BUI
CACH TUYEN - LE OJNH OON
BENH HAI VA BIEN PHAP PHONG TRll
BUI CACH TUY^N - LE
OJNH
DON
CAY HO
TIEU
BENH
HAI VA
BIEN
PHAP PHONG TRQ
NHA
XUAT BAN NONG NGHIEP
TP. Ho Chi
Minh-2013
1*
-
ii
V
I
MVC LVC
L6i gioi thifu xi
L6i noi dau xii
I. Sff lirgc ve cay ho tieu 1
II.
Dac diem hinh thai cua cay ho tieu 5
1. Dac dilm chung 5
2.
Dac diem nong hoc cua cay ho tieu 5
3.

benh 36
Tac nhan gay benh va dac diem gay benh 37
6. Benh d6m tao (dom rong) 38
Mo
ta
trieu
chung va tac hai cua benh 38
Tac nhan gay b?nh va dac diem gay benh 39
7. Benh than thu (kho la) 41
Mo
ta
trieu
chung va tac hai
ciia
benh 41
Tac nhan gay benh va dac diem gay benh 42
8. Benh tren hat sau thu hoach 43
Mo
ta
tri?u
chung va tac hai cua benh 43
Tac nhan gay benh va dac diem gay benh 43
IV.
Phong benh va
trir
tac nhan gay b^nh 48
1.
Dich
te hoc
ciia

vudn tieu
thuanva xen ca phe
Bang 5: Nguon
P.
capsici trong vudn ho tieu bi benh chet nhanh vao mua
kho (thang 2/2011)
Bang 6: SUtich ICiy nguon
P
capsici trong mua kho va mUa
d
hai mo hinh
trong ho tieu nam 2007 (Iran Thi Hadng, 2009)
Bang 7: Phan Cfng cua mot so cay chi thi vdi Meloidogyne spp. phan lap tCr
re nhieu giong ho tieu khac nhau trong thf nghiem chung benh
BIng
8:
Mat
so
tuyen trung Meloidogyne spp.
va
Tylenchulus sp. trong
vungrehotieu
Bang
9: Ti le (%)
la tieu benh theo tC/ng trieu chu'ng
d
cac vung dieu
tra
nam 2004
Bang 10:

benh vi
rut
nang va nhe
tren
giong
Vfnh
Linh
4
-
5
tuoi
trong
tai
huyen
Chau
Dufc,
tinh
Ba
Rja-Vung
Tau
B^ng 16:
SU
tap
nhiem
vi sinh
tren
hat ho
tieu
I<h6
ton

tfch
cay ho
tieu
va
sU
phan
bo
theo
dja phu'ong
Hinh3:
Cac loai
re
cay
tieu
Hinh
4:
Choi
than
non mau do nhat
Hinh 5:
Mau
sSc va hinh dang ngpn non cua ho
tieu
Hinh 6: Cac loai
canh
phat
trien
tren
cay ho
tieu

ho
tieu
Hinh 12: Trieu chufng benh
Phytophthora
capsici
tren
than
tieu.
Hinh 13: Cay ho
tieu
bj benh chet nhanh
Hinh 14: Cay
ho
tieu
bj benh chet nhanh con sot
lai
tren
cay choai va lay Ian
thanh
cum
tren
vudn
tieu
Hinh 15: Trieu chufng gay ra
tren
cac mau la
tieu
dung de "bay P
capsici"
trong

sau khi chung nam
duoc
each
ly (C), cay ho
tieu
bj nhiem benh vang la sau chung 14
ngay
(D).
vii
Hinh 20: Dai bao
tCr
va
tieu
bao tCr nam Fusarium spp.
Hinh
21:
Phan
ufng cua mot so cay
l<y
chCi
chi
thi
cho
siigay
benh cua tuyen
trung
Meloidogyne spp. phan lap tC/ re ho
tieu
Hinh 22: Su djnh cU cua Meloidogyne spp.
trong

benh
Hinh 28: Cay ho
tieu
nang suat cao, khong benh (A), mot vai la c6
trieu
chCrng
vi
rut
tim
thay
trong
tan la (B)
Hinh 29a, 29b: Trieu chufng va tac hai cua nam gay benh sdi chi (mang nhen)
tren
cay ho
tieu
Hinh 30:
Mufc
do benh dom tao
tren
trai
tieu
chUa
chi'n theo dp cao cua cay
Hinh
31:
Trieu chufng benh dom tao (dom rong)
tren
cay ho
tieu

va giam cong thu hoach
Hinh 40a: Trong cay lac dai Arachis pintoi (A) va c6 Stylosanthes gracilis (B)
giQa
cac hang cay
tieu
giup
giCf
am
vUdfn
vao mua kho, han che xoi
mon
dat vao mua maa.
viil
Hinh 40b: Trong cay lac dai Arachispintoi (C)
giQa
cac hang cay
tieu
giup giuf
am vudn vao mua kho, han che xoi mon dat vao mua mUa
Hinh
41:
SU che phu cua cay lac dai cho cay ho
tieu
Hinh 42: He
thong
tudi
nho giot giup
tiet
kiem
nUdc

tieu
khong benh va bp re cay khong benh
Hinh
47b:Cay
nhiem Phytophthora
capsici\/6\p re bj huy hoai
Hinh 47c: XCr ly Trichoderma virens
(T.41)
han che siJ xam nhiem gay hai cua
Phytophthora
capsici duy
trl
sU phat
trien
cua cay
tieu
Hinh 48: A: Tao ranh bon phan quanh goc
tru
choai, ngoai tan cay
tieu
0,5
met;
B:Tadi
dung dich thuoc benh theo nong dp khuyen cao vao
goc
tieu
tCr
3
- 5 lit giup thuoc ngam sau vao he thong re
Hinh 49: IVlpt so mo hinh

