# Daconil fungicide and heat

**URL:** <https://boards.straightdope.com/t/daconil-fungicide-and-heat/362940>\
**Category:** Factual Questions\
**Created:** [July 2, 2006, 3:05pm UTC](https://boards.straightdope.com/t/daconil-fungicide-and-heat/362940 "2006-07-02T15:05:58Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![burundi](https://avatars.discourse-cdn.com/v4/letter/b/3ec8ea/32.png) [@burundi](https://boards.straightdope.com/u/burundi)\
**Post date:** [July 2, 2006, 3:05pm UTC](https://boards.straightdope.com/t/daconil-fungicide-and-heat/362940/1 "2006-07-02T15:05:58Z")

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My tomatoes are showing signs of early blight, so I got some Daconil fungicide to treat them with. The label said not to use it in “hot and sunny weather.” I treated the plants this morning while it was still cool, but I’ve been left wondering:

1. How hot is “hot”?

2. What happens if you use the stuff during hot and sunny weather?