Education Center | Plant Disease Management Simulations
Management of Potato Late Blight: Simulation with Lateblight




Exercises

Late Blight Home

1. Disease resistance

2. Protectant Fungicides

3. Systemic Fungicides

4. Effects of weather

5. Disease thresholds

6. Sanitation

7. Certified Seed

8. Integrated Tactics




Exercise 7: Inoculum Reduction with Certified Seed

Many potato farmers save a part of their harvested crop to use as seed for the following season. This practice carries with it the risk of planting seed pieces from infected tubers. Certified seed producers use far more stringent measures of protection, inspection, and roguing than table stock producers could afford, and as a result their seed is likely to have a far lower incidence of infected tubers.

To show the effect of certified seed, let us first assume that all the inoculum comes from infected seed. In the Inoculum menu, select Sporangia..., and set "maximum sporangia per day" for both the cull pile and the unsprayed field to zero. Then select Infections... in the Inoculum menu and enter 100 infections per hectare to represent uncertified seed saved from the previous crop. Compare the results with those from a simulation with only 1 infection per hectare to represent certified seed. If certified seed cost you double what you would pay to plant your own seed ($.22/kg versus $.11/kg, adding $313/hectare to your production costs), would you plant your own seed or certified seed? (Explain your rationale.)

....proceed to EXERCISE 8

....return to Introduction


Contact: Phil A. Arneson
Last updated: July 9, 2004
Copyright 2002 Cornell University