Analysis of the sales trend in plant protection products between 1980 and 1998.

An analysis of the sales of plant protection products in Germany since 1980 shows a conspicuous decrease in sold amounts of active substances by more than 50 % at the beginning of the Nineties. The sales trend of the 1980s, which showed a continuous increase in the total amount of plant protection products sold, did not continue. On the contrary, domestic sales reached their low in 1993/94. The main reasons for that may lie in a decline by 1.23 million hectares in the growing of crops requiring intensive protection (cereals, silage maize, potatoes, sugar beets, pulses, fruit and vegetables), an 8 % increase in prices of plant protection products in 1993 over 1991, the extremely dry summer of 1992, and in old pesticide stocks which were still being used up in East Germany. Generally, changing legal conditions (Plant Protection Act of 1986) and consequent efforts by the chemical industry to bring environmentally more compatible products with lower application rates on the market had also contributed to this development. From 1995, plant protection product sales have plateaued at between 1.76 and 1.94 kg per hectare of arable land. Herbicides, fungicides and growth regulators make up most of the sales. In 1998, the last year considered in the analysis, the sold amount of active substances increased markedly over 1997. The sales trend of herbicides and growth regulators in particular shows again a clear correlation with growing area, ratio of various crops and, to a certain degree, weather conditions. Culm stabiliser, the efficiency of which varies strongly with cultivars, had a major share in the growth regulators. An evaluation of the trend of risk potentials in the period from 1987 to 1998 shows in the majority of cases a clear decrease in the bioavailability of the ten most-applied active substances each in the groups of herbicides, fungicides and insecticides. The risk of herbicides to water-dwelling animals and earthworms was reduced by more than 80 % in the majority of cases, while risk reduction was not that strong with fungicides and insecticides. On the contrary, the chronic biological risk of insecticides to water fleas and the acute biological risk of insecticides to fish reached a maximum value in 1998 compared to 1987 and 1994. The biological risk of fungicides to aquatic algae also increased in the same period. An evaluation of this relative increase, however, must not neglect the absolute risk indices which are all below the limit of 1. From this limit, worst-case scenarios by the SYNOPS model would no longer preclude that the substances might have any effects.