Abstract

The cocoa tree (Theobroma cacao L.) is primarily cultivated for its beans, which are used to produce chocolate. However, cocoa cultivation is frequently hindered by parasitic attacks, including those caused by Phytophthora megakarya, which result in significant yield losses. To enhance cocoa's tolerance to this pathogen, a study was conducted using organic fertilizers (laying hen droppings (LHD) and broiler hen droppings (BHD)) and triple super phosphate (TSP), as well as their combinations at varying doses. In a greenhouse setting, the development of necrosis on whole leaves was evaluated on 5-month-old cocoa plants over four infection cycles following fertilizer application. The fertilizers were applied in two phases: initially, all fertilizers were applied, and subsequently, only organic fertilizers were applied, followed by TSP application at the 8th week. The results showed that TSP improved tolerance to P. megakarya, although its effects were rapid and transient. Correlation and principal component analyses revealed that fertilizer treatments were negatively correlated with the control treatment, except for BHD and TSP, which were positively correlated. The most effective fertilizers for improving tolerance to P. megakarya were found to be the combinations of TSP + LHD and BHD, TSP + LHD, and TSP + BHD. These fertilizers have potential for use in integrated management strategies to combat brown rot in cocoa fields.

Key words: broiler hen droppings, fertilization, laying hen droppings, necrosis, Phytophtora megakarya, Theobroma cacao, triple super phosphorus.