Journal of Plant Production Research
Year:2009 | Volume:16 | Issue:3|Papers Count:15

This research was conducted to study the effects of water deficiency stress, nitrogen application rates, and plant population on Water Use Efficiency and Nitrogen of oily sunflower in 2007-2008 Agriculture and Research center of West-Azerbaijan. The study was consisted split-split-plot experiments using Randomized Complete Block Design with 3 replications. The factor main was consisted irrigation treatment including optimum irrigation, moderate stress and sever stress where irrigation was done after depletion of 50%, 70% and 90% of field capacity, respectively. Three nitrogen levels consisting of 100, 160 and 220 Kg N ha-1 were considered as sub plots and sub-sub plots consisted of three plant population of 5.55, 6.66 and 8.33 plant m-2.The results indicated that water deficiency stress, nitrogen and plant population on grain and biological yields, seeds per head, head diameter, kernel percentage to seed, 1000 grain weight, plant grain yield and harvest index were significant. The maximum grain yield (4200 kg/ha) was related to optimum irrigation treatment. Severe drought stress reduced the grain yield by 44% compared to the optimum irrigation condition. Grain yield increased with nitrogen application rate. The response of grain yield to increase in plant population was positive. All yield components were responded to the changes in plant population. The harvest index decreased with increasing severe drought stress and plant population. According to this research derived results application of 220 kg N ha-1 and plant population increase in optimum conditions and moderate drought stress is recommended for suitable yield, although nitrogen consumption and plant population increase has a little impact on grain yield in severe drought stress conditions.

Walnut is a plant belongs to Juglandaceae family. Among 21 species, of the Juglans genus, the Persian walnut (Juglans regia L.) is recognized as the best species. The main aim of the current research work was identification of genetic diversity among Persian walnut species in Golestan province, of Iran. Morphological traits used as an approach to evaluate 96 trees which belonged to the five native populations. All morphological characters of leaf, flower and fruits were recorded. There were observed sSignificant differences was bseen among these populations for thein respect to character of nut with husk and without husk. This range was between 14.88 to 55.88 gr for the earliest former and 5.64 to 25.91 gr for the latest one. Also the percent of kernel was in a range from of 19.95 to 50.19. Further results indicated a negative correlation between high altitude with protogeny and percent of age oil of kernels. Reversely, there was a positive correlation between altitude and protein content of the kernels. Other phenological traits such as seed biophysics and seed morphology (according to IPGRI and UPOV descriptors) were evaluated within this study. 

In order to study the effect of different nitrogen fertilizer rates and source-sink limitation treatments on yield and yield component of contrast rice (Oryza sativa L.) cultivars, a field experiment was carried out in the Rice Research Institute of Iran-Deputy of Mazandaran (Amol) during 2006. A split split experiment in the basis of randomized complete block design with 3 replications and 3 factors were used in which fertilizer rates in 3 levels (including 100, 150 and 200 kg/ha from urea source) as main plots, rice cultivars in 3 levels (including Tarom, Shafagh and Bahar1 hybrid) as sub plots and source-sink limitation treatments in 4 levels (including cutting of flag leaf, cutting of leaves except flag leaf, cutting of 1/3 the end of panicle and control or without limitation) as sub sub plots were the treatments. Results showed that nitrogen rates had not significant effects on the studied traits expect on panicle length but cultivar and source-sink limitations significantly affect all studied traits such as grain number per panicle, 1000 grain weight, panicle length, panicle fertility percentage and unfilled grain number. Bahar1 hybrid had the highest grain yield, biomass, total grain number, unfilled grain and filled grain among cultivars. Among different source-sink limitation treatments, the lowest grain yield were observed when all leaves except flag leaf removed from plant probably because of induced source limitation. Also interaction effect of nitrogen fertilizer in source-sink limitation treatments showed that the highest yield was observed in 200 kg.ha-1 and control treatment. Among the mentioned traits, biomass (r=0.76**), harvest index (r=0.50**) had the highest positive and significant correlation with grain yield. In general, modern cultivars (Shafagh and Bahar1) had higher sink capacity than Tarom cultivar (traditional) that considered as a sink-limited cultivar.

In order to investigation the effect of row spacing and seeding rate on alfalfa (Medicago sativa L. cv. Mesasirsa), an experiment was carried out at the research farm of Khouzestan Agricultural Research Center from 2000 to 2004. This research was conducted in the form of a split plot design in a randomized complete block, with four replications. Main plot was three row spacings (50, 60 and 70 cm) and sub plots were five seeding rates (5, 10, 15, 20, and 25 kg seed ha-1). Results showed that the highest seed yield obtained in the second year. Seed yield and racem per m2 increased with row spacing decreasing. Seeding rate did not have any significant effect on pod per racem, seed per pod and seed weight. The interaction of year and treatments on whole of traits was not significant. It was observed that correlation among seed yield and yield components was positive and significant. It was concluded that with using 15 kg seed ha-1 the highest seed yield obtained to increase in racem per m2 and seed weight.

