In nurseries growers suffer from several pests. The most important ones are aphids, mites and thrips. Depending on crop type several other pests may occur, such as scales, bugs, caterpillars. In recent years the use of chemical pesticides in these crops needed to be reduced dramatically due to restrictions in order to prevent pollution of surface water.
From chemistry to biology
For nursery growers a so called natural control program turns out to be an approach that has perspective in these situations. Here growers do hardly use any chemical product but instead they try to have optimal profit from natural enemies that are present in the environment. Research is being done to investigate needs of naturally occurring predators and what measures could eventually be taken to promote their activity in the crops. This could be to add flowers around the crop, to realize sheltered places for them to hide / overwinter etc. Apart from this introduction of biocontrol products can be useful to help the naturally occurring beneficials or to start up the program early in the season. Eventually in local hot spots of infestation beneficials can be introduced to prevent further outbreaks from these spots.
The choice of means for combating insects and fungi is then adjusted to avoid the natural enemies as much as possible. The natural enemies can help keep the plague below the damage threshold. Particularly when transitioning to an integrated control system, certain natural enemies in the orchard must be deployed, after which they can settle and multiply. This approach can take a while and requires patience and therefore proper guidance in this process is necessary.
Research wooly beech aphid
Entocare has been engaged in various research projects in natural control in tree or fruit cultivation. In one of them we demonstrated that wooly beech aphid s effectively controlled by naturally occurring predatory bugs after initial introduction of a predatory ladybug. In fruit production we demonstrated that, after initial introduction of parasitic wasps domestic parasitoids manage to parasite soft scales and thus prevent outbreaks of the scales. In apple orchards there are possibilities with a ladybug against wooly apple aphid. Due to our research and experience a proper monitoring of presence and activity of naturally occurring beneficials, with some help form introduced beneficials in the beginning has serious potential in realizing a successful natural control program. Measures to enhance presence of naturally occurring species will help in realizing even better results.