University of Guelph staff at the Simcoe Research Station were cleaning up their library and came across a book titled “Ginseng and Other Medicinal Plants” by A.R. Harding published in 1908 (A.R. Harding Publishing Co.). A lot has changed in the world of ginseng production in the last 105 years, but it is amazing how many things have remained the same. In a section titled “Shading and Blight” the author discusses cultivation of ginseng and susceptibility to disease:
“Ginseng is truly and wholly a savage. We can no more tame it than we can the partridge. We can lay out a preserve and stock it with Ginseng as we would with partridges, but who would stock a city park with partridges and expect them to remain there? We cannot make a proper Ginseng preserve under conditions halfway between a potato patch and a wild forest, but this is exactly the trouble with a large share of ginseng gardens. They are just a little too much like the potato patch to be exactly suited to the nature of Ginseng. The plant cannot thrive and remain perfectly healthy under these conditions; we may apply emulsions and physic, but we will find it to be just like a person with an undermined constitution, it will linger along for a time subject to every disease that is in the air and at last some new and more subtle malady will, in spite of our efforts, close its earthly career.”
As many growers know, trying to produce a crop adapted to a forest environment in a field is a losing battle. Eventually disease will take over, whether it is 3, 5 or 7 years after planting. The crop is grown with perfect fertilization and high density, which results in high yield, but also high disease susceptibility and rapid disease spread. The application of “emulsions and physic” (a.k.a. pest control products) only delays the inevitable. The only way to reduce the reliance on pest control products is to change the environment in which ginseng is grown to more closely resemble a forest environment (e.g. wider plant spacing, improved air flow, drainage, simulate the forest soil ecology etc.) or to change the crop itself (e.g. breeding for disease resistance). Breeding for disease resistance was already a recommendation in 1908.
Ginseng growers should remember that disease can be the result of another “undermining” issue. Correcting the undermining issue should be the first course of action, and application of pest control products should always be the last resort.
Not everything written in the book is as insightful. After discussing trials to test Bordeaux mixture (the first pesticide which was composed of copper sulphate and lime) to control the newly identified Alternaria blight of ginseng, the author states, “From these experiments it is evident that the problem of the control of the Alternaria Blight of Ginseng has been solved.” Control of Alternaria blight and all diseases of ginseng is an on-going battle 105 years later.
The author also mentions “I will venture to say that I don’t think we can grow enough (ginseng) in fifty years to over-run the market”. Yes, we can.