how do I tell the difference between early blight and fusarium wilt on the tomatoes?

Answer 1

Early blight typically has irregular patches of black surrounded by yellow areas.

Fusarium wilt symptoms begin with slight vein clearing on outer leaflets then yellowing of lower leaves.

Texas A&M have an excellent "Tomato Problem Solver" section in their web site. Ohio State is also an exellent resource.

Hope this helps!

Answer 2

Phew! Well they both start at the lower part of the plant. Fusarium tends to include more yellowing leaves, early blight more spotting initially.

The real clue is in the stem...literally in the stem. With fusarium the internal vasular system becomes stained dark (I'm fudging as I can't remember ....brown I think). You have to split the stems.

With early blight most of the problem is cankers on the stems (sunken sections) that eventually merge to girdle the stem.

I wouldn't want either. Both are soil borne problems. Alternaria (early blight) might.......and I do mean might be able to be burned out with high sulfur additions for a season. Better yet, solarize (pasturize) the soil using clear plastic.

Fusarium is harder to eliminate.......maybe solarization would work. Your best bet is to grown fusarium resistant tomatoes....there are various strains of fusarium so go with varieties with the widest resistance.