Both Botrytis and Phytophthora continue to show up in ginseng gardens. The risk of Botrytis is high due to the frost damage experienced in many areas. Weather conditions over the past few days have been favourable for continued development and spread of both Botrytis and Phytophthora. Continue to monitor gardens closely for development of both diseases. Apply Elevate once Botrytis levels appear to increase in the garden. Continue to maintain as much protection from Phytophthora as possible at this time. The risk of Alternaria is also high due to the presence of damaged plant material and favourable weather conditions for disease development. 

To De-bud or Not To De-bud: That is the Question

Frost has resulted in variable damage to the developing flower heads. Damage has occurred even on plants that appear to be otherwise unaffected by the frost. The decision to de-bud (de-flower) ginseng gardens has been complicated by this damage. It is not possible to simply scan the field and make this decision. The following will serve as a guide to help you. However, it is not possible at this time to predict exactly what will happen with the frost-damaged plants. Keep in mind that these calculations are dependent on many assumptions. There are three questions for you to answer in making your decision.

1. How much damage has occurred?

A survey of damage is required in order to make an informed decision about the de-budding process. First, divide your gardens into approximate areas of equal damage. For example, if you know you have extensive damage in a 3 acre section of a garden, then you would assess that area separately. The best way to assess damage is to count the number of healthy flower heads on 10 plants in 10 different spots in the area chosen. The more plants you assess the more accurate your survey will be. You should pick these 10 sites at random (not based on damage) and the 10 sites should follow an X or W pattern throughout the area so that all of it is represented. By now (10 days after the frost) you can assume that whatever flower heads appear damaged will not recover and whatever flower heads appears healthy will probably develop into a seed head. However, it is not known how healthy seed heads on damaged plants will develop. You will have to make an assumption about whether to consider these as healthy or not. Once you have counted the healthy seed heads on 100 plants you can assume that number represents the percentage of healthy seed heads in your garden. 

2. How much land do you save for seed production?

If you are deciding how much area to save for seed production you will need to do the following calculation:

[Area you planned to save for seed]/[percentage of healthy seed heads/100] = Estimated area you will now have to save for seed

For example: If you have a percentage of healthy seeds of 50% in your garden, and you originally planned to save 2 acres for seed production then:

• 2 acres/(50/100) = 2/0.50 = 4 acres will need to be saved for seed

3. Is de-budding more profitable than not de-budding?

If you just want to know whether to de-bud or not de-bud the calculations get much more complicated. Page 37 of Publication 610 contains a de-budding decision matrix and an example that you can follow to guide you in making this decision. Read the assumptions in the example carefully and consider how those have changed if you have flower and plant damage. 

The basic calculation is:

• With de-budding: expected root yield x expected price for roots = expected return
• Without de-budding: (expected root yield x expected price for roots) + (expected seed yield x expected price for seed) = expected return 

The example in Pub. 610 is based on an average yielding 3-year old garden of 2800 lb/ac. The increase in expected yield due to de-budding is assumed to be about 500 lb/ac based on previous research (2500 lb/ac without de-budding, 3000 lb/ac with de-budding). If your garden is damaged by frost or disease, you will have to estimate whether your yield will be lower than that example. If you expect your yield to be 25% lower than the example, then the expected increase in yield due to de-budding will also be about 25% lower (500 x 0.25 = 125 lb lower). This is only a rough estimate and will depend on the type of damage in your garden. 

Average seed yield in the example in Pub. 610 is assumed to be 300 lb/ac. You can use your percentage of damaged plants from Section 1 above to estimate how much seed yield you can expect (average seed yield x (percentage of healthy flower heads/100). If 50% of your flower heads were damaged, then your expected seed yield would be reduced to 150 lb/ac. Use these modified numbers to go through the calculations. 

The final thing to consider is that one of the major assumptions in the Pub. 610 example is that the labour cost of de-budding is about the same as the labour cost of picking seed. This may not be the case if seed yield will be low. In some cases it may not be worthwhile to de-bud or to pick seed. In these cases you will have to calculate how much labour you would save by not doing either practice and factor this into your decision.

As an example, we will pick a field with average expected yield but only 50% undamaged seed heads. The expected yield with de-budding is 3000 lb/ac. Normally, you would expect about a 500 lb/ac decrease in yield if you don’t de-bud. However, 50% of the seed heads were already killed by the frost. So you would now only expect a 250 lb/ac decrease by not de-budding, or an expected yield of 2750 lb/ac. For this example we will estimate the price of roots at $12/lb and the price of seed at $20/lb, and estimate 150 lb yield of seeds (since half are damaged by frost)

• With de-budding: 3000 lb/ac x $12/lb = $36,000/ac
• Without de-budding: (2750 lb/ac x $12/lb) + (150 lb/ac x $20/lb) = $36,000/ac

In this example, it makes no difference whether you de-bud or not (assuming you don’t need the seed). However, you would have to estimate what your labour costs of de-budding and picking seed would be under each scenario before you made the final decision. It is important to note that the impacts of frost on root and seed yields can only be estimated at this point. These calculations can only serve as a guide to help you make an informed decision.

Growing Forward: Food Safety and Traceability Program Information Session

Date: Tuesday, June 9, 2009

Time: 5:00 pm – 8:00 pm

Place: Simcoe Research Station Auditorium, 1283 Blueline Road, Simcoe

Funding is available to help producers and processors adopt food-safety and traceability programs and practices on the farm. Ginseng growers interested in applying at the $20,000 level should attend this information session. Growers applying at the $5,000 level do not need to attend. Please bring your food-safety questions to the session.

**REGISTRATION IS REQUIRED. Space is limited and organizers need to know how many growers are attending to determine if a second session will be necessary. Call the Agricultural Information Contact Centre at 1-877-424-1300 to register.

Questions about ginseng can be directed to Sean Westerveld, OMAFRA’s Ginseng and Medicinal Herbs Specialist at 519-426-4323; E-mail: sean.westerveld@ontario.ca.