Reduction of ppp use using non-chemical plant protection methods

Reducing the use of pesticides in agricultural production

The reduction in the use of phytopharmaceuticals in Slovenia is based on compliance with the requirements of the Act on Phytopharmaceuticals (ZFfS-1 - Official Gazette of the RS, No. 83/12 and 35/23), Regulations on training on plant protection products (Official Gazette of the RS, No. 85/13 ), Rulebook on conditions for trade in plant protection products and on management and transmission of data on trade in plant protection products (Official Gazette of the Republic of Slovenia, no. 107/13 and 30/18), Rulebook on requirements regarding the correct operation of devices for applying plant protection products and on the conditions and method of carrying out their inspections (Official Gazette of the Republic of Slovenia, No. 36/19), the Rules on the Correct Use of Phytopharmaceuticals (Official Gazette of the Republic of Slovenia, Nos. 71/14, 28/18, 56/22 and 155/22), the Rules on integrated protection of plants against harmful organisms (Official Gazette of the Republic of Slovenia, No. 43/14), Order prohibiting the circulation and use of certain phytopharmaceuticals on the territory of the Republic of Slovenia (Official Gazette of the Republic of Slovenia, No. 31/11 and 83/12 – ZFfS-1) , Regulations (EC) no. 1107/2009 of the European Parliament and of the Council of 21 October 2009 on placing plant protection products on the market and repealing Council Directives 79/117/EEC and 91/414/EEC (2009/1107), Directive 2009/128/EC of the European Parliament and of the Council of 21 October 2009 on establishing a framework for Community measures to achieve the sustainable use of pesticides (Text applies to the EEA) Text applies to the EEA. (2009/128) and Commission Directive (EU) 2019/782 of 15 May 2019 amending Directive 2009/128/EC of the European Parliament and of the Council regarding the establishment of harmonized risk indicators (Text applies to the EEA) (2019/782).

Regarding the reduction of the use of plant protection product (PPP), various non-chemical methods of plant protection are primarily used for the direct control of harmful organisms in integrated plant protection, which limit the populations of harmful organisms below the harmfulness threshold and have priority over chemical suppression (use of PPP). These methods are also referred to as low risk plant protection methods and include physical, biotechnical and biotic measures. Non-chemical plant protection methods also include the use of "low-risk PPP" based on microorganisms, plant extracts and pheromones, other low-risk substances and the use of basic substances.

Reducing the use of PPP on agricultural and non-agricultural areas is possible by using non-chemical methods of protection (mechanical control of harmful organisms, use of basic substances, biotic protection of plants...). In order to avoid as much as possible a greater risk to human health, the use of PPP is restricted or completely prohibited on non-agricultural areas and public areas where the safe use of PPP cannot be ensured, or where harmful organisms can be controlled by alternative methods. At the same time, it is also necessary to consider the possible exposure of people in public areas who could be exposed to risk when using PPP. On non-agricultural areas, such as roadsides, railways, non-chemical methods are used (e.g. weed control using steam...). In terms of reducing the use of PPP, the use of PPP on sports fields is limited to spot use and only if the use of PPP is necessary. This ensures the lowest possible exposure of people staying on the playgrounds after using PPP.

Physical measures

Physical measures are measures that prevent or limit the access of harmful organisms to cultivated plants and measures for catching or destruction (suppression) of harmful organisms. These measures can be used to reduce the use of PPP whenever possible. Physical measures include:

- cleaning of seeds and other planting material (removal of impurities - weed seeds, removal of infected plants from seed crops or other sources of planting material - in nurseries, mother plantations);

- heat treatment of planting material (immersion of seeds or other planting material (grafts, cuttings...) in a water bath for a certain time at a certain temperature - method of destroying pathogenic bacteria, phytoplasmas or viruses in planting material; exposure of seeds to low temperatures...);

- soil disinfection with the help of water vapor (in horticulture, especially when growing in protected areas);

- cutting out infected plant parts (apple powdery mildew, apple cancer or pear blight...);

- soil cultivation (reduction of the population of harmful insects in the soil – weevils, corn borer...; plowing can influence the emergence and growth of weeds – especially perennial ones);

- various pest control measures (manual removal of pests; washing with water or air stream; use of ash, diatomaceous earth...);

- the use of colored sticky boards, light baits and food baits for catching harmful types of insects (light baits, sticky boards of different colors and food baits are mainly intended to monitor the appearance of pests, but to a lesser extent they also reduce their abundance);

- use of various traps (for catching rodents...) and sound repellents (for birds or rodents);

- preventing pests from accessing plants with obstacles (overlays, insect nets - insect nets, bird nets, high barriers at the edges of fields against insect attacks, fences and electric herders against wild animals);

- mechanical weed control (mechanical or manual weeding, harrowing or brushing, mowing, mulching...) and

- weed control with steam, hot foam, burning with flame (roads, railways...)

