Nano-NPK and Nano-Sulfur Boost Vegetative Growth and Chemical Constituents of African Mahogany (Khaya senegalensis L.) Seedlings under Saline Soil Conditions

Abstract

Soil salinity is considered a serious and limiting factor reducing the crop productivity in particular under arid, and semi-arid conditions. Pot experiments were conducted at the Ornamental Department of the Horticulture Research Station in Sakha, Kafr El-Sheikh Governorate, Egypt during the season of 2021 and 2022. This study aimed to evaluate the effect of foliar application with nano-NPK and nano-sulfur using different doses on the growth and chemical compounds of Khaya senegalensis L. under salinity stress. The studied treatments were mineral NPK fertilizer at 5 g L-1 (as a control), applied nano-NPK at 1, 2 and 3 ml L-1, besides three combinations of nano NPK (2 ml L-1) and applied nano-sulfur at 1, 2 and 3 ml L-1, separately. The obtained results showed that the treatment of nano-NPK 2 ml L-1 + nano-sulfur 2 and/or 3 ml L-1 significantly increased plant height (cm), stem diameter (cm), fresh and dry weights of vegetative parts per seedling (g), membrane stability index, as well as root length (cm), number of roots and root fresh and dry weights per plant. The superiority of the nano-NPK at 2 ml L-1 + nano-sulfur at 2 ml L-1 treatment comparing with the control in both seasons. Most treatments recorded significantly higher chlorophyll a, b, carotenoids, catalase and peroxidase activity in the leaves than control. A superiority was found after applying nano-NPK 2 ml L-1 + nano-sulfur 2 ml L-1 in both seasons for nitrogen, phosphorus and potassium content in the leaves, which was significantly increased over the control.