enjoy high diversity regarding the features under study and make suitable genetic resource for breeding programs.

To identify suitable seeding rate and row spacing and their interaction effects on local alfalfa (Gara Yonjeh C.V.) forage yield, this experiment was carried out at Maragheh Dryland Research Station for four years. Experimental design was strip plot with 4 replications. Row spacing was assigned to horizontal plots (A1= 25 cm, A2= 30 cm, A3= 40 cm) and seeding rate to vertical plots (B1= 15 kg/ha, B2= 20 kg/ha, B3= 30 kg/ha, B4= 40 kg/ha). The Combined analyses of data in 3 years showed that there were significant differences between row spacing but there were not significant differences among seeding rates. Interactions of row space × seeding rate were not significant. Means comparisons showed that yield of A1B3 entry (row space=25 cm, seed rate=30 kg/ha) with 3135 kg/ha dry forage and 5653 kg/ha wet forage was higher than the yields of other entries. Relation of Yield related to rainfall was found to be a polynomial function.

To study the effects of water stress and animal manure on nutrients concentration, essential oil percentage and its chemical components in Cuminum cyminum, an experiment was conducted at the Agricultural Research Station of Zahak, Zabol, during 2003–2004 in a randomized complete block design arranged in factorial with four replicates. Treatments were there irrigation (I1: two times irrigation, I2: three times irrigation and I3: four times irrigation) and two animal manure levels (F1: no manure and F2: 20 ton/ha manure). The chemical composition of the essential oil was examined by gas- chromatography (GC) and GC-MS. The effect of water stress on Na, Ca, Mg, Fe, P and K percentages was significant but its effect on Mn, Zn and Cu was not significant. I1F1 had maximum of Na, Ca, Mg and minimum of micro nutrients. Using of animal manure was not effected on nutrients. The effect of water stress and animal manure were significant on essential oil and its chemical compositions. I2F2 had the highest of cuminaldehyde and ρ-cymene and the lowest of β-pinene, γ-terpinene and α-pinene. Result showed that there is a correlation among the main components of cumin essential oil under water and mineral stress.

In order to study of the effect of phosphorus suloblizing bacteria (PSB) and ammonium phosphate (AP) fertilizer on rapeseed yield this field experiments was conducted at Research Farm Station of Arak Branch, Islamic Azad University. Ammonium phosphate applications were at 3 rates (0, 125 and 250 kg/ha) and phosphor suloblizing bacteria at 4 levels (not application, application at seeding date in autumn, application at spring and application both in the autumn and spring). The treatments were used as factorial on randomize complete block design arrangement. The results showed that the differences grain yield, no. of pod per plants, no. of seed per pod, 1000 seed weight and harvest index were significant at 5% levels of probability when were used. Generally, oil percent, oil yield, and biomass yield showed significant difference when biological phosphate treatments were applied. Therefore, the effect of interactions among treatments showed significant difference for grain yield, no. of pod per plants and harvest index.

Determining new and higher and stable yielding varieties is one of the most important objectives of rice breeding. To achieve this goal, ten promising lines of rice along with two improved cultivars (Hashemi and Kadous) were compared at National Rice Research Institute in Rasht, Iran, for three years (2006, 2007 and 2008). The experimental design was randomized complete blocks with four replications in these three years. The combined analysis of variance indicated significant difference among genotypes, for the traits studied. This indicates genetic variation among genotypes understudy. The interaction of genotype × year for yield was significant which demonstrate different responses of genotypes during different years. Different stability analysis methods were used to determine the higher and stable yielding variety like: environmental variance, coefficient of variability, coefficient of regression proposed by Finaly and Wilkinson, Deviation from regression by Eberhart and Russel, Shukla's stability variance, Wricke's equivalence, coefficient of determination of Pintus and non-parametric method of rank. By using these analyses it was found that Hashemi was a stable yielding variety. It was also revealed that line No. 9 (IR78530-45-3-1-3), line No. 6 (IR76993-49-1-1) and 8 (IR78533-30-2-1) were found as stable producer lines.

In order to study the effects of different compounds of biofertilizer and Nitrogen on yield and yield components of three bread wheat varieties including Chamran, Pishtaz, and Bahar, an experiment was conducted at agricultural research station in Shirvanchardavol, Ilam province, 2007-2008. This experiment was arranged as split-plot in RCBD (Randomized Completely Block Design) with four replications. Chamran, Pishtaz, and Bahar cultivars were allocated to main plots and the compounds of biological and chemical fertilizers were arranged in sub-plots. The results of the studied characteristics variance analysis showed that the weight of 1000 seeds and protein content were not significantly affected by the variety, but other characteristics were significantly affected by the variety and different levels of fertilizer compounds. The results indicated that the compounds of fertilizer and Azotobacter compared to the application of the one by itself result in a higher yield. In addition, by applying Azotobacter, the amount of the applied Nitrogen would be reduced, but in the course of this experiment, high yield can only be achieved in the presence of the both. In the current research the 1000 seed weight, spike number per m2, and seed number per spike are significantly correlated with seed yield. The 25% Nitrogen and Azotobacter compound resulted in the highest yield, and the mere application of the biofertilizer resulted in the lowest yield.

Based on World Health Organization (WHO) report, our society’s health ranks 123 among 192 countries. Unfortunately, this ranking position is very low and its main reason is malnutrition due to imbalanced fertilization. Although more than 85% of Iranian people are not hungry, about 90% of them are suffering from cell hunger, because agricultural authorities and hence producers do not pay attention to food security. According to the latest information, about 86.5% of applied fertilizers in our country appertain to urea and triple super phosphate. In fact, this is an alarming issue in respect to the production of healthy agricultural products and it remains a threat to food security. At present, a total subsidy of more than 7,000 billion rials is paid for nitrogen (N) and phosphate (P) fertilizers. Whereas, it should be considered that, firstly, the efficiency of these fertilizers, due to different reasons such as mismanagement and existing subsidy level, is low and, secondly, the overuse of these fertilizers causes the accumulation of nitrate (NO3) and cadmium (Cd) in agricultural products. Furthermore, according to the law of minimum, the overdosed fertilizers do not have any special positive effect on sustainable production and society’s health. Paying for such high-cost subsidy just for N and P-fertilizers has caused farmers to overuse and waste these fertilizers in the country and moreover not having any tendency to apply biologic, organic and micronutrient fertilizers. Whereas, the application of these fertilizers, beside their adaptability with the environment, has a very positive effect on the human health. Therefore, at this time scientific management of production and application of all kinds of fertilizers is inevitable. In this case, by improving the quality of all types of fertilizers, and following the principle of balanced fertilization, besides achieving the desired yield increase, the quality of agricultural products will be enhanced and the level of society’s health will be promoted automatically. Furthermore, there is a close and positive relationship between balanced fertilization and production of healthy agricultural products. The authorities of the Ministry of Jehad-e- Agriculture are supposed to consider this important principle for a) supplying suitable kinds and amounts of fertilizers during application seasons in producing agricultural products; b) banning the act of burning the plant's residues; c) considering the rules of balanced fertilization; d) enrichment of agricultural products on the farm; e) scientific management of production and application of all kinds of fertilizers; f) implementing the criteria set for Article 61 of the Fourth Development Plan; g) avoiding the import of P-fertilizers which contain Cd in excess of 25 mg/kg and h) removing the subsidy on N and P-fertilizers in order to increase the yield and quality of agricultural products and enhance society's health.