Growth-promoting fungi and potassium doses affects productivity and nutrition of cherry type tomatoes

Abstract

Tomato plants show great potassium (K) demand and good response to potassium fertilization, whose insufficiency leads to a drop in fruit production and quality. On the other hand, the association of growth-promoting fungi (GPF) with roots has been shown to be able to optimize the absorption of not only phosphorus, but either other nutrients, like K, which opens possibilities of better nutrient use efficiency and consequently reduces environmental risks of fertilization. Thus the present work aims evaluating the yield and nutritional status of hydroponic cherry type tomato inoculated with Piriformospora indica and Arbuscular Mycorrhizal Fungi (AMF) and subjected to K doses. The experiment was carried out in a greenhouse, using drip irrigation system. The plants were conducted in recipients containing washed and sterilized sand. The minimum and maximum greenhouse temperatures, ranged between 10.8 and 16.5 °C and 28.2 and 35.4° C. Relative humidity ranged between 45% and 68% and between 25% and 50% in the morning and afternoon respectively. Colonization was found to be higher with P. indica and tended to reduce with increasing doses of K. Under nutritional stress, the P. indica inoculation reduced the number of fruits with green shoulder and increased fresh weight of commercial fruits. It also increased the concentrations of macronutrients and micronutrients. This symbiotic association favors the yield performance of cherry type tomato under nutritional stress.