Inasmuch as Sigatoka is so widespread and so problematic, I am surprised to find no conversations going on about controlling it with natural solutions. So, I’m wondering if that means the ECHO community is not that involved in bananas or if no one in the ECHO community is aware of natural solutions. Or, is this a topic that has just not been approached?
Anyway, I’d be interested in the opinion of the community members.
This is a great question that I think varies regionally! In my experience in East Africa, the best way to combat issues with Black Sigatoka is to plant resistant or tolerant varieties. I know IITA has worked on developing resistant varieties in the past in Uganda. My memory is from what they were doing in Uganda in 2015. It looks like they may have also wrapped up another project this year.
It looks like CIRAD also did some work and has the variety ‘Pointe d’Or’ which is resistant and available in the Carribean.
The University of Hawaii has some options for IPM strategies against banana fungal diseases. The first thing I think of is good fertilizer and irrigation management so that you have a healthy plant. And early detection and removal of leaves so that you slow the spread. The resource I liked above has a list of steps of how to do this as well as a list of resistant varieties.
Stacy, can you elaborate on what you mean when you say “removal of the leaves”? I’ve read that advice several places but no one ever elaborates on exactly what they mean. Does that mean after cutting them off the tree they are allowed to lay on the ground to decompose or does it mean moving them to another area outside of the banana field to decompose or does it mean burning them?
The guide also says “Cut leaves showing BLS necrosis should be placed upside down, with the upper side against the ground. This is because ascospores are produced on the upper leaf surface (Fig. 6-1). Under very severe conditions, during the first cycle of sanitary leaf removal growers should pile all the cut leaves at the end of a row. This is because only the top leaf in a pile is likely to emit spores, whereas the leaves within the pile are relatively contained.”
If there are livestock such as pigs, goats, or cattle, you can also feed removed leaves to livestock.
Weekly sanitary leaf removal is important, especially during rainy seasons where the leaves get regularly wet.
Another cultural control that can help is maintaining only 3-5 banana stalks per mat to help decrease canopy coverage.
Stacey, you are very helpful. Thank you. A follow up question. It seems like removing the leaves from the banana growing area to feed them to animals would be a similar process to taking them to a compost pile away from the banana field… So my question is, does transporting them help to spread the spores?
By way of background we are fairly new to growing bananas and plantains organically…15 months. We are constantly experimenting with ways to control the disease and we have been somewhat successful. That is, we seem to be doing about as well as our neighbors who do typical chemical-based farming. Most of our attention is given to prevention. But we also do a spraying program each two weeks using natural concoctions that we develop. However we had a month of nearly daily rains and then a week of flooding which kind of kicked us in the butt. However, I think we are still doing at about as well as our neighbors who use chemicals.
One of the things I found interesting in the Hawaiian guide is the guidance to spray the underside of the leaf because apparently that’s where the infection growth occurs but when disposing of the leaf to turn it upside down as a way to minimize the spread of the spores. So apparently the growth mechanism occurs on the underside of the leaf but the distribution mechanism occurs on the upper side of the leaf
I’m glad to be of help when I can. yes, feeding the infected leaves to animals and removal from the field would be similar in terms of potential spread through the carrying of leaves. Spores are spread through the atmosphere (wind) to new plants and this happens more quickly during the rainy times of the year when fungal growth is most rapid! I’m not sure how much spread you would get of spores by carrying. Usually I cut infected leaves during the middle of the day when leaves are most dry. I’m not sure if this is best or not, but this is what I do! Does anyone else have thoughts?
I think feeding leaves to livestock will completely eliminate the spread of spores at the end location while you may still get some spreading of spores if your compost isn’t made right away or if your compost isn’t hot enough to kill the spores during thermophilic processes.
Like you, we to tend to cut in the middle of the day but that’s mostly because of our work schedule. I’ve been thinking about shifting to doing it first thing in the morning when the leaves are wet thinking that when they are wet the spores are less likely to “fly around” while we are handling the leaves.
That is interesting Michael. Thanks for sharing that info. I am in Honduras and I travel throughout Honduras and wherever I go I see it…in commercial plantations, in peoples yard, etc. Not every tree I see is infected but some within every group of trees are infected. If there are any of the resistant varieties around here, I have not heard about them and I am fairly well connected with growers. I’m curious where you are and if in your area there are a large sampling of the resistant varieties.
I spoke with an longtime friend who is an agriculture engineer here in Honduras who is a producer of bananas and plantains as well as being employed by the largest agricultural education and support group here in Honduras. He told me there are no disease resistant varieties of bananas or plantains in Honduras unless they are in very limited supply in some experimental station with one of the universities or somebody like Chiquita banana or something like that. But there are none available to the public. So it seems for now at least, disease resistant varieties are not an option here.