An apple orchard drains into a reservoir. Moth larvae feed on the developing apples.
A parasitic wasp was tested as a biological control. In containment tests, the wasp attacked the moth larvae but did not attack three common non-target insect species.
The grower tested three treatments for one year on equal areas of the orchard.
| Treatment | Fertiliser added (kg per hectare) | Parasitic wasp released | Apple yield (tonnes per hectare) | Apples damaged by larvae (%) | Nitrate in water leaving orchard (mg per dm³) | Non-target insect species recorded |
|---|---|---|---|---|---|---|
| A | 0 | no | 18.2 | 24 | 1.4 | 21 |
| B | 120 | no | 26.8 | 23 | 10.8 | 21 |
| C | 60 | yes | 29.4 | 7 | 4.6 | 20 |
Discuss whether the grower should use treatment C across the orchard. Use the information in the table and your knowledge of fertilisers and biological control.
100 exam-style questions on Edexcel GCSE Biology 4.3 Selective breeding and genetic modification, covering 4.3.1 Selective breeding and its impact, 4.3.2 Tissue culture, 4.3.3 Genetic engineering overview, 4.3.4 Main stages of genetic engineering, 4.3.5 Advantages and disadvantages of GM organisms, 4.3.6 Agricultural solutions for a growing population, and 4.3.7 Evaluating genetic engineering and breeding. Each one has a worked solution and a mark scheme showing where the marks go.