Biotechnical measures

Biotechnical pest control measures are procedures that utilize some of the natural reactions of pests to certain chemical stimuli, and include the use of attractants (e.g. pheromones), deterrents and food baits.

Pheromones are substances secreted by insects in small quantities and intended for mutual communication between individuals of the same species. In plant protection, pheromones are mainly used to monitor the populations of certain economic pests in plantations or crops (to monitor various types of beetles - apple, peach, etc.), moths, owls and other pests. With pheromone baits, we determine the presence and abundance of pests in time and space.

Some pest control methods have also been developed based on pheromones, one of which is the method of confusion or confusion. Sex pheromones are used to distract males from finding females to mate with and therefore females lay unfertilized eggs. The bewilderment method is used to control apple and peach curlers. The method is more effective if the pest population is not too large, if the plantation is isolated and if it is in a larger complex.

Pheromones are also used in so-called "mass hunting". Pheromones are used to attract insects to be caught in or on traps. Traps with pheromones must be in the plantation or distributed evenly and in sufficient numbers to the production facility, so that a sufficiently large number of insects can be trapped in them and thus their population and, consequently, the damage they cause can be reduced.

Biotic measures

Biotic protection is a method of protection where one organism is used to reduce the population density of another organism. The goal of biotic protection is for other organisms to interact with pests or pathogens by destroying them or hindering their development. Plant pathogenic fungi also have their opponents (antagonists, pathogens), which either parasitize them or hinder their growth by emitting substances (antibiotics) that harm them, so there is a constant competition between organisms for space and food.

Organisms that, with their way of life, benefit the grower in the control of harmful organisms are called beneficial organisms = natural enemies. In biotic protection, knowledge about the relationships between species is used and with selected beneficial organisms, the populations of harmful organisms are reduced and they are kept below the threshold of economic damage. Beneficial organisms are insects, mites, entomopathogenic nematodes, fungi, bacteria, viruses. They can be used to control insects, mites, fungi, bacteria and even some weeds.

In biotic plant protection, living beneficial organisms are used to control harmful organisms. Depending on the mode of action on harmful organisms, beneficial organisms are classified into four groups:

1.) Predators: they are insects, mites... that feed on plant pests and destroy them. In order to successfully maintain a population of predators, there must be enough pests in the appropriate development stage and established environmental conditions that enable the development of predators. The most successful native beneficial predators among insects and arachnids are ladybugs, ladybugs, thrips, predatory rodents, predatory bedbugs and predatory mites. Predators regulate the abundance of plant pests outdoors and in sheltered areas.

2.) Parasitoids: are insects that are more host specialized than predators. They lay one or more eggs in the host (egg, larva, beetle or adult pest). The hatched larvae of the parasitoid feed on the host's tissue and its appearance changes but does not die immediately. An adult parasitoid emerges from the pest. An example of a parasitoid that is often used in protected areas is the greenhouse leafhopper (Encarsia formosa).

3.) Pathogens: are fungi, bacteria or viruses that infect their hosts, insects and other animal organisms. They penetrate inside them, causing them to weaken and possibly even die. The principle of action is parasitism. In insect pathology, they are also called entomopathogenic organisms.

4.) Antagonists: affect the survival or pathogenicity of harmful organisms, but do not use them as a food source. They inhibit the growth and reproduction of harmful organisms by competing with them for food and space (competition) or by disturbing them with substances they secrete (antibiosis).

