LAUSR

ABSTRACT Many crops are colonized with arbuscular mycorrhizae fungi (AMF), which can efficiently absorb nutrient from the soil and induce plant immunity. The purpose of this study was to investigate the effects of AMF and rock phosphate (P) fertilizer applications on available P and some secondary plant metabolite in robusta coffee. The experiments were laid out in a 3 × 4 factorial randomized complete block design with AMF inoculants (control, Glomus intraradices LU3, Glomus sp. 2TS5) and rock phosphate fertilizer levels (0, 100, 200, and 400 g plant−1). Parameters measured root colonization percentage, available P in soil, total P in leaf, salicylic acid and phenolic compounds in leaves. The results showed that there was significant interaction between AMF and P in root colonization density, available P in soil, total P in leaves, and salicylic acid content. AMF (both Glomus intraradices and Glomus sp.) improved root colonization density (64–65%), available P in soil (30–50%), total P in leaves (37–40%), salicylic acid content (8–19%), and phenolic compounds in leaves (53–74%) compared to the control. Also, higher P at 400 g plant−1 increased root colonization density, available P in soil, total P accumulation in leaves, and salicylic acid. Therefore, AMF and rock P potentially represent an alternative way to promoting P uptake and plant immune in coffee.