EFFECT OF SPENT MUSHROOM ADMIXED WITH TOPSOIL ON THE DRY MATTER PRODUCTION OF COCOA (Theobroma cacao) SEEDLINGS

ABSTRACT

Spent mushroom substrate can be admixed with top soil to make it suitable for the production of seedlings thereby helping to clean up the environment of this potential pollutant. A study was conducted between June and August,2023 at the screenhouse of the Department of crop science, Faculty of Agriculture, University of Benin, Benin city to evaluate the effect of spent mushroom substrate admixed in topsoil on the dry matter production of cocoa. The study involved five levels (0, 50, 100, 150, 200g) of spent mushroom substrate (SMS) admixed in 3kg of topsoil laid out in a randomized complete design in three replications. Data were collected on root and shoot length, shoot and root weight, root : shoot ratio and crop growth. Results showed that the addition of spent mushroom to topsoil improved pH and nutrient content of the soil but reduced exchangeable acidity and porosity. However, it increased bulk density and electrical conductivity. Application of SMS increased shoot and root length, shoot and root weight, dry weight, root : shoot ratio and crop growth rate. These parameters increased with increase in application rate of SMS. Plant with increase SMS rate of 100g had the heaviest dry weight (1.83g). Application rate of 200g per 3kg soil is thereby suggested for cocoa seedlings growers.