Mist opportunities: Fogging Techniques with Biorationals Boost Resilient Farming

Mist opportunities:

Fogging Techniques with Biorationals Boost Resilient Farming

The European Union (EU) has set ambitious goals in its “Farm-to-Fork” strategy, part of the European Green Deal, which aims for a fair, healthy, and environmentally friendly food system. A core objective of the new agricultural policy is to reduce the use of chemical pesticides and fertilisers. Resilient farming directly addresses this by using biological control methods and promoting natural resistance in crops. This can significantly reduce the use of chemical agents, contributing to cleaner soil and water quality.

Resilient farming

In recent years, more and more growers have shifted their focus from traditional farming systems to resilient farming. The goal is to cultivate crops that are more robust and better able to withstand external negative influences. Interest in additives and biorationals (green crop protection products of natural origin) is increasing. Crop protection is becoming more of a complex systems approach aimed at keeping disease and pest pressure low from the start of cultivation.

Certis Belchim is a market leader in the field of Biorationals. “Biorationals often have a strong preventive effect based on antibiosis or a short, direct effect through contact without residual activity,” says Patrick Zuijderwijk, crop manager at Certis Belchim. He continues to explain: “Applying them effectively often requires more knowledge and experience. Besides knowledge of diseases and pests, thorough product knowledge about function, spraying technique, and appropriate conditions during application is necessary to achieve satisfactory results.”

Misting collaboration

Last year, Certis Belchim collaborated with Veugen Technology to conduct several field trials to see if the Biorational BotaniGard could work even better when applied with a Low Volume Mister (LVM) or fogger equipment. For pest control in ornamental crops and fruiting vegetables, a systems approach with biological control agents and Biorationals is necessary. With BotaniGard at the base, whiteflys, thrips, and harmful bugs have much less chance of survival. Instead of crop sprays, growers can consider crop treatment with an LVM or a fogger. Use of this equipment provides comparable or better penetration into the crop and introduces less moisture into the greenhouse, plus saving on labour.

Botanigard effectiveness

BotaniGard’s effectiveness is based on the natural insect-parasitic soil fungus Beauveria bassiana strain GHA. Spores of this fungus land on the insect via the spray liquid or spray mist and germinate on the spot—the germ then drills into the insect, where the fungus further develops. The development and activity of infected insects stagnate, and they usually die within five to seven days.

Perfect for space treatment

“A high relative humidity (RH) plays a role in the effectiveness of BotaniGard, but growers need not worry about it as much as they might think,” says Zuijderwijk. “The pest insect is often on the plant, and here, due to the microclimate, the RH is almost always higher. The temperature is much more important. The spores germinate well between 15°C and 35°C, with an optimum around 25°C. This makes the product perfect for space treatment. It offers several advantages over crop spraying,” states Ed Gerrits, account manager at Veugen Technology from Nederweert. The company is a market leader in misting equipment for agriculture and horticulture.

Better product penetration

Misting equipment produces a much finer droplet (mist) than regular spraying equipment. This penetrates the crop more easily and deeply. “Misting increases the chances of insects coming into contact with the product, which is essential for contact products like BotaniGard,” Zuijderwijk explains. “Trials in Chrysanthemum cultivation have shown that, as a result of using this technique, the Biorational product works at least as well as synthetic chemical pesticide products. This will not be different in fruiting vegetables.”

Less moisture, less product

Zuijderwijk notes that much less spray liquid is needed to achieve good crop and pest coverage. For LVM or fogging, 30 – 60 litres per hectare suffice, whereas for crop spraying, at least 1,000 litres are needed. Since the dosage of the product is the same in both cases, a crop spray requires at least 20 times more water. “Introducing less moisture into the greenhouse means fewer fungal diseases, the crop grows better, the climate remains more consistent, and less moisture needs to be removed from the greenhouse,” says Zuijderwijk. “Removing moisture always costs energy and, therefore, money. Space treatment is very cost- effective, especially when done weekly.”

Multiple options

According to Veugen Technology’s Ed Gerrits, misting BotaniGard in ornamentals or fruiting vegetables can be done in three ways: via electric cold fogging (LVM) without compressed air (Powerfogger TB60 Double), via LVM with compressed air (Powerfogger P60), or via thermal fogging with a gasoline- powered pulse fogger. He says, “The advantage of LVM is that you do not have to stay nearby. You place the device on the central path and turn it on, after which the treatment is carried out fully automatically. Since most ornamental and vegetable farms do not have compressed air lines in the greenhouses, the Powerfogger TB60 Double is the most commonly used technique here. Support with fans is then desirable. Where these are lacking, thermal fogging might be a better choice.”

The Powerfogger TB60 Double.

Cooling system

Thermal fogging with a jet engine – that’s how pulsFOG works –may sound ominous, given the 46°C temperature limit for active spores. “Yes, that fear is often expressed,” laughs Gerrits. “However, I can reassure growers: all our pulsfoggers are equipped with two fluid lines. The first contains water that cools the airflow to about 40°C. A little further on, outside the reach of the combustion flame, the spray liquid is introduced through the second line. Our equipment is completely safe for biological products, and this principle applies to all equipment based on this principle. Such a cooling feature is essential, so pay attention to this when purchasing equipment. One must also realise that a pulsFOG machine must always be operated; the applicator remains in the growing area during treatment. For BotaniGard, provided the correct protective measures are taken, this is not an issue.”

Ease of use

Last but not least, Gerrits points out the enormous convenience of space treatments. The treatment duration is significantly shorter than that of a crop spray, and there is more freedom to choose the right application moment.

Application advice

Start the application simultaneously with the release of the first natural enemies and apply the correct dosage. It is important always to add a carrier substance. Apply in-block treatment with an interval of seven days; the interval can be shortened to five days if pressure increases. Certis Belchim’s Patrick Zuijderwijk adds, “Unlike the chemical agents of the past, green products like BotaniGard need to be used frequently to maintain effect. This is particularly true when beneficial insects are still in their build-up phase. BotaniGard is safe for most beneficial insects and can be incorporated early in the cultivation system. Based on effectiveness, cost, and practical considerations, the choice for space treatment is obvious. I expect growers to adopt this method quickly.”

Disclaimer: When using crop protection products, always follow the instructions on the label. This article assumes the Dutch label.
Source: FLORACULTURE INTERNATIONAL SEPTEMBER 2024