Home Depot sells Ortho Garden Disease brand concentrate in (green) pint bottles at their stores:
http://www.homedepot.com/h_d1/N-5yc1...atalogId=10053
Here's a link to locate a store near you that carries the GardenTech/GulfStream brand of Daconil concentrate in (red) quart bottles:
http://www.gardentech.com/Dac_wheretobuy.asp
Here's a link to locate a store near you that carries the Bonide brand Fungonil concentrate in either (white) pint or quart sized bottles:
http://www.bonideproducts.com/produc...ategory_id=879
All listed brands above use the 29.6% chlorothalonil formulation, which is most effective for the home gardener.
There are other brands, such as Hy-Yield, that are formulated with 12.5% chlorothalonil and therefore must be mixed with a higher percentage of concentrate to water. See (yellow) bottle image below.
Regardless of the brand,
chlorothalonil is a preventative treatment and not a cure. For best results, you should spray your plants weekly throughout the season. And remember... it helps other garden crops too, such as squash, melons and cucumbers!