جستجوی مقالات مرتبط با کلیدواژه "تبخیر و تعرق" در نشریات گروه "بیوتکنولوژی و ژنتیک گیاهی"

Silicon is a non-essential element with several reported beneficial effects on various crops. For investigating the growth and reproductive yield of the Persian Petunia, a factorial experiment with a completely randomized design was conducted at 4 levels of Si (0, 50, 100 and 150 ppm), during two stages of growth (4-6 and 8-10 leaf) with 4 replications. The experiment was carried out under the greenhouse conditions. Silicon was applied via foliar spray once every two weeks. The application of Si increased the number of the flowers on plants up to 73%. An increase was also observed in the height of the plants under the effects of Silicon and the stage of growth. Although the application of Si foliar spray increased the fresh, dry, and biomass weights during both stages of growth, these weight parameters were generally higher in plants which received Si treatment within 4-6 leaf stage. The fresh and dry weights as well as leaf surface area increased 57, 37 and 52% and leaves‟ evapotranspiration reduced up to 53% using Si, respectively. In conclusion, it can be claimed that the application of Silicon can increase the total biomass weight by reducing plant‟s evapotranspiration and increasing leaf‟s surface area, which in effect results in an increase in the number of the flowers per plant.

Estimating rate of actual evapotranspiration is very important for designing of the irrigation systems, storage construction and water conveyance structures. Many methods have been developed for estimating reference crop evapotranspiration. Amount of these methods are need different climatic parameters but providing all of the data those are necessary for ET0 is not always available and if have been provided, these data may be is not completely correct. Therefore some methods have developed to estimating ET0 with minimum data such as Hargreaves-Samani and Jensen-Haise methods. In this research, eight cases of these methods have been compared. These comparisons were made on the basis alfalfa lysimeter data from Kabotarabud, Isfahan. The results show that through of these cases, which were used Samani-Pessarakly equation for calculating Extraterrestrial Radiation, were estimating ET0 better than the others with 15 Percent Average Maximum Absolute Relative Error (MARE). In addition, these above mention cases were had higher correlation coefficient as compare to other cases, so with improved the main equations with linear regression, MARE were decreased until 9 Percent. Finally, as compared the two methods of calculating the HargreavesœSamani coefficient, Kt, the results showed that there was no considerable different between Allen's equation and Samani-Pessarakly's equation.