trong
Hinh 55: Tao vanh dai bon phan hQu co (10
kg/cay)
va micromate (50
g/cay)
Hinh 56: A: XCf ly thuoc trUc
tiep
tren
goc than cay benh; B: Quet thuoc goc
dong
len goc than va vung re sau khi
dapc
cat tia lam goc than
thongthoang
ix
Hinh 57: Ho trSng tieu Ba Ria - Vung Tau tham quan mo hinh trong tieu vai
try choai la
tru
be tong
Hinh 58: Lich thuc hien cac tac dong trong bao ve thuc vat va phan bon cho
cay ho tieu trong tai Ba Ria - Vung Tau
Hinh 59: Ho tieu trong tren tru choai song cay keo dau (Leucaena
leucocephala)
Hinh 60: Sir phan bo cua benh va tac nhan gay bfnh tren cay ho tieu
Hinh
61:
Bo sung Can-xi va Ma-gie giiip tang so trai/chum va so chum
trai/canh
L(i\G\($\J\\\%\}
Tieu

tieu.Tac
gii da phan tich ro dac diem
sinh
hoc,
sinh
thai cua cac
nhom ky
sinh
gay benh hai chinh nhU: Nhom nam gay benh chet nhanh,
chet cham, cac loai tuyen
trung
gay hai tren ho tieu c6
trong
dat va nhom
benh do nhieu tac
nhan
virus
gay ra.
Siitac
dong qua lai, tuong tac
giCa
cac
nhom ky
sinh
va cay
trong
tren co sd bien phap
canh
tac theo
htfdng

nhan
tCr
trong
dat, va dong
th6i
cay tieu phat trien
kh6e
manh
du
sufc
de khang lai benh hai la y tudng rat tien
tien,
co co sd
khoa
hoc.
Bien
phap quin ly djch hai
tong
hop cua tac gii de xuat dang la
djnh hadng cua nhieu mo hinh san xuat tieu ben vijfng cho cac vung
trong
tieu chinh cua ca nude.
Sach
la tai lieu
chuyen
khao
rat t6t cho nghien cufu, dao tao va
giup cho ngudi san xuat tang nang suat, sin luong va pha'm chat sin
pham ho
tieu.

bao cao ve
hien tuang
cay ho
tieu chet hang loat.
Cac
nghien
CLTU
ve
benh
hai ho
tieu dUgfc
cap
kinh
phi tii
nguon
dja
phuong
hoac
cap Bo va Nha
nUdc. Nhieu
ket qua
nghien cufu
da
duac
tong
ket,
pho
bien,
LTng
dung,

cay ho
tieu
lam
giam nang suat, giam chat lupng
va gay
chet
cay lam ton hai ve
kinh
te cho
ngadi trong
tieu.
So
lieu
va
hinh
anh
trinh
bay
trong sach
la ket
qua
nghien cufu
cua
nhieu
the he
thay
c6
giao,
sinh vien
da! hoc, cao hoc,

chet
cay
tieu tren
dao
Phu
Quoc
vao
thdi gian
dau cua
nhQng
nam
1980 den
giup
cac
tinh mien Trung,
Tay
Nguyen
va
Dong
Nam Bp vao
nhufng
nam
1990.
Cac
no
lUc
do
da
giup tfch
luy cac

cam
Pn sif
dong
gop tu"
lieu
va
hinh
anh
minh
hpa
c6 gia tri
khoa
hpc cua
sinh vien
va
hpc
vien
c6
ten trong
tai
lieu tham khao
va
hinh
anh
cung
cap bdi
Cong
ty
Hoa
nong

gia
xii
I.
sd
Li/ac
CAY
H6
Ti§u
Cay
ho
tieu dang dupe trong
la
loai
cay hai
la
mam c6 ten
khoa
hpc
Piper nigrum L,
2n=52
hp
Piperaceae dupe
cho la mpt
loai
lai
giu'a
cac
loai
hoang
dai

dUpc sCr dung
nhu'
mpt
loai
gia vj
trong
thUc pham, tinh
dau
chiet xuat
tii hat
dUpc dung trong chQa benh
cho
ngUdi
va
c6
trong thanh phan
cua mpt so
my
pham.
Hinh 1: Cac
sdn
pham
sit
dung
tit
hat
ho
tieu
A:
Hat

^
1
Qucin tfio
Trudng Sa
Hinh 2: Dien tich cdy ho tieu vd
si/phdn
bo theo dja phUcfng
(Nguon: Tong
hcrp
tCr
cac
tai
lieu
pho bien
trong
nam 2012)
Vdi
Ijch
sCf
thi/cfng
mai
di/gtc
ghi nhan
til
3.000
den 2.000 nam
tri/dc
c6ng nguyen
tai
An 06. Nguon goc ho

Tai
Viet
Nam, cay ho
tieu
dupe
trong
lau ddi va hinh thanh
nhCfng vung
dja
ly
trong
ho
tieu
chuyen
biet
nhu
tieu
Phu Quoc,
tieu
Ho Xa
(Quing
Tri),
tieu
Tien Phtfdc (Quang Nam),
tieu
Oat d6 (Ba Rja-Vung Tau),
tieu
Lpc Ninh (Binh Phudc). TCr khi hat ho
tieu
Viet

tuc hang nam
va
miJc
dp dau
ta
cang cao do
thuoc
bao ve thac
vat
va cong lao dpng cang
tang
da
lam
thu
hep
dien
tfch
mot so vung ho
tieu
Quing Nam,Tay
Ninh,
va
Binh Thuan. Du vay, dien
tich
cay ho
tieu
cua ca nude khong
ngC/ng
tang
them