In the water-limited areas, the great challenge of the agricultural sector is more production from less water that it can be achieved by increasing water productivity. A field study was conducted to compare various cultivars of wheat to water using line source sprinkler irrigation at Gorgan Research Station in 2005-2006. The effect of variable water supply on yield and WUE of six wheat cultivars were determined. Four locations with distance from the laterals were monitored all of the irrigations. Four irrigation treatments (W1, W2, W3 and W4) were provided by the reduction of irrigation water with distance from the line source. The experiment used a strip plot design to examine the effect of fixed irrigation rates on six cultivars (C1=Tajan, C2=N-80-6, C3=N-80-7, C4=N-80-19, C5=N-81-18, C6=Desconcido) with four replications. Each irrigation treatment of each strip was divided into six cultivars treatments, along the length of the laterals. Result indicated that the grain yield was affected by irrigation treatment and genotypes. Due to suitable rainfall during the growing season, soil moisture depletion was high in deficit irrigation treatment (W4) as compared to W1 treatment. Generally, the WUE was increased with decreasing applied water under supplementary irrigation. The optimum amount of water to achieve maximum WUE was a range of 290 to 320 mm in the above-mentioned cultivars. The highest and the lowest WUE was related to C5 (1.48 kg m-3) and C1 (1.3 kg m-3) respectively. The optimum yield to achieve the highest WUE was found between 4100 kg ha-1 (in C1 cultivar) up to 4900 kg ha-1 (in C3 cultivar).

The wild Pistachio, Pistacia atlantica subsp. mutica, is belonged to mountain of Irano-Turanian region, and distributed in northwest, northeast, center, east and south of Iran. The sexual identification mechanism of this species is unknown and denotation of gender is impossible until flowering. In this study sex ratio of populations of this dioecious shrub was evaluated by several hypothesis concerning biased sex ratio, in some microhabitates of Maymand region in ShahreBabak of Kerman province. The populations located in microclimatic gradient, such as slope, wind, altitude and edaphic factors display a male-biased sex ratio on stressful microhabitats. We found a significant correlation between biased sex ratio and density of plants too. Low density of plants correlates with a high preponderance of males, but the sex ratio approximately equal when density increases. So we found female preponderance when pollen grain competition exists. As results of this study, mortality of female plants and competition of pollen grain are effective factors in biased sex ration in wild pistachio populations in this region.

Tuberose aesthetically and commercially is an important flower that its importance is due to its potential for trade of cut flower, long vase life and essential oil industry. It is cultivated commercially by bulbs is needed to their storing properly after the harvest and quiescence to increase yield and flowering quality so that can be regulated flowering time according to market. Experiments were conducted to study the effect of temperature treatments of 4, 18, 25 and 30oC during 4 and 8 weeks storage and its influence on time and percentage of germination, leaf number and amount of vegetative growth of plantlets, days to emergence, length, diameter and number of inflorescence spike, total number of nodes per inflorescence, days to emergence of first floret, the first floret diameter, length and number of inflorescence and days to harvest. The experiment was carried out as a factorial plot in a complete randomized block design with four replications. All the data was subjected to analysis of variance (ANOVA) and the means separated using the Duncan's Multiple Rang Test. Results revealed that, period of growth and flowering decreased by 25oC and 30oC. Time and percentage of germination as well as vegetative growth in treatment of 4oC specially during 8 weeks was very low (26% and 63 day after planting) and only a little of these plants flowered with low quality. Flowering quality was proper in 25 and 30oC treatments but reduced length of flower spike, florets number and its diameter in treatment of 30oC during 8 weeks. The most length of inflorescent formed in 18 and 25oC treatments (26 & 28.5 cm) and the shortest was related to treatment of 30oC during 8 weeks (18 cm). Different treatments of storage didn’t mark on the total number of nodes. So temperature of 25oC during 4 and 8 weeks is advised as optimal temperature in storage of tuberose bulbs.

