Why did my pepper plants suddenly shrivel?

Question

I've been growing pepper and chili plants in a greenhouse on my balcony since March and they have been growing strong. However, I started a new job last week and have not had the time to tend to them. Now the leaves have curled lengthwise, some have turned yellow and some have grown a green moss on the soil. The soil near the plants is quite dry. Only the lower leaves are turning yellow on one plant. I have pruned some stems and found no discolouration within the stems.

Since starting the new job, I haven't watered or fed them, but the greenhouse has a fairly damp environment, with the walls and roof covered in drops of water. I've watered them with a little liquid food and left them out of the greenhouse in sun and light wind for 12 hours now and most of the leaves are starting to perk up. The yellow leaves on one plant have fallen but the upper leaves on the same plant have perked up.

Any ideas what might have happened to them? Could it just have been lack of food and water?

Answer 1

Too much moisture is not a problem I have and I've never seen moss growing around my peppers. I have the opposite problem!

So I looked in "The Edible Pepper Garden" by Rosalind Creasy, which is the better of the two pepper books I have. As well as appendices of problems, it has a reasonable cooking section and a thorough overview of varieties (including unusual species cultivars).

Anyway, there are a number of damp related pathogens she describes:

Verticillium Wilt Seems to be the most likely. Two fungi species infect peppers. Cool, moist weather during growing season. Sudden wilting of one part or all of the plant. Leaves dropping. Eventual death. Tomatoes and eggplants also affected. A cut stem will show vascular discoloring. No cure. No resistant varieties. Soil solarization may help (plastic mulch that uses heat to kill pests). Or grow in soil that has not seen Solanacaea before, or sterile soil. Discard plants.

Phytophthora Blight Also known as chili wilt. Can cause fruit rot, root rot, leaf blight. Loves high humidity and excessively wet soil. All or part of the plant suddenly dies. No cure for root rot. Solution: good soil drainage and do not overwater. Remove and destroy infected plants.

Fusarium Wilt Soil born fungus. More prevalent in warmer parts of the US.Poorly drained soil. Overall wilting, leaves turn yellow from the base of the plant upwards. Remove plants and destroy. Do not replant peppers in the same soil for many years or try soil solarization.

Damping Off Affects seedlings. Fungus on seeds just as they come out (okay I have seen this)

There are a few others which don't seem to match (eg. bacterial wilt - warm areas only). Nutritional deficiencies seem to be limited to pod drop/wilt. Similarly Tobacco Mosaic (TMV) doesn't match your described symptoms. She lists a lot of insect types that can cause problems.

Answer 2

It could be Verticillium dahliae note below:

Verticillium dahliae can infect pepper plants at any growth stage. Symptoms include yellowing and drooping of leaves on a few branches or on the entire plant. The edges of the leaves roll inward on infected plants, and foliar wilting ensues. The foliage of severely infected plants turns brown and dry. Growth of pepper plants inoculated with aggressive strains of V. dahliae in greenhouse or of pepper plants infected early in the season under field conditions is severely stunted with small leaves that turn yellow-green. Subsequently, the dried leaves and shriveled fruits remain attached to plants that die. Brown discoloration of the vascular tissue is visible when the roots and lower stem of a wilted plant are cut longitudinally. Another important soilborne disease of pepper in California, Phytophthora root rot, causes similar foliar symptoms; however, Phytophthora root rot causes extensive browning and rotting of the root cortex, while the roots of V. dahliae-infected pepper plants show no external discoloration or decay.

Read more: http://wiki.answers.com/Q/What_causes_green_pepper_plant_leaves_to_shrivel_or_curl_up#ixzz1PBCHVkbL

The only other thing you can check is if there are any type of whiteflies near your plants. These flies damage leaves causing them to shrivel and eventually fall out. To get back some color you could try applying nitrogen fertilizer, that should restore the plants green color and stimulate growth. You can also use a garden fertilizer, but that is to be used when you initially garden the plant.

Get in the habit of making time to care for these plants, as they are living creatures as well. Clean up the dead leaves, give them a fertilizer, make sure they have a good temperature and water them consistently to see better results. You cannot just abandon these plants and wonder why this is happening.