نشریه به زراعی نهال و بذر
سال سی‌ام شماره 4 (1393)

An experiment was carried out to evaluate the effects of three vegetative rootstocks MM106, MM111, M9 and three commercial cultivars, Golden Delicious, Fuji and Delbarestival on mineral elements uptake efficiency and some quantitative and qualitative characteristics of apple during two growing seasons 2011 and 2012. Yield efficiency, reducing sugars, titrable acidity, pH of fruit juice, tissue firmness and average of fruit weight, N and K of fruit and leaf and also leaf P, Fe, Mn, Zn and B concentration were measured. The most yield efficiency was measured in Delbarestival onto MM106 combination with 0.51 and the least in Fuji onto MM106 and MM111 with 0.17 and 0.18 kgcm-2 of tree cross sectional area, respectively. M9 in N and P uptake was more efficient than the MM111 and MM106, but MM111 and MM106 rootstocks in Fe uptake were more efficient than the M9 rootstock. There were significant positive correlations between leaf K concentration and trees yield efficiency and also between fruit K concentration, fruit weight and fruit juice titrable acidity, so the role of this element in apple trees nutrition is very important.

To evaluate the effect of delay croppings on forage yield production of clover cultivars, a field experiment was carried out in split plot (RCBD) with four replications in Karaj during 2010-12. Delay cropping was considered as main plot with three planting dates (15 Sept., 20 Sept. and 13 Oct.) and sub plot was allocated to ten clover cultivar 1. Late maturity Persian clover, 2. Moderately maturity Persian clover, 3. Early maturity Persian clover, 4. One cut Persian clover, 5. Persian clover line 13, 6. Persian clover line 7, 7. Persian clover population, 8. Berseem clover cv. Tolidi- Karaj, 9. Red clover cv. Naseem and 10. Crimson clover cv. Alborz 1. The results of combined analysis of forage yield showed that the effects of year, planting date, cultivar and interaction effects of these factors were significant on dry forage yield. Delay in planting decreased the forage yield of clover cultivars up to 50% in fall and 30% in spring. Mean comparison of spring and fall forage yield showed that spring yield with 2.61 tha-1 had superiority to fall yield with 1.18 tha-1. In the first cutting Persian clover and Crimson clover, in the second cutting Berseem clover, in the third cutting Red clover and in the total cuttings Red clover and Berseem clover with 13.91 tha-1 and 15.53 tha-1 produced the highest dry forage yield. Generally, for forage production in fall and spring, Persian clover on cut cultivar and Crimson clover with about 9 tha-1 and for both seasons Berseem clover, Red clover and Persian clover with 12-13 tha-1 dry forage yield can be recommend for Karaj area.

The study was conducted in order to determine the best planting pattern of Cal J-N3 tomato cultivar in Tape-Drip Irrigation system, an experiment was carried out using split plot in randomized completely block design with five row spacing(120,140, 160, 180 and 200 cm) in main plot and three levels of plant spacing(40, 50 and 60 cm) in sub plot with three replications in Boushehr Agricultural and Natural Research Resource Center during 2009-2010 and 2010- 2011.The results showed that interaction between row spacing and plant spacing effect on fruit weight, fruit length was significant at 1% and on plant yield, Berix and fruit diameter at 5% level of probability. The, effect was not significant on fruit yield. As the plantings of 120×40 and 120×50 cm with 38.52 and 37.65 tons per hectare were statistically located in the same class but planting of 120×50 cm has lower production costs for farmers, therefor, planting of 120 × 40 is recommended for the region due to higher yield and more water use efficiency.

To evaluate the Value for Cultivation and Use(VCU) of various cotton cultivars in Garmsar conditions, an experiment was conducted in a complete randomized block design with three replications in 2012 and 2013. Evaluated cotton cultivars were Varamin, Dr. Omumi, Sealand, Oltan, Tabladila, No. 210, No. 228, Asj. 559 and B. 557. Seed cotton yield and related traits were measured during the growing season. Results showed that cultivars were different in all evaluated traits. Tabladila cv. had the highest number of bolls per plant and the highest seed cotton yield (3847 kgha-1). The lowest seed cotton yield belonged to the Dr. Omumi cv. with 1177 kgha-1 which had also the lowest boll per plant. This cultivar had the maximum plant height about 139 cm and the minimum plant height belonged to No.228 cv. There was a relatively high positive correlation between seed cotton yield and its yield components such as boll per plant, boll weight and number of locule, but correlation with some vegetative traits such as first fruiting node position number, length of five end internodes and plant height was weak and negative. Based on these results, Tabladila cv. which had higher Value for Cultivation and Use(VCU), can be recommended for cultivation in Garmsar region.

