Hairy vetch hardly sounds like something that will help tomatoes taste more like summer and sunshine.
Yet, researchers at the Faculty of Land and Food Systems (LFS) are discovering that a green manure like hairy vetch – a cover crop which enriches the soil – along with other organic fertilizers can substantially boost tomato plant performance. And when coupled with hoop house production, local tomato growers may have a winning combination for commercial production.
LFS graduate student Greg Rekken and Assoc. Prof. Andrew Riseman aim to support the groundswell of interest in family and small-scale farming.
“However, the high price of land and equipment present substantial barriers to entry,” says Rekken, who is earning a master’s degree in plant science.
But the answer may lie in hoop houses, which are fairly simple and cheap to build, Rekken says. “Basically, it’s a frame made from metal or PVC piping bent into semi circles that’s covered with plastic.”
The protected environment of a hoop house would maintain ideal tomato-growing temperatures of around 17 degrees Celsius overnight and 23-27 degrees Celsius during the day.
The other part of the equation is a nutrient management system using a range of local and farm-derived fertilizers compatible with organic standards, explains Riseman, who studies plant genetics and efficient use of nutrients and intercrop interaction for sustainable production.
Along with hairy vetch, the study is evaluating composted poultry manure and a kelp-based liquid fertilizer.
“Our preliminary results show that these sustainable fertilizers can produce high-quality tomatoes in sufficient quantities to be economically viable,” says Riseman.
He points out that tomatoes are a high-value crop in great demand, “but tastes best when grown close to where it’s consumed.”
But that is not always possible. Tomato plants need hot, sunny weather. Given the months of damp and rain along B.C.’s coast and other regions, tomatoes are often vulnerable to blight.
And while vine-ripened tomatoes are readily available in most supermarkets, most are produced in hothouses, which commonly use a sawdust growing medium rather than soil.
“To many consumers,” says Riseman, “the tomato has become the embodiment of a food system that has lost its flavour.”
Some blame the widespread use of conventional fertilizers, he says, for today’s pallid, pulpy tomatoes. “As well, if tomatoes are being shipped a long distance, say from California, they’re picked green and treated with ethylene gas to hasten ripening.”
However, low-tech works equally well if not better, argues Riseman. “What the green manure does is give you a tomato that has the same qualities of an engineered plant without the engineering.”
Organic fertilizers enrich the soil with nutrients such as nitrogen, phosphorus, potassium and calcium, promoting strong healthy growth and larger leaves that last longer.
“Bigger leaves mean more photosynthesis which in turn diverts more energy and sugar into the tomatoes,” explains Riseman.
The study’s next steps will be to conduct additional analyses on fruit traits including sugar and protein content as well as total soluble solids.