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Simply Bananas
05-19-2009, 07:08 AM
Anyone have a clue about these Saba leaves? Only about 6 weeks of growth since a a hard winter cut back.

http://www.bananas.org/gallery/watermark.php?file=17524&size=1 (http://www.bananas.org/gallery/showphoto.php?photo=17524&ppuser=226)

http://www.bananas.org/gallery/watermark.php?file=17523&size=1 (http://www.bananas.org/gallery/showphoto.php?photo=17523&ppuser=226)

Thanks

proletariatcsp
05-19-2009, 09:43 AM
Hi Simply,

It looks like Black Sigatoka. According to the other members the best course of action is a Copper Sulfate foliar fungicide. You should be able to get some at HD or local garden center. I'll post a link of an earlier discussion. http://www.bananas.org/f2/blk-sigtka-i-officially-hate-fl-7949.html

http://www.bananas.org/gallery/watermark.php?file=17342&size=1 (http://www.bananas.org/gallery/showphoto.php?photo=17342)

Sigatoka is spread by spores carried in the wind and leaf on leaf contact. You do not have to remove the entire leaf, however. Cut off the pieces that are the most damaged (especially those touching other leaves). Don't worry about harming the plant, once Sigatoka has compromised 30-40% of the leaf, the photosynthetic membranes can nolonger feed the plant. I would remove the entire leaf you have pictured, and if the fungus is not that bad on other leaves just cut off the infected section. It is done very easily by slicing the leaf blade along the midrib, but not through the midrib.

Sigatoka does not kill the plant, but if left untreated it will kill the leaves and make it unable for the plant absorb sunlight. The sooner you treat the better because Sabas are fast growers and it should be able to outgrow the spread of Sigatoka once its treated.

Good luck with your bananas this season, I'm sure they will be fine in a couple months.

Chris P.

just j
05-19-2009, 09:53 AM
wind burn looks just like mine and they were perfect until it got windy the past few days now all the edges look like that

proletariatcsp
05-19-2009, 10:24 AM
wind burn looks just like mine and they were perfect until it got windy the past few days now all the edges look like that

Just J, can you post a pic of yours? Also, regardless if you suspect Sigatoka or not, according to resources for management of the disease, you can severly lower your chances of susceptability by treating your plants with a Copper Nutritional Spray. A nutritional does not contain as much Copper as Copper Sulfate and is safe to use. I only wish I had known about the copper back when I thought my bananas were only suffering from nutrient difficiencies and wind stress!

Take care, and I hope you have a productive growing season,

Chris P.

just j
05-19-2009, 11:18 AM
ill post a few pics later

Simply Bananas
05-19-2009, 01:10 PM
Just wondering if it could be some type of fertilizer burn(I used some of last years stuff that was mankey looking).

I don't know of black sig in SC, yet. Tomatoes get fusarium, but only in late summer. I will get some Copper sulfate and try that anyway.

proletariatcsp
05-19-2009, 06:51 PM
Just wondering if it could be some type of fertilizer burn(I used some of last years stuff that was mankey looking).

I don't know of black sig in SC, yet. Tomatoes get fusarium, but only in late summer. I will get some Copper sulfate and try that anyway.


Not to sound like a broken record, but. . .

When bananas are lacking vital minerals and minor elements they become much more susceptible to Sigatoka. I would imagine leaf injury in general, including wind, over fertilization, or prolonged root saturation would all increase susceptibility to the disease. I suppose that is why copper is ultilized before signs of Sigatoka? Either way, I will use fungicide on any future planting material in an attempt to get a head start on the disease, especially now that I know Sigatoka seems to be lurking in our midst.

I haven't heard of any Black Spot that far north either. My theory is that I possibly infected my bananas after handling fruit from the grocery store. I say this because the wild bananas in my area do not have any bacterial spots.

just j
05-19-2009, 07:53 PM
here a few pictures of leaf burn on my gros michel it was perfect until about a week ago it has been super windy all week by me and it took a toll on all my plants out side it even broke most of the leaves off some

lorax
05-19-2009, 08:07 PM
I'd say it isn't Sigatoka but some other kind of burn - Sig starts at the midrib and works its way down.

And I hate to contradict you, ProletariatCSP, but the whole leaf should be removed if it's Sigatoka damage, to prevent spread.

proletariatcsp
05-20-2009, 10:11 PM
I'd say it isn't Sigatoka but some other kind of burn - Sig starts at the midrib and works its way down.

And I hate to contradict you, ProletariatCSP, but the whole leaf should be removed if it's Sigatoka damage, to prevent spread.

Lorax, thank you for the correction because that is something I was not aware of. I was refering to literature and youtube vids that describe growers removing only portions of the leaves. I suppose they remove only portions of whole leaves when the banana is in fruit? What you said makes sense, however, because of the way the spores can easily spread.

In the pictures of the Saba leaves, I thought I could see the yellowish-orange streaks between the veins. The leaves are burning from the edges, but in the pictures of Sigatoka from Hawaii, some of their leaves spread from the edges inward. Could that be yellow Sigatoka? I also have leaves on my ice cream that only have black on the edges. There are symptoms evident along the midrib, but they are faint streaks and spots that are very hard to take a picture of.

I sincerely hope it is not sigatoka, however. Thanks again Lorax, and for the info you provided me with in my earlier post.

Chris P.

lorax
05-21-2009, 01:24 AM
You're bang-on about partial-affected removal during fruiting - a banana needs a minimum of 10 healthy leaves to set a good bunch and mature it, so I can see the logic behind removing portions of the leaf in that situation. However, if you're practising good plantation hygiene (ie detrashing, undergrowth maintenance, proper planting) then Sigatoka can be controlled just using the Copper Sulfate foliar.

Chris, the other reason that I'd say it isn't Sigatoka is the pattern of necrosis. Simply's Saba leaves are maintaining their yellow evenly, rather than small spots of localized black/grey tissue, which is indicative of Sigatoka. The damage to his leaves is more indicative of wind burn or similar.

Yellow Sig spreads and develops in the same manner as Black Sig - the same symptom set and everything, except that the streaking will be yellow before it necrotises. The spread of the leaf death on every infected plant I've ever worked with has been the same - midrib out to edges, and not the other way.

Simply Bananas
05-21-2009, 04:13 AM
Great discussion. I'll keep an eye on them and update in the coming months.