Local greenhouses are using numerous strategies to fight organisms harmful to their crops. At Delta View Farms, this battle is being led by head grower Gordon Yakel.
Yakel, a graduate of SFU's biology program, uses Integrated Pest and Disease Management to stay one step ahead of his adversaries. IPM and IDM use the principles of tolerant plant varieties, cleanliness, monitoring and treatment to deal with pests and diseases.
The first challenge is to match the right rootstock to a particular tomato variety while maintaining tolerance to the main plant diseases and still producing a tasty, high quality fruit.
"I do at least two years of greenhouse trials before choosing only the best performers to grow," states Yakel.
Starting clean is another important strategy. In December workers remove last year's crop, grow bags and the plastic ground cover used to stop weed growth. This is followed by a general wash down of the structure and a bleach application to disinfect the inside of the greenhouse.
"Basically we are preventing the carryover of last year's pests and diseases onto the new crop," says Yakel.
When the young crop reaches a height of about 1.2 metres, the bottom-most leaves are removed weekly from the plant. To stop the spread of disease, the knives used for leaf pruning are regularly dipped into a disinfectant. The disinfectant also acts as a desiccant, helping the wounds to dry quickly.
Catching problems early is also important. Plants from one row in each greenhouse bay or section are looked at once a week, so after five weeks every plant in the greenhouse has been inspected.
Monitoring includes checking top and undersides of leaves for pests and diseases. This is done in the top, middle and bottom of the crop canopy.
Monitoring is also done with yellow sticky cards, which attract and trap flying insect pests.