Natural Pyrethrum: A Solution for Whiteflies, Aphids, Thrips, Mealybugs, Caterpillars, Mites, Bugs, Beetles, Scales and Many More
Growers are faced with challenges from pests ranging from pests in the soil that attack the root system to those that attack the stems, leaves or buds posing an economic damage or aesthetic damage to the crops and thus leading to low production yields.
The most commonly found pests on crops are whiteflies, thrips, diamond backmoth caterpillars, African bollworm caterpillars, beet armyworm, mealybugs, aphids, stinkbugs, mites, leaf hoppers, jassids, cutworms, beetles, ants and others. There are different methods of controlling these pests ranging from biological controls, cultural methods, physical methods and chemical controls.
Farmers prefer a pest control method that has a fast action to the pests though they put into consideration issues of efficacy, post-harvest intervals (PHI), maximum residual levels (MRLs), phytotoxicity, resistance, safety of predators, pre-entry time after spraying, human and environmental impacts particularly on crops such as vegetables, flowers and fruits; and whether for export or for local market. For the export market there are regulations on the kind of molecules to be used on different crops by the consumer markets and significant issues with MRL’s. One of the molecules that has been in use for years for the control of pests is the pyrethrin molecule. Pyrethrins are the active ingredients in pyrethrum derived from the dried flowers of the plant.
The advantages of using pyrethrum based products for control of pests are:
- Pyrethrum is 100% natural
- Low mammalian toxicity: No other insecticide can claim such a long record of proven safety towards humans and warm blooded animals. It is one of the least toxic of all insecticides and is rapidly metabolized if accidentally swallowed (in tests toxicity to rats was found to be 4,000 times lower than toxicity to the house fly).
- No resistance issues as insects lack immunity to pyrethrins because of the complex structure of pyrethrins and thus one can spray pyrethrins continuously. Pyrethrins have six active compounds called esters and thus attacks the pests from six different points.
- Broad spectrum activity: this means that it has an activity on all insect pests
- Has a fast action: it gives a knockdown effect on the insect as it works by contact and also by affecting the nervous system of the insect.
- Environmentally friendly: pyrethrum quickly breaks down in sunlight leaving no residues.
- No Pre-harvest Interval: this allows pyrethrum to be applied to crops up to and including the day of harvest. It may also be applied post harvest.
- Repellency action: it is capable of repelling insects in addition to knock-down.
- Very low Re-entry Period: After spraying, workers may return to the greenhouse as soon as the spray mist has settled.
- No Residues: Pyrethrum quickly breaks down in sunlight leaving no residues. This is particularly significant where MRL’s are an issue (typically with export vegetables and fruit)
Pyrethrins are usually confused with pyrethroids but they are different in that pyrethrins are natural while pyrethroids are synthetic or man-made; pyrethrins have six active compounds while pyrethroids have one and this makes pyrethroids far more likely to be exposed to resistance by insects. Pyrethrins have a unique ability to induce excitation behavior in insects, characterized by erratic and increased movement by insects. This has the benefit of ‘flushing’ the insects out of hiding places, resulting in increased exposure to the Pyrethrins. Synthetic Pyrethroids do not have this flushing effect. Pyrethrins are naturally broken down by UV rays and PH variances and therefore have shorter environmental persistence than synthetic Pyrethroids.
KAPI LIMITED, a company based in Nakuru has specialized in pyrethrum formulations since 1964. It formulates a pyrethrum product called Flower DS 4% EC for agricultural use. Made with Kenyan pyrethrum, Flower DS 4 EC is a 100% natural formulation using only natural ingredients. Flower DS 4 EC may be used for conventional spraying in spray regimes in order to minimize the chance of resistance developing with the other insecticides used in the spray regime. It is also ideal for use on crops controlled by MRL’s. Flower DS 4 EC is also suitable for organic farming.
WINROSE J. MARIA, Sales Manager Agricultural Insecticides, Kapi Limited,winrose@kapiltd.co.ke, 0710615604