From the University of Waikato, New Zealand is this helpful article on the how & why Neem products function. Neem protects itself from the multitude of pests with a multitude of pesticidal ingredients. Its main chemical broadside is a mixture of 3 or 4 related compounds, and it backs these up with 20 or so others that are minor but nonetheless active in one way or another. In the main, these compounds belong to a general class of natural products called "triterpenes"; more specifically, "limonoids." LIMONOIDS So far, at least nine neem limonoids have demonstrated an ability to block insect growth, affecting a range of species that includes some of the most deadly pests of agriculture and human health. New limonoids are still being discovered in neem, but Azadirachtin, Salannin, Meliantriol and Nimbin are the best known and, for now at least, seem to be the most significant. Azadirachtin One of the first active ingredients isolated from neem, azadirachtin has proved to be the tree's main agent for battling insects. It appears to cause some 90 percent of the effect on most pests. It does not kill insects - at least not immediately. Instead it both repels and disrupts their growth and reproduction. Research over the past 20 years has shown that it is one of the most potent growth regulators and feeding deterrents ever assayed. It will repel or reduce the feeding of many species of pest insects as well as some nematodes. In fact, it is so potent that a mere trace of its presence prevents some insects from even touching plants. Azadirachtin is structurally similar to insect hormones called "ecdysones," which control the process of metamorphosis as the insects pass from larva to pupa to adult. It affects the corpus cardiacum, an organ similar to the human pituitary, which controls the secretion of hormones. Metamorphosis requires the careful synchrony of many hormones and other physiological changes to be successful, and azadirachtin seems to be an "ecdysone blocker." It blocks the insect's production and release of these vital hormones. Insects then will not molt. This of course breaks their life cycle. On average, neem kernels contain between 2 and 4 mg of Azadirachtin per gram of kernel. The highest figure so far reported - 9 mg per g - was measured in samples from Senegal. Although thousand-year-old Sanskrit medical writings mention neem's usefulness, the tree's exciting potential for controlling insects has only recently become clear. Neem's ability to repel insects was first reported in the scientific literature in 1928 and 1929. Two Indian scientists, R.N. Chopra and M.A. Husain, used a O.001-percent aqueous suspension of ground neem kernels to repel desert locusts. Not until 1962, however, was the real significance demonstrated. That year, in field tests in New Delhi, S. Pradhan ground up neem kernels in water and sprayed the resulting suspension over different crops. He found that, although locusts landed on the plants, they refused to eat anything, sometimes for up to 3 weeks after the treatment. Furthermore, he noted that neem kernels were even more potent than the conventional insecticides then available and that neem's repellency was as important as its toxicity. In neighboring insecticide-treated fields, for instance, the insects also died, but not before consuming the crops. Neem's insect-growth-regulating (IGR) effects were independently observed in England and Kenya in 1972. In England, L.N.E. Ruscoe, at that time an employee of the ICI Company, tested Azadirachtin on insect pests such as cabbage white butterfly (Pieris brassicae) and cotton stainer bug (Dysdercus fasciatus) and noted IGR effects in each case. The Azadirachtin was provided by D. Morgan, a Keele University chemist who had been the first to isolate Azadirachtin. In Kenya that same year, K. Leuschner, a German graduate student working at the Coffee Research Station in Upper Kiambu, observed that a methanolic neemleaf extract controlled the coffee bug (Antestiopsis orbitalis bechuana) by growth-regulating effects. Most fifth-instar nymphs treated with the extract died during subsequent molts and the few that survived to adulthood had malformed wings and thoraxes. Neem's fecundity-reducing effects were first recorded by R. Steets (another graduate student) and H. Schmutterer in Germany. Applying methanolic neem-kernel extract and Azadirachtin to the Mexican bean beetle (Epilachna varivestis) and the Colorado potato beetle (Leptinotarsa decemlineata) they found that females almost stopped laying eggs. Some females had been completely sterilized, and the effect was irreversible. Meliantriol Another feeding inhibitor, Meliantriol, is able, in extremely low concentrations, to cause insects to cease eating. The demonstration of its ability to prevent locusts chewing on crops was the first scientific proof for neem's traditional use for insect control on India's crops. Salannin Yet a third triterpenoid isolated from neem is Salannin. Studies indicate that this compound also powerfully inhibits feeding, but does not influence insect molts. The migratory locust, California red scale, striped cucumber beetle, houseflies, and the Japanese beetle have been strongly deterred in both laboratory and field tests. Nimbin and Nimbidin Two more neem components, Nimbin and Nimbidin, have been found to have antiviral activity. They affect potato virus X, vaccinia virus, and fowl pox virus. They could perhaps open a way to control these and other viral diseases of crops and livestock. Nimbidin is the primary component of the bitter principles obtained when neem seeds are extracted with alcohol. It occurs in sizable quantities - about 2% of the kernel. Others Certain minor ingredients also work as antihormones. Research has shown that some of these minor neem chemicals even paralyze the "swallowing mechanism" and so prevent insects from eating. Examples of these newly found limonoids from neem include DeacetylAzadirachtinol. This ingredient, isolated from fresh fruits, appears to be as effective as Azadirachtin in assays against the tobacco budworm, but it has not yet been widely tested in field practice. Cont'd........
