Integrated Systems for the Production of Organic Greenhouse Tomatoes

The choice of growing media and the strategy of application of organic fertilizers are considered major challenges in the development of systems for the production of organic greenhouse tomato crops. To develop an integrated organic tomato production system, a two-year study was conducted at the greenhouse facilities of Agriculture and Agri-Food Canada in Harrow, Ontario, Canada. In spring 2006, two organic liquid fertilizers and four organic media were tested, whereas in spring 2007, four liquid fertilizer feeds (three organic and the standard inorganic rockwool feed), and four media (two organic and one inorganic (rockwool) and one organic (coco coir) control) were tested on tomato (Lycopersicon esculentum L.). In-house formulated organic media (peat-based + soy meal) provided sufficient nutrition to container grown tomato plants. The pH and EC values in organic media were 6.5-7.6 and 2.5-3.0 ms cm(-1), respectively; well within recommended ranges. The nutritional status of plants grown on organic media resembled that of plants grown on rockwool or coco coir with inorganic feeding, as evidenced by leaf tissue analysis results. The highest marketable yields achieved with the best combinations of organic liquid fertilizers and organic media were 23.6, 21.6 and 21.2 kg m(-2); these yields represented 92.2, 84.4 and 82.3% of the corresponding rockwool (inorganic control), or 95.2, 87.1 and 85.5% of the coco coir (organic control) yields.