جستجوی مقالات مرتبط با کلیدواژه « saturation » در نشریات گروه « اکولوژی »

In order to investigate the effect of irrigation regimes and seedling age on rice yield and its components, present research was conducted as a split plot experiment based on randomized complete block design with three replications in Mazandaran province, Mahmoud Abad in 2017. The main factor included the irrigation method in three levels (flooding, saturation and low-irrigation) and the sub factor of seedling age at three levels (three, four and five weeks). The results showed that the effect of irrigation management only on the number of tillers and the effect of plant age on the number of tillers, panicle weight, straw yield and grain yield and harvest index were significant. Comparison of the average effect of irrigation treatments presented that the number of tillers in the flood treatment was the highest and in the low-irrigation (ecological) method the lowest was. Comparison of mean of simple planting effect of plant age displayed that the number of fertile tillers in the conventional treatment (4 weeks) was the highest and in ecological treatment (3 weeks) was the lowest. Regression analysis of panicle weight in different treatments at plant age level indicated a decrease in panicle weight. Therefore, 99.5% of the weight loss was due to the age of the plant. Similarly, the relationship between planting age and rice yield showed a decrease in plant yield with increase of plant age. So, based on the explanatory coefficient, about 97.5% of grain yield decreased due to age.  Considering the no significant difference in grain yield at irrigation factor levels, and lack of ecological methods benefits in flooding (conventional), ecological treatments (low-irrigation level and 3th week) are recommended. The flexibility of the proposed techniques in the ecological method suggests that there are opportunities that will provide the ground for moving towards agricultural sustainability.

In order to evaluate the effects of seed deterioration on capability of seed germination and seedling of three weeds-Malva neglecta L., Echinochloa crus-galli L.and Sorghum halepense L.-under saline stress conditions, an experiment was conducted at university of Ramin in Khuzesatan. The arrangement was factrorial in form of a completely randomized design with 4 replications (RCD) in 2012. In this experiment, The first factor was weed seeds at 3 levels (Malva neglecta, Echinochloa crus-galli and Sorghum halepense), the second factor was deterioration treatments at 4 levels (0, 3, 5 and 7 days), and the third factor was salinity (0,4,8 and 12dSm-1), and the forth factor was moisture stress at 3 levels (saturation field capacity(FC) and 50%FC). The results of experiment showed that seed deterioration and saline stress reduce all measured characteristics including time, speed, uniformity, persentage and emergence index, germination percentage, radicle length, plumul length, vigos index, and seedling dry weight. A significant difference was observed at %1 level. Saline stress resulted in reduction of determined characters in the experiment. Whwrase in Wherase in Malva niglecta moisture Stress of 50% FC, FC and saturation reduced percentage of germination, in barnyard grass and johnsongrass the highest germination percentage was observed in saturation tseated seeds and the least percentage of emergences was observed in %50 FC treated seeds. Our results indicated that seed deterioration increased the effect of salinity on weed seedling establishment and seed germination.