Improving the quality of media and Robusta coffee seedlings with mycorrhizal (AMF) and rock phosphate

Abstract

The quality of the nursery media is very important to producing healthy and good Robusta coffee seeds. This study aims to improve the quality of media and Robusta coffee seedlings by the application of arbuscular mycorrhizal fungi (AMF) and rock-phosphate (RP). The AMF as the first factor consisted of four levels, namely 0, 5, 10, and 15 g/polybag, while the second factor RP consisted of four levels, namely 0, 1.25, 2.50, and 3.75 g/polybag. Each treatment was repeated three times and the whole treatments were arranged according to a completely factorial randomized block design. The seedling in a nursery was planted in the polybag and placed in a screen house with 20% shade. Each polybag is contained 10 kg of Podzolic soil (Ultisols) which was collected in Keumala sub-district, Pidie, Aceh. Before being transferred to polybags, seedlings were planted on Rockwall media. After 90 days after planting (DAP), the soil was dismantled for analysis. Indicators of soil quality from the media nursery analyzed included pH, organic C, available P, and exchangeable K. The parameters of seedling growth measured were plant height, number of leaves, and mycorrhizal colonization percentage at 90 DAP. The results of the experiment showed that there was an interaction effect between mycorrhizae (AMF) and RP application. The application of AMF and RP can improve the quality of Robusta coffee seedling media, indicated by the significant effect on soil pH H₂O, available P, and the number of leaves. The best combination application was generally obtained from AMF 15 g/polybag and RP 2.50 g/polybag treatment.