2008
2009
2010
An
Dp 236.180 196.297 181.299
182.000
Indonesia 142.500 142.500 142.500
142.500
Vi^t Nam
50.000 50.000
50.000
50.000
Sri Lanl<a 29.976 30.655
30.506
30.714
Trung Quoc
21.000
22.687
23.545
24.000
Brazil
20.000
20.000
20.000
20.000
Malaysia 13.023
13.487
13.608
15.000
Madagascar

Nam 93.500 98.970 123.750
110.000
Indonesia
58.000
52.000
50.000 59.000
An Do
1
50.050 50.100 50.000 50.000
Brazil
42.500
41.000
40.700 34.000
Malaysia
20.000
22.000 22.000
23.50Q,.
Sri
Lanka
9.009 6.237
6.576
12.219
T6ng 273.059
270.307 293.026 288.719
(Theo
IPC,
2001-2010)
Bang
3:
Dien ti'ch

-
Vung Tau
Gia Lai
7.021
6.939
5.832
6.273
6.304
5.069
2,09
1,86
3,20
13.111
11.725
15.733
Dal<Lal<
4.898 4.384
2,67 11.715
Ci nude
50.000
2,5
100.000
4
II.
£)AC
DliM
HlNH
THAI CUA CAY H6
T|£U
I.Oacdiem chung

cua
cay, cung nhii
mufc
do
cham soc
va ky
thuat trong. Cac giong
ho
tieu dang trong hien
nay thu'dng diidc
goi ten
theo
dia
phaong nhu tieu
Phu
Quoc, tieu
Ha
Tien,
tieu Vinh Linh, hoac theo dac diem hinh thai nhU tieu Se
la
Idn, Se
la
nho,
tieu Trau, tieu
Ba
Chia. Cac giong nhap
noi
dUdc xac djnh nhu Lada
Belangtung, Karimunda, Panniyur 1, Kuching,
va

va
ijch sCr canh tac, cay
ho
tieu
da
thich nghi
vdi
vung
khi
hau
nhiet
ddi gio
mua
den
khong
khi
lanh
va am
Udt, mua
kho keo dai 4 - 5
thang,
mUa nhieu den
it
maa, trong
tdi
cao
dp
800 met tren mat bien (Gia
Lai),
va

mm,
vdi am
dp
khong khi tCr 60
-
70%, khong
c6
gio bao. Lupng nUdc tudi
vao mua kho cho cay tieu rat quan trong
vi
day
la
thdi gian cay tich ICiy chat
kho vao hat va
bat
dau cho chu
ky
sinh trUdng mdi. Anh sang tan
xa
thich
hop
cho cay
tieu sinh tradng
va
phat trien,
dac
biet trong giai doan
sau
trong va kien thiet co ban. Nguon goc xuat xCrtCr vung rCrng nhiet ddi chufng
to cay ho tieu thich nghi vdi dieu kien che bong, lUdng hufu co cao, va \ia

ho
tieu hinh thanh
2
loai
re
chfnh,
re
l<hi sinh
va re hut
dinh dadng.
Rieng
re
coc,
re
cai,
chi c6 khi
trong bang
hat.
Re
khi
sinh phat sinh
tai cac dot
than chfnh, dot canh cap
1
c6 nhiem vu neo
dot than vao tru choai. Viec neo bam se giup
dmh hinh tan cay, gia tang chieu cao, chieu
rong
tan
cay,

- 50 m. Ky thuat bon phan, tud\ va
tu
goc anh hadng rat Idn den sii phan bo he
re
trong vung tan cay.Tuy nhien, hadng
bo re
phat trien
an sau
xuong
dat se
giup
cay
chong chiu sUtan cong cua tuyen trung
va
nam gay benh, keo dai tuoi tho cua cay
tieu.
3.2. Than va
canh
ho tieu
Than
cay
tieu 6uac phan biet
bdi
mau sic, ki'ch thudc va
sU
phan canh. Than
chinh phat trien len
tren,
bam chat vao
tru

Than
chinh
7
nam
tuoi
(B);
Than
chinh
6
thdng
tuoi
c6 mau
xanh
Id cay (C).
Re
l(hisinh
bdm vao tru
choai
Hinh 3:
Cac
logi
ri
cay tieu
Hinh 5: Mau
sac
va hinh dang
ngon
non cua ho tieu
Canh
vwat

La tieu thuoc loai la don, c6 nhieu hinh dang nhu bau
tron,
thuon
dai hay hinh trai tim. La c6 gan hinh long chim, mpc
each,
c6 cuong la, kfch
thiidc, mau sac va hinh dang cua phien la thay doi tuy tCrng giong. Mat la
nhan bong, mat tren la c6 mau tiTxanh nhat den xanh tham, con mat dudi
la CO mau xanh luc.Tren cung mot cay, hinh dang la c6 nhieu khac biet theo
chieu cao cay. Sifthay doi mau sac, dp truong bong cua la giup chan doan
trinh trang dinh dadng va mufc dp bj benh cua cay.
8
Hinh 7: Cdc dang Id tieu
A,
B:
Mat tren va mat dudi la c6 hinh bau tron;
C,
D:
Mat tren va mat dUdi la c6 hinh thuon dai
3.4. Hoa va
chum
hoa
Hoa tieu thupc loai don tfnh
hay ludng ti'nh tuy theo giong, mau
trang,
c6 tCf 4 - 5 canh hoa, dai tC/ 7 -
12 cm, CO tir 20 - 60 hoa xep thanh
hinh xoan 6c tren
1
true tao nen chum

