Chronica - Acta Horticulturae

tive basic research with a keen interest in solving
practical problems. His broad knowledge
and continuous curiosity led to his many
achievements and made him a dominant figure
in fruit tree horticulture worldwide. He conducted
research on plant nutrition, carbohydrate
and nitrogen metabolism, post-harvest physiology,
and plant growth regulators and dormancy,
to name just a few. In every field he opened
new research lines. During his last years he was
interested in the origin of fruit species and
published review papers on the origin of peach,
cherry, apricot and plum. Faust was passionate
about strengthening horticultural science in
Eastern Europe and is credited with reviving
fruit tree research in China.
The Faust Award selection committee chose
Pedro Martínez-Gómez from a strong field of
candidates. It noted that his work embraces
several fields of scientific knowledge and
demonstrates the practical applications of basic
research. His strong commitment to collaborative
research is consistent with Dr. Faust’s belief
in international cooperation and networking as
essential elements for progress in horticultural
science.
We take this occasion to congratulate Dr.
Martínez-Gómez in the name of the all who
were involved in his selection. We also remember
with great fondness the great friend and
pomologist who was Miklos Faust.
ISSUES
Biological Pest Control in Horticulture
Aad Vijverberg
Forty years ago, a new method of biological control of arthropod pests was introduced: the
regular introduction of “beneficials”. In The Netherlands, biological control in glasshouses started
with cucumber production when red spider mite, Tetranychus urticae, became resistant
against acaricides. Bravenboer and Dosse (1962) first suggested Phytoseiulus persimilis as a
predator of T. urticae. Thus, a useful predator was available when the industry moved to biological
control in 1967. This predator is still a cornerstone of biological control (Schütte, 2006).
Labour saving has always been an important factor stimulating biological control! In the beginning
of biological control of cucumber in greenhouses, a systemic fungicide against powdery
mildew (Sphaerotheca fuliginea) became available (Vijverberg and Bravenboer, 1998). Thus,
the necessity of weekly applications of a pesticide was eliminated, provided red spider mite
could be controlled biologically.
At present, biological control of pests in glasshouse vegetable production in north-western
Europe is a standard. In The Netherlands, biological control in the production of tomato,
cucumber, pepper and eggplant is applied on about 95% of the cultivated area. Biological control
is not as popular in other countries as compared to The Netherlands. In Morocco, 80% of
greenhouse tomato growers use biological control in some way or another (Alami, 2003) while
in France, only about 10% of the growers use biological control (Callais, 2006). It is important
to analyse why biological control has become a standard practice in glasshouse vegetable production
in The Netherlands. This analysis will help us understand the possibilities for biological
control in other branches of horticulture and agriculture. For different branches of horticulture
I will analyse the main factors playing a role in the development of biological control.
GREENHOUSE VEGETABLES
Many factors have been important in the development
of biological control in this sector.
Research and Development
The Dutch government stimulated biological
control through efforts in basic research and
practical applications for industry (applied
research). This has strongly stimulated the use
of beneficials as a standard practice. The legislation
of the European Union requires new pesticides
to be evaluated on “useful arthropods” in
order to obtain permission to bring them on
the market. This legislation has been very
favourable for the development of biological
control. Much applied research is carried out by
industry. At present, 130 species are used in
biological control (Nijhof, 2004), and over 40
species are used in greenhouses (Malais and
Ravensberg, 2003).
Product
With fruit vegetables such as tomato and pepper,
leaves usually do not enter the trade channel.
Thus, practically no insects or mites are
entering trade channels. Formal trade barriers
do not play an important role (quarantine) nor
do informal barriers (the aversion of traders
and consumers to products that are infested
with arthropods).
Consumer Preferences
Rachel Carson’s book Silent Spring (1962) initiated
an aversion by consumers to pesticides.
This consumer reaction stimulated research and
efforts on biological control. Growers started to
offer their product with a guarantee in relation
to a minimal use of pesticides. Production in
artificial substrates such as rockwool diminished
the use of pesticides for soil pests.
Grafting on a resistant rootstock is another
method to realize this. Modernization in greenhouse
production was stimulated by the search
to diminish the use of pesticides as well as
fertilizers and energy.
Phytoseiulus persimilis, the first used
biological control agent against red
spider mite, Tetranychus urticae.
ISHS • 14