HISTORICAL DEVELOPMENT OF NEMATICIDES:

  YEAR TYPE
CARBON DISULFIDE (CS2) 1869 FUMIGANT
*CHLOROPICRIN 1936 FUMIGANT
*METHYL BROMIDE 1940'S FUMIGANT
**EDB " FUMIGANT
**DD (1,3-D+1,2-D) " FUMIGANT
**DBCP " FUMIGANT
*TELONE II (1,3-D) " FUMIGANT
FORMALDEHYDE " FUMIGANT
*MIT>>METAM-SODIUM (VAPAM, SOIL PREP, SECTAGON) 1950'S FUMIGANT
*NEMACUR (FENAMIPHOS) LATE ORGANOPHOSPHATE
*FURADAN (CARBOFURAN) 50'S & CARBAMATE
*MOCAP (ETHOPROP) 1960'S ORGANOPHOSPHATE
**DASANIT " ORGANOPHOSPHATE
*TEMIK (ALDICARB) " CARBAMATE
*VYDATE (OXAMYL) 1970'S CARBAMATE
*ENZONE (GY-81) SODIUM TETRATHIOCARBONATE>>CS2 1980'S FUMIGANT
CLANDOSAN 618 (CHITIN/UREA) " NATURAL
NEMATROL (SESAME CHAFF) " NATURAL
*DITERA (FUNGAL TOXIN) 1990'S KILLED MICROBIAL
*currently available for use on some crops in California
**no longer registered for use in California

Carbon disulfide was originially tested in Europe for control of Phylloxera on grapes. It has a broad spectrum of activity and was found to be active against nematodes and some plant pathogenic fungi as well. Nematologists experienced in its use speak of its flammability and cite instances of fields and tractors engulfed in flames if a shank were to strike a rock during application.

A large supply of chloropicrin or tear gas was left in the Hawaiian Islands after World War I. The pineapple industry supported a large ongoing research effort for nematode control and it was found that this product was both nematicidal and fungicidal. At the present time, its greatest use in California is for fungal control on strawberries in combination with methyl bromide.

The success of these first fumigants led to the development in the 1940's of several other products including methyl bromide, ethylene dibromide (EDB), dibromochloropropane (DBCP), 1,3-dichloropropene (Telone and one of the two components of D-D Mixture), and 1,2-dichloropropane (the other component of D-D Mixture).

These before and after shots of grapes infested with dagger nematode, X. index are indicative of the improved growth visible following treatment with DBCP. Methyl bromide is known as the cadillac of fumigants because of its broad spectrum of activity (nematodes, insects, fungi, weeds) and efficacy. At the present time, its continued use is threatened by the perception that it is damaging to the ozone layer. Considerable information on this topic is available from WWW pages maintained by the U.S. EPA.

The use of EDB, D-D, and DBCP was lost in the 1960's and 1970's because of the potential for groundwater contamination and/or carcinogenicity. None of these problems was apparent at the time of development. In fact, DBCP was considered safe enough for use by homeowners and could be purchased off the shelf at local hardwares and nurseries, as could methyl bromide.

In more recent years, Telone II has been placed in and successfully completed a U.S. EPA Special Review for suspected carcinogenicity. More recently, because of its volatility, its use in California was suspended for a period of time.

Although in other states, formaldehyde has registrations as a soil fumigant, in California, its use as a nematicide has been mainly as an additive in hot water treatment tanks for planting stock.

Metam-sodium which in soil releases methyl isothiocyanate which is a broad spectrum biocide was first investigated as a nematicide in the 1950's. At the time, its performance and ease of use was such that it could not compete with the other fumigants which were available.

In the 1950's and 1960's, a number of organophosphates and carbamates were developed as nematicides. In the 1970's, oxamyl was developed as the first truly systemic nematicide because it could move both upwards and downwards in a plant.

Nemacur is currently used for postplant treatments of grapes. Growth differences between treated and untreated rows are visible in this trial in the San Joaquin Valley in which the untreated check is on the left and nemacur treated vines are on the right. Although no longer used for lesion nematode control in California on Easter lilies, the differences between treated and untreated bulbs are clearly visible.

In this trial for foliar nematode on African violet, the Temik treated plant is in the center. In this sugarbeet trial, the Temik treated rows are on the right.

In the 1980's, Enzone which contains sodium tetrathiocarbonate as the active ingredient which breaks down in soil to release carbon disulfide was developed. Its registration in the early 1990's ended a more than 20 year span during which no new nematicidal ingredients were registered in California.

Two "natural" products, Clandosan 618 and sesame chaff developed in recent years have achieved U.S. EPA but not California registration. During the past year, DiTera a toxin produced by a fungus in fermentation has received both U.S. and California EPA registration.

When utilizing any pesticides, reading and following label directions is essential for the safety of the applicator and nontarget organisms, and to obtain proper efficacy.

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