tac, kfch thadc
trai
khac
nhau.Trai
tieu
luc dau
mau
xanh, sau do chuyen
sang
mau
vang va
khi
chin c6 mau do. Mau sac cua v6
trai
giup xac djnh
thdi
diem
thu
hoach
cho sd che va che bien
tieu
den hay
tieu
so.
Thdi
gian
khi
xuat hien hoa day
du
den

vung dia ly va khi hau
thdi
tiet,
mua thu
hoach
tieu
bat dau
tCf
thang
1
keo dai den thang 4 hang nam.
10
III.
B|NH HAI
TRiN
CAY
H6
TI^U
TAI
VlfT
NAM
t.
Benh
Phytophthora
tren
ho
tieu
Benh
phytophthora
con

top,
rung dot phan than non,
re
thoi
den mem
nhun,
mach
dan ben trong than bien mau tii trang
sang
nau den
chay
doc theo
than.
Nghien
cufu
trieu
chufng cho
thay,
tac nhan gay benh tan cong ca phan
tren
mat
dat nha choi non, la, chum
trai,
canh, va than
chinh;
va phan du6i mat
dat
nhu"
re
va phan

khang
benh,
khang
P.
copsici
chUa
duoc xac
djnh.
Hinh
10:
Cac
dang
trieu
chvtng
benh
do
Phytophthora
capsici
gay
ra
tren
la
ho
tieu
A:
Vet
benh
tai
cuong
la;

ria
ban la,
lien
ket
thanh
mang lam rung
la
khi dien tich vung benh chiem khoang 40% dien ti'ch
ban
la.
Vung benh cung xuat hien
tai
cuong
la
lam
la
rung
khi ban la van con
xanh.Tren
la
non,
vet benh
la
nhQng dom nau lam heo kho la nhanh chong.
Tren
cay,
la bj
benh khong
phu
thuoc

ho
tieu
A:
Choi
nggn
khoe
mqnh;
B:
Choi
nggn
nhiem
P.
capsici
4
ngay;
C:
Ngon
bi heo kho
sau
nhiem
P.
capsici
30
ngay;
D:
Vet
benh
dtgc
trUng
tren

sat
mat dat dan den heo toan
bp
cay mot each nhanh chong.
^
Thoi
muc goc
than
va he
re
Hinh
12:
Trieu
chCtng
benh
Phytophthora
capsici
tren
than
tieu
+ Su xam nhiem than ngam
qua
re
nam sau hon 60 cm gay hoi
chufng vang la, giam sufc sinh trudng cua cay, chet sau
1
-
2
nam hoac
vao

La
heo
toan
cay
nhi/ng
khong
rung;
C:
Thoi
goc,
la
vang;
D:
Phan
re
ngam
thSi
den
phan
mo
Hinh
14:
Cay
ho
tieu
bj
benh
chet
nhanh
con

2004),
Thai
Lan
(Tsao
va cs, 1997), Sri
Lanka
(Kularatne, 2002). d
Viet
Nam theo Nguyen Vinh TrUdng (2004), benh
vang la chet nhanh ho
tieu
d Quang Trj do Pythium sp., Phytophthora sp. va
Phytophthora
parasitica.lheo Nguyen
Tang
Ton (2005), benh chet nhanh ho
tieu
d Binh Phudc, Ba Ria - Vung Tau va Quang
Tri,
la do Phytophthora capsici
gay ra. Benh thudng xuat hien vao mua mUa, khi mUa nhieu va vao mua
kho,
khi nhiet dp cao. Benh nang d nhufng vudn
tieu
c6 dp
tuoi
Idn, do su
tich
luy nguon benh
trong

nhiet dp 25 -
30°C,
pH
tu'
5 - 6 la dieu kien thi'ch hpp cho P. capsici
phat
trien.
Nghien cufu cua
Tran
Thi Huong (2009) (bang 4) cung cho thay
ton
tai dang lai A1 va A2 cua P capsici trong vUdn ho
tieu
trong
xen ca phe,
va chi
CO
A2
trong
vadn
tieu
thuan
tai
Dong Nai. Hinh thai cua nnau P capsici
phan lap
tren
vUdn
tieu
thuan va xen ca phe c6 mot so dac diem nha chieu
daivachieu rpng tui bao tCrco sU

day
tren
moi
trudng
nuoi cay. P capsici c6 dang lai A2 va ca A1, c6 cung kieu
tiep
xuc
theo
kieu tui due bao xung quanh tui noan (Amphigynous).Tui noan hinh
cau
CO
mau cam sam vdi be mat
tron
lang hay xu
xi.
Cac mau P capsici phan
lap tu ho
tieu
c6 he spi phat
trien
phong len
tren
mat moi trUdng PGA va
CRA tao thanh dang hinh hoa hong hoac hoa thupc dupc c6 mep dang tia
ngan hoac
tia
dai.
Sau 6
ngay
u

khoang nhiet
do
thfch hop nhat.
d nhiet
do
thap hon
12°C,
chi mot so
ft
mau phan lap vao mua kho
6
vudn
tieu trong thuan phat trien. NhUng
d
35°C,
rat
ft
mau phan lap ton tai, ngoai
tru'
mau phan lap
d
vUdn tieu trong xen cay ca phe tai Dong Nai. Dac diem
hinh thai
va sa
phat trien cua
cac
mau
Phytophthora capsici
phu thupc vao
yeu

sanh hinh thai P.
capsici
phan
lap
d
vadn tieu
thuan
va
xen
ca
phe.
Chi
tieu tiieo
doi
Phytophthora
or
vaim
xen
Phytophthora
d
virorn
thuan
(n
= 12)
(n=12)
Bien
thien
Trung
binh
Bien

