جستجوی مقالات مرتبط با کلیدواژه « growth regulator » در نشریات گروه « اکولوژی »

Forage millet is a crop of tropical and subtropical regions which is considered due to abundant tillering, rebuilding ability, resistance to environmental stresses and diseases, high yield in poor soils and absence of prussic acid. Low amount of available water to plants results in drought stress and inappropriate morphological and physiological changes in the plant. Plants under environmental stress conditions accumulate low molecular weight organic solutions such as amino acids and sugars. Plant hormones affect plant growth in multifarious ways affecting a number of physiological and biochemical processes in plants subjected to biotic and abiotic stresses. Salicylic acid (SA) is one such plant growth regulators, which participates in the regulation of a number of physiological events in plants. The use of salicylic acid in wheat increased the photosynthesis rate, protein and sugar content of shoots, roots and leaf chlorophyll under drought stress conditions. Tomato and amaranth treatment with salicylic acid in different stages of growth during drought stress prevents reducing the production of dry matter of the plant.

To evaluate the quantity and quality fodder traits of foxtail millet Bastan cultivar under the influence of drought stress levels and salicylic acid concentrations in Sistan climate, a field experiment was conducted as split plot based on a randomized complete block design with three replications at the Agricultural Research Institute of Zabol University during 2017. Treatments included three irrigation levels as main plot (45, 65 and 85 percent humidity of field capacity) and sub plot including salicylic acid in four levels (0, 0.75, 1.5 and 3 mM). Spray application was considered for salicylic acid. Dry forage yield, dry matter digestibility, water soluble carbohydrates, crude protein, crude fiber, insoluble fiber in acid detergent, insoluble fiber in neutral detergent and ash were measured. Measurement of forage quality characteristics in the Research Institute of Forests and Rangelands was performed with NIRS device made in Sweden.

Results revealed that drought stress caused significant differences on dry forage yield, dry matter digestibility, water soluble carbohydrates, crude protein, insoluble fiber in acid detergent and insoluble fiber in neutral detergent at 1% significance level and on ash at 5% significance level. Drought stress increases water soluble carbohydrate, insoluble fiber in acid detergent and insoluble fiber in neutral detergent and decreases dry forage yield, dry matter digestibility, crude protein, crude fiber and ash. The effect of salicylic acid on dry matter digestibility, water soluble carbohydrates, crude protein, crude fiber and insoluble fiber in acid detergent at 1% significance level and on dry forage yield and insoluble fiber in neutral detergent were significant at 5% level. The interaction effects of drought stress and salicylic acid on dry forage yield, dry matter digestibility, water soluble carbohydrates, crude protein, crude fiber, insoluble fiber in acid detergent and insoluble fiber in neutral detergent were significant at 1% probability level. Maximum dry forage yield (12.34 t.ha-1), dry matter digestibility (68.85%) and crude fiber (40.79%) were obtained from full irrigation and application of 3 mM salicylic acid treatments. The highest water soluble carbohydrates (13.81%) and crude protein (18.93%) were obtained from intense tension × 1.5 mM salicylic acid and control× 1.5 mM salicylic acid, respectively. The highest insoluble fiber in acid detergent (41.31%) and insoluble fiber in neutral detergent (81.51%) were observed under severe drought stress conditions without salicylic acid.

The results of this study represent the adverse impact of drought stress on the quantity and quality traits of foxtail millet Bastan. Application of salicylic acid has a positive role in modulating the effects of drought and improves quantity and quality forage. Therefore, can be expressed that irrigation of 85% moisture filed capacity and spraying 3 mM salicylic acid as growth regulator can produce quantity and quality desirable performance in Sistan climatic conditions.