Journal of Plant Production Research
Year:2015 | Volume:22 | Issue:1|Papers Count:15

Land evaluation and its consistency with simulation model’s outputs could assist decision making to develop plants for cultivation. In this study land suitability and potential yield of cumin was determined using CUMMOD and sum of values method by climatic and topographic factors, respectively, as a case study in Khorasans provinces. Results revealed that despite of the majority of favorable and completely favorable zones, potential yield was not the same in studied provinces. The CUMMOD results revealed that southern, a part of central and a part of northern areas of northern Khorasan province have considerable capability to produce cumin (2.5 to 3 ton ha-1). Potential yield was in two classified ranges as 2-2.5 ton ha-1 and <2 ton ha-1, while, predicted potential yield for central and southern parts of South Khorasan province was <2 ton ha-1 and 2-2.5 ton ha-1 for corresponding northern parts. Slope and aspect for northern, aspect and maximum temperature for Razavi and maximum temperature for southern Khorasan were the most limiting factors. In this study, although limiting factors were detected, but the majority of zones were located in favorable and completely favorable zones, because sum of values method avoids exaggerated effects of some factors. Therefore, results are more realistic. Overall, our results confirmed that the potential yield will decrease along with moving from northern Khorasan province toward South Khorasan province, which stems from shortening of the growing season.

In order to evaluation of the process of genetic improvement rate and duration of grain filling among wheat cultivars, the field experiments were conducted at the Agricultural and Natural Resource Research Center of Golestan province. in the growing seasons of 2007-2008 and 2008-2009. The 16 cultivars were sown in a randomized complete blocks design with three replications. The results showed that wheat cultivars had not changed during breeding activities in order to improve yield in grain weight and duration of grain filling while rate of grain filling was increased. Also rate of grain filling was improved %26.19, in 38 years of the release, was observed %0.7 and it improvement. This increase was due to increasing grain number per unit area. In order to positive and significant correlation between grain filling rate and grain yield it seems that selection for high yield and grain filling rate is possible without the need to increase of grain filling duration.

The hydrothermal time models have been widely applied to describe the germination responses of seeds to temperature and water potential. In this study, three hydrothermal time models developed on the basis of different statistical distributions (Normal, Weibull and Gumbel) were compared to describe the Phalaris minor seed germination. Results showed that Gumbel (AICc=-762.8) and Weibull (AICc=-762.6) hydrothermal time models more accurately predicted P. minor germination than Normal (AICc=-737.6) hydrothermal time model. However, there was no significant difference among values of predicted hydrothermal time constant, base temperature and median base water potential ( yb(50)) for germination of P. minor using all three models and were estimated to be 1000 MPaoC h, 4.2oC and -1 MPa, respectively. Based on the Weibull hydrothermal time model, water potential threshold for the onset of germination (yb(0)) was equal to -1.5 MPa. Also, the distribution of base water potential for germination was right skewed (l=1.57). Weibull hydrothermal time model can be widely used to predict seed germination by considering the flexibility of distribution, the possibility of determining the base water potential distribution skewness and estimation of water potential threshold for the onset of germination.

Golestan province is one of the main tobacco growing regions in the country. Tobacco Streak Virus (TSV) is a destructive pathogen on tobacco that has a wide host range and occurs worldwide. In order to serological detection of TSV at 13 region of Golestan province, 500 infected samples belong to 8 families; Chenopodiacae, Amaranthaceae, Fabaceae, Solanaceae, Malvaceae, Poaceae, Cucurbitaceae and Asteraceae with leaf distortion, stunting, mosaic, yellowing, necrosis and terminal bud blight symptoms, were collected and tested by the DASELISA method using specific polyclonal antibody. The results showed 78 positive reactions out of 500 samples in ELISA tests. The infection of peanut, dahlia, tobacco, mung bean, common bean, soybean, pepper and potato was positive to TSV, and negative for other plants in ELISA test. Some of ELISA positive samples were selected and their extracts in phosphate buffer 0.1M, pH 7.4 containing mercaptoethanol was mechanically inoculated on indicator plants, tobacco, fat-hen and tomato. TSV infection was confirmed by ELISA on indicator plants. The mechanical inoculation of different isolates of 8 mentioned hosts on tobacco and tomato, caused similar symptoms.

