The global climate is changing and food demands are increasing. As a result, the threat of crop pests and diseases could mean widespread hunger, especially for at-risk populations. The nature of many agricultural pests and pathogens compound this problem as they are widespread, highly specified and difficult to detect.

Containment of these diseases can only occur once the diseases become detectable. By this stage, the damage has already affected significant amounts of crops beyond the point of recovery and containment. One disease alone can cause financial losses in the hundreds of millions. A single outbreak of Karnal bunt fungus in North Texas caused a $250 million loss in revenue in 2001.

More Food, More Pests?

The world’s food supply faces increased biological threats due to climate change, increased travel between countries and increases in large-scale food production. The need for food increases each year as well, with a predicted 9 billion people in need by 2050. Mass agriculture of staple crops, such as wheat, rice, palm, cassava and various fruit and vegetables, face dangers unique to each crop:

• Cassava Mosaic Virus: This virus leads to s-shaped stalks, stunted plant growth and low yields.
• Coconut Rhinoceros Beetle: The Coconut Rhinoceros Beetle (X. glabratus) spreads a fungus called Raffaelea Lauricola that kills redbay and avocado trees, effectively starving their pollinators.
• Wheat Rust: This fungus is caused by Puccinia triticina (Brown Leaf Rust) and it reduces wheat kernel yield and size. It is a prolific spreader that is present in major wheat-growing sites worldwide.
• Citrus Greening: This virus is rampant in the southeastern parts of the U.S. as well as in citrus and other orchards worldwide. As of 2019, the disease has reduced Florida citrus production by 75%.

Additionally, the loss of staple foods to crop pests and diseases can contribute to livestock malnutrition. Roughly 36% of the world’s crops are grown for feeding livestock. In some developing countries, these animals are essential to meeting a minimum caloric intake. Thus, famine in developing countries can commonly be exacerbated by a secondary loss in crop-dependent food supplies, such as cattle or goats.

However, a potential solution to the malnutrition of both humans and livestock lies in an unforeseen place.

Teaching Old Dogs New Tricks

A dog’s sense of smell is consistently strong, with some odors detectable in parts per trillion. The scent abilities of the world’s four-legged canine friends have an ancient history of benefits. This includes successful applications in hunting, national security, border patrol, medicine and agriculture. This skill also makes dogs well suited for training in detecting crop pests and diseases.

Dogs have a particular knack for new scents, described as a form of neophilia. “This technology is thousands of years old – the dog’s nose; we’ve just trained dogs to hunt new prey: the bacteria that causes a very damaging crop disease,” says U.S. Department of Agriculture Researcher Timothy Gottwald.

Agricultural scientists approve of this new application (detection of crop pests and diseases) of a canine’s olfactory system. Equally important to note is the cost-saving potential of training dogs over traditional identification and lab processing as money is a pivotal issue in developing countries when eradicating crop diseases.

Conclusion

Food security, the increase in crop pests and diseases and the costs of testing for agricultural diseases is a dynamic problem combination in need of unique solutions. To date, dogs have been successful in identifying crop diseases such as clubroot, wheat rust and citrus greening. The sensory abilities of dogs also show promise in early and accurate detection. These early successes imply that training canine companions can be a worthwhile and life-saving venture for millions of food-insecure people in the future.

– Katrina Hall
Photo: Flickr