tui
1,49
-3,87
2,69
1,66
-3,37
2,58
bao tu
(nm)
Kich
thuac
l6
phong 4,63
-7,78
5,65
4,20 -6,86
5,41
thich
tui
bao
tir
(nm)
Kich
thuac
chieu
dai
27,5
-
104,5
70,2

khi
nhiem 10^ dpng bao tCr/ml trong 20
-
30 ngay
d
dieu kien am
dp
cao. Dpng
bao tCr la nguon lay nhiem nguy hiem, trong vong
4
gid sau khi phong thfch
tii
tui bao tCr cac dpng bao tCf co kha nang xam nhap vao
mo
la, dinh
re
non,
va vet thapng tren than, choi non, md dau cho chu
ky
gay benh. Dpng
bao
tCf chi phong thich trong dieu kien am
dp
khong khi cao, nhiet dp thap, mUa
nhe,
trong gipt nadc. Mua kho,
he
spi
va tui
bao tCr la nguon gay benh

hay am
dp dat
vung
re
la
yeu
to
tac
dpng
den
siJ ton
tai va day tri
nguon
benh trong mua kho, phat tan vao mua maa.
Bang 5:
Nguon
P
cops/c; trong viidn
ho
tieu
bi
benh chet nhanh
vao mua
kho (thang 2/2011) (Huynh Tan True, 2011)
Do
sau lay
mau
dat
(cm)
Ti

trung
binh
(%)
0-5 23 7
16 15,3
5-10
13
2 9
8,0
10-20 11
2
0
4,3
20-30 13
0
7
6,7
>60
0
0
2
0,7
CV(%)
53,1
P
capsici
luon
ton tai
dadi
tan

co
nguon goc xuat
phat
tii
goc
-
tan cay
tieu,
v6i khoang each Ian truyen qua nUdc mUa tCr 1,0
m
den
1,5
m. Do
do
can tao cac mUPng thoat nadc tot, nham
cat
nguon benh
lay Ian
va
phat tan trong mua mUa. Cay trong xen, nha ca phe, cung la "vat
can"su'phat tan P
capsici,
giup han che nguon benh tfch luy trong vUdn
tieu.
Hinh
IS:
Trieu
chCTng
gay ra
tren cac

tra (n = 9 tru)
VCing
\iy
miu
Things
Thing 4
Things
Thang
9
Thang
10
Thang
11
VCing
\iy
miu
Trong
thuan
Tr6ng
xen
Tr6ng
thuan
Trong
xen
Trong
thuan
Tr6ng
xen
Tr6ng
thuSn

3,2
Q7
6,5
6,0
7,0
6,3
9,1
6,4
Nguon gene khang
P.
caps/c/trong cac giong ho tieu thupc loai
Piper
nigrum chua duoc xac dinh, nguon giong chong chiu benh de bj "tan cong"
d\Jd\p lac nguon benh c6 doc tinh cao. Dien bien cua benh chet nhanh
trong chu ky 1
nam c6 the thay doi theo vung sinh
thai,
dieu kien thcJi tiet,
CO cau giong trong vung, va bien
phap phong trCr da duoc ap
dung.
Trieu chufng cay tieu chet
hang loat thadng xay ra vao mua
kho,
dudi dieu kien nhiet do cao,
boc thoat hai nUdc nhieu, do he
re bj hu thoi nen cay nhanh
chong tan lui. Trong mua mUa,
hien taong cay chet xay ra khi
iUdng mira va so ngay mUa dat

nhiem thanh cong vao mo re
"binli
ttiUdng"
ton tgi
tren
cCing
1
tru
ctioai.
18
^^n khi xuat hien trieu chCrng chet nhanh phu thupc vao tuoi cay
tieu;
c6 the
1 _ 2 mua mua. Trong khi tren la, choi non, dot than non, va re to, P
capsici
chi can 4 -10 ngay da gay chay la, chet
choi,
rung dot than, va cay 6 thang
tuoi se chet sau 30 ngay bj xam nhiem (Nguyen Than, 2004). Dong bao tCr la
nguon xam nhiem chfnh trong mua mUa gay ra trieu chCrng benh rat nhanh
tren
la,
trai,
ngpn non, va dot than, trong khi he spi va bao tCrco the la nguon
xam nhiem vao re cay trong mua kho khi am dp vung re phu hop.
DUa vao so cay benh trong vadn c6 the du doan vj tri nguon benh
ton tai va dudoan trinh trang benh cua vadn sau nhieu nam. NhUvay, bien
phap"c6 lap" nguon benh ban dau se giup giam nguon benh tich luy va lay
Ian trong vadn va giQa cac vadn ho
tieu.

va dac diem gay
benh
Tac nhan gay benh thiidng do nhieu nguyen nhan khac nhau nha
do nam Fusarium oxysporum, Fusarium solani
f.
sp. piperis, tuyen trung gay
ha re, rep sap, va ca
P.
capsici. NhQng nghien cufu cua Iran Thi Thu Ha va cs
(2011),
da xac djnh Fusarium solani va Fusarium oxysporum c6 kha nang gay
benh vang la cho ho tieu trong tai Quang Tri, thdi gian Ci benh tCr 13 - 17
ngaysau chung.
Hlnh
19:
Mdu nam Fusarium
sp.
tren moi trUcfng PDA phan lap
tCtvUdn
ho tieu bi benh thoi re vang
Id
(A,
B).
Cay tieu sau khi chung nam dittic
cdch ly
(C),
cay ho tieu bi nhiem benh vang Id sau chung 14 ngay (D)
20
Chung tren cay tieu 2 thang tuoi trong vudn uom,
Fusarium spp. gay trieu chCrng vang la dau tien vao

