Improving vegetative growth of transplants of two olive cultivars by foliar application of some organic extracts and chemical fertilizers.

This study investigated the effects of foliar spraying with NPK, organic fertilizers, and seaweed extract on 2-month-old seedlings of Coratina and Aggizi Shame olive cultivars, to improve vegetative growth and reduce the tending time of transplants in the nursery. Growth parameters, minerals and photosynthetic pigment contents were measured. The trials were carried out in greenhouse of Horticulture Research Institute (HRI) during 2020/2021 and 2021/2022 seasons. The experiment was arranged using a completely randomized design. The results on the response of Coratina transplants to spraying NPK alone indicated significantly increases in the plant height and root length of transplants. However, the foliar application with compost tea (CT) + NPK increased the contents of chlorophyll-a and total carbohydrates. Treating cv. Coratina with foliar application of seaweed (SWE) combined with NPK greatly enhanced the root length and increased the number of lateral branches/plant as well as the contents of N, P, chlorophyll-b, and carotenoids. Furthermore, Aggizi Shame olive transplants which received a foliar application with vermicompost tea (VCT) + NPK showed the tallest transplants and the longest roots. However, the treatment of SWE+NPK achieved the highest number of lateral branches/transplant, and the highest contents of K, chlorophyll-a,-b and carbohydrate in the leaves of the two olive cvs. (Coratina and Aggizi Shame). The present investigation proved that either SWE or VCT in combination with NPK could be used as a foliar application for improving the growth of olive transplants successfully