agrokid
Full Member
Posts: 13
Joined: Wed Dec 01, 2010 5:18 pm

can anyone identify what's wrong (broccoli)?

Hello dear friends. this is my first post concerning a problem I'm having.

Some of my broccoli plants have some large white-brown spots on their leaves. These spots occured after some heavy rain and light hail that we had for more than 5 days last week. The occurences are mostly on the bottom leaves, and very very few on uppermost large leaves.

Actually it seems like an outter thin film of the leave is separated from the rest.

I'm also attaching a couple of pics (leave, front and back)

[img]https://i1220.photobucket.com/albums/dd456/agroxolos/mprosta.jpg[/img]

[img]https://i1220.photobucket.com/albums/dd456/agroxolos/pisw.jpg[/img]

Thank you all for your help!

User avatar
!potatoes!
Greener Thumb
Posts: 1901
Joined: Tue Apr 14, 2009 6:13 pm
Location: wnc - zones 6/7 line

i see what looks like hollowed-out paths through the leaf in the first pic? if that's the case, leaf miners are your culprit.

agrokid
Full Member
Posts: 13
Joined: Wed Dec 01, 2010 5:18 pm

i see what looks like hollowed-out paths through the leaf in the first pic?
yes there are, they are like 'tunnels', and they're harder than the rest of the leaf area.

is there any way of controlling leaf miners?

User avatar
Francis Barnswallow
Green Thumb
Posts: 696
Joined: Fri Sep 03, 2010 11:28 pm
Location: Orlando

I had a huge problem with leaf miners this year. I kept them at bay by seeking and squishing them. They're tiny but once you see one, you get good at seeing the rest. Just follow their trail until you see a small orange ball. That tiny orange ball is actually a tiny worm, so squish it!!

I've squished around 300 of those leaf miners the last 2 months and the plant is still growing and most importantly.....producing. I still see a couple of new leaf miners here and there though.

As for a pesticide, I was told that spinosad works.

agrokid
Full Member
Posts: 13
Joined: Wed Dec 01, 2010 5:18 pm

As for a pesticide, I was told that spinosad works.
well i'd rather keep my garden organic, so I suppose I'll go with hand picking/destroying.

should I also remove heavily infected leaves? say the ones that have more than 30% of the leaf area damaged?

User avatar
rainbowgardener
Super Green Thumb
Posts: 25303
Joined: Sun Feb 15, 2009 11:04 pm
Location: TN/GA 7b

Spinosad is organic: It is a bacterial exudate. It is completely safe for human beings, does not affect us. However, it can be harmful to honeybees, if they contact the spray when wet. To avoid this, use the spray at dusk, after the honeybees have gone home for the day. Once it is dried, it is no longer harmful to them, but still effective for the target populations.

However no sprays are very effective on leaf miners, since they are protected inside the leaves. The easiest thing to do for leaf miners is just to pick off all the leaves that have any of the little trails in them and remove them (not to the compost pile, out of the garden).

For next year, I discovered this year that the wildflower called velvetleaf makes a very effective trap crop for them. The leaf miners love those soft leaves and colonize them preferentially to anything else. Plant a few around your garden!
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

User avatar
applestar
Mod
Posts: 28035
Joined: Thu May 01, 2008 11:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M

We call them doodlebugs because they make doodles in the leaves. You can also cut out the doodles and dispose of them in the trash (not in compost). You can save the rest of the leaf as long as the main leaf vein/rib is not involved -- obviously, any portion of the leaf beyond where the main vein is cut will die.

agrokid
Full Member
Posts: 13
Joined: Wed Dec 01, 2010 5:18 pm

Spinosad is organic: It is a bacterial exudate.
Sorry, I didn't know that. I read in wikipedia that it is chemical based, but then I found out that it is qualified for organic gardening.

I will most probably use it, as I found out that I can locate the tiny leaf miners only by cutting down a leave and looking through it against direct sunlight. It seems quite impossible while on the plant...
You can also cut out the doodles and dispose of them in the trash (not in compost). You can save the rest of the leaf as long as the main leaf vein/rib is not involved -- obviously, any portion of the leaf beyond where the main vein is cut will die.
That's what I did but I'm afraid most of them have entered through the leaves' main vein and then move towards the leaves' circumference.

We'll see how it goes, and I'll let you know.

Thank you all for your help and info!

User avatar
rainbowgardener
Super Green Thumb
Posts: 25303
Joined: Sun Feb 15, 2009 11:04 pm
Location: TN/GA 7b

[quote="agrokid"] I found out that I can locate the tiny leaf miners only by cutting down a leave and looking through it against direct sunlight. It seems quite impossible while on the plant...

That's what I did but I'm afraid most of them have entered through the leaves' main vein and then move towards the leaves' circumference.

We'll see how it goes, and I'll let you know.

[quote]

all of the above is why I just pick off the whole leaf of any leaf with "doodles." Simple, easy, and effective as long as you start as soon as you see any. The only problem with it is if you wait until you have a whole infestation, in which case taking all the leaves defoliates your plants.
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

agrokid
Full Member
Posts: 13
Joined: Wed Dec 01, 2010 5:18 pm

all of the above is why I just pick off the whole leaf of any leaf with "doodles."
I have already done so, given that the infestation wasn't very extensive. Hopefully i have limited the population this way and see how it goes.

Thanks.

Return to “Vegetable Gardening Forum”