Studies on the Controlof Root-Knotand Reniform Nematodes ...€¦ · root-knot and r eniform...
Transcript of Studies on the Controlof Root-Knotand Reniform Nematodes ...€¦ · root-knot and r eniform...
rrECI-INICAL PROG.RESS REPORT NO.. 139 SEPTEMBER 1963
HAWAII AGRICUI-JTURAL EXPERIMENT STATION'COLLEGE OF TROPICAL AGRICULTURE
UNIVERSITY OF HAWAIIHonolulu, Hawaii
Studies on the ControlofRoot-Knot and Reniform Nematodes
with Soil Fumigation in Hawaii
O. V. Holtzmann* and M. Ishii**
INTRODUCTION
Root-knot (Meloidogyne spp.) and reniform (Rotylenchulus reniformisLind Ford and Oliveira) nematodes attack a wide range of crops in Hawaii(3, 4). Year-round production of many vegetable crops is frequent ly possiblebec a us e of a nl0derate wint.er climate. Presently, although chemical controlof nematodes in I-Iawaii is being practiced by so~e growers, little is understood as to the factors which affect the efficacy of the soil fumigation.
l'he objectives of these studies were: (I) to determine the relativeeffect of nematocides on root-knot and reniform nematod'es in the field, and(2) to determine whether fumigation in a particular growing season had aneffect on crop yield.
MATERIALS ·AND METHODS
Field and Soil Preparation': The fields selected for these tests werelocated at the Poamoho Experimental Farm of the Hawaii AgriculturalExperiment Station. These fields are used by the Horticulture Department
*Dr. o. v. Holtzmann is Assistant Plant Pathologist at the Hawaii Agricultural Exp eriment
Station.
**Dr. M. Ishii is Associate Plant Pathologist at the Hawaii Agricultural Experiment Station.
of the H:Af:S for testing nematode -resistance to breeding lines ' of tonulLo a ndlima beans , l'he constant recropping of .s us cept ib le plants assured "~l relatively high population of root-knot and reniforni nern~t()des. Very fe'w ofother plant-paras iti c nematode forms were present. The soil wa s a low hurnielatosol of the .Wah~iawa series.
Soil preparation was made by .s ubso i l i ng and discing 1 rnonth beforefumigation. Plots were disced and harrowed just prior to treatment.
P lot Design: The experimental design was a rand om i ze d cornpletebl ockv .e ach treatment was replicated 8 times. Each treatment plot consistedof treating a strip 3 feet wide and 10 ' feet long centered on a row. Rowswere spaced 4 f:eet apart. Three-foo't-w ide . untreated buffer zones wereleft between each plot in the row and on the ends of each row.
Treatmetits rt Tests 1 and 2 were designed to compare c ornmer c ia Isources and rates or" application 'of nematocides for root-knot and re niforrnnematode control. All treatments were made 4 weeks prior to planting. Intest 2 there was also included a postplant treatment which was made 2months after planting, 6 inches to each side of the row. Liquid formulationswere injected into the soil with a McC lean F'umigun at a depth of -6 incheson the center and 12 inches to either side of the center of each treatrne ntrow. Nematocides applied in this manner .were: 1,3-dichloropropene, 100%(Te lone}; 2. ethy lene dibromide, 83% by .' weight (EDS); 2 1,2-dibrolno-3chloropropane, 67,.5% by weight (DBCP); 3 and chloropi.crin. 2
Weighed qu~ntities of 85%. Mylone (3~'5-dimethyltetrahydro-l,3,5, .2Hthiad iaz ine-Zvth ione )" were spread ' by hand on the 3-foot-wide plot on therow. It was mixed ' into the soil by rototillering twice. Measured vo lume s ofVapam (sodium N';~e:thyldithiocarbamatedihydrate) was mixed with adequatewater to distribute the chemical over the 3-foot-wide ' plot. Each of theseplots was rototil le d twice. After treatment 'with chloropicrin, Mylone, andVapam the soil was thoroughly wetted; .
Methyl bromide (98%. methyl bromide 'a nd 2% chloropicrin)2 wasapplied in the 30-sq.-ft.-wide plot under a 2-mil polyethylene cover. rrheplastic cover was .removed after 2 days. Soil temperatures at a 6-inch depthfor tests 1 and 2 ·were 68 0 and.75° F, respectively.
IThe use of any chemicals in this test does not constitute a recommendation of the product
or its manufacturer by the' Hawaii -Agr i cultu ra l Experiment Station or its personnel • .
