Group Title: Mimeo report - Gulf Coast Station - 54-5
Title: Nematode control on sandy soils can be inexpensive and practical
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00067632/00001
 Material Information
Title: Nematode control on sandy soils can be inexpensive and practical
Series Title: Gulf Coast Station mimeo report
Physical Description: 7 leaves : ill. ; 28 cm.
Language: English
Creator: Overman, A. J ( Amegda J )
Walter, James M ( James Munday ), 1906-
Kelsheimer, E. G ( Eugene Gillespie ), 1902-
Gulf Coast Experiment Station (Bradenton, Fla.)
Publisher: Gulf Coast Station
Place of Publication: Bradenton Fla
Publication Date: 1954
Subject: Plant nematodes -- Control -- Florida   ( lcsh )
Soil disinfection -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Statement of Responsibility: A.J. Overman, J.M. Walter, and E.G. Kelsheimer.
General Note: Caption title.
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Bibliographic ID: UF00067632
Volume ID: VID00001
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: oclc - 71356971

Table of Contents
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Full Text


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source

site maintained by the Florida
Cooperative Extension Service.

Copyright 2005, Board of Trustees, University
of Florida



A. J. Overman, J. M. Walter, and E, G. Kelsheimer

Reduced yields due to nematode damage on crops grown in sandy soils have stimi

ulated interest in soil fumigation with such preparations as DD and EDB. Because

overall application of these chemicals to decrease nematode populations proved too

expensive for most operations, in-the-row soil treatment was devised. This row method

cuts down the amount of material needed per acre, since the fumigant is applied only

down the center of the bed.

In 1949 Walter and Kelshcimer of the Gulf Coast Experiment Station reported

experiments comparing the value of in-the-row fumigation with full-scale application

of soil fumigants on old land heavily infested with nematodes. For in-the-row fumi-

gation, a simple apparatus has been designed which can be constructed by any handy-

man farmer for as little as ten dollars. It is an attachment which may be mounted on

the bedding-cultivating tractor or adapted to a Georgia stock for use by the farmer

using mules. The accompanying sketch (Fig. 1) shows the following essential features:

Fig. 1

(1) A 10-gallon steel drum mounted on the front axle of the tractor, the

drum having, near the bottom, a galvanized pipe outlet soldered to it;

(2) A 5/16"-diameter copper tube extending from the outlet in the drum to

the proper position to place the trickle of fumigant in a line representing the

approximate center of the bed formed by the discs;

(3) A shut-off valve near the base of the drum and controllable from the

driver's seat; and

(4) A regulator valve in the line of copper tubing.

The regulator valve must be adjusted by trial and error to deliver a

specific amount of material per foot of row. The adjustment may be made as foll..2i~

(1) The driver determines the position of all controls when tractor is

moving at normal, steady pace in the preparation of beds;

(2) By taking the average of several readings, the number of seconds

required for the tractor to move 100 feet at the steady working pace is determined-

(3) By calculating the volume of soil fumigant required to treat 100 feet

of row at the desired rate is determined. The desired dose per 100 feet of row is

1/2 pint of either DD or a 20% concentration of EDB. If conditions of high soil

temperatures and low moisture levels prevail, it is advisable to increase the

dosage by a half in order to assure an effective treatment. This 1/2 pint volume

is often not sufficient to ensure a steady flow of the liquid from the tube, so

the apparatus illustrated is commonly set to apply 3/4 pint per 100 feet of row,

The rate of 3/4 pint per 100 feet means a 10-gallon per acre treatment on land

having rows four feet apart.

(4) The regulator valve is changed until it allows the proper volume of

material to flow into a graduated container in the number of seconds necessary for

the tractor to run 100 feet. The tractor is standing with motor running for thif



Fumigation, fertilization, bedding and "boarding-off" becomes one efficient

operation with this equipment. Obviously, the spti factory use of this type of

dispenser attached to a Georgia stock requires that the draft animal walk at a

steady pace.

A comparison was made between a single line of fumigant and two lines

one foot apart, with the total dosage per acre the same. No difference in yields

resulted, but rootknot was less severe where the single line of material was used.

Though some growers have constructed apparatus for delivering two streams to the

beds, no data indicating any advantage in this have been available.

Soil that is to be treated with a fumigant should be well worked, and

the upper 6" should be free of undecomposed plant material. Application of the

f!migant is normally made on the original soil surface, with the fertilizer, anr

a bed 6"-8" high thrown immediately over it. The top of the bed should be com-

cpacted or "boarded-off" to seal-in the material. If the soil is dry and hot at

time of treatment much of the fumigant will be lost quickly by evaporation. In

order to obtain the maximum benefit from the fumigant it is desirable that rain

mf'ficient to seal the soil surface fall immediately after application; growers

equipped with an overhead irrigation system can make good use of it for this

purpose. For those who do not have sprinkler equipment and can not arrange to

complete the treatment of a field just before a shower, it is advisable that appli-

cation be made when the soil is at the highest moisture content permitting


For crops grown on flat surface without any bedding, the fumigant should

be applied 4" under the surface behind a bull tongue or small shovel and a drag

to smooth and compact the surface should follow immediately behind the applicator,

Soil treatment on a small scale for the home gardener may be accomplished

by the use of a quart jar arranged with a delivery tube (Fig. 2).


---=`- --

Fig. 2

irTLth the soil at a high level of moisture, the beds should be made up and a furrow

6"-8" deep drawn down the center of the bed. After the fertilizer has been

applied the operator may proceed down the row dribbling the prescribed amount of

f.imigant in the bottom of the furrow. The bed should be closed immediately and

the fumigant sealed by compaction. If possible, the surface should be watered :to

a depth of 1/2" 1" to retard loss of the material by evaporation.

