Abstract

Bipolaris coicis, B. cynodontis, B. maydis and Curvularia lunata were leaf blight fungi detected from 45 seed samples of Job's tears and B. coicis was the predominant species in seed samples followed by C. lunata, B. cynodontis and B. maydis. When the seed components were plated on test tube agar, B. coicis and C. lunata were highly detected from invelucre, glume, endosperm and stamen, but not detected from plumule. Seed infection with B. coicis casued seed rot, coleoptile blight and seedling blight of Job's tears. Conidial characteristics of leaf blight fungi were as follows; B. cynodontis was fusiform, brown, slightly curved, 0~5 distoseptate, and 16.8-48$\times$7.2-16.8${\mu}{\textrm}{m}$ in size; B. cynodontis was fusiform, brown, slightly curved, 0~8 distoseptate, and 16.8-72$\times$9.6-19.2 ${\mu}{\textrm}{m}$; B. maydis was fusiform, brown, distintly curved, 0~10 distoseptate, and 28.8-110.4$\times$12-21.6 ${\mu}{\textrm}{m}$. C. Lunata was fusiform, brown, typically curved, 0~3 distoseptate, and 7.2-24$\times$4.8-12 ${\mu}{\textrm}{m}$. B. coicis was highly pathogenic to Job's tears and corn, weakly pathogenic to rice, but not pathogenic to wheat and barley. c. lunata was highly pathogenic to Job's tears (No. 2), corn, wheat and barley, weakly pathogenic to Job's tears (No. 1), but not pathogenic to rice. All treatments were effective to inhibition of leaf blight fungi when carboram, benoram, fludioxonil, prochloraz, thioram, and tap water treated to infected seeds.

Keywords

• Job's tears;
• leaf blight;
• Bipolaris coicis;
• B. cynodontis;
• B. maydis;
• Curvulara lunata;
• seed transmission.