Iranian Journal of Field Crops Research
Year:2005 | Volume:3 | Issue:1|Papers Count:21

In order to relate production of saffron and utilization of nutrients, a study was conducted in 2001 and 2002. Four selected locations for this study were Birjand, Gonabad, Qaen and Torbat- Haydariah, which are the main saffron production centers in Iran. This study was performed in 160 saffton farms, aged between 1 and 5 years. Manure, nitrogen and phosphorous fertilizers showed a positive linear relation with yield and length of flowering period, while nitrogen and phosphorous showed a negative linear relation with start of flowering period. Yield of saffron showed a significant and positive correlation with the amount of applied manure and the saffton farms with age 4-5 year had highest yield. Our results showed that manure was the most effective factor in production of saffton. The beneficial effects of manure could be due to slow release of nutrients and enhancing soil physical properties. Stepwise regression analysis of yield and fertilizer application showed that 67 percent of yield variations was attributed to manure and phosphorous application.

Effect of 13 planting depths and 6 flooding periods on germination and emergence of swallow wort were investigated under greenhouse conditions. Results showed that swallow wort seeds emerged from up to 6 cm depth. The highest emergence occurred in the first, second, third and fourth week after emergence from 0.5 cm; 0.5, 1 and 1.5 cm; 1.5 cm; and 1.5 cm planting depth, respectively. At the end of the fourth week, 6.5 cm depth treatment had zero emergence. Increasing burial depth resulted in induced secondary dormancy. Increasing flooding period, did not affect germination percentage. However, fresh weight, radicle and hypocotyle lengths under flooding conditions were decreased significantly compared to control. Seeds flooded for 3 and 21 days had the highest and lowest fresh weight, respectively. Hypocotyle length was highest under zero and one day flooding treatments, but lowest under 14 days flooding treatment.Radicle length was highest under 0, 1, 3 and 7 days flooding treatments and lowest under 14 and 21 days flooding treatments.

In order to determine the best seed vigor test in laboratory which may provide high correlation between alfalfa seedling stablishment in the field, two experiments were conducted in field as well as in laboratory. Four alfalfa cultivars Bami, Ghareyonjeh, Hamadani and Yazdi were used. Different seed vigor tests including standard germination, germination in low temperature (50C), germination rate, osmotic stress, accelerated ageing and electrical conductivity tests were laid out in a randomized completely design (RCD) with four replications in laboratory experiment. The second experiment was carried out in a randomized completely block design (RCBD) and each treatment replicated four times. Results revealed significant differences p£0.01) among different cultivars for establishment percentage and rate. Results also showed that there were significant correlations between electrical conductivity test and establishment percentage (r= -0.65, p £ 0.01) as well as establishment rate (r= -0.80, p £0.01). Correlation coefficients for rate and emergence percentage were significant and positive (r= 0.91, p £0.01).Stepwise method disclosed that the regression model (y=165.23 - 0.15 x, r2 =0.64), (p£0.01) for predicting rate of emergence could be recommended. In this model x (dependent variable) is value of electrical conductivity and y (independent variable) is rate of emergence.

In order to study the effect of drought stress on morphological and physiological characteristics of millets, a field experiment was arranged in a randomized complete block as a split-plot design with three replications during 2004 growing season at Research Farm of Ferdowsi University of Mashhad.Irrigation intervals (weekly interval, 14-day interval) and. three types of millet (Pennisetum glaucum, Setaria italica and Panicum miliaceum) were allocated to main and sub plots, respectively. Results showed that, grain yield, panicle weight, grain weight, number of tillers, number of fertile tillers, panicle harvest index, leaf area and percentage of nitrogen leaf was not affected by water stress treatment Although, type of millets had significant effect on these traits. Exposure of plants to water stress led to noticeable decreases in plant height for all three cultivars. In this experiment, grain yield, plant height, panicle weight, grain weight, panicle harvest index and percentage of nitrogen of Panicum miliaceum was lowest, also Pennisetum glaucum had relatively highest grain leaf yield, panicle weight, leaf area and percentage of leaf nitrogen and had favorable production potential in semi-arid tropical regions.