PRODUCTION Although bioactive compounds are found throughout the tree, those in the seed kernels are the most concentrated and accessible. They are obtained by making various extracts of the kernels and, to a lesser extent, of the press cake. Although the active ingredients are only slightly soluble in water, they are freely soluble in organic solvents such as hydrocarbons, alcohols, ketones, or ethers. No new or unusual technology is required for any of the processing. It can be done using either simple village-scale technology or hightechnology methods and industrialized facilities. The most common procedures are summarised below.(Preparations of aqueous, oil, powder, and press cake formulations, as well as other methods, are described in more detail in Stoll, 1986.) Water Extraction The simplest technique (and the most widely employed today) is to crush or grind the kernels and extract them with water. They may, for example, be steeped overnight in a cloth bag suspended in a barrel of water. For reasons not yet understood, this process is less effective than pouring the water into the bag and collecting the extract as it emerges. The resulting crude suspension can be used in the field without further modification. It can also be filtered and employed as a sprayable emulsion. This is the most promising approach for use in Third World villages. It has been estimated that by using water extraction, 20-30 kg of neem seed can normally treat 1 hectare. At this rate, the annual seed crop from one mature tree could treat up to half a hectare.(Such figures are only a rough average. The amount used, of course, is different for each pest and planting density.) However, it is necessary to use a lot of water because the active ingredients have very low solubility in water. Normally, the proportions employed are about 500 g of kernel steeped in 10 lifers of water. Water extracts of ground neem leaves are also very useful. Because neem is an evergreen, they are obtainable throughout the year. Hexane Extraction If the kernels are grated and steeped in the solvent hexane, only the oil is removed. The oil is not considered an active pesticide. However, new results show that it is an especially interesting material, which in certain cases can be used to kill the eggs of many types of insect, the larvae of mosquitoes, and various stages of certain pests (such as leafhoppers) that are often hard to control by other means. The residue left after the hexane extraction still contains the main active limonoid ingredients, and subsequent extractions with water or alcohol produce them in large amounts, clean and uncontaminated by oil. Pentane Extraction Pentane extracts of seed kernels are effective against spider mites. They reduce the fecundity (number of eggs) of Tetranychus urticae, for example. The active principles in the extracts differ from azadirachtin.(Sanguanpong and Schmutterer, 1991.) Alcohol Extraction Alcohol extraction is the most direct process for producing neembased pesticidal materials in concentrated form. Limonoids are highly soluble in alcohol solvents. The grated kernels are usually soaked in ethanol, but sometimes in methanol. The yield of active ingredients varies from 0.2 to 6.2 percent.(Good rates of extraction have been obtained with other solvents as well. In comparing extraction methods, it was found that the azeotropic mixture of methanol and methyl tertiary-butyl ether was efficient and simple. It achieved an extract yield of 4-5 percent. (Feuerhake, 1984.) ) Although water extracts are effective as pesticides, neem compounds are not highly soluble in water; the alcohol extracts are about 50 times more concentrated. They may contain 3,000 parts per million (ppm) or even 100,000 ppm azadirachtin. FORMULATIONS As noted, the simplest neem pesticide is a crude extract. However, for more sophisticated use, various modifications can be made. These advanced formulations may convert neem extracts into the form of granules, dust, wettable powders, or emulsifiable concentrates. Aqueous extracts can also be formulated with soap for ease of application against skin diseases. Other formulations may involve the addition of chemicals or even the chemical modification of the neem ingredients themselves. These changes may be made to increase shelf stability and reproducibility, and for ease of handling or of scaling up the process. They may also reduce phytotoxicity, the damage to sensitive plants. One particularly valuable class of additives are those that inhibit ultraviolet degradation. These include sesame oil, lecithin, and paraaminobenzoic acid (PABA). Additives Mixing neem extracts with other materials can boost their power 10- to 20-fold. Among these so-called "promoters" are sesame oil, pyrethrins (a type of insecticide mostly extracted from chrysanthemum flowers, see sidebar page 91), and piperonyl butoxide. They are used to produce a quicker kill. Combinations with synthetic pesticides also can work well - they add rapid "knockdown" to neem's ability to suppress the subsequent rebound in the pest population. The effectiveness of neem extracts can even be boosted with the insect-killing bacterium Bacillus thuringensis (Bt) to provide a multifaceted pesticide. METHODS OF APPLICATION Neem extracts can be applied in many ways, including some of the most sophisticated. For example, they may be employed as sprays, powders, drenches, or diluents in irrigation water - even through trickle- or subsurface-irrigation systems. In addition, they can be applied to plants through injection or topical application, either as dusts or sprays. Moreover, they can be added to baits that attract insects (a process used, for instance, with cockroaches). They are even burned. For example, neem leaves and seeds and dry neem cake are ingredients in some mosquito coils. SYSTEMIC EFFECT The fact that the extracts can be taken up by plants (and thereby confer protection from within) is one of neem's most interesting and potentially useful features. As has been noted, however, the level of this systemic activity differs from plant to plant and formulation to formulation. Extracts without oil, with a little oil, and with much oil exhibit different levels of systemic action. The systemic activity differs with the insect as well. It is not effective on some aphids, for instance. They feed in phloem tissues, where (for reasons yet unknown) the concentration of azadirachtin is very low. Phloem is the plant's outermost layer of conductive tissues and insects such as these, whose mouthparts cannot penetrate past it, are little affected by neem treatments. On the other hand, leafhoppers and planthoppers, that feed at least half the time on the deeper layer of conductive tissues (called the xylem), get knocked down.
Azamax and Azotrol are extracts of Azadirachtin. I used Azatrol on a stubborn case of spider mitesma few grows ago. Two doses three days apart is all it needed. I alternate the use neem oil and Spinasad as prevention now, and have not used the Azamax since. Thanks for the post LD.
MizzaFishKilla I've been using Spinosad for the past couple of months. It's my observation that for a total 'knock-out punch' this is a better pesticide, per se, than the neem or karanja oils. The price is a bit steep - about $3.00 per gallon vs. $.25 per gallon for the neem/karanja (application rate). BTW - both the Captain Jack's Deadbug Brew & Monterey Garden Products Spinosad Contentrate are produced in the same facility (Eli Lilly) so you can use either with confidence. The organic farm store carries the Monterey Garden product at about 25% less than the Captain Jack's product at the indoor garden stores. Knock me over with a feather! LOL LD
True dat. It's my observation too re the "knock out" power of Spinosad vs neem. I look at neem as being a great prevention policy and a "ok to good" killer of mites. It's when I get lazy and not apply it and get a few more mites, I give a dose ot two Spinosad and everything goes back to normal. The Azatrol is when I've been especially neglegent (too busy with work, the GF being too needy, when the fish are running well! etc). My garden needs only 1/3 gallon for complete coverage. I think Captain Jacks and Monterey have the distribution license from Eli lilly. I get Captain Jack's from Al's Garden Supply. It lasts me 9 months at the amounts that I use it.
I'm mildly surprised that adding other mite products works so well with neem. I ussually recommend growers use a knockdown spray like pryethrums/pyrethrins on a active infestation. Then start a every three days neem spray routine. I'll also mix it up by spraying lavender flower infusions in between neem sprays to make a death by a thousand cuts. Along these lines i just heard a new one. Using salt water to spray for mites. I heard it works well for about three days, lol. Then of course the leafs die......MIW
I have better results for an all around repellant/insecticide using neem mixed 50/50 with insecticidal soap. I've also mixed it with botanical pyrethrum for an outdoor knock out spray, and it delivered as promised- no mites came back.
poppybgood Grow your own - Pyrethrum Seeds - 100 seeds for $2.95 and you don't even have to have an account at the Boo or the Bay for these seeds! From their catalog: Ya can't get any more botanical than that! LD
Awesome. I've noticed most of the bottled chrysanthemum extracts also contain sesame or some other type of oil. Is this to preserve, or like what is mentioned above- to increase efficiency?
