The effect of mycoriza and silicon applications on production andplant development of pepper grown under limited irrigationconditions

Pepper, a member of the Solanaceae family grown as an annual in subtropical climates, is a very common and widely produced and consumed vegetable in our country as well as all over the world. There are many biotic and abiotic stress factors that limit the yield and plant growth of pepper. Water stress is one of the most common stresses. Drought and water stress also negatively effect metabolic defenses in plants. In case of water stress, the plant tries to adapt to arid conditions by developing some defense mechanisms. Mycorrhizal fungi present in soils contribute positively to the root system of plants by maintaining a symbiotic life with plants. In this context, the surface area of the root expands by the fungi hyphae and plant can take the nutrients and water in the form and amount that the plant cannot get from the soil, which are far away from the root so, can prevent the plants from water stress. Some minerals can also play a role in increasing the resistance of the plant against stress conditions. One of these minerals is silicon. Silicon is a trace element that has potential effects that protect the plant against abiotic and biotic stresses such as extreme heat and drought stress, mineral toxicity, plant diseases and insect pests, and increase its development, especially in unsuitable climatic conditions. In this study, it was aimed to increase the resistance of the plants against limited irrigation by using mycorrhiza (Mi) in order to make more active the root structure of the pepper plant grown under limited irrigation conditions and silicon (Si) in order to increase the resistance to stress conditions. For this purpose, some physiological, morphological and biochemical parameters occurring in pepper were investigated. In the study, full (100%) and restricted (50%) irrigation conditions, mycorrhizal (M+) and non-mycorrhizal (M-) growing media and 2 different silicon doses (0 and 2 mM) and their combinations were tested. The study was carried out in the spring production period of 2021, in a 400 m2 polycarbonate covered, unheated greenhouse belonging to Mardin Derik Vocational and Technical Anatolian High School and as soilless production. The research was planned according to the Random Blocks Trial Design and was carried out with 4 replications. The variance analyzes of the data obtained from the study were made in the TARIST statistical program. It was determined that while the membrane permeability and proline content of the plants grown under full irrigation conditions decreased, the other parameters significantly increased. Mycorrhiza application increased plant height, stem diameter, root length, average fruit weight, fruit flesh thickness and membrane permeability values; on the other hand, it was determined that the stem dry weight, total fruit number and fruit length values decreased. Silicon applications increased yield per plant, number of fruits per plant, fruit length and membrane permeability, while decreasing root length. According to the results of the study, it was determined that higher yields could be obtained by applying mycorrhiza and silicon together under limited irrigation conditions.