In order to study the effects of amount and timing of nitrogen application and weed density on wild mustard (Sinapis arvensis) seed production in winter wheat, an experiment was conducted in 2001 at Research Farm of College of Agriculture, Ferdowsi University of Mashhad. A Split plot design with three replications were used with factorial combination of weed density (0, 8, 16, and 32 plant/m2) and nitrogen (low=100, optimum= 150, and high= 225 kg/ha) as main plots. The sub plot factor included nitrogen splitting pattern (P1=1/3 at planting time+2/3 at tillering, P2= 1/3 at planting time + 1/3 at tillering + 1/3 at shooting). According to the results, wild mustard seed production increased with increasing wild mustard density and nitrogen rates, due to high wild mustard biomass production. Seed production of wild mustard was 161, 311, and 488 million/ha in low, optimum and high nitrogen rates, respectively. In the other hand, density and nitrogen rates had a significant effect on wild mustard fecundity: However, nitrogen splitting pattern showed no significant effect on wild mustard seed production.

In order to study the effects of different irrigation intervals and plant density on morphological characteristics, grain and oil yields of sesame, an experiment was conducted at Research Farm, College of Agriculture, Ferdowsi University of Mashhad. Four different irrigation intervals (one, two, three and four weeks) with four plant densities (20, 30, 40 and 50 plants/m2) were compared in a spilt plot arrangement based on randomized complete block design with four replications. irrigation intervals and plant densities allocated in main plots and subplots, respectively. Different characteristics such as plant height, distance of first capsule from soil surface, number of branches per plant, number of grains per capsule, number of capsules per plant, grain yield, 1000-seed weight, harvest index and oil yield were recorded. The results showed that there were no significant difference between different irrigation intervals in terms of distance of first capsule from soil surface, number of grains per capsule, 1000-seed weight and harvest index. Different irrigation intervals had significant effects on plant height, number of branches per plant, number of capsules per plant, grain yield and oil yield. There were significant differences between different plant densities in terms of distance of first capsule from soil surface, number of branches per plant, number of grains per capsule, number of capsules per plant, grain yield, harvest index and oil yield. The highest grain yield (798/7 kg/ha) and oil yield (412/8 kg/ha) were obtained at one week and four weeks irrigation intervals, respectively. Between all treatments, 50 plants/m2 and one week irrigation interval produced the highest grain yield (914/7 kg/ha) and oil yield (478/6 kg/ha). Because of shortage of water in Mashhad condition, the results recommended that, 50 plants/m2 and two weeks irrigation interval produced rather acceptable grain yield, with less water consumption.

Lentil (Lens culinaris Medik.) is one of the traditional pulses of arid and semi-arid regions which is cultivated under rainfed conditions. Germination is one of the main growth stages that successfulness in this stage is dependent on moisture content of soil at time of planting. This study examined germination characteristics of 12 lentil genotypes (MLC 129,MLC 4, MLC 13, MLC 40, MLC 232, MLC 80, MLC 191, MLC 187, MLC 183, MLC 179, MLC 245, ML313) under five levels of negative water potential (0, -4 , -8 , -12 , -16 bar) using a 5x12 factorial experiment based on a completely randomized design with three replications. Water potential significantly reduced germination percentage, germination rate, radicle and plumule length, radicle and plumule dry weight. The genotypes showed a significant difference in all traits except radicle to plumule ratio and radicle to plumule dry weight ratio. Based on this result plumule length as a plantlet trait and -8, -12 bars as negative water potential are suggested for evaluating drought resistance of lentil genotypes to water stress.

In order to evaluate effects of different treatments on breaking dormancy of Teucrium polium, an experiment was conducted with 3 replications in a completely randomized design. Seeds were subjected to different treatments including various levels of GA3, H2SO4, soaking with water and chilling. Germination of Teucrium polium increased with different concentrations of GA3. Percentage germination Maximum and rate was obtained at concentrations of 250, 1500 ppm (72h) GA3 and combination of GA3 (1500 ppm) and chilling (5°C) for a period of 14 days.GA3 (500 ppm) increased germination percentage but not germination rate. Soaking with water broke dormancy and induced 32% seed germination of Teucrium polium, but H2SO4, freezing (-10°C) and combination of both treatments had no effect on dormancy.