Some research indicates that N2 fixation in soybean cannot provide adequate nitrogen for proper yield. Therefore, the effect of nitrogen and Bradyrhizobium Japonicum bacteria on some agronomic characteristics and quality of soybean cultivars was examined based on split plot in a randomized complete blocks design with three replications in 2012 at Kerman Township. Treatments including control (without fertilizer and inoculation), 200 kg/ha urea, inoculation of soybean seeds with Bradyrhizobium Japonicum bacteria, inoculation of soybean seeds with Bradyrhizobium Japonicum bacteria along with 50 kg/ha urea were considered as the main factor. Soybean cultivars (M7, Williams and L17 line) were arranged as the sub factor. The results showed that significant effect of fertilizer treatments on plant height, internode length, number of pods per plant, number and weight of nodes in root, 1000 seed weight, seed yield, oil percentage, oil yield and protein percentage. All the mentioned traits except oil percentage and number and weight of nodes in root increased by 200 kg/ha urea application. Inoculation of soybean seeds with Bradyrhizobium Japonicum bacteria increased oil percentage. L17 showed the highest plant height and number of pods per plant. Also, Williams, that enlargement in internode length than other cultivars. M7 cultivar produced the highest 1000 seed weight. L17 had the highest oil percentage as affected by seed inoculation with Bradyrhizobium Japonicum bacteria. According to the results of this experiment in order to obtain highest oil and protein content in soybean under Kerman and similar climatic conditions application of 200 kg/ha urea and cultivation of L17 is recommended.

Considering the extent of salinity in soils of Iran, abiotic stresses such as salinity are serious threat to agricultural production, yield and essential oil of medicinal plants. Recognition of threshold for salt tolerance and determining the slope of yield loss in medicinal plants has an important role in the selection of suitable lands for their cultivation. The effect of salinity stress on soluble compound, relative water content (RWC) and biochemical indices were investigated in German chamomile (Matricaria chamomilla L.). This study was conducted in a randomized complete blocks design with three replications. Because the control salinity levels in the soil, during the experimental period was difficult, the hydroponic culture was used to do this research. Electrical conductivity (EC) levels were included: 2 (control, 50% of Hoagland solution), 4, 8, 12 and 16 dS.m-1 by NaCl salt. The results showed that with increasing salinity, chlorophyll a content was 29.9% and significantly decreased (P£0.01). With increasing salinity chlorophyll b, carotenoids and anthocyanin decreased 39.7, 22.7, 11.1 percent respectively, and were significant (P£0.05). Proline content measurement showed significantly increased (79.5%) with increasing salinity. Leaf relative water content (RWC) also significantly increased (20.1%) with increasing salinity (P£0.01). In general, the salinity stress was effective on physiological processes of chamomile and optimal yield was obtained in salinity 2 dS.m-1.

In order to study the effects of growth promoting bacteria (GPR) and mycorrhizal fungi on seedling emergence, establishment and growth of two ecotypes alfalfa under salinity stress condition, an experiment was conducted in greenhouse of college of agriculture and natural resources, University of Tehran in summer 2011. The experiment was arranged as a factorial with three replications. Experimental treatments including: three levels of salinity stress (0 (S0), 60 (S1) and 120 (S2) mm), two levels of alfalfa cultivars (Bami and Yazdi) and eleven levels of Bio-treatments. The bio-treatments were four growth promoting rhizobacteria (Azetobacter, Azospirillum, Pseudomonas and Sinorhizobium meliloti) along with mycorrhiza in single form, four different double integrated forms of Sinorhizobium meliloti with other bio- treatments as well as a quintuplet form of all bio- treatments. The results indicated that applying salt stress significantly decreased seedling emergence, establishment and alfalfa biomass. The descending trend in control treatment was more than that of treated seeds. Appling bacterial priming especially pseudomonas priming and compiled treatments played an important role in moderating the negative effects of salinity on measured traits. With respect to the results of this study, it seems that plant growth promoting bacteria and mycorrhiza by an improvement in water and nutrient absorption, improve plant growth in salinity stress condition.

