Using Different Substrate Materials (Local and Imported) For Producing Eggplant on Rooftops

Turning rooftops in Egypt to green cultivated tops full with vegetable crops can help in food security specially in big cities by increase the availability of fresh vegetables within cities and this can help in more stability in vegetable prices and reduce the extreme fluctuation in vegetable prices that happens in recent years. Furthermore, increase fresh vegetables help to secure food needs of citizens specially under the situation of continuous increase of Egyptian population. In this context, an experiment was carried out in the rooftop garden of Central Laboratory for Agricultural Climate (CLAC), Agriculture Research Center, Ministry of Agriculture and Land Reclamation, Dokki, Giza, Egypt during summer seasons of 2019 and 2020. The experiment was conducted to investigate the effect of using different substrate materials (local and imported) on the growth and production of eggplant cultivated in rooftop gardens. The tested growing media consisted of local substrates mixed together or with imported substrates available in the local market to reduce the cost of the growing media. 9 growing media have been tested in this study in relation to growth and yield of eggplant grown on rooftops and their description were as follow; v/v (SPe1), sand : perlite (2:1) v/v (SPe2), sand : rice husks (1:1) v/v (SR1), sand : rice husks (2:1) v/v (SR2), sand : rice husks (1:2) v/v (SR3), crashed red bricks (CRb) and small gravel (Gr). Different measurements have been recorded during the experimental time such as; plant height, number of leaves, fresh and dry weights of aerial parts and roots, ratios between aerial parts and roots using both fresh and dry weights values, yield per m 2 , (N, P, K) % in leaves, and initial costs of growing media in comparison to yield. Results indicated that, from all 9 tested growing media mixtures SR1 recorded the highest values regarding plant growth and yield followed by SR2. Nevertheless, when we compare between the cost of the growing media and yield, data indicated that SR2 was the cheapest growing medium followed by SRI. The initial cost of the growing media was about 13.5 and 10.75 E.P for SR1 and SR2 respectively and average yield was about 12.68 and 10.96 kg/m 2 for SR1 and SR2 respectively), while the most expensive growing media was SPe1 .The initial cost for SPe1 was about 92.5 E.P and average yield was about 6.60 kg/m 2 ). From all of that, both SR1 and SR2 can be considered as the most suitable growing media consisted of local materials (sand and rice husks) for producing eggplants on rooftops.