Combatting Food Inflation: The Urgency of Rapid and Accurate In-Field Testing to Tackle Crop Diseases
Food prices rose 9.9% in 2022, faster than any year since 1979, and in 2023, they grew another 5.3%. It’s a huge issue for families and has become a political issue for the upcoming presidential election as well. There are many factors fueling food inflation: labor shortages, new post-pandemic consumer shopping preferences and spikes in commodity pricing due to the war in Ukraine, Europe’s “bread-basket,” just to name a few. Nevertheless, basic supply and demand always applies. If growers can produce more food, and especially if they can do so at a lower cost, prices will come down.
Productivity, too, is a complex issue, but one of the biggest challenges to boosting crop yield is combatting disease. Combined, plant diseases and pests cause 40% of yield losses for wheat, corn, rice, potatoes and soybeans globally. Diseases, specifically, cost the global economy around $220 billion each year. Alone, fungal diseases — a growing threat to agriculture — account for 20% of global crop loss and annually cost $44 billion in lost agricultural revenue.
Arguably, one of the most destructive fungal threats is botrytis, but it is just one of the more than 19,000 types of fungi known to attack crops around the world. This fungus devastates specialty crops such as tomatoes, fruits, beans, potatoes, onions and dozens more, causing anywhere from $10 billion to $100 billion in annual losses to global agriculture. Botrytis is also a fungus that weakens plants significantly and allows other pathogens to infect – so botrytis is often found along with other diseases. And, while effective preventative measures exist for relevant pathogens, agronomists or crop protection advisors cannot simply look at infected plants to determine whether they are, in fact, suffering from a botrytis infection or something else. Other fungi such as rhizoctonia present very similar symptoms to botrytis but require different treatments. If a grower treats for botrytis when the actual pathogen is rhizoctonia, the operation will have wasted money and time on an ineffective treatment that allows the fungus to continue to destroy crops and reduce yield. So, when growers see evidence of an infection that looks like botrytis – or rhizoctonia — they must perform a test to positively identify and treat it.
The drawbacks of current testing
Unfortunately, current tests have significant drawbacks. The standard serology-based test is ELISA, which employs a colorimetric reaction with monoclonal antibodies. But, a 2021 paper in Frontiers in Chemistry points out, “Despite the fact that traditional ELISA has become as the golden standard in the detection of almost all types of pathogens whether in environmental, chemical, biotechnological, health and agricultural analysis, it still has relatively low sensitivity and accuracy.” Accuracy is critical. If a grower gets a false positive result, they will have wasted money treating the wrong disease. If the result is a false negative, the grower mistakenly eliminates botrytis as a possible pathogen and spends time testing for other possible diseases. All the while, the fungus happily spreads, consuming and ruining fruits and vegetables.
Another type of test that everyone is familiar with thanks to the recent COVID-19 pandemic is polymerase chain reaction, better known as PCR. This is a molecular test, which amplifies genetic material to a detectable level, making it very sensitive. A PCR test can accurately detect very small amounts of the target DNA. However, the PCR test requires a laboratory, because it requires a purified DNA sample which cannot be done in the field and the amplification process employs repeated, precise heating and cooling of the sample. This means that an agronomist employing a PCR test must collect a sample, ship it to a lab and then wait for the result, which can take anywhere from days or weeks, depending on how busy the lab is. And while the grower waits, the fungus continues to spread, reducing yields.
There are emerging technologies that may be able to address this gap. Loop-mediated isothermal amplification, better known as LAMP, is not a new method, but since it has recently come off patent, there’s been investment around innovating the technology so it can be deployed in the field. LAMP produces results within about 30 minutes and, because there’s no thermal cycling, a portable rugged version of this technology can now be used for diagnosis at the point of need.
But whatever technology is used, growers, agronomists, and crop advisors need diagnostic tests that are fast and accurate, yet affordable, so they can stop infections before they spread and limit the amount treatment or remediation they need to perform. By reducing the use of fungicides, growers not only lower costs, but also reduce environmental damage and slow the emergence of resistance to the treatments. Just as antibiotics are rapidly losing their effectiveness to treat human diseases due to overuse, fungi that attack crops are becoming resistant to antifungals.
Fungi like botrytis are a massive problem for agriculture, reducing yields and causing enormous economic damage. The first step in treating any disease is identification, and faster identification will enable faster treatment. It’s time for the agri-technology industry to provide agronomists, advisors, and growers with the tests they need to stop fungal infections early, which will increase yields and, in turn, keep food prices reasonable for the consumer.