The approaches in biotic protection are as follows:

- Protective biotic protection: it is based on measures with which we protect indigenous beneficial organisms and provide them with favorable conditions for settlement and reproduction;

- Classical biotic protection: it is a method of biotic protection, when we look for a non-native beneficial organism (most often in the area of origin of the pest) and introduce it to an area where a non-native pest has spread unplanned, which therefore has no effective natural enemies and

- Mass propagation and targeted release of beneficial organisms: The release of beneficial organisms to the place where the pest population needs to be reduced can be either by flood or by seasonal inoculation. Seasonal inoculative introduction of a beneficial species means the introduction of a laboratory or otherwise propagated indigenous or non-native beneficial species into the open air or into a protected area. Such an organism is introduced once or several times during the growing season, with the aim of automatic further reproduction.

Biotic protection has many advantages over chemical protection, because with biotic protection there are no residues of PPP in crops and biotic preparations do not have a grace period, they also do not damage plants, generally do not affect the phenomenon of resistance of harmful organisms, do not pollute the environment and are not dangerous to the people who use them.

The success of biotic protection depends to a large extent on the knowledge of the user, as a good knowledge of harmful organisms and the changes they cause on plants, as well as the thresholds of harmfulness, is necessary. Users must therefore be well trained to monitor the occurrence of harmful and beneficial species of organisms. One of the negative features of biotic protection is that it works slowly. Users must also know the developmental cycle and threshold of usefulness of beneficial organisms. It is also very important to know how we transport and store preparations with beneficial organisms, when we introduce them depending on the size of the pest population, what the conditions are at the place of introduction (temperature, lighting, humidity) and what PPP was used before introduction.

When using beneficial organisms, PPP cannot be used simultaneously, because they are only some PPP compatible with beneficial organisms. Using the wrong insecticide will harm or kill beneficial organisms.

More detailed procedures for the introduction, cultivation and use of beneficial organisms, i.e. insects, mites and entomopathogenic nematodes are regulated in Slovenia by the Rulebook on biotic protection of plants (Ur. l. RS, no. 45/06), the introduction and use of microorganisms (fungi, bacteria and viruses) is governed by the Act on Phytopharmaceuticals.

In biotic protection, an essential limitation is that we may only use beneficial organisms that have been proven to be unable to cause harm in the environment by affecting non-target organisms. Types of beneficial organisms can be native or non-native, a native organism (autochthonous) has always been present in an ecosystem, and therefore we do not expect negative impacts when using such an organism. A non-native organism (allochthonous, exotic) is an organism that is not present on the territory or was not present until it was inhabited by humans. Part of the mentioned rulebook are the lists of native and non-native beneficial organisms, the introduction and use of which are permitted in the territory of Slovenia. Only organisms listed on these lists may advise, recommend and advertise.

Reducing the use of ppp using “PPP based on microorganisms, plant extracts, pheromones, other low-risk substances and basic substances”

Under the term PPP we understand all substances that are intended for the protection of plants or plant products for protection against harmful organisms. In integrated plant protection, in order to reduce the use of chemical substances, PPP are preferentially used, which are less dangerous and less burdensome for human health, animals and the environment. This also includes the use of PPP made on the basis of microorganisms, plant extracts, pheromones and low-risk substances. The same legislative regulations apply to the registration and use of these preparations in Slovenia as for chemical PPP. The current list of registered PPPs based on microorganisms, plant extracts, pheromones and low-risk substances is available at the web address:

http://spletni2.furs.gov.si/PPP/REGSR/PPP_sezn.asp?L=1&S=4&top=1

Pest control with entomopathogenic microorganisms

Pest control with entomopathogenic microorganisms is a measure when entomopathogenic fungi, entomopathogenic bacteria or viruses are used to control harmful insect species and the control is based on insect pathology, then we are also talking about microbiotic protection. Fungi, bacteria or viruses must be ready for use, so that they can be stored and applied, while maintaining a high level of vitality in order to be effectively activated after application. Entomopathogenic fungi infect insects in various developmental stages (adult insects, larvae, beetles). Among the entomopathogenic fungi, fungi from the genera Beauveria and Metarhizium have shown the greatest utility in pest control, although many others are being used and tested. Among entomopathogenic bacteria, Bacillus thuringiensis (B.t.) has been widely used for pest control for decades. These bacteria form proteins in the form of crystals, which are converted into toxins in the digestive tract of insects and cause the death of the insect. Entomopathogenic viruses primarily infect insect larvae when they are ingested. Viruses with a narrow range of hosts are particularly suitable for biotic protection. In organic and integrated apple production, the use of a preparation based on the Cydia pomonella granulosa virus to control the apple borer has already become established in Slovenia.