Species composition in weed seed bank was studied in low, medium and high input wheat fields. Two fields were selected for each input level based on the intensity of external inputs, e. g. chemical fertilizers, pesticides (in particular herbicides) and soil manipulation. Soil samples from 0-30 cm depth were taken systematically at 40 points in each field. Sampling was conducted in spring (early growing season) and autumn (end of growing season) and weed seeds in the soil seedbank were identified using standard methods. Total numbers of 18 weed species, mainly annual broad leaves, were extracted in three input levels and two samplings. Shannon diversity index (H) for weed seedbank was generally low (H<1) but low input system had higher species diversity compared to other input levels. Species similarity between two sampling was highest in the fields with the same input level. However, similarity index reduced when field with different input levels were compared. Size of seedbank was at maximum in the lowest input but decreased with increasing input levels. In all input levels a significant linear relationship was obtained between seedbank size at the start and the end of the growing season. The slope of regression line was 0.77, 0.54 and 0.47 for low, medium and high input systems, respectively. Based on these results in high input systems only 47% of initial seeds in the weed seedbank were expected to regenerate by the end of growing season. It was concluded that in low input systems the life cycle of weed is completed successfully therefore, seedbank would restructure by the end of growing season.However, increasing input levels, especially herbicides, will lead to a reduction in reproduction ability of weeds.

In order to evaluate drought tolerance of chickpea genotypes and identifying the best indices of drought tolerance, an experiment was conducted at two regions of research field in Mashhad Collage of Agriculture and Agricultural Research Station in Nishabour in 2003 growing season. The 34 genotypes were tested using a randomized complete block design under two irrigated (non stress) and rainfed (stress) conditions. Quantitive drought tolerance and susceptibility indices such as Stress Tolerance Index (STI), Stress Susceptibility Index (SS!), Mean Productivity (MP), Harmonic Mean (HM), Tolerance Index (TOL) and Geometric Mean Productivity (GMP) based on yield in stress and non stress conditions were calculated.Significant differences were found among the genotypes for drought tolerance indices with exception of TOL and SSI .The highest yield was found in genotype numbers of 4,5,16,17,18,19 and 31 respectively genotypes ICCV 93040, ICCV 93042, MCC 13, MCC 448, MCC 5, MCC 10, MCC 16 in non stress conditions but genotype numbers 4,16 and 19 showed merely the highest yield in stress conditions in two regions. Results of regression analysis showed that MP, GMP, STI and HM indices had positive and high significance correlation with yield in stress and non stress conditions. These results indicate that MP, GMP, STI and HM are the most suitable criteria for screening drought resistant genotypes. Base on these criteria, genotype numbers of 4,16 and 19 that have the highest yield in stress and non stress conditions and rest near to vectors of drought resistance indices like MP, GMP, STI and HM in multivariate biplot space, Therefore, these genotypes may be recommended as drought tolerant genotypes in this study.

In order to study the dormancy breaking techniques of Ferula gummosa seeds and also determining the optimum planting date of this species, an experiment was conducted during 2003 and 2004 in Faculty of Agriculture, Ferdowsi University of Mashhad. A factorial experiment based on a Completely Randomized Design with two factors, washing seeds with tap water and unwashed control, and constant temperatures of 2, 5, g and 11°C, with four replications was used. Percentage of germination and germination rate were counted with daily interval. In addition the effects of different planting dates including, 22 March, 24 September and 23 December, on Ferula gummosa plantlets emergence, in pots and field conditions were studied in a Randomized Complete Block Design with four replications. Results showed that the maximum percentage of germination (97.5%) and germination rate (1.5 seeds per day) were obtained at 8 °c in washed treatment. Washing seeds with tap water increased percentage of germination (32-72%) in all temperature treatments; significantly. Increasing temperature above g 8 °c decreased germination rate and percentage of germination in both washed and unwashed (control) treatments, significantly. Our results showed that the maximum emergence (percentage), of Ferula gummosa was obtained in autumn and winter planting dates. No emergence of seedings was observed at spring planting date.

In order to develop a sustainability index (SI) for quantifying the sustainability of a wheat-cotton agroecosystem, a study was conducted in 2003 in the Khorassan province. Data of socio-economic, agronomic and ecological indicators were collected using 518 questionnaires. Results showed that only 18.6 percent of farmers gained the half or more of SI scores. The mean SI score was 44.0 which indicate that these agro ecosystems are not sustainable. Results of this study are in consistent with other reports in other regions of the country. Livestock production, crop production, and water and irrigation indicators had the lowest score (6, 31, and 37, respectively). The backward stepwise regression analysis indicated that SI can be predicted from a linear combination of field size, wheat yield, crop residue management, crop income and education and extension services, while application of chemical fertilizers did not add to the prediction ability of SI. Results also showed that any progress in farmers' education, economic viability, crop production management and water use efficiency could improve overall sustainability of these agroecosystems substantially.

