نشریه اکوفیزیولوژی گیاهی
پیاپی 45 (تابستان 1400)

This experiment was carried out in order to investigate the conventional and conservation tillage systems and different seeding rates on the response of new wheat cultivars in rainfed conditions during two consecutive growing years of 2016-18 in Sararood Dryland Agricultural Research Center, Kermanshah. The experiment was performed in the form of strip blocks based on a randomized complete block design with three replications at two adjacent sites as conservation tillage and conventional tillage. The first factor was wheat cultivars (Baran and Rijaw) horizontally and the second factor was seed rate: 75, 100, 125, 150, 175, 200, 225 and 250 kg / ha vertically. The results of the combined analysis showed that among the studied traits, Normalized difference vegetation index, SPAD index, leaf area index, plant growth rate, grain yield and harvest index in the first year showed a significant increase. Grain yield as the most important trait was increased 28.7% compared to the second year of the experiment. Conventional tillage operations also increased all the studied traits in comparison. So that grain yield increased by 22.25% in conventional tillage. The application of different amounts of seeds also significantly affected the Normalized difference vegetation index, leaf area index and plant growth rate, and the maximum values of these traits were obtained in 250 kg and the maximum SPAD index in 75 kg/ha. Finally, by applying seed densities of 150 kg/ha the grain yield increased by 15.42%, compared to 75 kg / ha.

 In order to evaluate the influence of nitrogen fertilizer and sowing dates on agronomic characteristics, yield component and seed yield of rapeseed cultivar RGS003, two field experiments (separate) were carried out base on a randomized complete blocks design with three replications in 2014-15 and 2015-16 during growth seasons in research field of Islamic Azad University, Gorgan Branch. First experiment (November 9) and Second experiment (December 9), was performed, each one in 7 nitrogen levels (50, 75, 100, 125, 150, 175 and 200 kgN.ha-1). The analysis of variance results showed that sowing date and nitrogen fertilizer had significant effect at p<0.01 for pod per plant, seed per pod, 1000weight, biological yield, seed yield and harvest index. Highest (3128 kg.ha-1) and lowest (2414.95 kg.ha-1) seed yield was observed in 200 and 50 kgN.ha-1) treatments respectively. In two year, seed yield, biological yield and harvest index reduction at second sowing date was related to insufficient vegetative growth before flowering stage. Under present experimental conditions, planting on November 9 and usage of 175 and 200 kgN.ha-1 can be recommended as an appropriate date for obtaining the highest seed yield.

13 bread wheat cultivars, including Alvand, Back Cross Roshan, Pishtaz, Arg, Tiger, Sirvan, Flamenco, Omid, Orum, Heydari, Mihan, Chamran 2 and Natasha varieties, were evaluated for two years in a completely randomized block design with three replications in the research center of Kerman agricultural education. After running the Bartlett test, composite analysis of variance was performed by SAS software and Duncan's mean comparison was performed at the 5% level, and then the results were interpreted. The results showed that Heidari, Alvand, Orum and Arg cultivars had the highest grain yield with average yields of 6300, 6263, 5546 and 5257 kg / ha, respectively. Also, Chamran 2, Sirvan and Tiger cultivars with average yields of 4488, 4566 and 4668 kg / ha had the lowest grain yields. On the other hand, Omid and Pishtaz cultivars with a weight of 44.24 and 44.04 gr per thousand seeds had the highest, while Flamenco and Tiger cultivars with a weight of 37.49 and 36.73 gr had the lowest weight of a thousand seeds, respectively. Chamran 2 cultivar with 39.83 had the lowest number of seeds per spike. Omid cultivar with 107 cm had the highest plant height and Mihan and Tiger cultivars had the lowest plant height with 81.00 and 79.83 cm, respectively. According to the results of this study (especially in terms of yield and dwarfness), Heydari and Mihan cultivars should be used to replace conventional and old cultivars in Kerman province's cold areas.

In order to evaluation of dry matter remobilization of assimilates materials amount and their contribution to the yield of different bread wheat varieties and lines in Ardabil, an experiment in randomized complete block design with three replications with ten cultivars (Includes: Uroom, Zare, MV-Magdalena, Soissons, MV-Toborzo, Mihan, Pishgam, FD-11111 and FD-12073) was done in Research Station of Agriculture and Natural Resources of Ardabil in 2015-2016. Analysis of variance showed a significant difference between the lines and cultivars studied, for different traits. FD-11111 line has the highest number of grain per spikes, grain yield per square meter, the share in the filling and grain growth (7417.9 grams per square meter).The MV-bodri variety has the highest biological yield per square meter, the percentage of share the transfer process dry matter from shoot (19.723%) in the yield and maximum transfer of dry matter from total of shoots to the grain. The MV-Magdalena variety also has the lowest biological yield and highest harvest index, the highest percentage (47.797%) of dry matter remobilization efficiency of shoots and with 3.57 percent was the highest current photosynthesis efficiency. The highest current photosynthesis contribution in Zare cultivar (89.923 grams per square meter) that has the lowest proportion of dry matter remobilization was obtained. So generally can be said that was much higher current photosynthesis contribution in increasing grain yield, and FD-11111 line between studied genotypes, was the best lines.

Lack of water resources and drought stress is the most important problems in the green spaces in arid and semi-arid regions. The use of some additives, such as super adsorbents, can help maintain and store moisture in the soil and make optimal use of limited water resources. In this research, the effect of four levels of Igeta Green-P (0, 3, 6 and 9 g / kg) and three irrigation intervals (5, 10 and 15 days) on growth indices and RWC , proline and chlorophyll index of verbena were investigated. The results of this study indicate that using super absorbent due to the moisture content in the root zone and, consequently, increasing the plant water utilization, provide better conditions for plant growth and development, especially under drought stress conditions. Application of super adsorbant Igita with concentrations of 6 and 9 g / kg improved vegetative growth and also improved RWC of the plant under irrigation conditions at intervals of 10 and 15 days. Increasing the irrigation interval from 5 days to 10 and 15 days caused the growth of the plant to decrease in terms of length and weight of the shoot, length and root weight, reduce the relative water content. Considering the positive effects of Igeta super adsorbent on the establishment and enhancement of growth of Pseudo and Peculiar seedlings, it can be concluded that the use of superabsorbent as a successful method for maintaining moisture in arid and semi-arid regions has suggested. Increased water use efficiency in the greenery.