PBG Sesame oil is cheap and because it has a low viscosity it doesn't require an emulsifier like neem oil. LD
Azadirachta indica (Neem) is a tree, native to India and Pakistan growing in tropical and semi-tropical regions. The medicinal properties of Neem have been described in ancient Indian medical texts (4000 B.C.). In India, the plant is variously known as "Sacred Tree," "Heal All," "Nature's Drugstore," "Village Pharmacy" and "Panacea for all diseases". Literally, every part of the tree has a use. The leaf and bark are used in teas, cosmetics, skin care, pet care and medicinal preparations. Neem twigs are used as tooth brushes and ward against gum disease. Neem oil, which is extracted from the seed kernel is excellent for its healing properties and is used in creams, lotions and soaps. It is also used in agriculture. In recent years the growth hormone regulating and anti-feedant properties of Neem oil have prompted a considerable amount of research. The United States Department of Agriculture has been studying Neem since 1972. The residue is Neem seed meal (aka Neem cake) which is used in agriculture as a soil amendment, protecting the roots and enhancing plant growth. Products made from Neem trees have been used in India for over two millennia for their medicinal properties. Neem cake organic manure is the by-product obtained in the process of cold pressing of Neem tree fruits and kernels, and the solvent extraction process for neem oil cake. Neem Cake has an adequate quantity of NPK (5-1-1) in organic form for plant growth. Being a totally botanical product it contains 100% natural NPK content and other essential micro nutrients as N(Nitrogen 2.0% to 5.0%), P(Phosphorus 0.5% to 1.0%), K(Potassium 1.0% to 2.0%), Ca(Calcium 0.5% to 3.0%), Mg(Magnesium 0.3% to 1.0%), S(Sulphur 0.2% to 3.0%), Zn(Zinc 15 ppm to 60 ppm), Cu(Copper 4 ppm to 20 ppm), Fe (Iron 500 ppm to 1200 ppm), Mn (Manganese 20 ppm to 60 ppm). It is rich in both sulphur compounds and bitter limonoids. According to research calculations, Neem cake seems to make soil more fertile due to an ingredient that blocks soil bacteria from converting nitrogenous compounds into nitrogen gas. It is a nitrification inhibitor and prolongs the availability of nitrogen to both short duration and long duration crops. Neem cake also protects plant roots from nematodes, soil grubs and white ants probably due to its content of the residual limonoids. It also acts as a natural fertilizer with pesticidal properties. Neem cake is widely used in India to fertilize paddy, cotton and sugarcane. Neem seed cake also reduce alkalinity in soil, as it produces organic acids on decomposition. Being totally natural, it is compatible with soil microbes, improves and rhizosphere microflora and hence ensures fertility of the soil. Neem cake improves the organic matter content of the soil, helping improvement in soil texture, water holding capacity, and soil aeration for better root development. One of the active ingredients in Neem is azadirachtin. You’ve probably seen or heard of products like Azamax, Azasol, or Azatrol. All are products that have isolated the azadirachtin in various concentrations, and claim biological insecticide or fungicides. Not only are these products more expensive, but they will be lacking a plethora of other active compounds found in neem. Research has shown that some of these minor neem chemicals even paralyze the "swallowing mechanism" and so prevent insects from eating. Most of the retail products contain Azadirachtal at 1,500 PPM. Many of the extracts are as high as 6,500 PPM so caution needs to be used when figuring out a mixing ratio. Here’s an article specifically addressing this: FUNCTIONAL BLOCKS OF NEEM OIL Dr.Ilangovan Ramasamy, B ... Neem's natural properties pose no danger of toxic reactions. It's main mode of action is classified as an "anti-feedant", meaning that insect pests usually refuse to eat any plant covered with neem and do so until they starve to death. Other effects are as a repellant and a reducer of the insect's ability to reproduce. Elimination of the insect pest occurs not by quick poisoning, but by starvation and drastic reductions in offspring. Birds and beneficial insects, which are not affected by neem, then feed on the remaining weakened pests and the small number of remaining offspring. The result is