Shredded Maize Stems as an Alternative Substrate Medium

Abstract

Abstract The interest in the use of mixtures of inorganic and organic materials as substrate media in soilless culture in greenhouses is increasing in parts of the world where the mixtures have not been used in common practice. In this study, tomato (Lycopersicum esculentum Mill.), cv. Belladona, plants were grown over a five-month period in a closed soilless culture system on seven different substrates (perlite or pumice and their mixtures with 25% or 50% shredded maize stems) and in Nutrient Film Technique (NFT), in an unheated glasshouse. Substrate affected some characteristics of plant development and fruit yield. Plants grown on NFT were taller and had more leaves than did plants grown in perlite. Stem thickness differed according to substrate and time of measurement at 0.15, 1 and 2 m above the substrate surface. The total number of flowers and fruit produced varied with time and substrate, but there were no differences at the end of the experiment. Increased electri cal conductivity (EC) of the nutrient solution resulted in reduced numbers of flowers. The addition of shredded maize stems to mixes resulted in a higher yield, indicating there are beneficial effects of adding organic substances to inorganic substrates. Treatments did not affect occurrence of gray mold (Botrytis cinerea Pers. ex Fr.) or blossom-end rot on fruit. The results indicate that addition of shredded maize stems in perlite and pumice could improve their properties over inorganic substrates alone, and lead to improved plant development and yield for greenhouse cultured tomato.