2Telone, EDB, chloropicrin, and methyl bromide were supplied by Dow Chemical Co-, San
Francisco, Ca l ifornia,
3DB C P was supplied by Shell Development Co., Modesto, Ca l if orn ia ,
4My}one was supplied by Union · Carbide Chemical Co., New York, N. Y~
2
Four weeks after application of chemicals, the plots were seeded with
Fordhook variety of lima bean, which is susceptible to both root-knot and ·reniform nematodes. Subsequent cultural practices were those reco·mmendedby the Hawaii Cooperative Extension Service for .lima bean culture. F'urrowirrigation was employed during the course of these studies.
Nematode Extractions and [Ieterminations : Profile soil samples weretaken in the rhizosphere to a depth of 6 inches in each plot. A compositeplot sample ·c ons is t e d of at least 10 subsamples. Samples were taken 3weeks after fumigation and at harvest. The nematodes were recovered fromthe soil by Anderson's modified Baermann funnel technique (1). tlowever, a40-cc soil sample was processed instead of 100 c c . Nematode counts weremade after re laxing.
Root-knot ·index was based on an average evaluation of at least 10 rootsysterns per plot: 0 == clean, 1 == few srna ll galls, 2 == slightly galled, 3 =moderately galled, 4= heavily galled, 5=:severely galled .
Ilarvest: Beans were picked biweekly and weighed. Only marketablebeans were corisidered.
EXPERIMENTAL RESULTS
Test 1: This test encompassed the period fr·om March 14, 1958 toAugust 6, 1958. F'umigants in general reduced root-knot and reniformnematode populations. There was an apparent inverse relationship betweenthe root-knot index and bean yield. A high index reading was associat edw ith a low yie ld and vice versa. The results s umrnar iz e d in table 1 showthat treatments EDB (96 lb /acre) , methyl bromide , DBCP (68 lb/acrc),Te lone (400 lb/acre), and EDB (48 Ib/acre) gave · yields s ign ifica nt lybetter at the 1% level than the untreated che cks , However, there was nodegree of high significan ce between the treatments EDB (96 lb/acrc),methyl bromide, DBCP (68 lb/acre), Telone (400 lb/acre) , EDS (48 lb/a cre),Te lone (200 lb/acre), chloropicrin, or DBep (34 lb/acre).
Test 2: This test encompassed the period from September 16, 1958 toFebruary 9, 1959. Nematocidal a ct ivity of the chemicals was similar to thatobserved in test 1. Table 2 shows that to a degree the inverse relationshipbetween yield and root-knot index is in evidence. No significance i·s foundbetween the y'ie lds in any of the treatments.
D.ISCUSSION
All the . chemicals tested were relatively effective in reducing theinitial soil population of both root-knot and rcnifonn ncma t odes . tIowcv er,the nematocidal effect of DBCP is less in the initial kill of the reniformnematode than it is with the root-knot nematode. 'The reduction in bean
yield in these tests is probably due to .the root-knot rather than to the reniform nematode infestation. Although the F'ordhook lima bean j is susceptibleto both root-knot and reniform nematodes, the reniform nematodes did notshow a high degree of parasitism on the roots.
Bean ' yields were significantly increased in the treatments EDB(96 Ib/acre), methy I bromide, Telone (400 Ib/acre), and EOB (48 lb/acre)in the summer-harvested test (test 1), whereas no significance was determined between the yields of the treatments in the winter-harvested test(test 2). The yield of the untreated check in the winter test outyielded thatof the summer test despite the fact that the roots of the beans in the winterwere more heavi ly ga l le d with root-knot nematodes. Th is yield variance maybe because of the low occurrence of environmental stresses during thewinter, i.e., high temperature and low moist.ure which accentuates theadverse effect on yields of root-knot infested plants (2).
The bean roots in comparative OBCP treatments were less heavilygalled in the winter test than in the summer test. This may be because ofthe lower soil ternpcrature s which prevailed during the fall and winter growing season. OSCP has a lower vapor pressure than does E.DB or Telone,.thus is able to act nematocidally over a longer period of time.
REFERENCES
1. Anderson, E . .1., and I. Yanagihara.1955. A method for estimating .numbers of motile . nematodes In largenumbers of soil samples. Phytopathology 45(4): 238-239.
2. Christie, J. R.1959. Plant Nematodes-Their Bionomics and Control. AgriculturalExper'irnent Stations, University of Florida, C;ainesville, I~'lorida. 256 pp.
3. Linford, M. B., and F'rancis Yap.1940. Some host plants of the reniform nematode In Hawaii. Proc.HelminthoI. Soc. Wa~hington, D.C. 7·: 42-44.
