Last week I mentioned that we are tracking five weather forecasting sites to determine which are the most accurate for Simcoe. That information will take more time than anticipated to analyse, so results will be available next week. All five forecast sites show no signs of significant freeze events over the next week.
All ages of ginseng are beginning to emerge through the straw. This is a critical time to protect plants from Alternaria and foliar Phytophthora. If any damage occurs to plants such as sandblasting, insect or slug damage or frost, Botrytis can also be a significant issue. Slugs are also already active and may start feeding soon if they aren’t already.
Some areas of the ginseng growing area have below normal soil moisture for this time of year. Although there would be no impact currently, growers will need to keep an eye on soil moisture levels over the next few weeks to ensure plants are not stressed later on.
A summary of our replant research to date was provided in both a December update meeting and at the OGGA AGM. This year we have 21 field and greenhouse trials on the go and an additional 19 field survey sites. The trials are focussing on many potential methods to control replant disease, understanding the causes of replant disease, and efficacy trials to test new products for ginseng disease management. A field tour will be arranged for later this summer to allow growers to see some of the research in progress.
One of the goals of our research this year is to determine what strains of Cylindrocarpon are present in Ontario fields. Research over the past few years shows that there are many distinct Cylindrocarpon strains and species that have different abilities to cause disease, and could produce different symptoms. Sorting out what we have in Ontario will help us to find better control methods and better ways to diagnose fields ahead of ginseng production so growers can avoid problem areas. If growers or consultants find suspected cylindrocarpon damage in fields, they are encouraged to drop off the samples to Amy Fang Shi in the OGGA office. Any unusual or abnormal root rot symptoms can also be dropped off. This is not intended to be a diagnostic service, but a report will be provided on what was identified on those samples. This may not be provided in a timely manner like a diagnostic lab.
Any growers who are intending to attempt replanting ginseng this year should also consider participating in our replant survey. We would like to compare a range of replanted gardens to the grower’s equivalent aged new garden. This could give us major clues as to which organisms and/or soil conditions lead to more aggressive replant disease. Students will come out monthly to visually assess the areas. At the end of 3 years we will come in harvest small areas to give a scan of the diseases present. Growers will get a wealth of diagnostic test reports for both fields that could help in their disease management. If you would be willing to be part of the survey, please contact Amy Fang Shi in the OGGA office.