JOURNAL OF CROP ECOPHYSIOLOGY (AGRICULTURE SCIENCE)
Year:2010 | Volume:3 | Issue:12|Papers Count:8

The effects of planting date and applying manure on yield and yield components of sweet corn (cultivar chase), were evaluated during 2007-2008 at Research Farm of Islamic Azad University of Miyaneh branch, by using a factorial experiment arranged in randomized complete block design with three replications. The first factor was animal manure with four levels (0, 20, 40, 60 t/ha) and second factor was planting dates with three levels (20th of April, 9th of May, 30th of May). The results showed that manure levels and planting dates had statistically significant effects at 1% levels on number of kernel per ear row, number of total kernel per cob, thousand kernel weight, seed weight per cob and biological yield. Effects of different planting dates on yield were significant. Higher seed yield (7.564 ton/ha) was obtained from planting date of April 20. The seed yields from other planting dates (9th and 30th of May) were about 18.5%, 32.2% less than those of first date, respectively. The effects of manure levels on yield were significant and highest yield (7.677t/ha-1 ) was obtained by applying 60 t/ha-1 of manure. The yield reductions from other treatments (0, 20, 40 t/ha-1 of manure) were 32.3%, 25.3%, 14.9% less as compared with 60 t/ha respectively. The results of this experiment indicated that at planting date of April 20, and application of 60 t/ha-1 animal manure may produce highest yield of sweet corn ("Chase" var.) in Miyaneh region.

Identifying drought tolerant maize hybrids to produce higher yields under water deficit conditions is of special importance. To achieve this objective, several promising single cross maize hybrids were evaluated in a split plot experiment arranged in RCBD under three levels of water deficit. Plants were imposed to water stress at vegetative stage (6-8 leaf stage) and, thus, irrigated after 50, 100, and 150 millimeters of water evaporated from a class A evaporation pan. Irrigation levels were assigned to main plots and hybrids to subplots. Analysis of variance of data collected indicated significant differences among hybrids for the traits studied. Using drought tolerance indices like GMP, MP and STI it was found that hybrid number 400 was the most drought tolerant one and produced highest seed yield, both under water stress and non–stress conditions.

To evaluate the effects of different proportions of manure and chemical fertilizer and drought stress on quantitative and qualitative characteristics of barley a split plot experiment was conducted based on randomized complete block design with three replications at Research Field of Zabol University, during 2008. Drought stress treatments consisted of application of Drought stress during grain filling stage (S1) and control (S2) which were considered to be main factor and different proportions of manure and chemical fertilizer treatments 100% manure (N1), 100% chemical fertilizer (N2), 50% manure+50% chemical fertilizer (N3), 75% manure+25% chemical fertilizer (N4) and control (N5) were named as the sub factor in this experiment.Results revealed that the effect of drought stress during grain filling stage had significant effect on all traits under study, with the exception of spike weight. The highest grain yield, among different proportion treatments, was obtained in N3 and N4 treatments and the highest biological yield belonged to N3 treatment. Among traits under study, grain number/spike and spike weight were not affected by fertilizer treatments. Drought stress during grain filling stage did not had any significant effect on nutrient concentration of seed, but different proportions of fertilizer treatments, had a significant influence on Zn and Mn concentration of barley seed, and highest concentration of Zn and Mn were obtained when 100% manure (N2) treatment was used.

To evaluate grain yield and physiological traits of 12 durum wheat lines under water deficit at anthesis stage, an experiment was conducted at the Islamic Azad University, Tabriz branch, during in 2008. This study was carried out in a split plot experiment based on randomized complete block design with four replications.Analysis of variance showed that there were significant differences among lines studied. Drought stress reduced yield, spike number per plant and harvest index. In spite of a general reduction in yield, we found some cultivars, such as Yazligh and D\86-20 to produce relatively high yields under drought stress. Using correlation analysis for all traits under both stress and non stress conditions, we conclude that length of peduncle, due to its supplying dry matter is useful in plant drought torelarnce. We used several selection indices, to evaluate drought tolerance of lines in this study. It was found that indices like STI, GMP, MP were appropriate to measure drought tolerance of durum wheat lines. Because there are the higher correlations between indices and grain yield under both drought stress and non stress conditions, we obtained Yazlig and D\86-20 to be the tolerant lines.