Dai bao tCt tren
dinli sal nam
Soi nam ptian sinh
Hinh 20: Dai bao tdrvd tieu bao tvfnam Fusarium
spp.
3.
Benh
do
tuyen
trung
i^o ta
trieu
chuTng
va tac hai cua
benh
Tuyen trung ky sinh tren re ho tieu gom tuyen trung ngoai ky sinh va
"^Pi
ky
sinh,
chi'ch hut dinh dadng td re lam suy giam sdc khoe cua cay, gay
ton thaong re ngan can sa hap thu dinh dadng va nadc, gay vang la cue
bo hoac vang toan bo cay, gay heo tam thdi vao mua kho khi thieu nadc
CO
nhieu u badu tren re, vet tham den tai
badu,
hoac badu bi muc nat,
» " 21
CO
rat It re non
diTcfc

Quang Trj hien dien 27 loai tuyen trung ky sinh, trong do
Aphelenchus
avenae,
Rotylenchulus
reniformis,
Meloidogyne
incognita
la nhQng loai pho
bien va c6 mat so cao, rieng
Aphelenchoides
trivialis
la loai duoc ghi nhan
dau tien tren vung re cay ho tieu (Trinh Thi Thu
Thuy
va cs, 2012).
Theo
Nguyen Ba
KhUOng
(1983), d vung ho
tieu
mien Nam Viet Nam c6 15 giong
tuyen
trung
dUdc
phan lap nhu
Criconemoides,
Dolichodorus,
Helicoty-
lenchus,
l-lemicriconemoides,

di/a vao phan ufng cua cac giong cay chi
thi
vdi nguon
tuyen
trung
Meloido-
gyne duoc phan tach thuan va cau true cua van hau mon, da xac dinh
Meloidogyne
incognita
va
Meloidogyne
arenaria
ky sinh
tren
re ho
tieu
vung
Ba Ria - Vung Tau. Trong do
M.
incognita
chiem Uu the vdi 78,4% mau re bi
ky sinh va
M.
arenaria
ky sinh
tren
21,6% mau re
(Bang
7).
Bang

0
0
92,6 ± 11,6
53,6 ± 10,7
17,5 ±1,5
67,0
±11,0
Se la Ian
0
0
98,0 ± 8,6
81,3 ±8,8
19,5 ±2,5
76,0 ± 5,0
VTnh
Linh
0
0
92,6 ± 14,2
67,6 ± 10,9
21,5 ±6,5
60,0 ± 9,7
Panniyur - 1
0
0
101,6+10,2
65,6 ± 12,5
17,0 ±4,0
80,3 ± 9,2
Lada

tieu
Ba Ria
-
Vung Tau va Dong Nai
(Bang
8).
Phan
ti'ch
mau dat va re ho tieu vung Lpc Ninh - Binh
PhUdcTran
Quoc
Hoai (2010),
xac dinh sii hien dien cua 19 loai thupc 16 giong tuyen trung
khac
nhau,
trong
do
Rotylenchulus,
Meloidogyne,
va
Tylenchulus
la ba giong tuyen
trung
pho bien trong 80 - 100% vUdn khao sat.
Diia
vao thanh phan giong
(genus)
va loai
(species)
ducfc djnh danh cho thay vung

cang
tot,
re hut dinh dudng
cang
nhieu,
tuyen trung
cang
phat
trien
nhanh ve dan so. Mat so tuyen trung tren mot dcfn vj khoi lupng dat
(50g, 100 g)
hoac
khoi luong re
(1
g, 5
g), so badu
tren
don vi dai cua re (cm)
hay khoi lupng re (1g), so tuyen trung cai trong
1
butdu
re, la cac chi tieu
dung de danh gia mu^c do nhiem tuyen trung cua dat trong va cay ky chu.
Vi vay, bien phap kiem soat dan so
tuyen
trung
can thiic hien vao
thdi
diem
cay ho tieu cd toe dp phat

sau hon 60 cm, vi vay ky thuat trpng va cham sdc chp he re phat trien
thep
chieu sau se giup cay"thpat"su'xam nhiem cua tuyen
trung.
Tuyen
trung phat tan thep
nUdc
mUa,
nUdc
tudi,
dpng vat di lai
trong
vadn, cay gipng nhiem tuyen
trung,
hpac
dp cpn ngddi di lai vp
tinh
•T^ang
dat nhiem tuyen
trung.
Tan du
re
cd
tuyen
trung djnh cd, cay ky chu,
•T^ang
trdng trpng dat la nOi
\Uu
ton nguon tuyen trung tren vUdn hp tieu
h^ng nam.

334
388
414
Vung
Tau
Sela
nh6(n= 10)
135 280
234
296
(Binh
Gia,
Se
la Ion (n =
7)
265
326
497
630
Ngai
Giao,
Phil
Qu6e
(n = 5)
369 424 449 506
Hoa
Long,
Karimunda (n = 16)
273 373 384 433
Long

266 252 354
Phu Qu6e (n = 5)
220
254 374 520
Karimunda (n = 4)
188
254 89
106
Pennijur -
1
(n = 5)
220
300 268
334
Lada belangtung (n = 4)
189 240 106 166
Tieu
trau (n = 4)
229 246 292 554
Se ba chia (n = 4)
273
406 200
256
Binh
Duong Se
la
nho
(n
=
4)

230 0
-
(Loc
Ninh,
Sela
nh6(n= 13)
237
506
230 338
Binh
Long)
Sela
lorn(n=
14)
382
460 256 336
Karimunda (n = 7)
264 410 390 605
Tieu
trau (n = 4)
305
376 0
-
Tay
Ninh
Vinh
Linh
(n = 4)
159 206
0

