Due to having spring and autumn genotypes and adaptation to weather conditions, rapeseed is considered as a point hope to provide edible oil of country. Two separate experiments were set up as split-plot in a RCBD design with three replications in two fall and winter seasons during two years (2014-2015 and 2015-2016) at the research field of Seed and Plant Improvement Institute to investigate the effect of SOWING season and DATE on the quantitative and qualitative yields of rapeseed genotypes in Karaj, Iran. In this study, the main plots were SOWING DATEs (7, 17, and 27 October in fall SOWING and 9 and 19 February, and 1 March in winter SOWINGs) and sub-plots consisted of genotypes (RGS003, Dalgan, Zabol10, Hyola401, and Hyola4815). Rapeseed genotypes grain and oil yields were 4330 and 1840 kg ha-1 in fall SOWING, respectively, while these traits were decreased 43.3 and 46.6% respectively, when rapeseed genotypes were planted in winter season. The highest grain and oil yields (5033 and 2202 kg ha-1) belonged to 7 October SOWING DATE in fall SOWING, while 9 February had the highest grain and oil yields (2996 and 1248 kg ha-1) in winter SOWING. In general, the Dalgan genotype is recommended for cultivation due to suitable agronomic traits such as number of silique per plant, number of grain per silique, silique length, 1000-grain weight, as well as high grain and oil yields in cold temperate regions with arid and semi-arid climates such as Karaj, Iran.

Influence of SOWING depth (3, 8 and 13 cm) and SOWING DATE (December and February) on germination rate of Quercus castaneifolia (C.A.Mey.) acorns was examined. The research was carried out on a sandy-loamy-clay soil in a non-regenerated open area of the plain forest of Noor Natural Resources and Marine Sciences Faculty (north of Iran). The experiment was as factorial trial and completely randomized design at three replications. The data analysis in mid-June revealed that the effect of SOWING depth and SOWING DATE and their interaction on germination rate was highly significant (P = 0.000). Irrespective of SOWING depth, germination rate was greater in SOWING DATE of February (66.2%) than December (18.2%) (P = 0.000). Irrespective of SOWING DATE, germination rate was greater in SOWING depth of 3 cm (51.3%) than 8 cm (42%) and 13 cm (33.3%). The best treatment combination was "February-8 cm" (77.3%), and "February-3 cm" (64%). Maximum seed germination (at 3 cm and 8 cm depths), sown in December and February occurred mostly in mid-June and late May, respectively. Generally, in each record DATE, germination rate in all SOWING depths was higher in SOWING DATE of February than December.

To achieve higher grain yield in wheat the coincidence of vegetative and reproductive stages of growth with the suitable environmental conditions via selecting appropriate planting DATE and use of desirable density is crucial. The experiment was conducted during 2001/2002 and 2002/2003 growing season using a spilit plot experiment with four replications. Main plots consisted of three planting DATEs (November 6th, December 6th and January 6th) and four planting densities (150, 250, 350 and 450 plants/m2) were sub plots. The results showed that planting DATE had significant effects on grain yield, number of grains per spike, number of spikes per m2 and 1000 grain weight, so the highest grain yield was achieved at second planting DATE and delay in SOWING was associated with significant decrease in grain yield. Number of spike per m2 and 1000 seed weight decreased by delay in SOWING. The number of spikes per m2, grains per spike, 1000 grain weight, plant height fnd HI were significantly affected by planting densities, so the highest number of spikes per m2 was obtained from the highest planting density (i.e.450 plants/m2), however, the highest number of grains per spike and mean grain weight "ere obtained from the lowest planting density (i.e.150 plants/m2). With increasing plant density, the number of spikes per m2 was the only yield component that increased in all planting DATEs. Overall, the results revealed that by incrsasing plant densisty in delayed SOWING DATE to some extend grain yield can be comensated.

