Wednesday, July 22, 2009

I think I'm Infected.........BCTV!

Beet Curly Top Virus or Big Bud Phytoplasma on Tomato OR just a very bad potassium deficiency?

One of my tomato plants is exhibiting the curled leaves and purple veining associated with BCTV. This was a seed grown plant that was progressinging quite nicely for a while. The under leaf vein color and leaf curling can also be indicative of a potassium deficiency.
But the stem tops have developed some odd looking growth that would seem to suggest something a bit more than a lack of vitamins. I've not been able to find other photos online of the weird looking growth at the top of the main stems. Its bunchy looking - more like a broccoli head than something you normally see on a tomato. I'm not positive yet that this is a case of BCTV. It could be Big Bud Phytoplasma - which is spread by the same insect. Perhaps a combo then?
As far as possible viruses go, BCTV is a better one than some other possibilities. It is not something that lives in the soil. Its spread by a Beet Leafhopper. By the time the plant shows symptoms of the illness, the little culprit is long gone. Without the leafhopper, the disease doesn't spread any further. From what I've read so far, the plant can even be composted as per usual rather than bagged and disposed. I went with the bagging and disposing route though since I'm really not sure what this is.
There is a vaccine for this virus. Who knew plants could be inoculated? Some tomato cultivars are more resistant than others. My little ill guy is an unknown type. He was grown from seed gathered from last year's crop - but we didn't mark the packages we kept the seeds in and grew several varieties.
This is my first experience with a virus in a veggie. We had an experience a few years back with a rose shipped from Canada showing the very bizarre signs of rose rosette disease. That one was bagged and disposed of - very sad as it was the Pat Austin Rose I had received as a birthday gift. I still don't have a Pat Austin among my rose collection. Someday I'll try again. It is a lovely rose and even my little ill one produced some beautiful blooms along with its strange succulent super-thorny uber-growth.

My infected bush had kicked out a tall branch with bright coloring and an abundance of thorns that felt kind of soft at the tips. The coloring was odd too - it was red like new rose growth is sometimes, but seemed a tad too bright. I'm kicking myself for not taking a picture before that one was shovel-pruned. Its definitely one of the more interesting looking plant diseases out there. Click here to read more about Rose Rosette Disease (RRD).