كليدواژه فارسي :
اصلاح¬كننده خاك , بيوچار , خشكي , صفات مورفوفيزيولوژيك , گوار
كليدواژه لاتين :
Soil amendment , Biochar , Water stress , Morphophysiological traits , Guar
چكيده انگليسي :
Abstract
Drought is one of the abiotic stresses and has an important effect on reducing the yield of plants. Organic modifiers such as biochar can be useful for plants under stress conditions. Due to the necessity of cultivating low water-demanding and industrial medicinal plants, guar plant was chosen to investigate the effect of drought stress and soil conditioner (biochar).The experiment was carried out in the split split plots and in the form of a randomized complete block design with three replications. The main factor was three levels of drought stress I1, I2 and I3 (10, 14 and 17 days irrigation round) and the first sub-factor was two local (Saravan) and commercial (RGC - 936) varieties (V1 and V2) and the second sub-factor is three levels of biochar B1, B2 and B3 (zero, 0.5 and 1 percent respectively equivalent to approximately zero, 5 and 10 tons per hectare). At the end of the experiment, the physiological and morphological traits of the plant including the amount of chlorophyll a and b, chlorophyll index SPAD, relative leaf water content, ion leakage, vegetation temperature, leaf surface, water use efficiency, number of lateral branches, number of clusters, length and diameter Stem, length and number of pods, number of seeds per pod, weight of 1000 seeds, percentage of gum, fresh and dry weight of shoot, root and plant, root length, concentration of calcium, magnesium, phosphorus, sodium and potassium elements in leaves were measured. Also the concentration of sodium elements, calcium and magnesium, acidity and salinity at two depths of 0 to 20 and 20 to 40 cm soil were measured. The results showed that the maximum amount of EC and calcium concentration in the depth of 20 and 40 cm of the soil was obtained in the 0% biochar treatment. the highest concentration of calcium (15.89 mg/g), the number of lateral branches (7.74) and the weight of 1000 seeds (48.87 grams) were observed in the Indian variety and the highest concentration of phosphorus (0.49%), leaf surface (861.83 mm2) and the number of pods (6.33) were observed in the native variety. There was no significant difference between the two varieties in terms of the concentration of magnesium, potassium, and sodium elements, as well as the parameters of SPAD and fresh weight of shoot and total fresh weight of plant. The highest number of pods (6.67), ion leakage percentage (46.25%), vegetation temperature (37.52 ˚C), concentration of calcium elements (17.96 mg/g) and potassium (67.32 mg/g) and use efficiency water (0.08 kg/m3) in treatment I3 and the highest chlorophyll a (1.53 mg/g), SPAD (98.47), leaf area (890.43 mm2) and concentration of magnesium elements (58.33 mg/g), phosphorus (0.51 %) and sodium (50.64 mg/g) were obtained in I2 treatment. The lowest number of seeds in the pod (5.28 number), ion leakage percentage (33.11%), vegetation temperature (33.79 ˚C ), concentration of elements potassium (18.65 mg/g) and sodium (28.88 mg/g) and the efficiency of water consumption in irrigation for 7 days and the lowest fresh weight of roots (2.58 g), canopy (42.41 g) and total of plant (44.99 g), length (46.54 cm) and diameter (5.95 mm) ) of stem, gum percentage (25.28%), relative leaf water content (0.28%) and magnesium concentration (42.14 mg/g) were obtained in I3 treatment. The highest values of most of the measured traits were obtained in the treatment of 1% biochar. In general, the 14-day irrigation cycle with the application of 1% biochar showed better results in both varieties.