To investigate the effects of different levels of biofertilizer and phosphorus chemical fertilizer on quantitative and qualitative yield of forage corn cv. SC 540 under different humidity regimes, an experiment was conducted as Line Source based on randomized complete block design with three replications in Agricultural Education Center of Shahid Naseri in Karaj during 2012 and 2013. The implementation of Line Source was applied as four levels of irrigation (non stress, mild stress, moderate stress and severe stress). Phosphorus factor was in five levels including the application of 100% triple super phosphate fertilizer without biofertilizer, 75% recommended rate of chemical fertilizer with biofertilizer, 50% recommended chemical fertilizer with biofertilizer, 25% recommended chemical fertilizer with biofertilizer, biofertilizer and without chemical fertilizer. The results of experiment showed significant differences among the fertilizer treatments for most of studied traits in the first and second years. The highest fresh and dry forage yield were obtained from the treatment of 100% triple super phosphate fertilizer without biofertilizer that was not significally different from the treatment of 75% recommended chemical fertilizer and biofertilizer. Moisture stress reduced forage yield up to 21.22, 12.07 and 2.78 percent in severe, mild and very mild stress conditions in 2012, respectively. Treatment of 75% recommended chemical fertilizer and biofertilizer had also the highest effect on forage quality parameters. The findings of this research indicated that growth promoting bacteria exist in biofertilizer, in addition to growth increasemend and reduction of fertilizer consumption, lead to increase plant tolerance under water deficit stress conditions.

The effects of irrigation levels and high corm density on replacement corms behavior and nitrogen uptake of saffron (Crocus sativus L.) were studied in a field experiment as split-plot based on a randomized complete block design with three replications at Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during the years of 2012 and 2013. The irrigation levels of saffron based on water requirement (50, 70 and 100 %) and high corm density (50, 100, 200 and 300 corms per m2) were allocated to the main and sub plots, respectively. Based on the results, the lowest nitrogen content in replacement corm and aerial part of saffron (6.02 and 5.62 gm-2, respectively) were observed by sowing 50 corms per m2 + 50 % irrigation. In both years, nitrogen uptake efficiency, nitrogen use efficiency and nitrogen harvest index of saffron was significantly decreased by increasing the corm planting density. In the second year, nitrogen uptake efficiency, nitrogen use efficiency and nitrogen harvest index were more than the first year. It seems that higher planting densities, which named dense corm planting, can be considered as an alternative approach for increasing nitrogen use efficiency in saffron.

This experiment was conducted to determine the best transplanting date to earliness the onion, at Behbahan Agriculture Research Station for two years (2012-2014). Experiment was performed in factorial based on RCBD with three replications. The factors were four onion genotypes, including: Improved population of Behbahan onion, Ramhormoz landrace, Primavera and Texas Early Grano cultivars and three transplanting dates, including: 23rd September, 7th and 23rd October. To produce sets, 10-12 g seeds of onion genotypes were sown per square meter in late February and sets were harvested in late January. Based on the results, threshold of day length related to bulbing for Primavera cultivar was shorter than for other genotypes. The highest total and marketable yield was produced on 23rd October transplanting date. Percent of bolted plants and doubling bulbs decreased by delaying transplanting date. The minimum bolted plants and doubling bulbs belonged to Primavera cultivar. The highest total and marketable yield as well as mean bulb weight obtained from primavera cultivar. Interaction effect of genotype and transplanting date showed that the most total and marketable yield was produced by Primavera cultivar on 23rd October transplanting data and marketable yield of this cultivar on transplanting date of 23rd September was about 25% lower than transplanting date of 23rd October. Nevertheless, due to 20-30 days crop earliness in transplanting date of 23rd October and 50% reduction in onion price at this time of the season, and also by considering this fact that the farmers will obtain more income from the 23rd September transplanting date, therefore this date is recommended for transplanting of Primavera onion set in Behbahan region.

Incidence and severity of various diseases in plants can be reduced by mineral nutrient management. To evaluate the effects of different levels of N and K on severity of infection of cytospora canker of apple trees, a factorial experiment based on randomized complete block design was conducted in greenhouse in a hydroponic system on two years old seedlings of apple cultivar Golden delicious. The experimental treatments consisted of four levels of N (0, 105, 210 and 315 mgkg-1) and K (0, 115, 230 and 345 mgkg-1), respectively. After six weeks, seedlings were inoculated with a highy pathogenic and virulent isolate of Cytospora cincta Fries, and six months later, mean lesion size on trunk of seedlings were measured. The results showed that changes in the amounts of N and K caused change in severity of infection. The highest and lowest severity of infection was observed in treatments whithout N (N0), K (K0) and optimal (N210K230) use of them. Severity of infection decreased with increasing of K level, while, with amounts less than optimum level of N (N210), severity of infection was variable, so that with amounts higher than optimum level, disease severity increased significantly. However by application of optimum levels of N and K, disease severity showed a significant decrease.