[mybeans420]

i've been using neem for years but never new it could be used as a systemic soil drench. has anyone had experience with this application?
thanks for your time folks

[Pactivist]

I do not believe that Neem as a soil drench works systemically, The main reason to use Neem as a soil drench would be to prevent any insect larva in the soil from reaching adulthood. to this end it works great! Neem oil works by inhibiting the insects ability to molt, and with no adults to lay eggs the population of insects will soon die out. since neem cannot kill eggs, it will need to be reapplied to catch any critters that have hatched since the last time it was used. there is the added benefit that neem contains small amounts of nutes, so it is good for your plants. peAce pacT

[mybeans420]

actually since i posted that i've been doing a bit of research on the topic and found that neem does in fact have systemic properties.
thanks for the reply though.

[Dutchgrown]

Perhaps better might be to get live nematodes...natural predators...they come in a suspended state and once mixed with water and applied (whether directly into soil or hydro res) they wake up hungry and are ready to devour the root larvae, then die off themselves. Works fast, have used them before and always with success.

dg

[mybeans420]

this would be for pests at the canopy level such as mites dutchgrown. nematodes don't leave the soil. i'm gonna dig up my research and post up what i've found so far later tonight if anyones interested.
i just hate spraying anything, but especially oils because they can clog the stomata so easily.

[Dutchgrown]

confused..... Live nematodes are applied to the medium....thought that's where the problem area you were referring to was. So you're saying it's canopy level? If it's canopy level then why the soil drench?
dg

Hi all

- yeah there was a thread on OG about it - apparently the neem is meant to travel into the plants system and the thrips/mites are put off when they take a bite (!?!). Any thoughts on this anyone?

I use neem and have just germed a garlic plant in the veg cab to see if that put's 'em off as well!

cheers

pb

[mybeans420]

here's what i got:

NEEM OIL
The following information was prepared by Al
Fassezke, Master Gardener in Bay City, for San
Toshi, the Tri-City bonsai club. This is a condensed
version of his text.
Neem oil is extracted from the neem tree,
Azadirachta indica. The active ingredient,
azadirachtin, is a naturally occurring insecticide. It
should be noted that naturally occurring (or
organic) does not necessarily mean safe, several
natural compounds are quite toxic. Neem extracts,
however, are used as topical compounds for minor
wounds, as an insecticide in grain storage
containers, and in many other applications.
As an insecticide it works both as a topical (applied
to the plant surface) and as a systemic (watered in
and carried up into the plant cells). It deters egg
laying, it is a growth inhibitor, a mating disruptor,
and a chemosterilizer. Among other effects, it
interferes with the formation of insect skin,
thereby stopping pupation in larvae.
The most common use of neem oil is in a water
suspension as a foliar spray or soil drench, diluted
to a 0.05% solution. (Recommended use for bonsai
is 1 tsp pr quart of warm water). A drop of dish
soap (not detergent) helps keep the oil emulsified.
Neem oil breaks down quickly in water and/or
sunlight. Don’t mix more than you will use in a
day.
Insects ingesting neem oil take about 3-14 days to
die, so there is no immediate result after
treatment. The great benefit is the prevention of
future generations of insects. It is said to be fairly
specific in attacking insects with piercing or
rasping mouthparts. Unless beneficial insects like
spiders, lady beetles, certain wasps, etc. come in
direct contact with spray, it does little to diminish
their numbers.

[mybeans420]

THE NEEM ALTERNATIVE

POTENTIAL FOR NON-TOXIC CROP PROTECTION

Chemical pesticides have proven an abject failure on a worldwide scale. Total pesticide usage increases annually, while insect-related crop damage continues to escalate at an alarming rate. Over 500 insect pests have now developed resistance to one or more insecticides, and the indiscriminate destruction of ‘beneficials’ (pests’ natural enemies) with toxic chemicals has seen the recent resurgence of several serious pest problems. The ‘beneficials’ are not the only unintended victims of this toxic rescue chemistry. Recent updates on a 1989 World Health Organisation report estimate 1.2 million pesticide poisoning cases each year, and around 25,000 deaths directly associated with these poisonings. These figures do not take into account the possible role of these chemicals in the cancer plague currently afflicting the developed world. The concept of a non-toxic alternative, which is pest-specific, harmless to humans and other animals, less prone to pest resistance and resurgence, bio-degradable and more cost-effective, sounds too good to be true, but there are several natural substances that can claim some or all of these features. The most promising of these ‘soft options’ are undoubtedly those products derived from the neem tree. There is much hype and confusion surrounding the relative benefits of this fascinating botanical, and the opportunity for clarification is hindered by the fact that neem is not a registered pesticide, and as such it is not legal to comment on this control capacity. In the following article, I will summarise international neem research and findings to help separate the myths from reality. Hopefully this will provide growers with some kind of guideline when attempting to evaluate the potential of neem in agriculture - Graeme Sait.