4. Oliveira, Juliette M.1940. Plant-parasitic and free-living nematodes in JIawaii. Bernice P.
·Bis hop Museum, Occasional Papers 15(29): 361-373.
4
ri
Tab
leL
Eff
ect
ofn
emat
oci
de
trea
tmen
ton
roo
t-k
no
tan
dre
nif
orm
nem
ato
de
po
pu
lati
on
s
and
yie
ldin
lim
ab
ean
s,M
arch
14
,1
95
8to
Au
gu
st6,
19
58
(Test
1)
IA
ver
age
no
.**
ofn
emat
od
esp
er1
00
ccof
soil
Tre
atm
ent
Do
sag
e*R
oo
t-k
no
tR
enif
orm
RK
Av
erag
ey
ield
*:t
afte
rat
afte
rat
ind
ex*
*in
Fu
mig
atio
nH
arv
est
Fu
mig
atio
nH
arv
est
Ib/
1O
-ft
row
Tei
on
e2
002
213
5242
14
82
.68
.5ac
de*
**
Te
lon
e4
00
34
68
-49
1.7
9.3
bce
ED
B4
816
425
517
91.
28
.9b
cde
ED
B96
"3
271
42
331
.09
.5bc
DB
CP
341
918
5128
234
83
.48
.4ac
de
DB
CP
6842
104
718
24
92
'79.
4b
c
Myl
one
300
161
68
914
436
"3.0
7.7
ade
Va
pam
200
616
796
13
3.8
7.4
ad
Ch
loro
pic
rin
500
348
96
27
1.2
8.5
acd
e
Met
hyl
bro
mid
e8
726
284
233
0.9
9~4
be
Un
trea
ted
ch
eck
173
227
335
216
43~
97.
2a
'"P
oun
dsof
ac
tiv
ein
gred
ien
tp
erac
re.
**A
ver
age
me
an
of8
rep
lica
tio
ns
.
*'!'*
Tre
atm
ents
foll
ow
edby
the
sam
ele
tte
rdo
not
dif
fer
atth
e1
%le
vel
ofs
ign
ific
anc
eac
cord
ing
toD
un
can
'sm
ult
iple
ran
ge
test
.
0\
Tab
le2.
Eff
ect
ofn
emat
oci
de
tre
atm
ent
onro
ot-
kn
ot
and
ren
ifo
rmn
emat
od
ep
op
ula
tio
ns
and
yie
ldof
lim
ab
ean
s,S
epte
mb
er1
6,
195
8to
Feb
ruar
y9,
195
9(T
est
2)
Av
era
ge
no.*
*of
nem
ato
des
per
10.0
cc.
.of
soil
IT
reat
men
tD
osa
ge
*R
oo
t-k
no
tR
enif
orm
RKA
ver
age
yie
ld*
·
afte
rat
afte
rat
ind
ex*
*in
Fu
mig
atio
n.H
arv
est
Fu
mig
atio
nH
arv
est
Ib/1
0-f
tro
w
Tel
one
200
4683
473
972.
•490
5
Tel
on
e40
02
502
143
1.7
9.5
ED
B48
37
251
8612
4I
1.0
9.7
IE
DB
9622
306
7882
1.1
9.6
DB
ep
Pre
pla
nt
on
ly34
1519
312
313
11.
39
.8
DB
CP
Pre
pla
nt
34
Po
stp
lan
t34
2319
215
416
31.
29
.2
DB
CP
Pre
plan
ton
ly68
2831
320
422
61
.29
.6
Un
trea
ted
chec
k28
63
16
43
36
368
4.5
8.2
*P
ou
nd
sof
acti
ve
ing
red
ien
tp
erac
re.
**A
ver
age
mea
nof
8re
pli
cati
on
s.
WARNING
The chemicals used in this test should be considered dangerous. Themanufacturers' recommendations for handling should be strictly adhered to.F'urther, the United States Department of Health, Education and Welfareunder the provisions of the Pest ic ide Chemicals Amendment to the FederalFood, Drug, and Cosmetic Act has established criteria to govetn the use ofeach chemical to which clearance for use has been given. Growers. shouldalways check the current status of any pesticide with their county agent 01'
the local U.S.l1.·E.W., F'ood and Drug Administration representative, beforeuSIng.
UNIVERSITY OF HAWAIICOLLEGE OF TROPICAL AGRICULTURE
HAWAII AGRICULTURAL EXPERIMENT STATIONHONOLULU, HAWAII
THOMAS H. HAMILTONPresident of the University
",ORTON M. ROSENBERG·Dean of the College and
Director of the Experiment Station
~. DONALD SHE . ANAssociate Director of the Experiment Station