Cây hồ tiêu bệnh hại và biện pháp phòng trừ

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, 200

BUI CACH TUYEN - LE OJNH O O N

BENH HAI VA BIEN PHAP PHONG TRll

BUI CACH TUY^N - LE OJNH DON

CAY HO TIEU

BENH HAI V A

BIEN PHAP PHONG TRQ

NHA XUAT BAN NONG NGHIEP

TP Ho Chi Minh-2013

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 Dac diem hinh thai cay ho tieu 6

III Bfnh hai tren cay ho tieu tai Vift Nam 11

1 Benh Phytophthora tren ho tieu 11

Mo ta trieu chung va tac hai cua benh 12 Tac nhan gay benh va dac diem gay benh 15

2 Benh vang la 19

Mo ta trieu chung va tac hai cua benh 19 Tac nhan gay benh va dac diem gay benh 20

3 Benh do tuyen trung 21

Mo ta trieu chung va tac hai cua benh 21 Tac nhan gay benh va dac diem gay benh 22

4 Benh do vi rut 28 Trieu chung benh do vi nit gay ra 28

Tinh trang benh vi nit tren cay ho tieu 31 Xac dinh tac nhan vi nit bSng ky thuat phan tu 32

Xac dinh phuomg thiic Ian truy6n benh vi nit 33 Tac hai cua benh vi nit tren cay ho tieu 34

iii

4

5 Benh sai chi (mang nhen) 36

Mo ta trieu chung va tac hai ciia 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 benh hai tren cay ho tieu 48

2 Nh&ng giai phap chinh trong han che dich benh tren ho tieu 50

3 Mot so bien phap cu the 63

Tai lieu tham khao 71

iv

DANH SACH BANG

B l n g l : Dien tfch trong cay ho tieu tren the gidi (hecta) ,

Bang 2: San \uang hat ho tieu tren the gi6i (Tan)

Bang 3: Dien ti'ch cay ho tieu tai 6 tinh trong tieu chinh d Viet nam (VPA,

2011)

Bang 4: Mot so chi tieu so sanh hinh thai P capsici phan lap d 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: Ti le (%) tru tieu benh theo tCrng trieu chu'ng va tuoi cay d cac

vung dieu tra nam 2004 Being 11: Ket qua phan tich mau benh bang ELISA Bang 12: Ti le xuat hien TMV trong cac trieu chufng benh (So lieu dieu tra

nam 2003) Bing 13: Sii Ian truyen vi rut qua hom giong trong giam canh tieu VTnh Linh

theo trieu chu'ng Bang 14: So sanh so chum trai/canh, chieu dai chum, so trai va kich thi/dc

hat trung binh tren tieu Vinh Linh 4 - 5 tuoi trong tai huyen Chau Dijfctinh Ba Ria-VungTau

Being 15: So sanh nang suat tieu hat giu'a cay tieu 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 trCf tai B^ Rja - Vung

Tau (dieu tra thang 5/2012)

BSng 17: Ty le (%) hat tieu tai Ba Rja - Vung Tau nhiem cac loai Aspergillus

vi

DANH SACH HlNH ANH

Hinhl: Cac sin pham sCr dung tCf hat ho tieu Hinh2: Dien 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 Hinh 7: Cac dang la tieu

Hinh 8: Chum hoa va hoa ho tieu Hinh 9a, 9b: Cac dang trai tieu

Hinh 10: Cac dang trieu chu'ng benh do Phytophthora capsici gay ra tren la

thanh cum tren vudn tieu

Hinh 15: Trieu chufng gay ra tren cac mau la tieu dung de "bay P capsici"

trong dat, nhiet do phong sau 4 ngay Hinh 16: Trieu chufng "teo t6p"cS chum trai tieu xanh la dau hieu nhan biet

cay bj benh chet nhanh, khong the phuc hoi Hinh 18: Hoi chCrng vang la

Hinh 19: Mau nam Fusarium sp tren moi triTdng PDA phan lap tCrvUdn ho

tieu bj benh thoi re vang la (A, B) Cay tieu 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 re ho tieu

Hinh 23: Re cay ho tieu bj u budu do tuyen trung Meloidogyne spp

Hinh 24: Tuyen trung tren cay ho tieu

Hinh 25a, 25b: Cac dang benh do vi rut gay ra

Hinh 26: Benh vi rut tren cay ho tieu

Hinh 27: Dien di DNA-PCR vdi cac primer chuyen biet giup xac dinh sii hien

dien cua vi rut PYMoV trong la ho tieu 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

