JOURNAL OF RESEARCH IN CROP SCIENCES
Year:2009 | Volume:2 | Issue:5|Papers Count:10

An evaluation on the effects of drought stress on plant height, height of first capitul from land surface, capiltul diagonal, the number of the lateral branches, nucleus ratio to total seed, seed yield and oil percentage in spring safflower was carried out in Research center of Agricultural and Natural Resources in East Azerbaijan, during 2007. The experiment was factorial including 2 safflower cultivars (local in Arak-2811 and local in Isfahan) and 4 irrigation levels (non stress and drought stress during stem elongation, flowering and seed filling stages) based on complete randomized block design with 3 replications. The results indicated significant decrease by drought stress on plant height, height of first capiltul from land surface, capiltul diagonal, nucleus ratio to total seed and seed yield. The influence of irrigation cutting at stem elongation stage caused the plant height and height of first capiltul from land surface to be reduced; also drought stress affected on capiltul diagonal and nucleus ratio to total seed, and its decrease, by irrigation cutting at seed filling stage. Under the influence of drought stress the rate of seed yield was also reduced, which reached from 3263/5 kg per hectare at normal irrigation to 2388/5 kg per hectare by irrigation cutting at flowering stage squinty. The attained results showed that, the number of lateral branches and oil percentage weren’t affected by drought stress and that there was a significant effect between cultivars about seed yield and oil percentage. Generally it can be concluded that Isfahan local cultivar with average of 2978/75 kg per hectare having most seed yield excelled over Arak-2811 local cultivar with average of 2735/66 kg per hectare, so is recommended.

To study the effects of fertilizers containing microelements Zn, B and Mn on the quality and quantity of sugar beet, an experiment was conducted at Miandoab Agriculture Research Station in 1385. The experimental design was Randomized Complete Blocks in a Factorial arrangement with 3 replications and 3 treatments. Each of The factors A (Zn fertilizer), B (Boric acid) and C (Mn fertilizer) were at three levels without control, usage of the recommended amount and use of fertilizers two times as much as recommend amount with simple, double and triple effects in the form of solution-spray application. The main root, tail, root (trunk), crown and the scalp were pulped to study the traits. The analysis of variance and mean comparison of data were calculated. Results of this study for tail, trunk (root), crown and head showed the effectiveness of fertilizers Zn, Mn and those they out ranked the check and two-fold application regarding % pure sugar, % impure sugar, root yield, extraction coefficient and pure sugar yield. The combined effects of Zn, B and Mn on the quality of sugar beet head and crown were more efficient and significant. Among applied fertilizers Zn and Mn outranked B (Boric Acid), so that the foliar sprays with Mn and Zn had greater means regarding the studied traits. Foliar sprays with Zn and Mn in view of root impurities were significant and had a sharp decrease relative to the control. In each one of root sections the fertilizer application according to recommended amount relative to the control and two-fold of the recommended amount had increase in pure sugar and extraction coefficiency. By the mean comparison of sugar content, tail, crown and head placed at 1st, 2nd, 3rd and 4th levels, respectively. The use of Zn and Mn in form of foliar sprays not only increases quality and quantity of sugar beet but also this method can have considerable economic aspects in reduction of fertilizers costs including: quick removal of deficit, easy function, lack of pollution in underground water and decrease in toxicity resulting from accumulation of elements.

The main objective of this research is to compare two different irrigation methods according to parametric evaluation System in an area of 15831 hectares in Kheran plain in Khuzestan province. Soil properties of the Study area including texture, depth, electro- conductivity, drainage, calcium carbonate content and slope were derived from a semi- detailed soil study regarding Kheran plain in a scale of 1: 25000. After analyzing and evaluating soil properties by means of Geographic Information System (GIS), suitability maps were generated for both methods. The results showed that about 3444 hectares of the under study process lands for level-irrigation method and merely 163 hectares expected for drop-irrigation are highly suitable and furthermore, about 9482 hectares are moderately suitable for drop-irrigation, and in both irrigating methods soil sery code 3, with an area about 406 hectares has been recognized inappropriate at the time being. The main limiting factors in using both gravity and drop irrigation methods in this area were soil salinity and drainge and the drop irrigation method added calcium carbonate to them.

To investigate nitrogen stress and plant density on agronomic traits of rice (Tarom variety) in different growing and developing stages, an experiment was carried out in split plot on the basis of Completely Randomized Block Design with three replications in Amole Region in 2008. Main factor was nitrogen stress in three levels (start of tillering, panicle initiation, complete panicle stage and control) and plant density as a sub factor in three levels (80, 120, 160 plant m-2). Results showed that lack of nitrogen use in the start tillering stage caused plant height to decrease and increase panicle number per m2. Nitrogen stresses in complete panicle stage caused, a decrease in 1000-grain weight, panicle number m-2 and fourth internodes bending moment. Plant height, effective tiller per hill and fourth internodes bending moment were decreased in amount of 6, 9, 46, 3 and 18.7 percent with increased in density until 160 plants per m2 respectively but panicle numbers m-2 was increased 15%. Interactive effects of nitrogen stress with plant density had significant effect on plant height at 5% probability level.

