Diseases

Fusarium spp. - Maize Seedling Blight

Systematic position.

Division Deuteromycota, class Hyphomycetes, order Tuberculariales, family Tuberculariacea, genus Fusarium.

Biological group.

This is a facultative parasite.

Morphology and biology.

Thin pink or white bloom of the fungus appears on the surface of sprouting maize. Soon after emergence of shoots they turn brown and die. Surviving shoots have weakly developed root system; infected plants are characterized by delay of growth, their leaves dry, and some plants can be lodged. The disease agents are mold fungi, particularly Fusarium fungi. They are kept in seeds, soil, and on plant residues.

Distribution.

The disease is distributed everywhere.

Ecology.

Disease development is enhanced by low temperatures during the period of seed sprouting, high soil moisture and acidity, very deep or shallow sowing of seeds and high density of crops. Data on the influence of fertilizers on disease development are contradictory.

Economic significance.

The severity of seed infection strongly influences the disease development. With low levels of infection the germinating ability of seeds decreases by 14%, and by 40% with strong levels of infection. In Krasnodar about 40% of plants are affected by Fusarium spp. Under unfavorable conditions the disease can cause 60-70% thinning of plants. The disease is especially harmful in zones with prolonged springs and wet weather. In these districts the seedlings can appear as early as 20-30 days after sowing. To protect maize from the disease the following measures are recommended: treatment of seeds by fungicides, sowing on optimal dates into warm soil, use of hybrids that are resistant to the disease.

Reference citations:

Ainsworth J., Bisby H. 1995. Dictionary of the Fungi. 8th ed. Wallingford: CABI International, UK. 616 p.
Ivakhnenko A.N., Dudka E.L., Zhurba G.M., Borisov V.N. 1983. Selection of early-ripening maize hybrids resistant to Fusarium rot root. Doklady VASKHNIL 12: 15-16. (In Russian)
Ivashchenko V.G., Shipilova N.P., Sotchenko E.F. 2000. The most harmful disease of seeds and ears of maize. Agro XXI(7): 6-7. (In Russian)
Kalashnikov K.Ya., Shapiro I.D. 1962. Pests and diseases of maize. Leningrad: Sel.khozgiz. 189 p. (In Russian)
Nemlienko F.E. 1957. Diseases of maize. Moscow: Sel.khozgiz. 230 p. (In Russian)
Sokirko V.P., Balde Ch.A. 1985. Root rot of maize . harmful disease on Cuban. In: Zenyuk V.A., ed. Improvment in agronomic practices of maize growing in Krasnodar region (Proc. Kuban SKHI, 255(283)). Krasnodar: Kuban SKHI. 33-36 p. (In Russian)
Stoikov S., Videnovich Zh., Iovanovich Zh. 1996. Influence of agrotechnical methods on Fusarium causing root rot and stalk rot. Kukuruza i sorgo 5: 20.21. (In Russian)

© Levitin M.M.