Banana cover crop reduces Black Sigatoka
 

Duamed Colón Carrión is growing dwarf plantains in Puerto Rico using a cover crop of Canavalia ensiformis. In another area not planted with the cover crop the Black Sigatoka is worse on the same dwarf plantains. Possibly healthier plants due to the N being more available? Maybe the spores get trapped under the leaves of the cover? Check out the healthy roots at the surface under the cover!

Canavalia from Wikipedia

Re: Banana cover crop reduces Black Sigatoka
 

I hate that vine, it takes a lot of effort to keep it maintain as in the photo. He probably has to clean the vines off the pseudostems 2 or 3 times a month. He isn't growing any suckers which makes cleaning a little easier but any work wearing that outfit is difficult. I prefer to work in beachwear and barefoot, and controling the vines is much easier than trying to maintain them. Most of my plants are heavily infected with BLS by harvest time and that is pretty much normal in Puerto Rico. I would expect his plants will also have it before harvest, but they do look great now. If he was growing ARH he would not even be concerned with BLS or weevils for that matter, but that's the trade off for growing the short plants.

BTW, we have a much better ground cover here than those vines. It grows much thicker and feels great to walk on, I can pronounce the name but have no idea how to spell it. Most people use it to feed their animals and from chickens to macaws love it.

Re: Banana cover crop reduces Black Sigatoka
 

Thanks for sharing this article on cover cropping! Great photos. Years ago, at CSU,Fresno, I took "Integrated Pest Management (IPM)" for my major in Agriculture (Plant Protection). Unfortunately, pesticides were King at the time (big $), and the class was mostly smirked at, if not actually ridiculed. When I worked at a USDA experimental station in Fresno, there was a bottle of 2,4-D in the refrigerator, although its use having been illegal for years. With a B.S., I became a licensed California Pest Control Advisor in Weeds and Pathogens, but left the profession w/i two years due to exasperation (nightmares) over irresponsible use of organophosphates, carbamates, and organochlorines. We were mortgaging our lives to a dying environment. Home-wise, it's deep mulching/chips, pruning, cover-cropping, chelated iron for this tight, river-rock Sacramento Valley clay...and snail bait for the gangs of silent monsters that eat tender tips of semi-dwarf citrus in the middle of the night, and after each rain.

Re: Banana cover crop reduces Black Sigatoka
 

Does it help control Black Sigatoka?

Re: Banana cover crop reduces Black Sigatoka
 

Perhaps you meant something other than 2,4-D?
Perhaps you meant that the previous use had been removed from the label?
Perhaps you can explain what you mean by illegal?

LV 400 2,4-D, 1 gal. - 4201056 | Tractor Supply Company

Re: Banana cover crop reduces Black Sigatoka
 

Mea culpa. Thank you for pointing out my error and allowing me to correct myself. In this particular case, there were bottles of DDT...not 2,4-D. My mistake. DDT was first synthesized in 1874, and banned in 1972 (in the US).

Re: Banana cover crop reduces Black Sigatoka
 

no problem

BTW I'm the Mad Chemist Gardener :ha:

Re: Banana cover crop reduces Black Sigatoka
 

Was this post intended for me? I am only a fan, and definitely not an expert in this field. IPM (Integrated Pest Management) integrates a range of practices for economic control of pests. I read where “Timorex Gold” (a non-residue biofungicide) uses the plant extract Melaleuca alternifolia in preventing and suppressing Black Sigatoka; including fungi and bacteria in tomatoes and cucurbits. It also claims definite curative properties in affected plants. With a zero toxic load, workers can re-enter the fields immediately after application.

The cover crop sounds interesting! Perhaps the dense layer of leaves exudes a toxic pH environment for the spores, etc. It may physically prevent ascopores from discharging during wet periods and dispersing by wind. Soil nitrogen-fixing might be a bonus. Low nitrogen and potassium soil levels allow Black Sigatoka to dominate the plant more quickly due to the plant’s slow leaf emergence. When N and K levels are boosted, the fungus is not eradicated; however, the healthy plant grows replacement leaves more quickly and stays ahead of the fungi's major effects. In any case, great subject and photos!

Re: Banana cover crop reduces Black Sigatoka
 

It appears you did some minor research before making this post, by including ascopores but failed to included conidia.
I have more than 23 years of experience with this particular vine and would not consider it dense or thick, quite the opposite.

Re: Banana cover crop reduces Black Sigatoka
 

If I were to guess, the reason the plants look better probably has more to do with better plant health. Having some kind of thick cover like that around here would increase the dew-period which would increase disease problems. I wonder how the cigar end rot problem is in that field. Having some type of cover crop like that seems like it would make a great habitat for rats and mice. Does anyone in Puerto Rico use dairy manure on their bananas?

