Last year I had two varieties of peppers, Jalapeno and little, 1-1/2 cmlong ones from seedlings that the nursery didn't have a name for; several of each in containers. Both developed leaf miners. Through most of the season, I was able to control them, more or less, by removing affected leaves; toward the end of the season (in early December) I just gave up.
The little variety has grown back nicely in its containers, for the third year. Yesterday I spotted a few leaves with tunnels, and removed them. The Jalapenos were dead by year end, but this would have been their third year too, so this was not unexpected. They, as well as Poblanos and a large chili called on the envelope only "Thai", have been planted from fresh seedm in fresh soil.
What to do about the leaf miners that would a) relieve me of the necessity of destroying foliage, and b) not, if systemic, leave a poisonous compound in the fruit?
The Neem tree (Azadirachta indica) is native to India. It is marketed under various names, but generally the active ingredient will be described as 'Neem oil' or as 'Azadirachtin.'
/begin quoted material/
"What's in a Neem?"
Finally, a nature program on TV that has featured a good old, sedentary, not-fuzzy-and-cute, cold-blooded plant, the neem tree (Azadirachta indica). CBC's The Nature of Things devoted a full hour to discussing the current and possible uses of this tropical tree. This native of India is a very good plant for growing in hot dry areas on poor soils, and it has been spread by humans to various areas in Africa, the Middle East and the Caribbean. In India almost every village has its neem tree and the villagers call it their "village pharmacy". There is a use for all parts of the tree [to repel insects, to treat skin infections, to kill internal parasites, to treat fevers, to clean teeth, as a contraceptive, etc.]. Neem tree seeds can be processed to produce neem oil and neem cake [solid residue]. Neem cake is used as a fertilizer (it is said to improve nutrient uptake by plants and to repel insects in the soil) and can be fed to livestock (it combats intestinal parasites). A major use of neem oil in India is in the manufacture of soaps, toothpaste and other toiletries [such products are now being sold in Germany and other countries]. The effect of neem oil and of aqueous extracts of neem cake on insects has attracted the attention of large chemical companies. Concerted efforts are under way to synthesize the main active ingredient, azadirachtin, which can act [with remarkable specificity to insects] in several ways. It is an antifeedant, causing insects to stop feeding on whatever the compound is sprayed on. It can also act as a hormonal substance, interfering with the normal development of the insect [there are problems with molting to produce the adult reproductive stage]. Both effects would enable third world grain producers to combat the massive losses of stored grain that currently occur. A small amount of neem oil sprayed on the stored grain is effective in deterring feeding by bruchid beetles [major destroyers of stored grain]. Aflatoxins, potent carcinogens causing liver cancer in humans eating certain seeds infected with two species of Penicillium, could be controlled by the neem extract. Experiments with cotton show that the neem extract prevents the seed-infecting fungi from producing the aflatoxins. There is one problem with the neem extract, however. It is unstable with respect to heat and light. For those of you who did not view this program, a research team from U.B.C. which was featured on the program has published an excellent review of neem tree usage in the Canadian Journal of Botany [86(1): 1-11, 1990].
I used to have leafminers in my columbines. We kept it under control by simply cleaning up all the dead leaves and yard debris in our yard in early winter instead of spring. Putting everything in the composter probably got rid of all the over-wintering leafminers. All the kitchen scraps we put in our composter over winter probably cooked any survivors.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.