In order to study the effect of SOWING DATE and plant density on ear of sweet corn an experiment was conducted in Gorgan Reaserch station since June 2001 during 3 years. In this experiment five SOWING DATE (24th June, 9th July, 24th July, 18th Agust and 23th Agust) and four plant density (45000, 55000, 65000 and 75000 plant per hectar) were evaluated in form of factorial experiment (5×4) within randomized comelet block design. Results indicated that ear length, plant hight, can seed weight, grain/ear ratio and harvest index was under the influence of year and maximum ear weight obtained amount 12810 kg/ha in theirty year. With delay SOWING DATE until 9th July amount of ear weight was fixed but amount of it in July was smaller than June. Although with delay SOWING DATE in July ear weight was fixed and maximum ear weight achived amount 13690kg/ha in 24th June. Stistically there wasn’t any different between plant density for ear weight and can seed weight but with increase plant density ear length and grain/ear ratio decreased. So for obtain maximum yield and marketable 45000-55000 plant/ha for sweet corn in summer SOWING can be recommended.

Regarding to the importance of Pistatia atlantica in Zagros forests and its various usages this study was established to improve the ecological knowledge of this species in Garize nursery in Sanandaj. In this experiment completely randomized with factorial design with three treatments include SOWING time (January 9th, January 29th and February 19th), SOWING depth (surface, 4 cm depth, 8 cm depth) and weed (weed and non weed) with three replicates and five seedling in each row were used. In the end of first growing season determined that January 9th and January 29th SOWING times increased the collar diameter whereas did not have any significant influences on survival, height, shoot/root length ratio and shoot/ root dry weight ratio. 4 cm SOWING depth treatment increased collar diameter and survival and decreased stem to root dry weight ratio whereas did not have any influence on other parameters. Weed treatment only have the significant influence on stem to root dry weight ratio and it could reduce this parameter. Interactions of three treatments indicate that the usage of weed, 4 cm SOWING depth and January 29th SOWING time result in the best results.

In order to study the effects of SOWING DATE and plant density on vegetative characters, yield and yield components of rapeseed varieties, an experiment was conducted at Agricultural Research Station of Gonbad during 2000 - 2002. The experiment was a split factorial arranged in a RCBD with 4 replications. Four SOWING DATEs (Qct. 22 nd, Nov. 6th, Nov. 21st and Dec. 6th) were as main plots and two varieties (Sarigol and Hyola 401) and two row spacing (24 and 36 cm) were subplots in a factorial arrangement. The results of combined analysis for two year showed that plant height, the number of days from emergence to flowering and physiological maturity, duration of flowering and number of pod per plant decreased significantly with delay in SOWING DATE. The number of grains per pod and 1000 grain weight of Hyola40I hybrid were more than those of Sarigol variety. The number of pod per plant and the number of grains per pod in 36 cm row spacing were more than those of 24 cm row spacing; however 1000 grain weight of 24 cm row spacing was greater than that of 36 cm. Generally grain yield of rapeseed decreased with delay in SOWING DATE. The first SOWING DATE had the highest grain yield (4513 kg/ha), whereas the fourth SOWING DATE produced the lowest grain yield (3228 kg/ha). The grain yield of Hyola 401 hybrid (4139 kg/ha) was more than Sarigol variety (3550 kg/ha). The grain yield of 24 cm row spacing was more than that of36 cm row spacing .The grain yield of row spacing 24 and 36 cm were 4238 and 3451 kg/ha, respectively. The combination of first SOWING DATE, Hyola 401 hybrid, and 24 cm row spacing treatment produced the highest grain yield (5169 kg/ha).      