The neem tree is a botanical cousin of Mahogany. It has foliage similar to that of white cedar, and it bears masses of white flowers, which produce numerous olive-like fruits. The neem tree lives for 200 years, reaching heights of over thirty metres, but it is commercially productive within three to five years, and it can be cut for timber within six years. The neem tree taproot can be double the height of the tree (in younger specimens), and this water-pulling power allows the plant to flourish in marginal soils. Conversely, wet feet will rapidly destroy new plantings, and irrigation requirements (if any) should be monitored closely.


A native to India and Burma, neem trees are only suited to the tropical and semi-tropical regions of Australia (Northern NSW, QLD and the Northern Territory), and they can be killed by frost.
The beneficial properties of the neem tree have been part of Indian folklore for thousands of years. Dubbed ‘the village pharmacy’, it has numerous medicinal properties, aiding conditions ranging from digestive disorders to diabetes and from high cholesterol to cancer.


The rich biochemistry contributing to the curative powers of this species is also the source of an impressive, natural pesticidal capacity. Many plant species have developed chemical defenses against insects as a part of their evolution. Recent research, involving 250 plants with pesticidal properties, revealed that neem was the most effective and environmentally friendly source of these bio-active botanicals yet discovered.


Neem’s chemical weapons are extraordinary. In tests during the past two decades entomologists have isolated 390 different insect species that are affected by the bioactivity of this unique tree. A broad range of mites, nematodes, fungi, bacteria, and even some viruses are also affected. Several of the major pest species controlled by neem extracts are resistant to chemical pesticides or are inherently difficult to control (eg: flower thrips, diamond-backed moth and several leaf minors).


LOW KNOCKDOWN - HIGH SHUTDOWN


Neem contains several active ingredients, of which the most important is Azadirachtin. It has been estimated that Azadirachtin accounts for up to 90% of the bioactivity of neem, but there is so much synergism at work in this pesticidal cocktail of four major and twenty minor active components, that it is impossible to quantify a percentage.
Neem compounds bear no resemblance to synthetic pesticides. They are composed only of carbon, oxygen and hydrogen and contain none of the chlorine, phosphorus, sulfur or nitrogen atoms found in synthetic chemicals. Chemically neem resembles steroid compounds like cortisone and oral contraceptives, and there is a very different mode of action compared to the conventional “Wham, bam, thank you Maam!” of the toxic knockdowns. In most cases neem extracts are not knockdown killers. Instead they create hormonal disruption, which prevents the insect from feeding, breeding or metamorphosing. It is a far more subtle process, which eventually prevents the insect from causing further damage. It is a hormonal shutdown rather than an instant knockdown.


HORMONAL LOOK-ALIKES ALLOW EASY ACCESS


The active compounds in neem belong to a general class of natural products called ‘Triterpenes’, or more specifically, ‘limonoids’. There are at least ten limonoids in neem, but the most researched of these are Azadirachtin, Salannin, Meliantriol and Nimbin.


Azadirachtin is the most significant of these. Thirty years of research suggest that Azadirachtin is one of the most potent growth regulators and feeding deterrents ever tested. It is in fact so potent that quantities as low as 1 ppm (part per million) will totally repel some insects. Meliantriol and Salannin are powerful feeding inhibitors, while Nimbin has been found to have antiviral activity.


Neem compounds have a very similar shape and structure to several critical insect hormones. This look-alike feature tricks the insects’ bodies into absorbing the neem compounds as if they were the vital hormones. The neem infiltrators shut down the endocrine systems, and the hormonal chaos that follows sees populations plummet.


REPULSION, REGULATION, DISRUPTION AND DETERRENCE

- SEVEN DISTINCT MODES OF ACTION


Neem limonoids produce seven distinct modes of action, and they include the following:
1) Feeding Deterrence: This is the most commercially significant property of neem. The presence of Azadirachtin, Salannin and Melantriol on the leaf surface disrupts the gut of leaf-eating insects, creating the equivalent of a vomiting sensation. The associated feeding deterrence is so profound that, after experiencing the sensation, many species will never eat again.