an almost immediate halt to plant damage- without poisoning the environment. Neem garden spray is non-toxic to animals and people. Areas sprayed with neem are not poisonous areas to be avoided for days as those sprayed with the typical synthetic insecticides. Neem is also a natural, bio-degradable product. Only insects that eat plants are affected by neem, leaving honeybees and other beneficial insects essentially unharmed. In fact, in those areas sprayed with neem, the average size and number of earthworms is greater that in unsprayed areas. Neem oil kills: Garden Snails And Slugs Aphids, Armyworms Bean Leaf Beetles, Colorado Potato Beetles, Cucumber Beetles, Japanese Beetles Moths Hornworms, Cabbageworms, Melon worms, Tomato fruit worms Ants Loopers Squash Bugs Fruit Fly Whiteflies It is safe to use on both ornamental and edible crops and can be sprayed on herbs and vegetables up to the day of harvest. Applying neem oil to a drought-stressed plant can burn the foliage, so water plants thoroughly before using it. Fungicidal Neem oil provides plants with protection from many types of fungi. In several tests, spraying neem oil on plants prevented the outbreak of powdery mildew better than popular commercial products. It seems to work best as a preventative rather than a cure once the fungus has become established. My experience with using neem oil is that it's most effective using liquid potassium silicate (Dynagrow ProTekt) as an emulsion and aloe or yucca root extract as a surfactant. The recipe for foliar applications I use is: 1-2 t. of neem oil (or split it 50/50 with karanja oil) 1 t. of Dyna-Gro Pro-TeKt which is a liquid silica product. The addition of the liquid silica will emulsify the neem oil, in other words, break it up into small pieces. To that add 1 quart of TEPID water (i.e. 85F - 95F) as hot water will denigrate the effectiveness of the neem oil. You do need the water warm enough to keep the neem in suspension and fully solubilized. I add 1 T. of organic aloe vera as a surfactant (try to find one without preservatives). As a substitute to the aloe, you can add 2 or 3 drops of liquid soap - go for any liquid soap that does NOT contain the phrase "anti-bacterial" - we're not trying to kill bacteria here. Dr. Bronner’s liquid soap would be a good example. Mix well and apply to each and every leaf (top and bottom) and every branch, stalk, etc. - make the leaves hang low from the spraying process. For indoor plants under artificial light, it is best to apply right before “lights out.” For outdoor plants, application is best done in the evening. Do not spray if temperature is over 90 degrees. If used in higher temperatures it could cause leaf curling. When dealing with fungus gnats, aphids, or any other soft-bodied insects, do this every 3 days to circumvent the 'adult-larva' cycle until the infestation is under control. I also mix Neem cake in my soil mix at a rate of 1 cup/cubic foot of potting soil. The best source of Neem products I have found is Neem, Neem Oil, Karanja Oil, Neem & Karanja products. Their Neem products contain exponentially higher levels of azadirachtin than other brands found in hydro shops or on ebay. Resources: Wikipedia Neemresource.com http://www.epa.gov/oppbppd1/biopesticides/ingredients/tech_docs/brad_025006.pdf LumperDawgz2 (Thanks!)
Neem Tree Farms out of Florida. Check out their other plants that you could certainly grow in your part of the world. Good folks! LD
Are you going to do a graph on them? plot their growth, actually it would be pretty cool to grow neem trees. I doubt they would survive here though. It's 3 degrees out right now. Any idea on how long till you have neem nuts? MIW
I'll do a graph if someone asks nice. No idea how long it will take. Most likely not in my lifetime. This is a present for future generations. e2a: Guess I had that wrong. http://neemtreefarms.com/downloads/California.pdf More info here. http://www.neemtreefarms.com/growing-instructions-a-22.html
WeeDroid I've got over 100 Bookmarks on neem & karanja trees and the products that are used. Most are from India, Pakistan and Morocco and old records from Iraq and Iran. Let me know. LD
Thank you. Give me a few days. I just got over a flu bug (while working, ugh) that lasted about 2 weeks. I need to get myself a bit sorted at home first before i take on any more big projects.