In order to evaluate the genetic diversity and identify quantitative trait loci (QTL) controlling agro-morphological triats such as leaf length, leaf width, leaf number, internode distance, dried leaf yield per plot, plant height and stem girth, the genetic population including 225 F2:3 families from the cross between two oriental-type tobacco genotypes ‘SPT 406 (paternal) × Basma seres 31 (maternal) were evaluated with sample lattice design under field conditions. Statistical analysis revealed a meaningful difference among F2:3 families for studied traits except for internode distance. Genetic diversity was evaluated by using multivariate statistical methods such as cluster analysis and principal components analysis. By using principal components analysis and cluster analysis via Ward method, the studied F2:3 families were classified into four different groups. QTLs were mapped using a linkage map comprising 23 SSR and 19 ISSR amrkers. 18 QTLs were detected for the studied traits in F2:3 generation and maximum number of QTLs was identified for the leaf number trait.

In order to study of hydropriming, planting depth and nitrogen split application effect on yield and yield components of double cross hybrid of corn, an experiment was carried out as factorial based on randomized complete block design (RCBD) with four replications. Nitrogen split application included (400 kg/ha at sowing date, 100 kg/ha at sowing date and 300 kg/ha 25 to 50 days after sowing date, and 100 kg/ha at sowing date, 150 kg/ha 25 to 50 days after sowing date and 150 kg/ha 50-70 days after sowing date) as first factor, hydropriming levels included (prime and non prime) as second factor and planting depth included (5 and 10 cm soil depth). Results showed that hydropriming and nitrogen split application affected of grain yield, biological yield, 1000-seed weight, number of seed per ear, number of row per ear, plant height, ear length, ear weight, cub weight and cub diameter. All of studied traits except 1000-seed weight and number of seed row per ear affected significantly by planting depth. Interaction between hydropriming and nitrogen split application significantly affected grain yield, biological yield, 1000-seeds weight, plant height and ear weight.

In order to Study of nutritional role of silicon nano-particles on physiological characteristics of minituber potato production an experiment was carried out as factorial based on randomized complete blocks design with three replications in hydroponic culture at Ferdowsi University, Mashhad. Treatments were included particle size of sodium silicate (nano and micro) and concentrations in levels of 0, 0.3, 0.6 and 0.9 mM. Concentration of 0.3 mM sodium silicate has the highest positive effect on stomatal conductance, maximum chlorophyll fluorescence, quantum yield of photosystem II, yield and number of minituber per plant by 8.3, 6.1, 2.6, 26.6 and 34.5 percent increase, respectively. But, leaf chlorophyll index increased up to 0.6 mM level, significantly. At 0.6 and 0.9 mM, application of nano-particles had negative effect on the quantum yield of photosystem II. At each level of concentration, positive effect of nano-particles on membrane stability index was greater than micro particles and only at the highest concentration, there was no statistical difference between two particle sizes. Minituber yield significantly increased by increasing concentration of micro particles, but positive effect of nano-particles on mentioned trait was up to 0.3 mM. Overall, positive effects of nanoparticles application due to high absorption efficiency, appeared at low concentrations, but, at higher levels it had phytotoxin effects on physiological characteristics and potato yield.

