Crop Production
Year:2013 | Volume:5 | Issue:4|Papers Count:11

Yield in most crops is resulted from a number of physiological processes which occurred during plant growth and development. These processes are realized at morphological, pheonological and physiological levels and often are controllded by many genes. In order to determine the effective of physiological traits onseed yield of soybean (Glycine max L.) cultivars and their relationship with yield components, a field study was conducted in 2010. In this study, six cultivars (Gorgan3, Sahar, Sari, DPX, Hill and Telar) and two Genotypes of soybean (032 and 033) were used in a completely randomized block design with four replications. leaf area index, dry matter and crop growth rate revealed that cultivars have the same trend. The analysis of aforementioned traits in R1 (flowering) and R5 (seed filling onset) stages indicated that cultivars had significant differences. But correlation coefficients did not confirm significant relation among traits with seed yield. Analyzed data showed yield enhancement in high- yield cultivars is stemed from high harvesting index which inturn resulted from more pod and seed number. Recorded weather data in the growing period showed the tempratuers higher than 38 to 41oC in flowering stage. Results showed that extended vegetative period faced the plants by high temperatures through delayed flowering, as thise cultivars with lower pod and seed number, had lower yield.

In order to investigate the agro-morphological and physiologic characteristics of different silage corn genotypes, an experiment was carried out at Agricultural and Natural Resource Research Center of Tehran Province during 2009-2010. In this experiment, twenty genotypes of silage corn were compared in the form of Randomized Complete Blocks Design with four replications. Evaluated traits were growth period, number of leaf, plant height, stem diameter, dry and fresh weight of leaf, stem, sheath, ear as well as dry and fresh forage yield and its quality. Correlation among studied treats showed, dried weight of stem, ear and sheath had the highest correlation with forage yield. The genotype No.2 (K3547.4×MO17) had the highest correlation in the most of investigated characteristics such as number of leaf, stem diameter, dry and fresh weight of sheath and ear, growth period and dried forage yield, but didn’t showed appropriate quality. In respect to forage quality, the genotypes of No.16 (KLM76004.2-1-7-2-1-1-1-1 ×K19.1) and No.18 (KSC670 (K3653.2×K19)) showed the highest percent of dry matter digestibility and the genotype No.2 pointed out the highest percent of crude protein, percent of dissolved fiber and ash percent. The genotype No.18 allocated the highest percent of metabolizable energy. So, it seems that the genotype No.16 with middle height but folious, middle stem weight and relatively high ear weight and produced forage quality is of particular importance and can be a suitable option for the region.

In order to investigate the effect of sodium chloride, potassium chloride and calcium chloride on organic and inorganic solutes and antioxidant enzymes activity in root and shoot of Alfalfa (Baghdaadi cultivar), a factorial experiment base on CRD was conducted using NaCl (0, 100 mmol), KCl (0, 40 mmol) and CaCl2 (0 and 20 mmol) with four replications in greenhouse of Islamic Azad University (Khorramshahr branch) at 2010. Results showed that NaCl reduced K+, Ca2+ and Mg2+ concentration in shoot and root. Applied of KCl and CaCl2 led to significant increasing of root weight. Also effect of KCl on Na+ concentration in root and shoot was significant. A negative and significant correlation was seen between Na+ and Ca2+. KCl and CaCl2 increased in Cl- concentration in root and shoot. NaCl caused to raise the chlorophyll b content while carotenoids concentration was decreased. Soluble proteins, peroxidase and ascorbat peroxidase activities were increased under NaCl stress.

This study was aimed to assess of priming effects on soluble proteins and antioxidant enzymes of as a Nigella Sativa medicinal plant under different levels of salinity and drought. Two greenhouse factorial experiments with three replicated Randomized Complete Block Design were conducted. Treatments included five levels of priming (potassium nitrate 1% and salicylic acid 0.2 mM in 6 hours, potassium nitrate 3% and salicylic acid 0.5 mM in 12 hours and hydropriming in 24 hours) as main factor and four salinity levels (Control, 75, 125 and 175 mM NaCl) and three levels of drought by osmotic potential of Control, -3 bar and -6 bar by polyethylene glycol6000 as the second factor in each experiment. Results showed that the interaction of salinity and drought stress on seed priming were significant for all traits. Soluble protein concentration decreased along with increasing drought and salinity stress and antioxidant enzymes activity, (which proline plays a protective effect against stress), and MDA were increased. But, using priming, the antioxidant enzymes activity and proline content were increased while MDA was decreased. In this study, plants treated with integrated salicylic acid, potassium nitrate and distilled water had usually higher antioxidant activity (catalase, peroxidase and polyphenol oxidase) and soluble proteins in comparison with untreated seedlings.

