It might sound outlandish to most people, but MIT researchers are exploring ways to administer injections – life-saving treatments – to plants with drones.
At the same time that the world of humans is struggling with the Covid-19 pandemic, there are several ongoing epidemics that affect crops and put global food production at risk. Fruits and vegetables, such as oranges, bananas, olives, and all kinds of plants, are already under threat in many areas because of diseases that affect plants’ circulatory systems, which cannot be treated by applying pesticides.
These diseases are difficult to proactively detect early and to treat, due to lack of precision tools to access plant vasculature to treat pathogens and to sample biomarkers. The MIT researchers team took some of the principles involved in precision medicine for humans and adapted them to develop “plant-specific biomaterials” and drug-delivery devices.
The method uses a multitude of microneedles, which are made of a silk-based biomaterial to deliver nutrients, drugs, or other molecules to specific parts of the plant.
Evidently, plants, like people, get sick. The traditional treatment, in such a case, involves using chemicals designed to alleviate the disease. The problem with this method is that spreading, or spraying, chemicals usually results with a significant amount of the treatment being absorbed in the soil, rather than the plant. Therefore, these MIT researchers are testing a new type of needle that can be used in the future to shoot medicine directly into diseased plants, rather than spreading or spraying chemicals by the traditional method.
According to Science News for Students:
“Similar to the way COVID-19 sickens and kills people, disease epidemics are wiping out entire groves of bananas, oranges and other crops. To treat plant diseases, farmers usually spray chemicals. Some of these target the germs that cause disease. Other chemicals target the pests that carry those germs.”*
But as MIT researcher, Yunteng Cao, points out, “. . . less than 5 percent [of the chemicals] go inside the plant,”
The more precise shot delivery method of giving plants medicine is called a phytoinjector. “It’s a tiny patch containing even tinier barbs that pierce the plant. Those barbs are microneedles. And they’re made to dissolve. As they do, they release their medicine. Later, the patch falls off or can be removed,”* says Science News.
A similar technology is already available for humans.
The microneedles can be made in a variety of sizes and shapes, and can deliver material specifically to a plant’s roots, stems, or leaves, or into its xylem (the vascular tissue involved in water transportation from roots to canopy) or phloem (the vascular tissue that circulates metabolites throughout the plant). In laboratory tests, the team used tomato and tobacco plants, but the system could be adapted to almost any crop, they say. Not only can the microneedles deliver targeted payloads of molecules into the plant, but they can also be used to take samples from the plants for lab analysis.
One of the key challenges agronomists face in using this technology is delivery. After all, if the delivery is approached with a traditional approach it would mean that the patches would be attached by hand to each individual plant. This would probably make such technology too impractical for large farming operations.
Drones, however, are already used in agriculture extensively and researchers equipped a small drone with a toy dart gun, can easily inject the needle into the plant.
Here we see the combination of research and technology in agriculture with an ideal delivery system, such as drones.