Biological control - promising examples

In the last few years attempts have been made to provide more natural methods of plant protection, relying to a considerable extent on biological interrelations. Innovations in special fields of insect, fungus and weed control in which BASF agricultural research has played a part are in some cases already undergoing commercial testing. Thus in insect control, a new boxed capsule formulation of viable eggs of the parasitic wasp Trichogramma evanescens maidis, Trichocap, has proved effective to very effective in the control of the European corn borer, Ostrinia nubilalis. The bacterium Bacillus thuringiensis var. israelenis (B.t.i.) selectively kills the larvae of mosquitoes and black flies. The favourable dosage response curve makes it suitable for the control of European mosquitoes and the vectors of dangerous diseases, such as malaria, encephalitis and river-blindness, in the tropics. The development of a strain which does not produce spores, Bacidor, is an additional advantage from the point of view of public hygiene. The first pheromone product to receive official registration in Europe was RAK 1, in 1986. This was for the large-scale control of damaging moth species. With 80- over 90 per cent efficacy it specifically prevents mass outbreaks of the grape berry moth, Eupoecilia ambiguella. As regards control of fungal pathogens, powder or liquid preparations of Sachalin knot-grass, Reynoutria sachalinensis, have proved to have a strengthening effect on various vegetables and ornamental plants. The general condition of the plants is visibly improved and they have an increased chlorophyll content, more vigorous habit and flower initiation and demonstrate greater resistance to mildew (Erysiphe, Podosphaera, Sphaerotheca) and Botrytis. On account of this special mode of action the preparation must always be applied preventively. All novel biological or biotechnical procedures are selective and environmentally safe and they offer an interesting alternative method of plant protection when used wisely and carefully