Dong
VTnh Linh
(n = 4)
373
496 0
-
(LOc
Nga,
Se
la
nho
(n
=
8)
180 268 0
-
Loc
Thanh - Se la
Icrn
(n = 9) 190 310 105 225
Bao
Loc)
Phu Qu6c (n = 4)
181 255 0
Tieu
trau (n = 5)
238 355 0
Dak Lak
VTnh Linh
(n = 5)

Tieu
trau (n = 5) 313 370 0
-
Kien
Giang Phu
Quoc
(n= 15)
177 270 0
-
(Kien
Tieu
se (n= 10)
115 166 0
-
Lucmg,
Ha
Tieu
trau (n = 5)
94 120 0
-
Tien,
Phu
Tieu
Ha
Tien
(n = 10) 174
210 0
Qu6c)
Quang Tri
VTnh Linh

khong
cd
bUdu
tuyen
trung
Re
cay
dau
phdng
khong
c6
bUdu
tuyen
trung
Hinh
21:
Phan
Ctng
cua mot so cay ky chu chi thi cho sit gay
binh
cua
tuyen
trung
Meloidogyne
spp.
phan
lap tit re ho
tieu
25
Hinh

re
do
butdu
phinh
to
(Phan
Thanh
San,
2004)
Cay
tieu
bi
benh
Re
bi
benh
vdi
budu
gay
bien
dang
re
4.
Benh
do vi rut
Doi vdi cay tieu thong thudng ngudi trong dung phaong phap
giam canh de nhan giong trong trong nridi va trong thay the nhufng cay tieu
chet trong vadn.Oacdiem phan hoa canh nhanh cua cay va sutac dpng cat
tia tao tan hang nam da lam lay nhiem vi rut theo kieu ngau nhien gia tang
mure dp nhiem benh tren dong rupng. Benh xuat hien tC/vUdn uom den sau

thu^cfc nhp khpng binh thudng, chop la cong
xuong,
be mat la nhan nhum, loi lom, c6 nhieu
vet kham, dom. Ngpn npn bi chun lai, cay sinh
trUdng cham hpac lun vang ca cay. Dpi khi
trpng cung mpt cay chi
CP
mpt phan hay mpt
vai nhanh tieu
CP
trieu chtTng benh,
CP
it chum
trai,
sp trai/chum ft, hat rat nhp.
Vang la: Phan vang la phan gi6i han giufa cac
gan chinh cua la, khpng phan biet rp rang giQa
vung benh va khpng benh, la khpng bien
dang.
Trieu chCrng thadng thay d la banh te va
la gia. Trieu churng benh gipng nhu cay thieu Khamxoan la
dinh dadng.
Dom vang nhat: Thadng thay d la gia, tren mat la cp nhieu vet ddm nhp
mau vang, dadng kinh khpang 1 - 3 mm, vet benh khpng hpai tCr, khpng
mat di, la khpng bj bien dang. Cay phat trien binh thadng.
Kham
xanh:
Gan la xanh, bien dang d mep la,
CP
nhieu vet xanh dam Ipi

tren
cay ho
tieu
30
frinh
trang benh
vi
rut
tren
cay ho
tieu
Nghien curu
cua
Phan Dufc San (2003) xac djnh
c6 9
loai
vi rut gay
hai tren cay ho tieu tai cac vung tieu Phu Quoc
-
Kien Giang, Ha Tien
-
Kien
Giang,
Chau
Ddc -
Ba Ria
-
VungTau
va
Loc Ninh

khong
phai toan
bp
la, canh deu c6 trieu chCrng benh,
vi
vay rat kho nhan biet tinh
trang benh
cua cay
sdm. Trieu chtTng benh
va
mufc
dp
benh
vi rut
khong
lien quan den tuoi cay ho tieu va vung canh tac (bang 9,10), cay ho tieu
I6n
hPn
5
nam tuoi nhiem
vi rut
khong cao hpn cay nho hpn
2
nam
tuoi.
Vi vay,
can kiem soat
sU
Ian truyen nguon
vi

Vang
la
gan xanh 12,7 30,2 10,1 30,1
La nhd bien dang
9,5 5,3 7,5
5,3
Vang
la
6,4 10,2 6,8 10,1
Dom vang nhat 4,8 10,5 20,0
-
Kham xanh
8,3
4,1
8,8
17,4
(-):
Khong
xac
djnh,
dieu
tra tren tieu 1-8
nam
tuoi
(Trich
ket qud
nghiin
ciru
cua
Phan

5-8 1-2 5-8
Dom hoa
la 58,7
54,5
33,3
38,8
44,0
45,2
33,3 30,7
Vang
la
gan xanh
12,0
9,2
21,5
38,8
12,3 7,8 31,5 27,7
La nho bien dang
10,2
9,7
10,3
0,3 1,8
12,7
3,3 7,3
Vang
la 12,8
0,0
14,3
6,2
13,2 0,7

quy
luat,
c6
khi
la
benh xuat hien
tren
mot
so
nhanh phan dudi thap, hoac mot
vai
la
trong
cung mot nhanh, mot vai nhanh trong cung mot
cay
tieu.
Trong vUdn,
cay
benh xuat hien
va lay
Ian theo kieu "ngau
nhien".
Tai
Chau
Dufc
chi c6
trieu
chufngVang la gan xanh,
Kham
xanh, va

SCrdung
phadng phap
ELISA
vdi
cac
khang the don
va da
dong,
da
xac djnh TMV hien dien trong tCrng
trieu
churng benh ngoai dong ruong
(Bang
11).
TMV pho bien
tren
cay
ho tieu trong tai Binh
Phadc
va
Dong Nai,
va
la
mot trong nhQng
tac
nhan
tao nen
trieu
chufng benh.
Chung

