40% of world production crops It is lost every year to pests, weeds and disease.. The problem is getting worse globalization and the massive transfer of herbal products. Real pandemics are also recorded in the agricultural world. And they appear resistance to phytosanitary products is used against them. Scientists are looking for solutions. A recent study concluded that: Crop mixing is an effective tool to control pests.
The agricultural sector currently faces major challenges. climate changeencouraging greater presence extreme temperatures And older soil erosion risksThis makes it more likely that pests will proliferate. Controlling them is a challenging task.
A new study from the University of Florida published in the ‘Journal of Applied Ecology’ concludes: Intercropping, the practice of planting mixtures of crops (intercropping), can be an effective tool for pest control worldwide.
The analysis compiled results from 44 field studies on six continents and focused on four types of crops—cabbage, squash, cotton, and onion—planted alone and mixed with related plant species.
In these studies, scientists recorded 272 estimates of the abundance of 35 different species of herbivorous insects on plants; This represents one of the most comprehensive evaluations of intercropping effectiveness to date.
“Crop diversification offers a promising solution to meet growing global food demand while preserving ecosystem services“, because they reduce pest abundance. Overall, ‘dual culture’ produced a strong reduction in insect abundance in the focal crop.
‘three sisters’
“Generally, intercropping has proven to be very effective against pests“Although it varies depending on the pest and its feeding preferences,” says Philip Hahn, an assistant professor in the department of Entomology and Nematology at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) who led the study.
“This also depends on the type of crop, so cabbage and pumpkin show the strongest resistance, while resistance is less strong in onions and cotton,” he explains.
There are some common defragmentation methods that work. For example, Non-commercial crops can be placed at the edges surrounding the field to repel or inhibit pests. before damaging the cash crop.
Complementary crops can also be planted in the field to prevent pests from settling in main crops. A common combination that works against pests is known as: ‘Three sisters’: corn, squash and beans.
Another finding of this study was that: Mixed planting schemes such as ‘Three Sisters’ make it difficult for pests to locate their preferred host plant and more effective than border plantings.
“In the studies we reviewed, we found that intercropping was the most effective method. general pests “It feeds on a variety of crops,” Hahn notes. special pests “A targeted product type was less affected,” he adds.
The explanation for this phenomenon is that specialized pests typically have a long history of coevolution with the plants they target and therefore may be less affected by the presence of a neighboring companion plant.
Better results in tropical regions
Researchers have long been interested in investigating its value. planting togetherprovides rich previously published data.
Hahn included studies from earlier analyzes as well as more recent research, allowing for a comprehensive assessment of the conditions that best support the benefits of mixed cropping.
While variability emerges as a common point in all studies, Hahn states that a geographical pattern emerges, albeit weak. “We found greater benefits in pest suppression at lower latitudes; that is, in tropical systems compared to northern temperate systems,” the entomologist emphasizes.
“Of course, there are many reasons why we came up with this model; Tropical regions are where more insect species are found throughout the year. “To my surprise, this model was not as strong as I expected,” says Hahn.
The analysis will serve as a starting point for future research because Neighbor plant selections may be key to success in intercropping systems. In fact, this new research offers recommendations for using the most effective companion herbs while highlighting herb pairs that appear to be less effective.
“There are some combinations that seem particularly effective in reducing pest abundance,” the researcher explains. “For producers interested in organic methods in general, mixed cropping seems to be a very effective tool,” he concludes.
https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.14382
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