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Prevent corn head burn by sowing insensitive variety
Corn head burn, simply head burn or head smut mentioned, is advancing further. Especially in lower wet areas, but also beyond. The disease is being detected more and more often in maize, not only in the Netherlands, but also in Belgium. Corn plots can fail completely due to damage by corn head burn. Fortunately, a targeted choice of corn varieties can limit or even prevent damage!
Corn head burn is an infection with the fungus Sphacelotheca reiliana. This fungus remains in the soil and can damage the corn through the root even in the seedling stage. If the maize grows too slowly in the second to third leaf stage, the fungus can reach the growing point, resulting in damage to the inflorescences, panicle and cob from the inside.
Until the end of August there is usually hardly anything visible on the plant, only the plant length lags behind somewhat. Around September 1, black fungal growth sometimes appears on the plume and in the bract. A large hairy fungal ball develops at the site of the cob, which then takes the place of the entire cob.
The chance of severe damage is greater if the initial development of the maize up to the fourth or fifth leaf stage is poor due to stress (cold, wet soils, night frost, etc.). We see this same increased risk in sensitive varieties, for example after less severe winters and wetter weather conditions. The damage between varieties varies from less than 0,1% to even more than 50%.
The consequences
The fungal balls form spores that fall to the ground or are spread by wind. In case of heavy infestation, a black dust cloud of spores can be seen during chopping. Spread also takes place via machines. In the hole, heavy infestation causes a dirty black layer that resembles wet black soil.
If the damage is severe, corn head burn can render the entire corn crop unusable. With headburn damage above 10%, the starch content and nutritional value are disappointing because the cob is completely moldy. The dry matter yield is also lower. With 50% or more affected plants, the starch content is more than halved and the yield may be 25% lower.
Little is known about toxicity, but the palatability of corn infected with corn head burn undoubtedly decreases considerably. Corn burn is therefore a much bigger problem for livestock farmers than blight, with which the fungal disease is often confused. With more than 25% infestation, the advice is not to harvest the corn, but to leave it on the field and spread it.
Sow resistant maize varieties
In many tests, maize varieties have been assessed for maize head burn damage. Naturally, this is investigated on plots where damage has occurred in the past. All these studies have shown that some varieties appear to be very sensitive to corn head burn, while other varieties are not. Since this year, the breed differences with regard to susceptibility to head burn have been listed in an extra column on the Dutch CSAR Recommended Variety List 2024.
On plots infected with corn head fire, livestock farmers can grow a number of varieties with almost no problems, because these varieties have on average only between 0% and 1% risk of infection. By choosing the right variety, failure of maize cultivation on these plots can be prevented.
Varieties that have been shown to be resistant to corn head burn attack MEGUSTO KWS en GENIALIS KWS. In addition, based on a previous review of KWS EMPORIO a correction was made very recently. Also for KWS EMPORIO it has been clearly demonstrated that it is insensitive to corn head burn damage, as can also be read in the latest update of the Dutch CSAR Recommended Varieties List 2024. Therefore, do not take any risk of damage as a result of a corn head burn attack and sow these corn varieties!
Do you have any questions about corn head fire or about the KWS corn varieties? Please contact your advisor!