Plants showing root and crown rot were collected from 48 bean fields in the Khuzestan and Markazi provinces During 2005-2006. Using specific primers (FsphR/FsphF) for these forma specialis, three isolates were identified as F.s. f.sp. phaseoli. Conidial suspension of one of these isolates were irradiated (in a 60Co- gamma cell with activity of 2500 curi and 0.38 grey per second dose rates) with 130 Gy. Pathogenicity and root colonization tests confirmed two avirulent mutants. Molecular comparison using 10 primers between avirulent mutants and wild type showed that, avirulent mutants M22 and M23 have 73% and 50% similarity with wild type kh12. These results showed that, avirulent mutants were produced due to genetical differences. This is the first step to induce mutation and screening for avirulent mutants which are promising prerequisite for biological control of this important disease in bean.

Dutch elm disease is one of the most destructive vascular wilt diseases in the world. Ophiosatoma ulmi and O. novo-ulmi had been the most important causal agents of the Dutch elm disease in the last century. So, in order to manage of disease, their identification and distinction is necessary. These fungal species were distinguished based on morphological, physiological and molecular characters. Perithecium dimensions of fungal isolates such as: neck length, bowl width and their ratio, on the MEA, are the most important primer factors for their distinction. In this study, neck length, bowl width and their ratio for isolates of fungal causal were estimated in vitro. In this research, every isolate with two standard isolates of A and B type was cultured on MEA supplemented by powder of elm wood and was inoculated in temperature 20°C. The results of estimating perithecium dimensions were showed, the isolates had significant difference, so that isolates of O. novo-ulmi to have higher neck length (290-640 micrometer) and shorter bowl width (70-100 micrometer) than O. ulmi were distinguished. Neck length to bowl width ratio for the isolates of O. ulmi and O. novo-ulmi was also calculated 2.76 and 5.87, respectively. The potential using of Perithecium dimensions of fungal isolates as one of primer morphological factors to distinguish isolates of the causal agent or agents Dutch elm disease in Iran was discussed in this paper.

Priming is one of the seed enhancement methods that might be resulted in increased seed performance (germination and emergence). The objective of this research was to evaluate effect of priming on seed emergence and yield under wide ranges sowing dates in cotton. Treatments were combinations of 6 sowing dates and 2 seed treatments (control and primed seeds). Hydropriming method was used; seeds of Siokra 324 were moistened in water for 16 h at 25oC. Results indicated that priming affects seed emergence components. Primed seeds had faster and more uniform emergence at all sowing dates. Priming also affected germination response to temperature; primed seeds “emerged” at lower base temperature. Base temperature was 15.4oC for control seeds, but was 13.5oC for primed seeds. Primed seeds had high yield than unprimed seeds (control) at all the sowing dates.

Stomata are closed by moisture stress, reducing carbon assimilation and yield production with dry land agriculture. Relative 13C to 12C molar ratio assimilation by a plant is a function of time stomata remain open during plant life time, itself a function of moisture stress. The purpose of this study was to test the existence of any relationship between stomatal conductance and assimilation rate and final yield of treatment. The field experiment was established in Why College Estate, Kent, England. Employing the repeated measures method for statical analysis suggests no significant differences between subjects and no significant time interaction effects, The only significant subject was time effect itself (P=0.0001), suggesting an increasing Delta value for maize as a consequence of age and consequently accumulation carbon dioxide in crop. Although the extra yield production by heavy mulch and incorporation could be attributed to their extra canopy production (ground cover), the extra yield by light mulch with the same canopy cover as control and ammonium nitrate fertilizer (compost mulch treatment, at 100 t/ha versus compost incorporation treatment, at 50 t/ha) requires greater rates of carbon dioxide assimilation, which in this experiment is not attribute to the Delta value and hence stomotal conductance, (i.e. other unknown physiological processes might enhance carbon assimilation without affecting stomotal conductance). If the result from carbon discrimination in this experiment are reliable, they elude other factors involved in carbon dioxide assimilation rather than stomotal conductance.

In this research, the antagonistic effects of Bacillus subtilis isolates against the causal agent of tomato damping-off, Rhizoctonia solani were surveyed under laboratory and greenhouse conditions. Isolates B4 and B18 showed the most inhibition ratio in the volatile and non-volatile metabolites tests which were 50.3% and 58.6% respectively. The six out of 25 isolates studied more and their antagonistic effects were surveyed under greenhouse conditions as inoculated into soil and covered on root and crown of seedlings. Interaction among the bacterial isolates and the fungus was calculated as percent of increasing of seedling length, percent of increasing of seedling dry weight and percent of decreasing of diseased plants. The results showed that bacterial isolates have different antagonistic effects. In the greenhouse tests, both methods, B2 isolate was the best at significant decreasing of disease rate and at significant increasing of considered growth factors in this test.