Septoria Leaf Spot

[HunkieDorie23]

This might be jumping the season a bit but for the last 2 years I have had this destroying my tomatoes. I knew it was some type of fungus but with all the snow we have had I got some quality time surfing the net and found the demon fungus.

From what I have read... I have two options Daconil or Soap-Shield. Has anyone ever had this and what have you used to get rid of it?

Could this be what has been attacking my cucumbers also? My cucumber vines just start drying up and stop produce. The leaves turn brown and dry up as well.

 

[lesa]

It seems the most important action you can take is crop rotation. You will find some posts on this subject. A lot of gardeners were plagued last year, mostly because it was so wet. Perfect breeding ground... I am going to be very careful to try rotation, and see if I can avoid problems this year... Good luck!

 

[HunkieDorie23]

I did rotate. Actually both years for new spots for tomatoes. This year I am going back to a spot I used for 3 years with no problems then I rotated like I was supposed to and I got a demon fungus. I know it was the weather and probably not the spots but I am going back to what worked.

 

[Lavender2]

I have had to deal with the Septoria leaf spot menace also.

I tend to grow too many tomato plants and do not have enough prepared garden space to rotate crops efficiently.
I also have some nightshade weeds in the area that probably harbor the fungus over winter... (doing my best to organically control these, as many types are considered noxious weeds here) The fungus can be spread by insects.

The leaf spot tends to appear later in the season here, so it does not seem to affect my my crop.
Humid, or warm wet summers, may cause it to appear earlier.

Controls that work for me:
Remove all bottom leaves at planting time
Mulch, and water ground only, no splash
Watch plants closely and remove spotted leaves immediately (bag and dispose)
I prefer organic soap shield - it helps somewhat - (only used if leaf spot appears early in the season.)
(Do note though, soap shield is a preventative, not a fungus killer)
Meticulous clean-up immediately following last harvest ...

More good info ... Septoria leaf spot

Septoria leaf spot is inclusive to the solanum/nightshade family... tomato, potato, eggplant, nightshade and horsenettle weeds.
Your cucumber problem - with no apparent spots, fungus, or leaf mold... or real noted bug problem ... possibly Bacterial wilt ... ???
Curcurbits can get SO many diseases tho ...