TOPIC: Tops dieing back...help

I've started a little group of about ten seng plants in my wife's garden. They are only on their third year. A few of them seem to die back, but come back the next year. I've added some gypsum, we've been getting a lot of rain (it's well drained)and tried to shade it out more. The only thing I can think of is to much afternoon sun, even though its good shade, they do get some late sun. Funny, some are doing well!

Any thoughts?

Maya,

Have you noticed any sign of disease (on the leaves/stems or root) before or after they die back ?

Yellow/brown bullseye type spots or lesions on the leaves (Alternaria blight).

Or if you inspect the root after the top dies back, does it look healthy or diseased (possibly root rot).

Do you know what the PH and Calcium levels are in the garden soil ?

If it's not disease or soil issues then it could be the shade problem.

I think the ideal situation for seng and sunshine is this --- good early morning sun (say from sunup to 11 AM) and then very little direct light in the evening. I have some seng that grows in a situation like that near my house - It is on a east facing bluff and gets very good sun all morning, but then in the evening gets nothing but indirect light. The plants there are huge, with big bulby roots, big berry pods, just overall what you want to see in seng plants.

The early morning sun helps to dry off the top after the nights dew (good to help with fungal issues). The evening sun it usualy just too hot for seng (especially down south here in my area) and needs to be seriously limited.

Good Luck !

TNhunter

I tested ph...6.7, so I did add soil acidifier, but that was 3 days ago. Also added a little gyp at that time. There is also some bugs eating at the leaves, however I don't see a fungus/blight problem. Here is some pics... This is the best looking one. All withing 2 sq feet.

One right next to the first one..bad color, but no spots, just holes.

Maya,
Could be as simple as insects chewing the stems below ground.

One I dug up that I beieve was a small two stem. Root it tiny but no sign of any rot. Its got a lot of tiny hair roots. The top was fallen right over on it's side as if it were dried up. but it wasn't dry.

Maya

As far north that you are, I don't believe that it's a sun light issue. I plant most of my seng on SE and SW facing hill sides. And at this time of year I have quite a few plants that get afternoon sun, And they are doing well. They all have nice dark green leaves.

I think it's more along the line of disease or soil condition.

It's perhaps what they call TIP-Over which is a damping off disease, but that usually happens in the early spring.

Hope you can figure out whats causing this.

Classicfur

TN is offering sound advised.

Listening to the description, I\"d be suspecting phytophthora or pythium root rot. I dug a couple 6 year olds the other day that were yellow and wilting...the roots were all but gone. If this is a more or less circular area, I would suspect either of these diseases too. But, if you have good drainage, phytophthora isn't normally a big problem.

However, the picture of the little one you show seems to be mostly healthy. The abscense of developed feeder roots seem to suggest cylindrocarpon. Unfortunately, the only thing that I know of registered for use on ginseng to control cylindrocarpon is Cannonball (fludoxonil). Even then, it might be too late for the plants that are infected.

I too think your ginseng is getting chewed up pretty good. Did you put out snail bait? If not, start there. I don't think its damping off this late in the season with dry, warm weather.

What do the worst plants look like? Ones that are a few days gone? If its fungal infection, you might be able to identify it in a completely infected root. Does it smell really bad? What color are they? What happens when you squeeze the root in your fingers?

BCastle

I agree with you in that it's probably not damping off. But I think where Maya lives has probably gotten the same weather we have had up here in Maine. Rain off and on over the past three weeks and cooler temps in the 60's coming out of canada.

In Maine we have'nt had more than about three dry days in a row, then we get more rain. So what disease would cause that in moist cool weather?

classicfur

classicfur wrote:

BCastle

I agree with you in that it's probably not damping off. But I think where Maya lives has probably gotten the same weather we have had up here in Maine. Rain off and on over the past three weeks and cooler temps in the 60's coming out of canada.

In Maine we have'nt had more than about three dry days in a row, then we get more rain. So what disease would cause that in moist cool weather?

classicfur

Most of the diseases can show up in those conditions. But, when it is damping off, through any of the pathogens (Alternaria, phytophthora, pythium, rhizoctonia or botrytis most commonly) there is almost always a 'pinched' area on the stem. alternaria causes the plant to bend sharply, and also shows a visible stem lesion when not folier, so I don't think thats it.

I'm thinking he is dealing with either cylindrocarpon or fusarium. The bad news is that as far as I know, nothing is registered for use on fusarium in ginseng. There are a number of fungicides which are recommended for fusarium, but none labeled for ginseng. A quick internet search can show things like iprodione or azoxystrobin (and the brand names they are sold under) may have some effectiveness against fusarium. Unfortunately, there isn't as many people growing ginseng who spend thousands of dollars a year on agri-chemicals as do the turf grass guys.