Environmental conditions including metrological parameters (precipitation, temperature, humidity and etc.) various stresses and nutrition, could affect germination and seeds vigor during of development, ripping and leven after harvesting of soybean seed. For this, experiments of completely randomized design (as Nested)by four replications were performed in seed laboratory of Gorgon University of Agricultural Science and Natural Resources. Treatments were 14 seed ladings of four soybean cultivars viz. of DPX (Gorgan, Gonbad, Azad-shahr Ali-abad and Kurd-koy), Sahar (Gorgan, Gonbad, Sari, Babolsar, Ali-abad and Kurd-koy), Williams (Ardabil; Gonbad) and Hill (Sari). First, standard germination and seedling growth test and then, accelerated aging test were done following by standard germination and seedling growth on degraded seeds. Results showed that environmental conditions have been caused different classes of seed vigor in seed ladings of every cultivar. Among 5 lading of DPX cultivar, Gorgon and Kurd-kuy ladings had the most and least seed vigor respectively. Babolsar and Sari ladings were superior than others in Sahar cultivar in respect to seed vigour and Kurd-kuy ladings had the least vigor (EC=26.46 ms. cm-1). Among Williams’s ladings, Ardabil lading had the most germination percentage and the least Electrolyte leading. There was significantly negative correlation between results of electrical conductivity test and seedling growth and normal seedling percentage test. Therefore, it seems that more farmer knowledge of farmers on site-specific and these environmental conditions could result in different seed vigor in the same cultivar. Environmental conditions help to select suitable area for seed production.

This experiment was conducted to investigate and evaluate the phenotypic and genotypic diversity of a population including of 94 doubled-haploids lines, their parents and five Iranian local bread wheat (Triticum aestivum L.) cultivars. Thirteen agronomic and morphologic traits were recorded including; grain yield per unit area, harvest index, spike length, seed number per spike, spikelet density, total tiller number, fertile & infertile tiller number, flag leaf length & width, plant height and number of node during four cultivation years (2006-2009) at field conditions using lattice design. The results of canonical discriminate analysis (CDA) showed that two canonical variables (components) were significant, where the 1st canonical variables including; seed number per spike (0.68), tiller number (-0.19), spikelet density (-0.4), 100 grain weight (0.33), spike length (0.3), fertile tiller number (-0.19) and grain yield (0.27), had a great contribution (0.85) in fractionating the cultivars because these trait had the most coefficients of function 1(irrespective to related sign). Moreover, the canonical factors which had important role classify were used to the groups. Cluster analysis could also categorize the cultivars in accordance to the results of CDA. In this study, the CDA has been effectively utilized to investigate genetic diversity of agronomic traits, which had the best interpretation of traits of diversity among cultivars.

Laboratory and greenhouse experiments were conducted to determine the effects of drought and salinity stress, temperature, pH and soil depth on rye germination and emergence in Gorgan University of Agricultural Science and Natural Resources. Optimum temperature for germination between 25 to 34.51 oC and base and ceiling temperatures were estimated as 3.3 and 40 oC, respectively. This volunteer plant with standed against salinity stress in respect to germination. salinity stress up to 257 mM had no effect on rye seed germination, but germination decreased as salt concentration increased. The drought and salinity levels were enough for 50% inhibition of maximum germination were as -17.9 bar and 456 mM, respectively. The optimum pH for germination of ray seeds was between 4 to 6. Germination at pH 4 to 6 was over 60%, and declined at alkaline pH levels (pH 7-9). Maximum emergence occurred when the seeds were planted at 2 cm depth. Seedling emergence was higher (70%) for seeds placed at a soil depth of 2 cm than for those placed on the soil surface (63%). Germination decreased with increasing depth and no seed emerged from a depth of 8 cm. considering that rye seeds can germinate under a wide range of environmental conditions, it is not surprising that it has became a serious invasive weed in wheat fields.

