With lengthening periods of dew coupled with leaf tissue beginning to senesce, growers and consultants are starting to see more signs of foliar diseases. Botrytis and Alternaria appear to be increasing in ginseng gardens this week. There have also been reports of Cylindrocarpon. With rain predicted for much of the ginseng growing area over the next few days, remember that this can further increase the risk for both foliar and root diseases. Growers should be monitoring for all foliar and root diseases, and taking them into account when making decisions about harvest. Some gardens may show signs of early senescence over the next few weeks, due both to the early warm temperatures experienced this spring and heat and moisture stress.
Seed heads are developing and will likely be ready for harvest in another few weeks. There have been some reports of fungal diseases on seed heads, so monitor berries closely. As we approach seeding, be aware of soil moisture levels. We have little experience seeding into very dry soil, but the concern is that, if soil is too dry, the seed may dry out under the straw and this could prevent proper stratification. This could be more of an issue in fields that had significant weed cover after fumigation, as the weeds could have removed extra moisture from the soil. Hopefully the rain forecast for this week will avoid this situation. If soil moisture is a concern at seeding, irrigate or consider delaying seeding until there has been sufficient rain or soil is cooler.