Pest control methods for the private garden

The availability of pesticides in private gardens is limited by local law i n the State of Baden-Wurttemberg in south-west Germany. Only 26 insecticide s, fungicides and molluscicides are permitted. Hence, only pesticides such as Bacillus thuringiensis, Granulosis Virus, pyrethrum or the pheromone mat ing disruption method (PMDM) can be used for moth control in apple. The use of beneficials like Trichogramma sp. or Chpysoperla carnea is not limited. PMDM had not been previously investigated in allotments until the experime nts reported here were carried out in 1998 and 1999. In these experiments, PMDM was compared with the use of the egg parasites, Trichogramma dendrolim i and T. cacoeciae. The observations were done in 102 allotments, each of a bout 300 m(2). The gardeners are members of a special club for the allotmen ts and they often organize the bulk acquisition of plants or fertilizers fo r the club. Sometimes the club obtains plant protection products when somet hing has to be done in ail allotments. The codling moth and the plum fruit moth are important pests in these allotments. In 1997, attacks of codling moth were generally low throughout the southern Germany. This was reflected in the allotments where there was less than on e per cent fruit damage with PMDM or the egg parasites the following year. During 1999, the attacks were generally much higher resulting in a higher u se of insecticides in commercial German orchards. In the allotments, about six to eight per cent of fruits were damaged by the codling moth in both ex perimental treatments. The results indicate that PMDM can be successful in allotments and is equal ly as effective as the use of egg-parasites. But further experiments are re quired.