Building upon prior research demonstrating the excellent antifungal and nematicidal efficacy of Annona squamosa Lin. seed extracts, this study extends its scope to investigate similar properties in seed extracts from two other Annonaceae species: Annona muricata Lin. and Annona glabra Lin. The focus is on assessing their effectiveness against tomato late blight (TLB) and wheat leaf rust (WLR) diseases, as well as their broader antifungal activity against Colletotrichum sp. and Fusarium sp. The A. glabra seed extract exerted a superior control efficacy against TLB (85 % at 62.5 μg/mL) and WLR (75 % at 125 μg/mL) in vivo. The two Annonaceous extracts also exhibited in vitro antifungal inhibition against Colletotrichum sp. and Fusarium sp., as well as toxicology against pine wilt nematodes and Artemia salina. Besides, they showed phytotoxicity against Raphanus sativus seed germination. Squamocin G, a potent bioactive acetogenin, was isolated from A. glabara, which was found to occur at high contents in the following ascending order in A. glabra, A. muricata and A. squamosa dichloromethane extracts. To investigate the antifungal mechanism, molecular docking and molecular dynamic of squamocin G ligand were also performed for the first time at the active site of succinate dehydrogenase and β-tubulin.