Application of Arbuscular Mycorrhizal Fungi (AMF) at the nursery to suppress the basal stem rot disease incidence in oil palm.

Ganoderma boninenseis the main pathogen in oil palm plantation areas and can infect new plants, thereby shortening the economic life of the crop cycle. Until now, no effectivecontrolmeasurehas been found to minimize the incidence ofthisbasal stem rot(BSR) disease.Preventive control strategy through replanting and applying Arbuscular Mycorrhizal Fungi (AMF) and Trichodermasp.in thenursery can be an approach in controllingBSR disease.This study aimsto determine the effect of AMF and Trichodermasp.as biocontrol agents intheoil palmnursery on the incidenceof BSR in the field. The treatments were types (MM, MR, and MT) and dosages (25,50 and 75 gper seedlings) of AMF products and each treatment was replicated three times. Arbuscular Mycorrhizal Fungi was applied atthe main-nurserystageand atthe time ofplantingin the field. Observations were made on AMF and Trichoderma sp.spore density and AMF colonizationontheplants at4, 5, 6, and 7 years-olds,while the incidence of BSR was observed for ten years, from one year before replanting up to8-year-old.The experimental designcarried out was a randomized block design. The results showed that the MM-25 treatment was the best treatment in terms of AMF colonization percentage(98%)and total AMF spores (688 sporesper 100 g soil)at seven-year-oldplants.However, the population of Trichodermasp.showed inconsistentnumbers during the observation. Before replanting, the oil palm plantation area showed a BSR incidence of 21.37%. However, after replanting with the application of AMF and Trichoderma sp.on the seedlings,the incidence of BSR has become0%untilthe plantsateight-year-old. In general, the application of AMF reducedthe BSR incidence onoil palm in the field.