There is a type of Canavalia that grows on the beaches in Puerto Rico. Pretty awesome plant.

Re: Banana cover crop reduces Black Sigatoka
 

In my first post I was attempting to make my point in a positive yet subtle manner, now I'll be more direct.

I think the photo is beautiful but misleading.

If you think cultivar names are confusing from region to region and country to country, you can then imagine how leaf diseases are. I will use the terms upper and lower which could also be substituted with younger and older.
It appears BLS can be divided into two groups, one that infects the upper leaves and one that infects the lower leaves. I have never seen a plant or even a photo of the upper infection and in PR the lower form is widespread. The good news is that if you have the lower form and no longer want it, you can simply read this quote from the Australian Dept of Ag and BLS will no longer be your problem.

"The unfurling and youngest fully expanded leaves on large plants and suckers are the most susceptible to infection. As the leaves mature, they become resistant to infection."

My approach has been to keep the area between the ground and the lowest leaves as dry and distant as possible, with the goal of having a sufficient amount of less infected upper leaves to complete fruit filling. Planting the entire field at the same time will make this method more effective.

This is what I see when viewing the photo.

Well manicured plants of similar size missing their lower leaves, which would be the leaves first infected by BLS. What I see as misleading is the height of the vines obscures the missing lower leaves. When I view a photo from the Mainland I am amazed at how beautiful the plants are with their lower leaves.

Re: Banana cover crop reduces Black Sigatoka
 

When I first started taking care of bananas I had inherited a cavendish planting with a very bad Black Sigatoka problem. At one point in time I just had to make a sacrifice and I burned all the dead leaves and started over from scratch.

This is what sigatoka was doing to me back then

Re: Banana cover crop reduces Black Sigatoka
 

Nick, do you remember if the leaves were infected during the unfurling process or at a later date.
That photo would be somewhat common here at harvest time, but difficult to detect at what stage it happen.


This bunch only needs about 7 more weeks of fruit filling, and should be fine.

Oct 9
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Oct 3
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Re: Banana cover crop reduces Black Sigatoka
 

The bottom leaves were usually the ones that showed symptoms, but I think infection may have occurred soon after unfurling. The control guides usually tell you to cover new growth with fungicide. But the symptoms would generally appear on the 3rd or 4th leaf. Of course here in Florida we have a cool dry season where we can get things under control. I have been using serenade as my main control strategy since last year and it seems to work for me.

Re: Banana cover crop reduces Black Sigatoka
 

That might be good news for me, maybe I don't have BLS after all.
I generally make it to bloom with the upper 6 to 8 leaves visibly symtom free and the youngest leaf seldom ever gets infected and if it did it would be towards the very end of fruit filling.

Re: Banana cover crop reduces Black Sigatoka
 

Referring to potential beneficial properties of the Canavalia ensiformis in the photo (And I sincerely bow to PR-Giant's 23 years of experience), I imagined ascospore wind-travel being limited by the (smothering?) presence of the vine. I did not include conidia as I understand that it is mostly transmitted via water travel on the leaves. I would be interested in learning more about the thick groundcover that PR-G prefers over this vine. It will be interesting to see how SERENADE® (Bacillus subtilis) and SONATA® (based on Bacillus pumilus strain QST 2808) biofungicides do. Thanks.

Re: Banana cover crop reduces Black Sigatoka
 

You might have yellow sigatoka, which starts lower and is less aggressive

Re: Banana cover crop reduces Black Sigatoka
 

I suspect that the winds generated during a tropical wave are sufficient to move the spores long distances. From what I gathered reading on the internet it has spread throughout the caribbean only within the past 10 years or so. Serenade has worked well for me, but you have to use it frequently.

Re: Banana cover crop reduces Black Sigatoka
 

It´s intresting the link with N levels....................most soils have 90% mineral residue.............and about 10% organic matter....................

Bananas in the wild.........grows almost in the decayed layer of Organic Matter...........in the Forest bottom.................

Maybe in some cases they do not reach the mineral layer.............

???

A bit acid PH...............lots of Tanin.................

I think that in natural habitat...........they have acess to much more N............than in regular garden.........or comercial field................

Most N came from decaying leaves................I think..............???

Improvement of N............with Green Cover..............maybe is simulating the levels founded in superior layers of the Forest Original Soils..............???

And this could make the Plants more resistant to Fungus........achieving the optimum levels of nutrients needed by Bananas............................


I like that stuff...............TNX..............

Re: Banana cover crop reduces Black Sigatoka
 

It is usually much less than 10% due to the high temperatures. Tropical soils are generally poor. Everything rots so quickly that those nutrients are available and used very quickly. It's important to remember that rapid growth and high yields would not be likely in the wild.