Effects of Vermicast and Arbuscular Mycorrhizal Fungi (AMF) on the Establishment of Cacao (Theobroma cacao Linn.) Seedlings Grown in Degraded Soil

Abstract

Declining soil fertility poses a significant challenge for cacao production, particularly for establishing seedlings. This study investigated the potential effects of vermicast and arbuscular mycorrhizal fungi (AMF) to enhance cacao seedling establishment in degraded soil conditions. The study was conducted in a low-cost protective structure established at the Abaca Project Experimental Area of the University of Southeastern Philippines, Mampising, Mabini, Davao de Oro, from December 2018 to April 2019. Furthermore, a Completely Randomized Design (CRD) was employed with eight (8) treatments and three (3) replications with eight (8) sample plants per replicate. The following are the treatment combinations: No Application (T1), Recommended Rate (T2), Vermicast (T3), AMF (T4), Vermicast + AMF (T5), Recommended Rate + AMF (T6), Recommended Rate + Vermicast (T7), and Recommended Rate + AMF + Vermicast (T8). The results of the study reveal that the application of vermicast and AMF combined with inorganic fertilizer based on the recommended rate increased the growth and development of cacao seedlings in degraded soil in terms of plant height (16.40%), length of leaves (14.59%), the width of leaves (12.11%), number of leaves (1.26%), leaf color (41%), stem diameter, shoot weight (60%), dry matter yield (116%) and root:shoot ratio (63.16%) compared to control or no application. Thus, the judicious use of inorganic fertilizer, vermicast, and AMF improves the establishment of cacao seedlings in soils with degraded conditions.