Introduction to Biological Control in China
It is a relatively generalized concept among agronomists and other Western investigators, that in the People’s Republic of China biological control is used as the principal control measure for crop protection. The classic story of the first known usage of biological control with human intervention in the world having been in China, through the usage of predatory ants, of the species Oecophylla smaragdina, in citrine orchards, of which the first record remounts to 324 BC, contributes to establishing that image.
Unfortunately, this Western agronomist imaginary conception about China does not correspond to reality. China followed the patterns of the Green Revolution during the 1960’s. Following this path, which has been dominant in the world for the last decades, China was able to situate itself among the main pesticide producing and consuming countries, even being, according to some estimates, the second and third world producer of pesticides, varying its position each year.
The proportional distribution of the production of different classes of pesticides in China, between 1993 and 1995, was approximately 74% insecticides, 10% fungicides and 13% herbicides. The trend in this relationship, already in a near future, will be the increase in the percentage of production and consumption mainly of herbicides, but also of fungicides, to the detriment of insecticides.
As such, the praiseworthy government project of creating “township enterprises”, subsidized by the State, is provoking the reduction of available workmanship for agriculture (men and youths), reflecting itself on changes such as the necessity of applying insecticides with a greater persistence than those made on the basis of Bacillus thuringiensis, with the impossibility of manually transporting manure to the rice plots and in the face of the gradual abandonment of manual weeding.
While emphasising an interest in developing pilot projects in eco-agriculture, no reference is made to biological control or integrated pest management in the official agricultural yearbooks, which in addition associate a growth of chemical control to an increase in productivity. However, despite the evident predominance of chemical control, there is in China a vast group of researchers and institutions which embrace, in an almost complete way, the diverse themes of biological control.
According to some investigators, in 1992, biological control was practiced in China across approximately 30 million ha, including actions within the context of natural biological control. There are opinions that in the decade of the 90’s biological control underwent development in China, reaching an area of approximately 23 million ha. The immense variety of situations in which biological control is practiced in a single country, which incidentally is also the arena for an original diversity of socio-economic policies, antagonistic in the past but now simultaneously carried on, provides a unique opportunity for the study of the complexity of biological control, as a result of social and biological interactions.
Nevertheless, one must keep in mind that investigation about China, calls for the necessity of certification of some statistical data, since it may have been conditioned by diverse reasons. For example, if one was to accept as correct the areas of application of biological control, and considering that China had a cultivated area of about 95 million ha in 1994, one would conclude that method of protection would have been used in at least 24% of the cultivated area that year, which, to those who have had any real contact with this country, would unfortunately inspire a profound doubt due to the high percentage.