Growth and yield response of organic cocoa (Theobroma cacao L.) to mycorrhizal biofertilizer prototype and pruning

Abstract

Cocoa is one of the industrial plants that have a high market demand. Bali as a cocoa center requires efforts to improve the quality and quantity of cocoa production. Efforts to increase organic cocoa production can be gave by applying mycorrhizal biofertilizers and pruning. This study aimed to find prototypes of mycorrhizal biofertilizers with different carrier media and the best pruning on organic cocoa growth and yield. This study used a randomized block design with 2 factors and 6 replications. The first factor was the prototype of mycorrhizal biofertilizer consists of 3 levels, i.e., without mycorrhizal biofertilizer prototype/control, mycorrhizal biofertilizer prototype with zeolite spore carrier media, and mycorrhizal biofertilizer prototype with volcanic sand spore media. The second factor was pruning which consists of 2 levels, i.e., without pruning and pruning the ends of twigs (2-3 segments), dead twigs, twigs attacked by pests and diseases and unproductive twigs. The results showed that mycorrhizal biofertilizer prototype with zeolite spore carrier media gave the highest weight of sun-dried seed per plant and number of seed per plant, while pruning the ends of twigs (2-3 segments), dead twigs, twigs attacked by pest and diseases and unproductive twigs gave higher cocoa yield in the form of weight of sun-dried seed per plant than that of without pruning. The interaction between the mycorrhizal biofertilizer prototype and pruning had a significant effect on leaf chlorophyll variables.