2) Insect Growth Regulation: Ecdysis or moulting is the shedding of skin to facilitate the growth stages of larvae or nymphs, and it is governed by the enzyme Ectyzone. Neem suppresses Ectyzone, and the insect becomes trapped in the larval stage, eventually causing death. If there are insufficient neem triterpenes present, the larvae may enter the pupal stage, but dies soon after, and if in the presence of very low neem concentrations, the adult emerges from the pupal stage sterile and malformed.


3) The disruption of mating and sexual behaviour: It is not known if independent hormonal disruption is responsible for this complete confusion in mating routines or if the insects just feel so bad that they are sexually incapacitated. Whatever the cause, the end result is a population retarding effect and is probably quite hilarious.


4) Oviposition Deterrence: Neem also reduces pest populations by deterring females from laying eggs - a phenomenon called oviposition deterrence.


5) Repulsion: Neem oil contains several sulfur-like compounds that can repulse insects in much the same way as garlic sprays. Some insects are particularly susceptible to this repulse response, while others cannot detect neem by taste and do not find it repulsive.


6) Adult sterilisation: Most susceptible males are sterilised by neem compounds, and many of the female species are similarly affected. The sterilisation of eggs has also been recorded.


7) The poisoning of larvae and adults: As previously mentioned, neem does not have a universal knockdown capacity. However, there are some species, including mosquito larvae, fruitfly and headlice, which are killed on contact.
There are also other less important modes of action, which include the blocking of the ability to ‘swallow’ and the inhibition of the formation of chitin (the hard section covering the exosceleton).

[mybeans420]

NEEM-AFFECTED INSECTS


Some 390 insect species are affected by neem extracts, including many that are resistant to conventional pesticides. There is such a complex interrelationship between the many components of the neem compound that, to date, there has never been a recorded case of developed neem resistance. This may not prove the case when refined Azadirachtin products hit the market in the future. When man tries to dilute and simplify natural phenomena, there are often unanticipated consequences.


Neem products are medium to broad-spectrum pesticides of phytophagous (plant-eating) insects. Most phytophagous insects are susceptible to neem products, including those listed below.


ORTHOPTERA: The anti-feedant affect is particularly important with this species. Several of this species will refuse to feed on neem-treated plants for periods ranging from one to four weeks.


COLEPTERA: All beetles and weevils are sensitive to neem products. The larvae of beetles refuse to feed on neem-treated foliage. Some beetle larvae are actually killed on contact.


HOMOPTERA: Cicadas, leaf hoppers, aphids, scale insects and psyllids display a varying response to neem extracts, eg planthopper and leafhopper nymphs show considerable anti-feedant and retardant effects, but scale insects show little response. White flies are affected on some crops but not on others. Aphids often respond to foliar treatments but are not good candidates for systemic, soil-based applications. Neem also influences the ability of homopterous insects to carry and transmit virus diseases. This may have particular relevance with mosaic virus in cucurbits.


LEPIDOPTERA: Numerous field trials have confirmed the efficacy of neem extracts in moths, fruit borers, corn borers, skippers, mullers and butterflies. Neem acts as both a growth retardant and anti-feedant in the larvae of most lepidopterous pests.


THYSANOPTERA: Thrip larvae in the soil are well controlled with neem extracts, but there is reduced efficacy with heavy infestations of adults on the plant. Neem oil has been more effective than other formulations in controlling adult thrips, perhaps due to an oil-related suffocation effect.


DIPTERA: Fruit flies, house flies, march flies, buffalo flies and mosquitoes are all candidates for neem-based protection. In Australia neem extracts have proven effective against blowfly strikes on sheep and buffalo flies on cattle. Trials with the dreaded Mediterranean fruit fly in Hawaii were particularly successful. Spraying with diluted neem solutions under fruit trees resulted in 100% control.


HETEROPTERA: The rice bug and green vegetable bug and other juice suckers are affected by foliar and systemic neem treatments. Both feeding behaviour and development are disrupted.


STORED PRODUCT INSECTS: Pest control in stored products is one of the oldest traditional uses of neem in Asia. Traditionally neem leaves are mixed with grain kept in storage. Repulsion seems to be the principle mode of action here. Neem oil-treated sacks prevent weevils or flour beetles from penetrating for several months. Neem can also extend the storage life of potatoes by up to three months.


NEEM PROTECTION BEYOND INSECTS


The effect of neem on insects is now well documented, particularly on the internet, where numerous sites are dedicated to this natural pesticide. The effects on non-insect pests are less understood, but the research data increasingly points to other examples of control potential for this remarkable, problem-solving botanical. Nema-todes, patho-genic fungi, viruses and snails can all be negatively affected by neem products. Indian trials with tomatoes, using neem cake fertiliser, reduced the root-knot index to zero.