The effects of drought and application of manure on dry matter yield and essential oil content of Moldavian dragon head (Dracocephalum moldavica) were studied in greenhouse with 15 treatments and 3 replications by using a strip Plot in a randomized complete block design arrangement in Jiroft. Three levels of irrigation treatments (irrigations at 75%, 50% and 25% of F.C.) were used as vertical factor and four levels of manure applications (10, 20, 30 and 40 t/ha) as horizontal factor. The results showed that the effects of water stress on dry matter and manure on essential oil content were significant at 5% and 1% levels of probabilities respectively. Drought stress resulted in dry matter reduction. Maximum dry matter (7573.7 kg/ha) belonged to the least stress condition (irrigation at 75% of F.C.) and 40 t/ha of manure application. The highest essential oil produced was 13.1 kg/ha. When drought stress was moderate (irrigation at 50% of F.C.) and 30 t/ha at manure was applied, essential oil amounted to be 9/91 kg/ha, but the difference between 40 and 30 t/ha of manure was not significant. It can be concluded that moderate drought stress and application of 30 t/ha of manure would be suitable to produce Moldavian dragon head in Jiroft.

In this research an Arabidopsis thaliana mutant which showed hypersusceptibility to Hyaloperonospora arabidopsidis infection, and was generated during the generation of the Arabidopsis transgenic lines to study resistance genes, have been characterized.The results indicated that the observed susceptibility of this mutant to pathogen infection is related to insertion a transfer DNA from the Agrobacterium in a putative gene encoding for a polygalacturonase enzyme, that are from cell wall’s important enzymes which play key roles in response to exterior biotic and abiotic stimuli. The reason is that the second independent T-DNA insertion line showed a same phenotype and constitutively overexpressing the PGase gene in a loss-of-function mutants, which the expression level of the mentioned gene is 70% decreased, leads to loss of the susceptibility to pathogen infection. Hence, these data confirmed the role of plant cell walls in response to pathogen attack.

Tomato fields in several regions of East Azerbaijan province (Azarshahr, Osku, Bonab, Tabriz, Shabestar, Ajabshir, Maragheh, Marand, Malekan and Miyaneh) were surveyed for tomato root and crown rot during mid-spring and summer of 2008 and 2009. Wilted tomato plants, with or without necrosis on their crown along with soil around their roots, were sampled and transferred to laboratory in plastic bags.778 fungal and fungal-like isolates on PDA, PCA, CMA and CLA culture media were isolated and identified as Fusarium oxysporum, Fusarium solani, Fusarium equiseti, Fusarium acuminatum, Fusarium latertium, Fusarium semitectum, Rhizoctonia solani, Verticillium dahliae and Phytophthora drechsleri. Pathogenicity of 26 selected isolates were tested on tomato cultivar "Super Chief " in East Azerbaijan and percentage of the infected plants were calculated 75 days after inoculation of plants with each of fungal species.

This experiment was carried out in randomized complete block design to study the effect of ionophore anticoccidial drugs (Salinomycin, Semduramicin and the combination ratio) and compare their effects on the behavior of the broiler chicks. In this experiment, we considered 272 one-day-old commercial broiler chicks from the Ross 308. These chicks were divided into 4 groups and each group included 4 subgroups containing 17 chicks per sub-group. The groups were: 1) Basal diet, 2) Basal diet + 25 mg/kg Semduramicin, 3) Basal diet + 60 mg/kg Salinomycin, 4) Basal diet + 12.5 mg/kg Salinomycin + 30 mg/kg Semduramicin. The features studied were weight gain, feed intake, feed conversion, calcium, sodium and potassium concentration and also carcass characteristics. The results showed that, the group receiving combined drugs, reduced the body weight at the entire period of raising and the ages of 42 and 57 days-old (p<0.05), while there was not any significant difference of weight gaining in those groups that received Salinomycin and Semduramicin (T2 and T3). The feed intake was reduced, at the age of 42-day-old in group received combined drugs (T4) (p<0.05), while there was not any significant difference in the experimental groups, considering the feed intake at the ages of 21 and 56 days-old, and during entire raising period. Feed conversion was significantly reduced in the group receiving semduramicin (T2) (p<0.05). The results showed that there was a significant effect of the kind of drug being used, on the percentage of abdominal fat and the amount of calcium in blood serum (p<0.05). These two features in the group receiving Semduramicin, were higher in relation to the other group. The mutual effect among the experimental groups on the features of weight gain, feed conversion, feed intake and also the percentage of abdominal fat and the concentration of calcium in blood serum, were significant (p<0.05).