عنوان مقاله [English]
Background and Objectives
Drought is one of the major environmental constraints that limit plant growth and productivity more than any other environmental factor. Recently MA application to alleviate drought stress in many plant have been reported. Besides its application led to improvement in plant growth and enhanced minerals intake which can reduce the amount of chemical fertilizers. The latter is the aim of sustainable agriculture plus it can upgrade plant tolerance toward drought stress.
Vermiwash can be used in two forms of foliar application or adding it to the media. It contains several enzymes, plant growth hormones, vitamins and macro and micro minerals which can boost plant’s tolerance toward disease, as well as crop yield efficiency.
Materials and Methods
In order to investigate Mycorrhizal Arbescular fungi and Vermiwash foliar application on gazania (Gazania rigens L.) growth and flowering characteristics under drought stress, a greenhouse experiment with factorial design based on complete randomized blocks by considering 3 factors including MA fungi in two levels (incubation with MA and non-incubated plants), Vermiwash foliar application in 4 levels (0, 50, 100 and 200 ppm) and imposing drought stress in 3 levels (40, 70 and 100% FC) with 3 replications in the greenhouse and laboratory of the campus of agriculture and natural resources of Tehran University was conducted in 2018.
Studied traits were involved of plant height, number and leaf area index, flower diameter, aerial fresh and dry weight, chlorophyll and carotenoid amount, N, P and K quantity of leaves. Analysis of variance’s results indicated that the influence of main effect of drought stress, MA and vermiwash on the measured traits were considerably functional. In such a way that drought stress led to increase in leaf’s carbohydrate.
The maximum value of leaf’s carbohydrate was achieved in drought stress with the high severity in 40% of FC witch was 32/46 mgr/gr. MA caused elevation in macro elements amount of the leaves. Foliar application of vermiwash increased flower number and dimension and macro elements amount as well.
Comparison of the mean of dual effect of vermicompost in drought stress showed that the highest plant height in 200 ppm vermiwash was 100% irrigation and the lowest value was in 50 ppm vermiwash in irrigation 40% of field capacity was observed. The lowest amount of chlorophyll a was observed in 40% water capacity and no mycorrhizal fungi application. The highest leaf carbohydrate content was observed in irrigation treatments with 40% and 200 ppm vermiwash.
Considering the reaction of plant to level of imposed levels of drought stress, it can be concluded that this plant reacts more sharply toward severe level of drought stress than moderate level and this level of drought stress in comparison with control can decline traits related to crop yield seriously. Hence, it is recommended to avoid severe drought stress during plant growth period. To achieve this aim, applying MA combination with Vermiwash to improve plant tolerance toward drought stress can protect plant’s growth.