جستجوی مقالات مرتبط با کلیدواژه « ارتفاع بوته » در نشریات گروه « آب و خاک »

The study of the climatic condition of Iran shows that arid and semi-arid areas are often scattered in the central areas of Iran, and salinity in these areas is one of the limiting factors for crop production. Fenugreek is a genus of Fabaceae family and one of the important products of semi-arid regions. This medicinal plant is used in the treatment of a wide range of diseases such as diabetes. Fenugreek seeds and its leaves are rich in minerals, protein and carbohydrates. The expansion of fenugreek cultivation in the world has caused this plant to face abiotic environmental stresses during the growing season. Silica plays a role in reducing the amount of sweating and preventing the side paths of sweating. Therefore, this research was conducted with the aim of evaluating the effect of silica fertilizer in increasing salinity tolerance of fenugreek plants.

The present study was conducted in order to investigate the effect of silica fertilizer on some morphological and physiological characteristics of edible and medicinal fenugreek plant in the fall of 2022 in Behbahan city in the form of pots in the form of a completely randomized design with three replications in the open air. The treatments included salt stress at three levels (0, 75 and 150 mM sodium chloride) and silica fertilizer at two levels (0 and 3 g/l) and a total of 18 pots. Fenugreek seeds are obtained from a reputable seed store (Rahimi vegetable seed store in Behbahan city). Fenugreek seeds were planted in small plastic pots with a height of 7 cm and a diameter of 8 cm filled with garden soil, leaf soil and perlite (ratio 1:1:1) so that finally there were five plants in each pot.

The results showed that in the fenugreek plant, the maximum root length (6.95 cm) and the dry weight of the aerial parts (0.046 g) in the treatment without salt stress (control) and without the use of silica fertilizer and the lowest root length (2.63 cm) ) and the dry weight of aerial organs (0.03 g) was observed in the treatment of 150 mM salinity stress and without the use of silica fertilizer. Also, the decrease in chlorophyll fluorescence (Fv/Fm ratio) in response to salinity stress was lower than the decrease observed in salinity stress without using silica fertilizer. In the salinity stress of 150 mM and the use of silica fertilizer 3 g/liter, the amount of chlorophyll fluorescence (Fv/Fm ratio) was 0.09 more than in the treatment of salinity stress of 150 mM and no silica fertilizer. The highest value of greenness index (SPAD) was obtained in the condition without salinity stress (11.60) and the lowest value was obtained in the salinity stress of 150 mM (2.30), which was significant at the five percent level. Stress causes disturbances in the path of electron transfer and destruction of tissues related to photosynthesis, and in this way, it prevents the optimal energy consumption of the plant. In this study, silica treatment reduced the negative effects of severe salinity on root length, wet and dry weight of shoot and chlorophyll fluorescence, and reduced the harmful effects of salinity on fenugreek plants.

In this experiment, it was observed that the application of silica fertilizer in severe salinity stress significantly reduced the amount of chlorophyll fluorescence in comparison with its non-application. The present study showed that adding silicone fertilizers to saline soils reduces the negative effects of salinity stress in fenugreek plants.

In order to investigate the effect of irrigation volumes under drip irrigation condition on grain yield and morphological parameters of corn cultivars, an experiment was conducted during 2018 and 2019 in Gorgan agricultural research station. The experiment was laid out in a randomized complete block design in form of split plot factorial experiment and replicated three times. Treatments were including three irrigation volumes [Irrigation at %100 (I1), %75 (I2) and %50 field capacity (I3)], as A factor, and varieties (SC704, SC705 and SC706) as B factor. The results of analysis varians showed that; effects of irrigation treatments on yield and yield components was significant at %1 probablity and the difference between Varieties was significant at %1 probablity, but intraction effects of two treatments on yield and yield components was not significant. Investigation of grain yield at irrigation treatment showed, the highest yield of I1 treatment was 7.85 ton ha-1, and reduced by %15.03 and %29.68 respectively when the irrigation interval was reduced by 75% to %50 field capacity. Comparison of grain yield at varieties showed, yield of single cross 706 with 7.03 ton ha-1 was%12.84 and %3.68 higher than single cross 704 and single cross 705 respectively. Interaction effect of irrigation value and variety showed, the most grain production was belong treatment of single cross 706 and irrigation at %100 field capacity. Investigation of WUE of showed, irrigation at %75 field capacity and single cross 706 with WUE of 1.15 kg m-3 grain yield had the most WUE compared to other irrigation treatments and varieties. With dimitation of irrigation, plant height and ear length also decreased.

Drought stress is the most important environmental factor limiting growth and development of plants worldwide. Growth reduction due to drought stress has been reported more than other environmental stresses. So far, many studies have been conducted on the relationship and correlation between important agronomic traits in rapeseed, which have introduced 1000-grain weight, number of seeds per pod and number of pods per plant as the most important traits with high correlation in yield. The results showed that the application of drought stress had an effect on the yield components of sesame and the cultivars that were more sensitive to drought stress had a greater decrease in their yield. The aims of this study were to investigate (1) the effect of consumed water volume as the independent variable on other variables of the study, and (2) the effect of total independent variables (yield components and other independent factors) on yield and water productivity (dependent variables). Finally, the most important independent variables affecting water productivity and the most sensitive variables to the amount of consumed water were determined.

In order to achieve aforementioned objectives of this study, an experiment was conducted during two growing season of 2011-2011 and 2010-2011 in Behbahan Agricultural Research Station. The experiment was conducted as randomized complete block design with 4 replications. The applied amount of water in drip irrigation was composed of four levels of 50, 75, 100 and 125% water requirement in main plots and two canola varieties Hyola 401 and RGS003 in sub plots were placed.