Kham
xanh thu tCr
ho tieu trong tai
Gia
Lai. Nhu vay, CMV,TMV,
va
PYMoV
la
ba
loai vi rut duoc
xac nhan
gay
trieu
chuCng
benh
cho ho
tieu hien nay. Trieu
chCfng
benh
ngoai dong ruong
la
he qua
cua cac
tac dong phufc tap cua nhieu loai
vi
rut
khac
nhau cung hien dien trong
cay
(Lockhart,! 997;

tliUdc
DNA
dagc
tong
hap
la
450 bp, gel
agarose
1,5%,
80
V.
I
ladder
100
bp
2,
doi
chCfng
di/ong
3-5,
mau
benh
6, mau
khong
benh
32
Bang
11: Ket qua phan ti'ch mau benh bang
ELISA
Ten

cac
trieu
chufng benh
(So
lieu dieu
tra
nam 2003)
Viing
dieu
tra
Ti
le
(%)
la c6 TMV theo trieu
chiiTng
benh
(Huyen)
Dom
Lanhd
Vang
Vang
06'm
KhSm
hoa
la
la
gan
la
vang
xanh

3,3
Ba Ria-
VCingTau
Xac
dinh
phi/orng
thuTc
Ian truyen benh
vi
rut
Vi rut
Ian
truyen
qua
nhieu phuong
each
khac
nhau, trong
do qua
horn
giong
la
con dudng chi'nh doi vdi nhieu loai vi
rut,
vi
cay
ho tieu thong
thudng
du'oc nhan giong
v6

canh khong
c6
trieu
chufng benh
van
xuat hien
trieu
chCrng
benh
tren
choi 1 thang
tuoi
doi
vdi
giong tieu
Se, va
sdm
hon
doi
tieu
Vinh Linh
(Bang
13). Trieu chufng benh
tren
choi thadng
la
dom vang
nhat,
dom hoai tCr
tren

tCr
vung tieu nay
sang
vung
khac, khong
phu
thuoc
vao
vung
dja ly gay
kho
khan trong phong trCf.
Lockhart va
cs.
(1997)
va
Bhat va
cs.
(2003) cho rang rep
sap
{Ferrisia
virgata
*
33
va
Planococcus citri)
dacrc
xem
la
vector

ho
tieu.
Bang
13: Sif lan
truyen
vi rut qua
horn giong trong giam canh tieu
VTnh Linh benh theo trieu chufng
Horn Tieu
So
horn giong the hiien trieu chuTng benh
do vi
rut sau khi giam
Vinh Linh
ISngay 25ngay 35 ngay
45 ngay 45 ngay
50ngay
mang trieu
chuTng
IHS
IHB
IHS
IHB IHS IHB
IHS
IHB IHS
IHB IHS
IHB
Hoa
la
115

51
8 50 26 38 18 36 18
28
19
nhat
Khong benh 116
2
24
2 20
6 17 3 17 8 13
6
IHS:T6ng
so
horn
song,
IHB:Tong
so
horn
bi
benh.
mchke„uingMencaucu.WnTMNgocMn.20o,)
Trieu
chiJng
benh xuat hien tCf
hom
giong I<h6ng benh gom: Hoa la, la nh6.
Tac
hai cua
benh
vi rut

truyen
qua
nhieu
nam
gay hien taong xoan la, chun
dot
canh,
va lun cay.
Do
ky
thuat
cat
canh
tao
tan cung
vdi tac
dong
cua
phan
bon,
so
canh
mdi
xuat hien
doi khi
khong
hoac chaa
c6
trieu chiTng benh
lam cho sa

thay
sa
khac biet
len den
50%
nang
suat
hat
tieu thaong pham
6
cay
tieu
4 -
5 nam
tuoi,
lam
giam
thu
nhap
cua
ngacJi trong
tieu,
thiet
hai nay
tadng Crng
vdi
50%
tru
tieu
bi

giup
cho so
trai
con
lai
tren
cay
benh nang
va
nhe
khong
c6 sa
khac biet
ve
trong laong
hay
kfch
thadc. Trong laong
1.000 hat
tieu
va ti le
tieu taoi/kho khong khac biet
Idn
34
giaa
cac
mau
so
sanh. Thiet
hai

dai
chum,
so hat
va ki'ch thadc
hat
trung binh tren tieu Vinh Linh
4-5
tuoi trong
tai
Chau
Oac -
Ba
Ria
-
Vung
Tau
Ti?ih trang Tieu benh
nhe
Tieu benh nang
So Chieu
So
KichthUdc
So
Chieu
So
KichthUdc
chum/
dai hat/ hat
chum/
dai hat/ hat

86,4
29,6
3,21 5,3 60,7
18,4
3,3
-:
Khong c6
ketqui ITrlchkdqudnghl^noAi
cua
TrdnThiNgocHdn, 2004)
Bang
15: So
sanh nang suat tieu
hat
giaa
cay
tieu benh
vi rut
nang
va nhe
tren giong Vinh Linh
4 - 5
tuoi trong
tai
Chau
Ddc -
Ba Ria
-
VOng
Tau

Vadn
1
10.840 4.247
70,0
32,0 2,6
3.970
1.329 66,8
30,5
3,0
Vadn2 10.358 4.622
98,3
41,9
2,2
5.885
2.356
97,5 41,0
2,4
Vadn
3
8.770 3.204
102,8
46,5
2,7
4.142
1.424
99,8 39,6
2,9
Vadn
4
11.220 4.658