ประสิทธิภาพของยีสต์ปฏิปักษ์ในการควบคุมโรครากเน่าอะโวกาโด ที่มีสาเหตุจาก Phytophthora spp.

Abstract

Avocado root rot caused by Phytophthora sp. does severe damage to avocado trees. The main symptoms are rotten root hairs with decayed outer tissues revealing the white inner tissues, dieback, and shabby trees, as well as black lesions on the trunk oozing clear exudates. The fungal isolates from adjacent soil samples of the diseased roots were identified as Phytophthora spp. The isolates were subjected to pathogenicity tests. Among the tested isolates, three Phytophthora sp. isolates CPC-Ph1, CPC-Ph2, and CPC-Ph3 were able to infect four avocado cultivars: Hass, Peterson, Pinkerton, and Booth-7, two days after inoculation. Avocado root rot control efficiency was tested using antagonists yeasts under greenhouse conditions. Seven isolates of antagonistic yeasts successfully controlled the avocado root rot under greenhouse conditions. Further, five essential oils viz. basil (Ocimum tenuiflorum), ginger (Zingiber officinale), betel (Piper betle), lemongrass (Cymbopogon citratus), and eucalyptus (Eucalyptus globulus) were tested against isolates CPC-Ph1, CPC-Ph2, and CPC-Ph3 using well diffusion and volatile assay.