In Australia, ginger growers have also experienced excellent results trialling neem cake for nematode control. Neem cake is applied at 250 to 400 kg per hectare. Research confirms bioactivity against root-knot nematodes (the type most devastating to plants). Neem inhibits the larvae from emerging and the eggs from hatching. Ginger, garlic, onion and potato seed pieces can be sprayed or ‘dipped’ in neem extracts as an anti-nematode strategy. Peanuts and chickpeas can be treated similarly. Seed treatment reduces the penetration of second-stage juveniles.


FUNGICIDAL QUALITIES


There has been little research work conducted upon the anti-fungal qualities of neem, but several research projects suggest considerable potential for bio-control. One Indian trial reported the protection of chickpeas against Rhizoctonia Solani, Sclerotium Rolfsii and Sclerotinia Sclerotiorum. Neem also slowed the growth of Fusarium Oxysporum but didn’t kill it. Neem oil was also shown to be highly effective against powdery mildew in the very early stages of the disease. Similarly, neem extracts have given 90% control of bean rust when applied before the plants were severely affected.


AFLATOXIN
Aflatoxin is a chemical produced by a fungus called aspergillus flavus. In hot, humid conditions this fungus can form on peanuts, corn, cottonseed and other food crops. Aflatoxin has been conclusively linked to liver cancer, and as such its presence suggests grave health and economic consequences. US Ag Department microbiologist, Deepak Bhatnagar, in experiments with neem leaf extracts, has shown that, although these extracts do not kill aspergillus flavus, they stop it from producing aflatoxin. Neem oil and neem cake can themselves be infected by aspergillus flavus, but import/export restrictions now involve stringent testing, and this potential is no longer a problem.


EFFECTS ON OTHER BENEFICIALS
Research has shown that neem cake and neem extracts can actually increase earthworm populations by up to 25%.
Neem products must be ingested to be effective. In this context leaf eaters are targets, but pollinators like butterflies and bees and predators like spiders, lady bugs and wasps are generally not affected. Predators and pollinators rarely ingest sufficient neem concentrations to trouble them.


NEEM PRODUCT DETAILS
Commercial neem products include neem oil, neem cake, aqueous kernel extract and aqueous leaf extracts. Neem cake is used as a soil amendment, while the liquid products are used as foliar sprays or through irrigation. A systemic response is possible with neem cake and fertigated soluble extracts. The potential for a systemic foliar response can be enhanced with additives used to increase foliar uptake. Humic acid is particularly effective in this regard.


AVAILABILITY IN AUSTRALIA
There is no neem product registered as a pesticide or fungicide in Australia, and as such there can be no claims made regarding this potential on labels or information brochures. However, neem cake is sold in Australia as a fertiliser, and neem oil is also available as a wetter/sticker for organic fertilisers or as a liquid fertiliser ingredient.


TEN TIPS FOR INCREASED NEEM EFFICACY


Neem products are registered as broad-spectrum pesticides for most crops in the US. The following hints are derived from the American experience.
1) Neem oil can be applied with humic acid on a litre for litre basis to magnify the systemic potential. Humic acid should be included whenever neem is used as a foliar or through irrigation. Humic acid is also a sunscreen, which can help reduce the UV-degradation of neem compounds.
2) Pyrethrin with Piperonyl Butoxide can be successfully combined with neem to produce a faster kill.
3) Neem oil can be included with the insect-killing bacterium Bacillus Thuringensis to provide a multi-faceted pesticide.
4) Conventional growers in the US use neem as an additive with synthetic pesticides to add rapid knockdown to neem’s ability to suppress the subsequent rebound in the pest population.
5) Sesame oil and white oil are recognised neem power-boosters.
6) A combination of eucalyptus oil, tea tree oil and canola oil can be another effective adjunct to magnify the strike action of neem.
7) Beneficial microbe blends (like Nutri-Life 4/20) can be combined with neem solutions for increased bio-control.
8) Late afternoon is the best time to foliar-spray neem products to avoid UV-degradation.
9) Other valuable ultraviolet inhibitors include sesame oil, lecithin and paraaminobenzoic acid (PABA).
10) Balanced soil nutrition provides increased insect resistance. Neem should only be considered as an adjunct to appropriate nutrition rather than instead of these corrections. There is no substitute for a healthy plant.