Floriculture and nurseries are a really active and technologically advanced sector of agricultural productions. Cultivation systems can be carried out in a protected environment (tunnels, cold or heated greenhouses) in the soil or “soil-less”, namely without the soil substrate.
Floral and ornamental plants, destined to the domestic and foreign markets, make up 5% of the Italian agricultural production. This sector is characterized by a great productive diversifi cation and requires high investments in order to guarantee suitable organizational and infrastructural resources. Plants can be imported or exported only if provided with the phytosanitary certifi cation or passport (in the EU countries) attesting both plants’ immunity from dangerous and spreading pests, and conformity with the current regulations of the importing country. In the last years horticulture, floriculture and nurseries have reduced production costs and increased qualitative standards, thanks to incentives for farms employing biological and integrated techniques and thanks to constant technical and scientifi c innovations and assistance aimed at production, processing and marketing.
1. Operative sheet Biological control in greenhouses
Greenhouses are artificial, closed and isolate denvironments, with autonomous microclimate and high plants density where the natural balance between preys and predators are altered to the advantage of pests which can multiply enormously and destroy the entire production. In these cases chemical control is the most immediate defense based on broad spectrum pesticides. However, this method may have serious contraindications for farmers’ and consumers’ health (increasingly worried about chemical residues in food) and also for the environment because even harmless species are hit and eliminated by such treatments. Moreover, the repeated use of phytochemicals selects resistant insect populations which manage to survive to increasingly higher doses of poison.
Therefore, the best strategy to avoid pesticides is to operate exploiting the biological control principles, namely the arms made available in nature, using some organisms (bacteria, fungi, mites, insects, nematodes) which can in turn be parasites or antagonists (useful) of the pest populations to be limited.
These regulating mechanisms are exploited by following some precise guidelines and operating strategies of the biological control:
• classical biological control, carried out against importation pests, consisting in the introduction of antagonists from the area of origin of the pest itself;
• protection and augmentation of antagonists present in the natural environment;
• reproduction and release of antagonists present in the natural environment: this is a real treatment to control harmful organisms, carried out by reproducing these insects, called auxiliaries, in bioindustries and then throwing them over the fields.
In order to restrain the pests population quickly, several techniques are applied: inundative launch, inoculative launch, prevention launch; “pest in first” and “banker plants” methods.
a. The inundative launch consists in the mass introduction of antagonists as soon as the pest exceeds a fixed threshold. Generally launches are repeated according to dosages, timing and methods shown in the operating programmes. Such technique is advantageous because it can be applied against most pests, but it has to be carried out with timeliness and with very careful monitoring.
b. In the inoculative launch the auxiliaries are very early introduced in small quantities so as to settle quite a numerous population capable to contrast possible pest infestations from the very beginning. This implies that antagonists may survive even in absence of pests-preys, without preying on other auxiliaries or damaging crops. This kind of auxiliary insects have a lower growth rate than their preys. Therefore, this method is advisable if the crop has quite a long vegetative cycle (over 4 months); if the crops grown in the greenhouse are subject to the same pest; or when, in absence of the main target, in the greenhouse there are other minor pests, preys for the inoculated auxiliary, which can reproduce and increase innumber, being useful at the same time. The inoculative launch can be integrated by inundative launches when the pest growth rate unexpectedly increases.
c. The prevention launch can be regarded as a variant of the inundative: it is applied when the auxiliaries are parasitoids repeatedly introduced in small quantities, in order to keep the development of potential pests under control.
d. The “pest in first” method is based on the idea that, for the antagonists population level to be high and stable enough to control pests, it is necessary to provide antagonists with preys to feed on, so a certain amount of pests to prey on, has to be already available. Therefore, the controlled introduction of pests is carried out, trying to maintain the right balance between the predatory needs of the auxiliary and the necessity to have the lowest controlled crop damage. Needless to say, this method is quite hard and challenging and requires a deep knowledge of pests’ biology; but it has the great advantage to make the antagonists population development easy and permanent and, consequently, obtain a more stable and lasting pest control.
e. The “banker plants” method is effective and economical but applicable to few pests species.
It consists in an early association, between a parasitoid and an alternate host to the main pest, developed on purpose on plants which aren’t grown as a crop but reared in vases in a controlled environment. Actually, the auxiliary insect is straight reared in order to permanently guarantee a certain amount of such insects in the greenhouse. The “banker” plant mustn’t be a host plant for the same pests of the crop to be protected, while, in turn, the alternate host mustn’t be harmful to the crop. For a successful method it is necessary to introduce “banker” plants promptly in the greenhouse and check they always maintain a sufficient population of parasitoids / alternate hosts. Rearing “banker” plants in vases also allows their prompt replacement, should they be lost for different reasons.
2. Operative sheet The plant passport
Within the borders of the EU there haven’t been customs barriers since 1993: the free movement of goods and plants (seeds, cuttings, nursery productions, etc.) is guaranteed but the possible spread of any pests has to be prevented at the same time, because they can spread unpredictably and uncontrollably and they are known as “quarantine organisms” due to their high degree of danger.
Among the legislative methods aimed at preventing the uncontrolled spread of possible pests, the plant passport is really important and represented by an offi cial and obligatory label, released by the breeder and certifying the plants’ origin and the absence of those harmful organisms.
The passport can’t be reused or duplicated and it has to be directly attached to the plant or its derivative products, either to the package or to the means of transport employed.
All the professionals (breeders, wholesalers, farmers) have to be given the passport and they have to keep it for a year.
The Phytosanitary Service has to register goods on a special loading and unloading Register and certify the movement of passports along the whole chain.
There are three kinds of passport:
1. ordinary, accompanying the goods and certifying the necessary requirements;
2. protected zones (PZ), for the movement of plants which enjoy special protection inside one or more EU countries, considered immune from some harmful organisms. This passport has to show, as well as the ordinary information, the Community Code of the Protected Zone and the wording “PZ”.
3. replacement passport (RP) is used to replace ordinary or ZP passports when stocks of plants are subdivided and commercialized to different customers, without any intermediate manipulation. The replacement passport always has to bear the name of the original producer.
In order to be considered a valid passport, it has to bear the following information:
1. EU plant passport;
2. Indication of the member state (code);
3. Indication of the offi cial responsible organization or its code;
4. Registration number,
5. Single number of series, week or stock;
6. Botanical name of the species;
7. Amount in its unit of measure;
8. The wording “PZ” for the protected zones passport and, in case, the name of other protected zones where it is valid;
9. The wording “RP” for Replacement Passports;
10. The name of the country of origin or of the shipping country for products travelling to third countries.
There is also a simplified passport, made up of a simple commercial document (dispatch note, delivery note or invoice) bearing, as well as information about the plants, (botanical name and amount), the wordings “member state”, “Regional phytosanitary service”, “Producer Code”, “Series Number”.
Moreover, each passport has to:
1. Be printed on non-perishable material labels;
2. Be typed or written in capital letters with marking ink;
3. Bear the botanical name of plants and vegetal products with their Latin name.
The passport is not valid if it bears invalidated erasures or changes.