Pulses, particularly lentil, as rich sources of protein for human and animal feeding, soil nitrogen fixation and having long roots suitable for increasing depth of cultivable soil and soil fertility, have major importance in dryland cereals rotation. This research was conducted to investigate the effect of seed density and weed control on yield and its components of two lentil dryland-specific cultivars in 2009-2010 growing season. The experiment was arranged in a split-split plot scheme with a RCB design in three replications with three factors viz. cultivar at two levels (cv. Mahalli and cv. Gachsaran), weed control at two levels (control vs. non-control) and seed density at 4 levels (100, 150, 200 and 250 seeds per m2). Some important traits including pod number per plant, seed number per pod, thousand seed weight, grain yield and biological yield, were recorded during growing season. ANOVA results showed that cultivar's effect was significant at 1% of probability level only on grain yield, thousand-seed weight and harvest index. Weed control effect was significant on biological yield and number of lateral branches. Seed density had significant effect on pod number per plant, number of lateral branches, biological yield, grain yield, and harvest index. Cultivar × weed control interaction was significant only for grain yield and, finally, tertiary interaction of cultivar × weed control × seed density was not significant on any of the studied traits. mean comparisons showed that improved cultivar Gachsaran, produced the highest yield when weeds were controlled and 250 seeds m-2 was applied. In the case of cv. Mahalli, weed control and sowing 250 seeds per m-2 resulted in higher yield.

In order to study the effect of water deficit on root morphological treat of sesame, a three replicated split plot experiment was conducted based on randomized complete block design during 2008- 2009 growing season in Agriculture and Natural Resources Research Center in Parsabad, Ardabil province. In this experiment, irrigation as the main factor with three levels (100 (field capacity), 75 and 50 percent of plant water requirement) and ten sesame cultivars as the secondary factor were included. To calculate the water requirement of the sesame, the CROPWAT software (Penman- Monteith method) was used according to FAO-56. Results showed that difference between cultivars and irrigation regimes in respect to root treat was significant at root characters. Also, interaction between cultivars and irrigation regimes were significant in all traits. Comparing of means showed that under water deficit condition, all root treats (diameter, volume and surface, wet and dry mater), were reduced. In this study difference among cultivars in respect to root system was considerable and should be considered in drought résistance breeding programs. Grouping of cultivars showed that the Karaj1, and Ultan cultivars with suitable root system, were tolerant cultivars against water deficit. The Indian14 and Yellowhite cultivars had weaker root system. Generations which are derived from crossing between tolerant and susceptible cultivars could be used as segregating population in genetic and molecular studies.

In order to study the yield and forage quality of intercropping barley (Hordeum vulgare) and mustard (Sinapis alba) in different planting dates, a factorial experiment based on randomized completely block design with three replications was carried out at Farm Research Station, Gonbad –e- Qabus University. Factors were included as three planting dates (15 November, 6 and 20 December 2006) and four intercropping patterns (sole barley, 33.3% and 66.7% mustard instead of barley in replacement series, sole mustard). Delaying in planting decreased forage dry matter, plant height and protein yield, while protein percentage increased. Percentage of digestible dry matter, in soluble in acid fibers, water soluble carbohydrates and ash were not affected by planting date. The maximum forage dry matter, in soluble acid fibers percentage, protein yield and plant height. Sole cropping of mustard belonged to dry matter digestibility, protein and ash percentage belonged to sole barley. Land equivalent ratio in 66.7% and 33.3% mustard instead of barley were as 0.95 and 1, respectively. High yield of mustard comparing to barley increased intercropped treatments yield while intercropped treatments yield was lower than mustard sole cropping. generally, despite of lower protein content and digestible dry matter (as important forage quality criteria) mustard sole cropping was superior than others treatments, resulted from higher forage and protein yield.

This study was conducted in order to sustainable conservation and utilization of Trifolium genetic resources. A total of 1333 accessions of Trifolium under 32 species from 27 provinces were collected according to IPGRI descriptors. Collected germplasms are conserved in mid- and long-term conservation at National Plant Gene Bank of Iran. Statistical parameters of tendency to center and dispersion were estimated for 26 characters of samples collection site. The most collected germplasm related to T. pretense L., T. repens L. and T. resupinatum L. with 214, 188, and 142 accessions, respectively. Altitude related distribution of collection sites were differed from -21 m in Noshahar to 2850 m in Orumieh and Marand. The results revealed that over grazing and natural erosion were as the most important factors resulted in genetic erosion of Trifolium genetic resources in Iran. Whereas agriculture was not an effective factor on genetic erosion of clover landraces, because the farmers prefere to conserve their landraces. A few numbers of T. pretense, T. repens and T. resupinatum accessions were collected from saline sites. Distribution of clover species showed that West and North-West of the country could be considered as primary centers of clover genetic diversity in Iran.