However, it is possible that it is infected with a fungus or disease such as verticillium wilt, which can cause leaf drop much as you described.    From Wordnik.com. Reference

No evidence was found supporting earlier reports that a verticillium fungus is causing the disease.    From Wordnik.com.  [8: Plant protection and pest control] Reference

Resistant to fusarium storage rot, black leg and verticillium wilt.    From Wordnik.com.  [Skippy's Vegetable Garden] Reference

The effect of verticillium wilt on resistant, tolerant and susceptible tomato varieties.    From Wordnik.com.  [xml's Blinklist.com] Reference

Effect of annual soil fumigation and preharvest vine burning on verticillium wilt of potato.    From Wordnik.com.  [xml's Blinklist.com] Reference

"Even if verticillium causes a small yield loss, these top performers should still deliver well.".    From Wordnik.com.  [FWi - All News] Reference

"Growers in England need to know what variety they should grow where verticillium wilt is present," he points out.    From Wordnik.com.  [FWi - All News] Reference

"If you have any verticillium, you really need to be looking at a least 1 in 4 rotation, preferably longer," he said.    From Wordnik.com.  [FWi - All News] Reference

HGCA-funded trials being conducted with Farmacy on an infected site in Lincolnshire have given some useful preliminary information on variety performance in the presence of verticillium wilt.    From Wordnik.com.  [FWi - All News] Reference

You should avoid places other plants have been grown for 3 years such as eggplants, peppers, potatoes or tomatoes since they are susceptible to verticillium wilt which is associated with those plants.    From Wordnik.com.  [CreationWiki - Recent changes [en]] Reference

In the course of a season, the fungi that cause scabby skin patches may proliferate, along with root-killing verticillium fungi (which also damage tomatoes and eggplant) and tiny nematodes that injure potatoes.    From Wordnik.com.  [Mother Earth News Latest 10 Articles] Reference

There were very high levels of verticillium wilt present, so the premature ripening associated with the disease was obvious. ".    From Wordnik.com.  [FWi - All News] Reference

"Planting varieties that yield well in the presence of verticillium wilt is the best way we know to minimize verticillium wilt losses.    From Wordnik.com.  [Media Newswire] Reference

On poorly drained, heavy soils, jojoba, like other crops, contracts waterborne fungal diseases - verticillium wilt, fusarium, pythium, and phytophthora, for example.    From Wordnik.com.  [3 Production] Reference