Wetenschap - 10 september 1998

International Page

International Page

International Page
Exposing Soil Genesis and Culture Shock
The hilly landscape scarred by gully erosion in large areas of a province in southeast Brazil is the result of 40 million years of geomorphic and pedogenic processes. This in itself is not surprising, but understanding exactly how the soils and landscape have developed to their present form is the subject of a recent PhD, Polygenetic Oxisols on Tertiary Surfaces, Minas Gerais, Brazil - Soil Genesis and Landscape Development
This was an unusual type study for which Cristine Muggler had to struggle to get support at the WAU as it involved fundamental rather than applied soil research. Normally there is very little support for this type of study in Wageningen, because it is not considered to be relevant anymore. But in Brazil, basic knowledge on soil development is incomplete, so this study was necessary before research on practical solutions to landscape degradation can be performed.
Fourteen (horizontal and vertical) sections of gully walls, roadcuts and soil pits, some as deep as 30 metres, were analyzed. By combining distinct techniques such as micromorphology, x-ray diffraction and laser grain-sizing, Muggler identified important recent and relict features which indicated up to ten phases of evolution of these Oxisol soils
Muggler originally chose the WAU because of the presence of a chair in Tropical Soils as well as an international soil museum (ISRIC), English as the working language, research possibilities for her husband, and the chance to go back to her European cultural roots. However, one by one, all of her expectations eroded, and changed form. Just before arriving, Muggler found out that the Tropical Soils chair no longer existed, though a good alternative was found. ISRIC turned out to be an independent institute which did not play a role in her PhD research, but she has managed to develop an extra project on soil education with the institute. Her husband completed an MSc programme, but did not manage to obtain adequate funding for the research he had planned
A common complaint among international PhD students, the assertion that English is the working language of the WAU, was also not completely true. Muggler explains: It is difficult to follow what is happening in the University as all communications are in Dutch unless information is aimed specifically at the international community. Even learning Dutch well enough to be able to read internal mailings, Muggler always had the feeling of leading an incomplete life in Wageningen because of language and cultural barriers
I never expected to experience culture shock in Europe because I have Swiss parents, but I have never felt so Brazilian before. In her four years here, she has never got used to the reserved nature of the Dutch and their lack of display of emotion. In her twelfth PhD proposition she wonders whether the fact that the Dutch tend to push a lot is a compensation for lack of physical contact because of reservedness. The amount of bureaucracy also remains a stumbling block. We would call Dutch bureaucrats square-minded - they demand all sorts of official documents and cannot understand anything that lies outside the square.
After four years here, her family is still having problems because they do not have the right official stamps on their marriage declaration. On the other hand, Muggler greatly appreciates Dutch respect for egalitarianism and the principles of democracy. In Brazil, there is not as much respect for individual rights. These sorts of things have given me and my family another view of the world and helps us define our own utopia.
EU Funding Slow
Two MSc students have been delayed in beginning their studies in Wageningen. Last year the same thing happened when two students from Malawi had to wait until mid-October before they could start the Tropical Forestry MSc programme. Catching up on the compulsory study points before conducting their research component was not easy. Evert Kamphuis from the Dean's office explains why these delays are likely to continue to exist. The European Union Development Fund (EDF), which issues grants only to Lome Convention countries, has a much longer approval process than other funding agencies, with a long chain of bureaucratic steps
Students must first approach the EU office in their own country, which then consults with the EDF head office in Brussels. They in turn contact NUFFIC (Netherlands Universities Foundation for International Cooperation), who then consults with the University on the eligibility of the students in question for a MSc study. The process then traces all the steps backwards, until the students are finally notified about the approval of their grant. The extra EDF steps of contacting the local and head offices makes contact with students even more bureaucratic. Kamphuis cannot find any specific pattern in the approval process of EDF grants. Some years, ten students are delayed, and others two - and every year a different country seems to be involved.
Baculoviruses good alternative to chemical pest control
Insect pests are becoming increasingly resistant to chemical insecticides in China. The environmental problem is very real. Farmers have to use increasingly higher doses of toxic chemicals. The newspapers advise people to buy vegetables with holes, because these are believed to contain fewer chemicals, says Rose Hu, head of the laboratory of virology, Wuhan University in China
Baculoviruses are attractive biological alternatives to chemical insecticides for pest control, according to Hu. These viruses are ingested by caterpillars and multiply in their bodies, eventually killing them. They do not induce resistance in insects and have minimal effects on non-target insects, such as bees. In China about 100,000 hectares of cotton and hot pepper are treated annually with baculovirus
More than 600 baculovirus isolates have been described and classified into two genera: Nucleopolyhedrovirus and Granulovirus. These provide a good source for crop protection. However, little is yet known about most of them, and no databank has been compiled
Hu was one of the first researchers to study the genetics of a Nucleopolyhedrovirus; she chose the one that infects Buzura suppressaria. This insect causes damage to about 60 plant species including tea, tung-oil tree, metasequoia and Mandarin oranges, and has been reported in China, India, Burma and Japan
Hu, who defended her PhD thesis on September 8th, found that most baculoviruses have up to 80 percent common genes. She developed a new method, GeneParityPlot, for classifying the genome organization of baculoviruses. Classification can help virologists to pinpoint the right virus for a pest insect more easily
Besides the lack of a databank, one drawback to using baculoviruses in insect control is their relatively slow speed of action. Normally it takes a few days for a virus to induce feeding inhibition in larvae. When it is the part of the crop which is to be harvested that gets eaten by insect pests, this delay is a problem. Knowledge about the molecular genetics of a virus can be used to improve the viral insecticidal properties through genetic modification
Baculoviruses are produced in insects. When an infected caterpillar dies, the virus particles are released. Virus particles from 100 - 500 infected caterpillars are needed to successfully protect one hectare of crops. The production of viruses does not require expensive facilities and is relatively easy to organize in Chinese villages. (MS)

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