Protection against diseases based on fungi and bacteria

In the protection against diseases based on fungi and bacteria, organisms are used, such as fungi and bacteria that parasitize fungi or hinder their reproduction and development. In addition to parasitism, competition, and antibiosis, some beneficial microorganisms also act to increase plant resistance to disease or promote plant growth, which makes it easier to withstand damage caused by harmful organisms. Similar to how we use a protective approach in biotic protection against pests, we can also use microorganisms that are already present in the growing area, or increase their abundance and diversity, in the control of pathogenic fungi or bacteria for plants. By adding organic matter (green manure, organic fertilizers, composted bark and other composts), loosening the soil and ensuring adequate humidity, we encourage the reproduction of saprophytic fungi and bacteria. When using microbiotic preparations to control plant diseases, the warnings regarding mixing with other fungicides must be followed in order not to destroy the active microorganism. The preparations are effective in a limited temperature range, with some of them it is also necessary to pre-prepare the spray slurry to accelerate the germination of spores of the beneficial fungus. There are no withdrawal periods for microbiotic preparations, or they are very short.

Use of PPP based on plant extracts, pheromones and low risk substances

Plant extracts consist of one or more substances found in a plant and obtained from plants or their parts by a process of pressing, grinding, crushing, distillation, extraction, fermentation or other process. Protecting plants from pests involves the use of various substances that are produced in the metabolic processes of plants and that play an important role in protecting the plant from harmful organisms. Among the more well-known and useful substances of plant origin in the world are preparations containing the active substance pyrethrin, which is a natural insecticide obtained in the form of powder or oil of the flea beetle Chrysanthemum cinerariifolium or Chrysanthemum coccineum. Among the more commercially available preparations with insecticidal activity, we also find an extract obtained from the Neem tree (Azadirachta indica) - neem oil. This contains a number of secondary metabolites, including salanin, which acts as a deterrent and deters insects from feeding, and azadirachtin, which inhibits growth in insects and causes disturbances in reproduction and metamorphosis. In addition to its insecticidal effect, neem oil also has a nematocidal, bactericidal and fungicidal effect.

The PPP group includes all substances, with the exception of nutrients that affect the life processes and growth of plants (plant growth regulators, substances to promote resistance in plants) and substances that are used in the procedures of biotechnical methods of control of SO (pheromones, deterrents or repellents). Some of the listed substances are defined as low-risk substances based on special criteria. Information on low-risk substances is available in the European PPP database:

https://ec.europa.eu/food/plant/pesticides/eu-pesticides-database/active-substances/?event=search.as.

Use of basic substances

Basic substances that can be used for plant protection are those substances that are not problematic, do not cause hormonal imbalances and do not have neurotoxic or immunotoxic effects. They are approved for other purposes and are not normally used for plant protection and are not placed on the market as plant protection products - PPP, but are nevertheless useful for plant protection, either directly in preparations consisting of basic substances. Substances that meet the criteria for food can be considered basic substances. The use of basic substances in the European Union (EU) is approved by the European Commission.

The list of permitted active substances that are approved as basic substances for plant protection can be found on the MKGP-UVHVVR website: https://www.gov.si/teme/osnovne-snovi-za-varstvo-rastlin/. Next to Slovenian names in the first column, Latin or English names are listed in the second column. Some of these substances can also be used by the user in organic production, which is indicated in the third column

References

- https://www.gov.si/teme/trajnostna-raba-fitofarmacevtskih-sredstev/

- Act on phytopharmaceuticals: http://www.pisrs.si/Pis.web/pregledPredpisa?id=ZAKO6355

- Order prohibiting the circulation and use of certain phytopharmaceuticals on the territory of the Republic of Slovenia: http://www.pisrs.si/Pis.web/pregledPredpisa?id=ODRE2109

- Regulations on integrated protection of plants against harmful organisms: http://www.pisrs.si/Pis.web/pregledPredpisa?id=PRAV11530

- Rules on the correct use of phytopharmaceuticals: http://www.pisrs.si/Pis.web/pregledPredpisa?id=PRAV11541

- Rulebook on the conditions for trade in plant protection products and on the management and transmission of data on the sale of plant protection products: http://www.pisrs.si/Pis.web/pregledPredpisa?id=PRAV11540

- Regulations on training on plant protection products: http://www.pisrs.si/Pis.web/pregledPredpisa?id=PRAV11537