Introduction13 Given recent droughts, Medicago scutellata Var. Rabinson has taken an important position in crop rotation, especially in semi-arid regions. Therefore, agronomy management factors play an important role in improving its growth. Also, regarding its short growth period length, its quantitative and qualitative forage yield has been high, and it can be sown through dry-farming in regions with 300-500 mm of rainfall. On the other hand, given the importance of forage cultivation in agriculture and water shortage in Iran, we can try to cultivate fallow lands. The aim of this study was to evaluate the effect of different agronomic management methods on the quantitative and qualitative snail medic forage yield and to compare the relative contribution of components to increasing it under the climate of Arak. Materials and Methods In this study, two SOWING DATEs (July 15 and 22, 2017) as main plot, two SOWING depths (1-2 and 2-4 cm), and four seeding rates (2. 5, 7. 5, 12. 5, and 17. 5 kg ha-1 equal to 20, 50, 80, and 125 plants m-2) as subplots were investigated. The experiment conducted in split plot factorial based on randomized complete block design with three replications. It is noteworthy that due to seed hardness, the average number of germinated seeds was low. The measured traits in this study included forage dry weight, stem dry weight, pod dry weight, leaf dry weight, number of pods per m2, leaf area index (LAI), dry mater digestibility (DMD), crude protein (CP), crude fiber (CF), crude ash (CA), acidic detergent insoluble fiber (ADF) and neutral detergent soluble fiber (NDF) in the final stages of forage harvesting. Finally, using the statistical software SAS, we performed analysis of variance, comparison of means using Duncan’, s multiple range test at 5% probability level and correlation analysis. Results and Discussion The results showed that the highest dry forage weight and dry stem weight (2884. 13 and 1361. 71 kg. ha-1, respectively) were observed in the treatment of seeding rate of 12. 5 kg ha-1, at SOWING depth 1cm and on the SOWING DATE of July 21. Accordingly, the amount of dry forage obtained from the SOWING DATE of July 21 and the SOWING depth of 1 cm was 10. 77 and 19. 84% more than that of the SOWING DATE of July 5 and the SOWING depth of 2 cm, respectively. The portion of dry stem weight in the SOWING DATE of July 21 and SOWING depth of 1 cm was 53. 96 and 55. 24% of the dry forage weight, respectively. Furthermore, the portion of the pod and dry leaf weights from the dry forage for SOWING DATE of July 21 were respectively reported as 34. 13 and 11. 91%, and for SOWING depth of 1cm were, respectively, 33. 56 and 11. 18%. As the amount of seeding rate increased, the CF increased, and the percentage of CP decreased. By taking into account the absolute value of the slope value of the equations of these two traits, it was found that the effect of density on the CF is more than the effect of this treatment of CPP. According to the obtained results, the SOWING DATE of July 21, the SOWING depth of 1 cm, and the consumed seed of 12. 5 kg ha-1 showed an appropriate quantitative and qualitative yield. Also, according to the results of the correlation test, it was determined that the dry forage produced had a positive correlation with the stem dry weight (0. 99**), the pod dry weight (0. 99**), the leaf dry weight (0. 98), the number of pods per m2 (0. 43*), the CA (0. 71**), DMD (0. 78) and NDF. On the other hand, a negative correlation was found with LAI (-0. 66**) and ADF (-0. 53**). Conclusion Regarding the absolute value of the slope in the equations pertaining to these two properties, it was found that the susceptibility of fiber percentage to density was higher than the susceptibility of crude protein percentage in this treatment. In deeper SOWING, the obtained protein percentage was 1% lower, while the lowest fiber percentage occurred in shallow SOWING. Generally, we can say that this crop has a high sensitivity to high densities. Based on the results, there were the relation between regression and correlation results.

Due to growth of peanut seeds inside the soil, determination of proper time for planting and harvesting has special importance. For determination of proper time of maturity with high vigor and yield, an experiment was conducted in two crop years in complete block design in research station of Gorgan University of Agricultural Sciences and Natural Resources (GUASNR). In first and second year the study was performed in five and two planting DATEs respectively. The Sampling repeats weekly when seed developed in pods and were transferred immediately to the laboratory. Seed germination and moisture content was determined and electrical conductivity test was measured after drying the seeds. Results showed that seed moisture content in final stage, germination percentage, electrical conductivity, seeds filling rate, seed filling period and seedling vigor were significantly affected by planting DATE. Seeds which planted early had lower moisture content in harvest time and higher germination percentage than seeds which planted late. Different SOWING DATE significantly affected seed yield in the first year, while in the second year delay SOWING had no significant effect on total seed yield. Reduce seed filling period in late planting DATE of first year and facing this period with the end of season rainfall led to significant decrease in seed vigor and quality. Although the data obtained in this study examine just one cultivar in one location and two years, but results suggested between weather parameters, temperature and rainfall during seed filling period had significant effects on peanut seed vigor and yield. So adjusting planting DATE according to location weather condition could results high quality and vigor seeds in harvest time.