The results of the analysis of variance of the regression model showed that the higher absolute value of beta coefficients and t-statistic of each independent variable caused that variable to be introduced as the most sensitive independent variable affecting the dependent variable. Therefore, the independent variable of water volume, with beta coefficient of 0.860 and t-statistic of 13.246 had the greatest effect on plant height variable. In terms of yield, the studied variables (the number of pods per plant, the number of seeds per pod, and 1000-seed weight, consumed water volume, flowering period, growth period and plant height) showed 74.1% of variation (R2 = 0.741) of dependent variable (Yield of canola). The consumed water volume with the highest absolute value of beta coefficient of 0.563 and t-statistic with 2.967 had the most significant effect on yield at the level of 1%. Among the dependent variables, the consumed water volume with the highest absolute value of beta -1.013 and t-statistic at -12.415 had the most significant effect on water productivity at the level of 1%. consumed of water volume with the highest absolute value of beta coefficient of 0.563 and t-statistic with 2.967 had the most significant effect on performance at the level of 1%. The results of Pearson correlation coefficient showed that the highest correlation between the number of pods per plant and seed per pod with both plant height were calculated to be 0.763 and 0.849, respectively, indicating that increasing plant height was effective in increasing the number of pods per plant and seed per pod.

The results of analysis of variance of regression model showed the effect on volume of consumed water as an dependent variable through other variables (number of pods per plant, number of seeds per pod, yield, water productivity, 1000-seed weight, flowering period, growth period and plant height). Results showed a significant effect of all variables at the level of 1%, except for the variable of flowering period which had a significant effect but just at 5%. The volume of consumed water by r= 66.2% on grain yield variation in the pods, had the most significant effect on yield components. Therefore, seed number in the pods received the most negative effect from reducing water consumption due to drought stress. With increasing the growth period of canola, water productivity showed a significant decrease at 1%. The results of Pearson correlation coefficient showed that grain water productivity had a negative and significant correlation at the level of 1% with all variables. The highest correlation between water productivity (r = -0.939) was calculated with volume of consumed water, which indicates the importance of reducing water consumption in increasing canola water productivity.

Drought stress is one of the important challenges of agricultural crop production in the arid and desert region. In order to increase yield, indrouction of drought resistance cultivars, and reduction water consumption, this experiment was conducted to recognize effects of drought stress and planting date on morphophysiological and yield of two varieteds of millet.

Materials and Methods :

The experiments were carried out as a split plots arranged in randomized complete block design with three replications in Zahak Agricultural Research Station in 2015 and 2016. The main factor included planting dates (1, 15 and 30 March and 15 April) and drought stress (50, 65 and 80% of field capacity) were in sub sub plots. Grain yield and traits of plant height, plant height, 1000 seeds weight, dry forage yield, chlorophyll, proline, day to maturity, and day to flowering were determined.

Results :

The results showed that maximum and minmun grain yield was obtained at 50 and 80 percent of filed capacity with average of 1679 and 469 kg hg-1, respectively. Grain yield, day to flowering number, day to maturing number, chlorophyle concentration, dry forage yield, 1000 seed weight, and plant height was affected by cultivars. Maximum grain yields was in Bastan cultivar (1200 kg ha-1). Grain yield, day to flowering number, day to maturing number, chlorophyle concentration, dry forage yield, 1000 seed weight, and plant height was infulunced by interaction effects of planting date, drought stress, and cultivar. Maxium grain yield (2711 kg hg-1), day to maturing (72.2 days), cholorphyle concentration (6.50 mg g-1), dry forage yield (9475.6 kg ha-1), 1000 seed weight (4.55 g ), and planting height (122.5 cm) were for Bastan culrivar in 15 March and 50 percent irrigarion.

According to the obtained results of forage and grain yield, it seems that planting at 15th March play a key role in increasing yield of millet, because of water and temperature suffiencny. The plant at this date had more contribution to transfer the produced phytotsenythetic materials to seeds. Howerver, delay in planting date resulted in late season heat stress at seed filling time and abnormality in photosynthesis to transpiration ratio which it can dercrease the transfer of photosynthetic materials to seeds. It seems that sowing of cultivar of Bastan in comparison with conventional one has resulted in highest resistant to drought stress. We can recommend as resistant cultivar of millet at 15th of March palnting date and 50 percent of field capacity For the Sistan region the relationship between farmers and extension specialists, and researcher can increase yield in drought years. Although Millet is resistant to drought, increasing the soil moisture to 80 percent of field capacity resulted in reducing chlorophyll and yield components. Sowing tin 15 March because of availability of moisture and proper temperature, has significant role in increasing yield. The millet in this date was able to transfer its photosynthetic products to grains; however, delay in sowing as result of hot weather the relative of photosynthesis to transpiration in grain filling period.

Oil seed rape (Brasica napus) is an important crop, which is cultivated in Iran for oil production. As a management practice deficit irrigation strategy is applied to cope with water shortages, especially during drought periods. This research was conducted to study the effect of water stress on physiological parameter of oil seed rape in the experimental research field of Collage of Agriculture (of shiraz university) during 2004- 2005 and 2005- 2006. Licord cultivar of oil seed rape was planted and experimental design was random block with five treatments and four replications. Treatments were full irrigation in all growth stages, water stress in vegetative stage in early spring, water stress in flowering and podding stages, water stress in grain filling stage and dry land treatment with supplemental irrigation in time of planting. Water stress caused decrease in water potential of plant, an increase in canopy temperature, and decrease in plant height especially in dry land treatment. Leaf area index decreased as water stress increased. The decrease in leaf area index was more severe in vegetative stage water stress treatment. At the end of water stress period leaf area index increased again. Rate of decrease in leaf area index at the end of the growing season was higher in grain filling stage of water stress treatment.