The period of waiting between treating and planting depends greatly on

the soil type and moisture content of the land as well as weather conditions after

fumigation. Since studies on this question have been conducted on sand soils, no

recommendations can be made for the marl, peat, and muck soils of Florida. If

the weather is warm and the soil not excessively moist, plants may be set 54 hoori

after application of the fumigant. It is necessary to stir the treated soil to tb-


full depth at which the material was applied, before transplants are set or

delicate seed planted. The rows should be opened with a narrow shovel at least

6 hours before the planting operation is to begin. Exposure of the open furrow

to sun and air facilitates escape of remaining fumigant. Growers who seed

directly into the field may expect less damage planting after a 48-hour wait for

the fumigant to take effect since the seed are placed relatively near the surface

,,nicre the fumigant does not linger in high concentrations.

Crops can be badly stunted or even killed by toxic amounts of the fumigant

persisting in the soil due to the effects of cool, wet weather. Plants should rno

b," set if the odor of the chemical can be readily detected in a h'-'dfull of the

soil lifted from the zone in which the chemical was placed. Sh i. .-'v rains

ir cool weather prevail after treatment, frequent stirring of th. created soil

and a delay of from two to three weeks before planting may become necessary. This

stirring of the soil must, of course, be accomplished without destroying the bed.

It is also important to avoid throwing non-treated soil from the middles to the


No practical method has been devised for applying fumigants so as to

free a tract of land completely of harmful nematodes and to keep it free for any

considerable period. This has proven the case with the most thorough overall

treatments thus far devised. An explanation of the comparative effectiveness of

in-the-row fumigation in giving increased yields is that it greatly reduces

nermtode populations for the four or five weeks required for the plant to develop

a good root system. In-the-row fumigation has repeatedly given protection from

nematodes for approximately four weeks. In order to give the plant the full

benefit to be derived from in-the-row fumigation, cultivation to eliminate weeds

and side-dressing with fertilizer should be held to a minimum for 4 weeks after

the plants are set. These operations commonly reinfest the treated soil area

with particles from the untreated areas in the bed and hasten reinfestation about

the plant. Nutritional sprays containing nitrate-nitrogen may be useful during

this time to supplement the fertilizer which was applied during the bedding pro-

cedure. These many be applied in the regular fungi,:ide--insecticide schedule.

Research thr.cvugh some four years has shown that in-the-row fumigation has

given yield in.-reases; equal to those resulting from full-scale application when

proper s-nitary measures are practiced. The method reduces the possibility of

to.-c residues building up in the soil after repeated seasonal application, since

the vo':..nc used per acre is inversely proportional to the betwen-roi- spacings.

To be beneficial on sand heavily infested with nem.at.des, in-the-row soil

fumigation must be employed before each susceptible crop grown. There is no

dependable carry-over effect from one crop season to another. Nematode damage is

usually greater in the spring season, but fumigation prior to the spring crop w-il

not protect a following fall crop. Rather it seems that, in time, the popula-

tions of some parasitic nematodes increase to many times those present before

treatment. In the intensive vegetable-growing areas of Florida, therefore, where

rrop rotation and other cultural practices for nematode control are often ruled

oit, fumigation is necessary each time the land is prepared for susceptible crops

in fields that have become so badly infested with ner.todes as to warrant fumiga-

tion at all. With long-term crops such as cantaloupe, in-the-row fumigation nay

not give satisfactory results because protection from neimatode damage 4is limited

to the early stages of the growing period.

For our general usage of chemicals for nematode control, EDB is given

preference because it is easier handled, but DD (dichloropropene-dichloropropane)

and the 20% concentration of EDB (ethylene dibroride) have proven approximately

equal in effects. DD is used undiluted since no satisfactory diluent is known.

One important advantage of several EDB preparations is that they can be diluted

with mineral-spirits, enabling the user to adjust volume of material applied to

his convenience. EDB is sold in concentrations ranging from 85 percent down to


20 percent, under trade names such as "Soilfume" and "Dowfume". Proper calcu-

lations will indicate the amounts to use per 100 feet of row, the desired dosage

rate on which to base the calculation being 1/2 pint 20 percent EDB or 1/4 pint

40 percent DB, As stated in a foregoing paragraph explaining the adjustment of

the home-made applicator, it has been found best in this case to arrange that a

x'oluime of 3/4 pint be delivered to 100 feet of row in order to obtain a uniform

distribution of material in the soil. Using two measures of mineral spirits to

one measure of EDB "60-40" to load the drum thus gives the prop:a- concentration of

T.3 in the volume of liquid convenient under the described conditions. With rows;

4 feet apart, this dosage rate supplies approximately 10 gallons per acre.

If one applies 10 gallons per acre of a solution containing 3.3 gallons of

,0 percent EDB at $2.10 per gallon and 6.7 gallons of mineral spirits at$.16 per

gallon, the cost is $8.00. This is very little when considered in comparison with

the value of the yield increase of 100 bushels of tomatoes per acre the treatment

.las given in several trials.

The inexpensive apparatus for applying the fumigant and the low cost of

the material considered in contrast with the increased yields normally obtained

as a result of careful application of fumigant is a combination that should appeal

to the grower.

The practice of soil fumigation is not reconrended as a "preventive" where

nematodes are not a limiting factor; but in locations where severe nematode

damage to crops has made it impractical to farm, this "cure" can both efficiently

and inexpensively enhance the productivity of the soil.


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