Dear colleagues,
I have the serious problems with strawberries. At the young leafs the specific spots are appeared. Then the size of spots is icreased, leafs are curled. The life of plants is shortened, and quality of harvest is became worse.
I attached the photos of leafs.
Sincerely, Mehdi Ali..
The most likely reasons according of photos can be:
1. Spider mites - (Tetranychus urticae), please check back of leaves by magnifying glass or better by microscopes. if there are mites - apply acaricides - Massay (100 - 150 G/100 L), Envidor (200 G/100 L) or something like this 7 -10 day interval with rotation of different mode action acaricides.
2. Check, If there are not mites - next proposal can be - leaf scorch - Diplocarpon earliana - some varieties of strawberry are very susceptible to this disease especially in not proper greenhouse conditions (too wet and warm). Application Topsin M or Aliette can be useful, but without elimination reasons (high humidity) control will be sometimes impossible...for Better control to start with protective fungicides....
3. The last proposal can be Leaf spots of Strawberry (Mycosphaerella fragariae) - this is depends of cultivars - San Andreas is susceptible, Albion - is more or less tolerant...
I dont think that this spots is caused by phomopsis leaf blight - in this case spots should be V -forms, which I don t observed in photos...
Best regards,
Zviad Bobokashvili
Dear Zviad,
Let me first express my deep gratitude for your help!
We use full organic methods for strawberry cultivation. For biological control of spider mites we apply the Californicus system (Amblyseius californicus). Sometimes the population of these pests are increased rapidly; but now all is well.
Perhaps it is a leaf scorch or leaf spots. I'll send the specimens for analysis. If the diagnosis is confirmed — can you inform me an organic remedy? Unfortunately, I cannot use inorganic fungicides.
By the way, I use the seedlings from the Holland. We cultivate the Elsanta variety. Could you inform about the another good nursery not far from the Caucasus — and more resistant variety, with the similar taste?
Sincerely,
Mehdi.
Dear Mehdi,
Thank you for kind feedback!
Organic way cultivation of strawberries in greenhouse is quite difficult task, but not impossible.
for control leaf spots is quite effective is copper (Kocide, Kuproflow, KuproCafaro and etc - 0,5 % -1,0 % solutions) and colloid sulphur (Sulpolak and etc) 0,3-0,5 % solutions) applications. Can be good version use of Bacillus Subtilis (Serenade) for control botriticis - 1,5-2,0 L/100 L...
The insects can be control by biopesticides like (Azadirachtin, Spintor)
for greenhouse production Elsanta is not best choice, however this is very good variety in case of taste and appearance. Anyway I will recommend to try Albion, Camarosa, Marmolada, Sweet charly and etc.
Good varieties of strawberry plants you can find in Turkey (yediverencilek and etc) and Italy( Salvi vivai and etc).
Best regards,
Zviad Bobokashvili
Dear Zviad,
I believe, it's more convenient for us to use colloid sulphur. Although, I know that the sulphur isn't dissolved. Can you inform me about the method of colloid sulphur liquid preparation?
I was try to use Azadirachtin (NeemAzal) for pest control (1.1%, if I haven't forgotten). Unfortunately, it burns the young plants; during the harvesting any liquid damages the fruits. So, I prefer the entomophagous insects.
Can you inform about the strawberry nurseries at the territory of Turkey?
Sincerely, Mehdi.
Dear Mehdi,
The colloid sulfur - means that it is easily dissolved in water . Sulpolak is fully solvable for example...
Neemazal 1 % is too high - basically 0,3 % is working well. 1 % can be damage young plants. Yediverencilek is turkish nursery for strawberries - you can just google it.
Best regards,
Zviad Bobokashvili
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