Karnal bunt

While Karnal bunt generally does not lead to devastating crop losses, it has the potential to dramatically decrease yield, and poses additional economic concerns through quarantines which limit the export of suspected infectious wheat products from certain areas, including the U.S. Several chemical control methods exist for Karnal bunt of wheat, but much work remains to be done in identifying resistant host varieties.

Another factor which makes Karnal bunt difficult to readily diagnose in the field is the fact that most infected kernels do not show symptoms prior to maturity.

[5] The disease is primarily spread through contaminated seed or farm equipment, although it may also be carried short distances by the wind, especially following the burning of wheat fields.

During harvest teliospores fall from the kernels to the soil from which point they may be carried elsewhere by wind or tools, thereby restarting the disease cycle.

Several other methods, such as delaying planting so as to avoid the weather conditions which favor teliospore germination, have been proven to be effective to some extent, but also pose the risk of reducing yield.

Other cultural controls such as crop-rotation may be practical as the planting of non-host species for several years may reduce the number of teliospores in given field significantly.

In a 1986 study, Smilanick et al. were able to eradicate over 80% of Tilletia indica infection in wheat following two foliar applications of the fungicide propiconozole.

[12] In a similar effort, researchers tested a variety of plant extracts in the hopes of finding a non-chemical control method of Karnal bunt of wheat.

The researchers found extract of Acalypha indica and Lantana camara, when sprayed on wheat leaves, to reduce the number of infected plants by 65%.

Researchers analyzed the HD29 cultivar of Triticum aestivum, or common wheat, in order to explore the possibility of control via host resistance.

Significant economic losses in wheat crops occur due to quarantine and other export restrictions placed on infected areas.