When farmers spray their fields with pesticides or other treatments, only 2 percent of the spray sticks to the plants. A significant portion of it typically bounces right off the plants, lands on the ground, and becomes part of the runoff that flows to streams and rivers — often causing serious pollution. But a team of MIT researchers aims to fix that.
By using a clever combination of two inexpensive additives to the spray, the researchers found they can drastically cut down on the amount of liquid that bounces off. The findings appear in the journal Nature Communications, in a paper by associate professor of mechanical engineering Kripa Varanasi, graduate student Maher Damak, research scientist Seyed Reza Mahmoudi, and former postdoc Md Nasim Hyder.
Previous attempts to reduce this droplet bounce rate have relied on additives such as surfactants, soaplike chemicals that reduce the surface tension of the droplets and cause them to spread more. But tests have shown that this provides only a small improvement; the speedy droplets bounce off while the surface tension is still changing, and the surfactants cause the spray to form smaller droplets that are more easily blown away.
The new approach uses two different kinds of additives. The spray is divided into two portions, each receiving a different polymer substance. One gives the solution a negative electric charge; the other causes a positive charge. When two of the oppositely-charged droplets meet on a leaf surface, they form a hydrophilic (water attracting) “defect” that sticks to the surface and increases the retention of further droplets.
Leaves of many plants have a natural tendency to be hydrophobic (water repelling), which is why they often cause droplets to bounce away. But creating these tiny hydrophilic bumps on the leaf surface strongly counteracts that tendency, the team found.
When the MIT team began studying the problem of pesticide runoff, which is a major agricultural problem worldwide, they soon realized that part of the reason for the limited success of earlier attempts to address the problem was that the droplet bouncing happens so quickly, in a matter of milliseconds. That means that most countermeasures, especially those based on chemical properties, just didn’t have time to make much of a difference. “So we thought, what else can you do? And we started playing around with charge interactions,” Varanasi says.
They found that the combination of the two different polymer additives “can pin the droplets” to the surface, “and this all happens during the time it’s spreading,” before the droplets starts a retraction that leads to their bouncing away, according to Varanasi.
Read more at MIT News






Announcements
Job Offers
- Packing Supervisor
- Head Grower Greenhouse Canada
- Post Entry Quarantine Facility Manager
- Economic Policy Officer Agri-Tech Kentucky
- Licensing Manager North America
- Junior Sales Executive
- Fruit Breeder/Trait Discovery Scientist
- General Manager
- Regional Sales Manager – DACH Region
- Country Manager – Italy
"Tweeting Growers"
Top 5 -yesterday
- Heritage Farms' new greenhouses enter second season, with new growers?
- Pure Harvest to build more indoor farms in Saudi Arabia
- Why irrigation and nutrients should be well distributed in substrate bags
- A more natural form of artificial lighting with an LED pulse technology system
- Paper packaging solution now also available as banderole
Top 5 -last week
- Combining vertical farming and greenhouse horticulture to decentralize lettuce production
- Fresh produce chain hit by Lakeside Produce’s bankruptcy
- Growy acquires assets and team of Kalera International (&ever)
- Positive vibes on the first day of IPM '23
- CAN: Land Betterment acquires 50% ownership in greenhouse operations
Top 5 -last month
- How farmers are cutting out supermarkets
- Combining vertical farming and greenhouse horticulture to decentralize lettuce production
- Higher light transmission and lower heat demand with double foil greenhouse
- Fresh produce chain hit by Lakeside Produce’s bankruptcy
- 30MHz declared bankrupt, curator 'optimistic about restart'
Receive the daily newsletter in your email for free | Click here
Other news in this sector:
- 2023-01-30 Combatting ToBRFV with new varieties Ferreira and Novero
- 2023-01-30 A transnational collaboration leads to the characterization of an emergent plant virus
- 2023-01-30 New trial using nutrition to build plant resilience against ToBRFV
- 2023-01-27 California unveils plan to sustainably manage pests and eliminate high-risk pesticides by 2050
- 2023-01-26 International IPM program drives sustainable management of Tomato Leafminer
- 2023-01-26 Plant protection of the future may come from the plants themselves
- 2023-01-25 Pestalotiopsis causes losses of up to 50% in Michoacan's strawberry production
- 2023-01-24 A natural solution for destructive stink bugs
- 2023-01-24 US: Food safety certification for specialty crops program deadline
- 2023-01-20 Strawberry bud weevil: Changing thresholds?
- 2023-01-20 Dogs sniff out destructive voles to help farmers with control
- 2023-01-19 Project funding for tomato research and plant pest detector dog teams
- 2023-01-19 Fresh produce most commonly seized undeclared item for NZ biosecurity officers
- 2023-01-17 Is ozone effective against ToBRFV?
- 2023-01-11 Greenhouse sanitation is key to disease management
- 2023-01-11 Beneficial nematodes doing their work in your crop
- 2023-01-11 US (NY): New formulation from BioWorks shows good results for botrytis protection
- 2023-01-10 Automated beneficials dispenser saves money & helps optimize control
- 2023-01-09 USDA completes environmental assessment for biological control agent of spotted-wing drosophila
- 2023-01-09 "The screen blocks 99% of pollen, and manages mold and micro-insects"