Although some cold tolerant chickpeas have been recognized for fall planting in the highlands of Northeastern Iran, there is no information about the growth and development of these accessions. The study was undertaken to evaluate the phenology and morphology of cold tolerant chickpeas in fall and spring planting. Thirty three chickpea genotypes (32 cold tolerant genotypes and one susceptible genotyp) across four planting date (28 Sep., 16 act., 2 Nov. and 7 Mar.) were sown during 2000-2001 growing season at the Research Farm of College of agriculture, Ferdowsi University of Mashhad as a split plot design with two replications. The planting dates were imposed as main plot and chickpea genotypes as subplot. Effects of planting dates on days from planting to emergence, vegetative growth, growth stage before cold, height of plant at harvest and number and length of branches per plant were significant (p<0.05). In the first planting date, days from sowing to emergence were fewer than in the other planting dates. Vegetative growth duration in fall plantings was more than spring planting (an average of 162 days against 37 days, respectively). However, in fall planting dates, vegetative period in the. First planting date was 24% more than the third planting date. Plants from earlier planting in the fall were on the advanced vegetative phase on the onset of the cold. On the other hand in fall planting dates, vegetative components of the plants improved, so in the first planting, height of the plant, number and length of the branches were 1.9, 3.5 and 5.3 times more than spring planting, respectively. There were significant planting dates x genotypes interactions in the days from planting to emergence, vegetative period, height of the plant and number and length of the branches. MCC 207 in the third planting date and MCC 510 in the first planting date had the highest and the lowest emergence duration, respectively. Just as expected, in most genotypes vegetative period decreased as planting date changed from fall to spring, while some genotypes such as MCC 283, 496, 458 could not produce any flower. MCC 202 in the first planting date and MCC 83 in the fourth planting date had the highest (52.2 cm) and the lowest (15.9 cm) plant height, respectively. The most and the least no. of branches were observed in MCC 349 in the first sowing (15.5 branches per plant) and MCC 264 in fourth planting date (1.2 branches per plant), respectively. On the other hand MCC 496 in the first planting date had the longest branches (603 cm) but the shortest branches were observed in the MCC 264 on the fourth planting date (23 cm). Overall, early fall planting improved the growth and development of the cold tolerant chickpeas.

Previous research in Mashhad collection chickpeas (MCC) has shown that there are some cold tolerant genotypes for fall planting in the highlands. To obtain more detailed information about the reaction of these genotypes to fall and spring planting, the yield and yield component responses of 33 chickpea genotypes (32 cold tolerant genotypes and one susceptible genotypes) to four planting dates (28 Sep., 16 Oct., 2 Nov., and 7 Mar.) were evaluated in 2000-2001 growing season. The experiment was conducted at the Research Farm of College of Agriculture, Ferdowsi University of Mashhad as a split plot design with two replications. The planting dates were imposed as main plot and chickpea genotypes as subplot. Effects of planting date and genotype on percent of plant survival (PPS) after winter, number of pod per plant, 100 seed weight, yield and Harvest Index (HI) were significant (p<0.05). In the third planting PPS was more than the two previous plantings and in 84% of cold tolerant genotypes were more than 95%, also susceptible genotype had the lowest PPS (41.7%). Averaged over genotypes and fall planting, number of pod per plant, 100 seed weight, yield and HI were 10.5, 1.2, 62.4 and 2.4 times more than spring planting, respectively. Among the fall planting treatments, number of pod per plant and seed yield in first planting were 1.8 and 2.1 times more than the third planting, respectively. Number of pod per plant in all cold tolerant genotypes was more than susceptible genotype (with the exception MCC 202). MCC 426 had the highest 100 seed weight. MCC 83 and MCC 505 (susceptible) had the highest and lowest seed yield, respectively (98.1 and 10.7 gr/m2). Effects of planting date x genotypes on number of pod per plant, 100 seed weight and seed yield were significant (p<0.05). MCC 476 in first planting (with 41.9 pods per plant) and MCC 458, 496 and 283 in the fourth planting (without any pod) had the highest and the lowest pod per plant, respectively. The greatest 100 seed weight was observed in MCC 426 in the second planting (36.0 g) but the smallest seed belong to the MCC 332 in the first planting (6.7 g). MCC 476 in the first planting (with 188.7 gm-2) and MCC 283, 458 and MCC 496 in the fourth planting (without any seed) have had the most and the least yield, respectively. With due attention to the final goal from introduction of fall planting chickpea in the highlands (increasing the yield and productivity), it is necessary that growth and yield of these genotypes be evaluated in the replicated experiments in other areas.