To compare the yield and study the effects of drought stress on five bread wheat (Triticum aestivum) varieties under irrigated and non-irrigated conditions and experiment was conducted in a RCBD (Randomized Complete Block Design) with three replications. Five bread wheat varieties (Chamran, Atrak, Zagros, Koohdasht, and Chanab) were cultivated both in irrigated and non-irrigated conditions in Saleh Abad, Ilam Province, 2005-06. Attributes, including plant height, length of spike, number of seeds per spike, 1000 kernels weight, yield and also phenologic traits were measured. Analysis of variance showed that most of attributes differed significantly in two conditions. The results indicated that Seed yield had significant positive correlation with phenologic traits, such as days to heading, days to maturity, seed filling period, number of spikelet per spike, and number of seed per spike and negative correlation was observed only with plant height and 1000 kernels weight. Results of stepwise regression indicated that when the seed yield considered as the dependent variable, number of seed per spike and spikelet per spike and 1000 kernels weight had the most influence on yield and accounted for nearly %93 and %96 of yield variation in irrigated and non–irrigated conditions, respectively. Principal components analysis under non-stress condition showed that the four principle components included 95.3% of total variance as: yield attributes elongation growth, 1000 kernels weight, and yield components, respectively. Under drought stress condition five principal components included %95.18 of total variance as: yield attributes and elongation growth components, respectively. Finally, these results can be used for breeding programs and selection of high yield drought tolerant varieties by using a desirable compound of characteristics.

To study of drought stress tolerance by using chemical desiccation in the bread wheat genotypes, the present examination was carried out by RCBD split plot design with two main plots (rain fed and supplemental irrigation), and 20 wheat genotypes (sub plots) with three replications, during 2007-2008 crop season in Meragheh Dry Land Agricultural Research Station. Wheat genotypes were sprayed three days after anthesis by NaClO3 and KCa solutions 3.5% for creating artificial stress (disordered photosynthesis). Result analysis variance showed that, under the supplemental irrigation there were significant differences between genotypes in grain yield and 1000 kernel weights. Also, under drought stress conditions there were significant differences between genotypes in 1000 kernel weight but no significant differences in grain yield. Spraying of KCa and NaClO3 caused a reduction in grain yield and 1000 kernel weight. Using chemical desiccation under supplemental irrigation caused a reduced 20% of grain reduction yield and also 1000 kernel was reduced about 7% with spray. This yield reduction is probably attributed to photosynthesis stop after the chemical (KCa and NaClO3) spray. In general genotypes with and without spraying showed high stability to grain weight and were considered drought tolerant. Therefore chemical desiccation can be used as a drought tolerance selection criterion in wheat breeding programs.

Simple sequence repeat (SSR) markers are valuable tools for many purposes, such as mapping, fingerprinting, and breeding programs. However, they are only available in some economically important crops because of the high cost and labor intensity involved in their development. Comparative mapping reveals a high degree of colinearity between closely related species and genera, which allows the exchange of markers between them. Our objective was to examine the transferability of sorghum SSR markers to sugarcane (Saccharum spp) and maize (Zea mays). Of 29 sorghum SSR markers, 20.7% and 6.9% were amplified in sugarcane and maize, respectively. SSR markers were informative, even though only six varieties of each species were examined. The number of fragments amplified by the polymorphic primers ranged from 4 to 9 with an average of 6.2 and 2-3 with an average of 2.5 in sugarcane and maize, respectively. Fragments amplified revealed size variation in target species, as compared to the sorghum markers. One marker, amplified among three related species, suggested that these allelic regions of the primer binding sites were conserved. These markers with transferability between species can be used for breeding and genetics studies.

Tomato Fusarium wilt disease is one of the most important diseases of tomato in East Azerbaijan Province. Relative resistance of some common tomato cultivars originated from U.S.A, Italy, Denmark and Iran was evaluated in greenhouse. Young seedlings of Linda, Urbana, Mobil, Super Chif, Super Stren B, Laleh and native cultivars were inoculated and percentage of infected leaves was used as the evaluation index. Results showed that Super Stren B was the most resistant cultivar among tested cultivars. Mobil (21/88%), native (14/06%), Laleh (10/94%) and Super Chif (7/813%) was known as semi-resistant and Linda (45/31%) and Urbana (28/13%) was known as tolerant.