عنوان مقاله [English]
Growth-reducing factors play a key role in significantly reducing seed germination, reducing plumule length and radicle length growth, reducing seed vigor index and reducing seedling length. The most important of these factors are biological and non-biological stresses that several studies have reported have a significant effect on reducing seed germination. In Iran, chickpea cultivation is usually rainfed (about 92%), the seeds use the moisture stored in the soil and in this case the seeds are exposed to drought stress. Exposure to drought stress will eventually lead to reduced germination, improper posture, reduced plant yield. Water potential is the most important factor in seed germination and its reduction directly affects the physiological processes of germination and indirectly affects seed growth and nutrient reserves. In modern agricultural methods, the use of organic fertilizers to improve seed tolerance to stress conditions is recommended. One of these biological and organic fertilizers is compost and vermicompost. The use of vermicompost in addition to adding to the soil can be in the form of adding vermicompost extract (tea compost) to the soil. The unique properties of vermicompost extract are: 1. Contains beneficial aerobic microorganisms such as Azotobacter, 2. No anaerobic bacteria, fungi and pathogenic microorganisms, 3. High water holding capacity, 4. Humic acid (these substances have it has similar effects to growth regulators and hormones), and 5. Contains macro and micro nutrients such as nitrogen, phosphorus, potassium, calcium, copper, manganese, iron and zinc. Due to the problem of drought and water shortage in many parts of the country, especially Khuzestan province, the use of modern agricultural methods to increase the yield and yield of crops is essential. The main purpose of this study was whether the use of compost tea can play a role in improving the negative effects of drought stress on the germination stage of chickpea seeds?
Materials and Methods
A factorial layout based on a completely randomized design with three replications was conducted at Khatam Al-Anbia University of Technology in Behbahan. The first study was four levels of tea compost such as of 0, 5, 15, 25 and the second treatment was drought stress caused by polyethylene glycol, which included levels of -0.3, -0.6 and -0.9 MPa. In each petri dish, 35 chickpea seeds of Adel cultivar were placed and then the experimental units were numbered based on the studied treatments. Daily examination of petri dishes was continued for 14 days and germinated seeds were harvested from experimental units 15 days after the start of the experiment to measure germination parameters. Characteristics such as percentage, rate and vigor germination, seed vigor index, endosperm consumption, seedling length, plumule and radicle length, plumule and radicle dry weight were measured.
Results and Discussion
The results of this study showed that the application of compost tea had a positive and significant effect on all indices of chickpea seed germination, so that the results related to the simple effects of this application showed that the use of 5, 15 and 25% levels of compost tea significantly increased radicle dry weight, plumule dry weight and endosperm consumption. Under drought stress treatment, the results showed that in all germination and growth indices with increasing stress intensity from -0.3 MPa to -0.9 MPa had a significant decrease. In the study of the interaction effects of compost tea and drought stress, it was observed that in non-stress conditions, the levels of compost tea used (5, 15 and 25%) significantly increase germination rate, germination vigor, vigor index seed, radicle length and seedling length were compared to the control treatment. Under stress conditions of -0.3 MPa, all levels of compost tea caused a significant increase in seed vigor index, germination percentage, rate and germination vigor compared to the control and also in these conditions, 15 and 25 levels were able to significantly increase plumule length and seedling length relative to control. Under -0.6 MPa stress, levels of 15 and 25% of compost tea caused a significant increase in germination percentage and germination vigor, seed vigor index, plumule length and seedling length. Under stress conditions of -0.9 MPa, application of compost tea levels (5, 15 and 25%) in comparison with the control treatment significantly increased germination percentage, germination rate, radicle length, plumule length and seedling length. Under these conditions, 15 and 25% of compost tea also significantly increased germination vigor compared to the control treatment.
According to the results of this study, application of compost tea (vermicompost extract) at levels of 15 and 25% in conditions where chickpea seeds are exposed to drought stress, is recommended.