DECEMBER 2019 • COUNTRY LIFE IN BC
Cannabis growers square off against diseases, pests
New industry needs to be aware of threats by PETER MITHAM
ABBOTSFORD – With cannabis production at commercial scale, growers are facing issues common to other commercially produced crops. Some of the discoveries could hold lessons for the horticulture sector at large.
The emerging threats were discussed at Cannatech West, held during the Pacific Agriculture Show in Abbotsford earlier this year. Speaking to an audience of
approximately 200 people, Zamir Punja, a professor in plant biotechnology at Simon Fraser University, acknowledged that he tends not to be a bearer of good news thanks to his focus on pests and disease. However, cannabis growers need to be aware of the risks facing their plants. While botrytis and powdery mildew may be familiar, many growers may not know fusarium. “Any grower of any
vegetable – tomatoes, peppers, cucumbers – will recognize fusarium and pythium as being common,” he said. “These two organisms are starting to show up on cannabis plants.” Punja focused his comments on fusarium species, a group of fungi that aren’t specific to cannabis. Spores may have been in the environment where cannabis is being produced, or are
moving in thanks to air currents or hitching a ride on clones and other materials. “There are spores in the
environment – there’s spores in the hydroponic solution, there’s spores in the air, there’s spores on the benches,” Punja said. “There’s many sources that as producers you need to be aware of where these diseases are coming from.” Complicating matters for cannabis growers is that a diseased plant may be easy to recognize, but there's no definition of a perfectly healthy plant. This means infected plants with mild symptoms might be overlooked, contributing to the disease’s spread. Ironically, producers’ efforts
to provide a disease-free environment may be covering up sick plants. “We’re not necessarily seeing plants dying from fusarium infection,” Punja explained. “We think that possibly because the plants are being provided with a great environment – there’s no stress – they’re surviving the infection.” But infection rates can be high. A survey by Punja’s team found Fusarium oxysporum in 70% of samples, for example, while new effects such as damping off were noticed at three locations in 2018. Some growers also
reported pith necrosis, a greater concern for Punja that’s likely attributable to the
39
Pear-fect
As the outdoor farmers market season winds down, L&B Orchards in Carrs Landing was marketing their Asian pears at Kelowna's midweek market. Sometimes referred to as apple pears, the fruit is a true member of the pear family. The farm has four varieties, the last of which was harvested at the end of October. MYRNA STARK LEADER PHOTO
fast-moving Fusarium proliferatum. The disease moved eight centimetres in five days, enough momentum to eventually kill a plant. “The name itself tells you
[it’s] something you need to worry [about],” he said. “If something’s proliferating, it’s
growing really fast. … It’s something that we’re watching and monitoring to see how extensive this fusarium is on cannabis.” While the origins of the fungal disease are unknown, Punja warned growers to be careful of where they’re
sourcing plant material. “There is material moving
across Canada, and possibly between LPs, that has fusarium and potentially other diseases on them that need to be checked,” he
See PEST on next page o
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48