Achieving the self-sufficiency in producing agricultural crops and decreasing the pressure on the available water resources need determining the fertile places for cultivation based on the suitable evaluating indices. In this research, the prioritization of different township in Sistan and Blouchestan Province for onion cultivation, as one of the most important production in the province, was carried out. In order to, the weather data, yield, cultivated area and irrigation method were used through 2000 to 2011. The prioritizing was done based on virtual water, unit water value and economical irrigation water use efficiency indices. Sistan and Bluchestan was self-sufficient in onion producing. The 12-year average excess onion production was 38.6 thousand ton, 70 percentages of which was produced in Sarbaz and Chabahar townships. More than 65 percentages of the onion cultivated area are located in the suitable cultivation class based on the evaluating indices. However, decreasing the cultivated area in Konarak, Chabahar and Iranshahr and allocating them to Sarbaz or Khash would considerably increase the annual return of onion cultivation. The result showed that applying a suitable spatial cultivation management and promoting the irrigation efficiency to 85 percentages would increase the economical irrigation water use efficiency by 123.68 percentages which would led to 13554.9 to 56809.2 Rs increase in the economic return of onion cultivation per unit cub meter water use.

In order to investigate the effect of crop rotation on relation of seed bank with nightshade (Solanum nigrum L.) weed seedling population during the growth season of corn, a field experiment was carried out in Dasht-Naz Crop Company in Sari, during 2012. At the first, farm was divided into 2×2 m networks and the cross points was signed and all sampling were taken from those points. Sampling of seed bank and nightshade seedlings were done in two and three stages, respectively. Spatial distribution maps at the end of cropping season indicted that patches with high density of weed seed increased in corn-faba bean-corn rotation while decreased in soybean-wheat-corn rotation. There were strong and medium correlations for nightshade weed seeds at all sampling stages. Also, two crop rotations had a significant difference in terms of seeds averages and emerged seedlings. Since, seeds averages and emerged seedlings were lower in corn-faba bean-corn rotation than corn-wheat-corn rotation; therefore, faba bean was more appropriate in rotation with corn to reduce nightshade weed density not only in the field but also within seed bank.

Fusarium root and foot rot of wheat is caused by the fungus Gibberella zeae (Fusarium graminearum). This disease causes significant yield loss under infested soil and favourable condition. The aim of this study was to evaluate the efficacy of selected fungus strains against the wheat soil-borne pathogen F. graminearum under greenhouse and field conditions. The most potent isolates were 3 isolates (all of isolates were identified as Trichiderma harzianum) out of 15 isolates, which have numbers 2, 10 and 12. These isolates were selected for the following experiments. Mycelial growth of F. graminearum (F3) was reduced by cell free and volatile metabolites of Trichoderma harzianum strains. T. harzianum strains 12 significantly (P£0.5) reduced the incidence (8.3%) and severity (4.1%) of disease, 35 days after inoculation and increased the 1000 grain weight (38 g) in greenhouse conditions. For confirmation of the greenhouse tests, the selected antagonists were reexamined in field trials. This strain could also reduce the disease incidence (10%) and severity (3.1%).

This study examined the environmental impacts of irrigated and rainfed barley agroecosystems of Iran based on nitrogen levels by using LCA methodology during 1999-2013. Four steps includung goal definition and scoping, inventory analysis, life cycle impact assessment and integration & interpretation were considered. Impact categories were acidification, eutrophication and global warming. Functional unit was considered as one tonne grains. The results revealed that the maximum aquatic eutrophication for irrigated and dryland barley were 2.42 and 1.64 PO4 equiv./t grain for 140-180 and 30-40 kg N ha-1, respectively. In irrigated barley agroecosystem, the maximum global warming was computed 898.24 CO2 equiv./t grain for 140-180 kg N ha-1 and it was 604.66 CO2 equiv./t grain in dryland for 30-40 kg N ha-1. Eco-Index ranges for irrigated and rainfed agroecosystems were computed with 0.27-0.46 and 0.28-0.31 per one tonne grain for aquatic eutrophication and acidification, respectively.