Onderzoekingen over Ophiobolus graminis Sacc. en Ophiobolus herpotrichus (Fr.) Sacc. en over de door deze fungi veroorzaakte ziekten van Triticum vulgare Vill. en andere Gramineae

Due to the increasing importance of the wheat disease 'tarwehalmdoder' in the Netherlands, research was started on its occurrence and cause. An extensive literature review proved the identity of 'tarwehalmdoder' with take-all or whiteheads, which were caused by 0. graminis. The symptoms of the disease were root rot, decreased growth with drying of the leaves, blackening of the stem base and premature ripening.
Other fungi found on the stubble of Ophiobolus-diseased plants were described.

Ascosporous isolates of O. graminis and O. herpotrichus in pure culture were used in artificial inoculations. Inoculation with 0. graminis resulted in whiteheads. Only about half the isolates of O. herpotrichus were virulent on wheat and barley causing death of seedlings. This symptom was different from foot-rot and root-rot.

The occurrence of O. graminis on many Gramineae was reported. Resistance did not occur in existing wheat varieties. Environmental factors influenced the severity of the disease. Good crop rotation and cultural practices could limit economic losses.