Hinh 32: 6 tao gay benh dom tren ho tieu

Hinh 33a,33b: Benh than tha tren cay ho tieu

Hinh 34: Cay ho tieu bj benh vang la va than thii v6i vet benh tai chop la

Hinh 35: Nam Aspergillus sp

Hinh 36: Nam Penicillium citrinum

Hinh 37: Nam Fivsanum sp

Hinh 38: Nam Mucor sp

Hinh 39: Trai bat (A), Iu6i (B) cho thu hoach ho tieu nham han che SLftap

nhiem 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 va d i m bao dp am dat

vao mua kho

Hinh 43a, 43b: Vadn aom cay con va san xuat cay ho tieu giong Hinh 44a, 44b: Cac dang tru choai cho cay ho tieu

Hinh 45: Cat tia cac canh vung sat goc tieu tao sU thong thoang; B: Vadn

ho tieu da tao sU thong thoang

Hinh 46: Vudn ho tieu dUpc sii dung thCr nghiem che pham vi sinh BCF

chLfa Bacillus subtilis tai Chau DiJc, Ba Rja - Vung Tau, 2012

Hinh 47a: Cay 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 canh tac ho tieu tai Ba Ria - Vung Tau Hinh 50: Tan du benh chet nhanh cay ho tieu

Hinh 51: Cay ho tieu Vinh Linh dUpc ghep tren goc tieu dai Hinh 52: San xuat cay ho tieu qua nuoi cay mo nham tao cay sach vi rut Hinh 53: Ky thuat dudng canh tieu luon cho lam hom giong

Hinh 54: Cay giong khoe manh diipc chuan bi 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 la cay trong sieu loi nhuan, tuy nhien ngadi trong tieu gap rat nhieu rui ro, vi cay tieu c6 nhieu benh hai Hon the nufa, nhieu nam qua trong tieu 6 nUdc ta chu yeu tham canh b3ng bien phap hoa hoc (phan b6n

va thuoc bio ve thUc vat hoa hoc) lam cho benh hai cang them pha hai nang ne

Quyen sach"Cay ho tieu - Benh hai va bien phap phong tru"da gi6i thieu tom t^t day du dac diem sinh hoc, nong hoc va nhufng benh hai chinh cua cay ho 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 tham canh hoa hoc, thieu ben vijfng da lam benh hai them nghiem trong, nhieu vu'6n tieu bj benh chet hang loat

lii nhufng dac diem cua cay tieu va nhufng benh hai chinh co tCr

trong dat, tac gia quyen sach da de xuat bien phap phong trCf theo IPM chu yeu tren nen canh tac theo hadng hOfu co, bio ve do phi trong dat, lam co s6 cho quan the vi sinh vat co fch va doi khang phat trien du sufc khong che benh hai co nguyen 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

Tran trong gidi thieu den ban doc

GS.TS Nguyen Thor

xi

iCf\I DAU

Benh tren cay ho tieu da dugfc nghien cufu vao nhCng nam 80 khi

hat ho tieu Viet Nam daac chu y tren t h i trUdng hang nong san va d o n g t h d i

xuat hien nhieu bao cao ve hien tuang cay ho tieu chet hang loat Cac

nghien C L T U ve benh hai ho tieu dUgfc cap kinh phi tii n g u o n dja p h u o n g

hoac cap Bo va Nha nUdc Nhieu ket qua nghien cufu da duac t o n g ket, p h o

bien, LTng dung, dem lai hieu qua ky thuat va kinh te cho ngadi trong tieu

va gia tang san iupng hat tieu xuat khau d e m ngoai te ve cho dat nadc

Npi d u n g trinh bay t r o n g cuon sach nay t a p t r u n g vao cac benh

t h a d n g thay tren cay ho tieu lam giam nang suat, giam chat lupng va gay

chet cay lam t o n hai ve kinh te cho ngadi t r o n g tieu So lieu va hinh anh

trinh bay t r o n g sach la ket qua nghien cufu cua nhieu t h e he thay c6 giao,

sinh vien da! hoc, cao hoc, va nghien cufu vien cua nganh Bao veThUc vat,

Cong nghe sinh hoc, thuoc Bo m o n Bao v e T h i i c vat Bp m o n Cong nghe

Sinh hpc cua TrUdng Dai hpc Nong Lam t h a n h p h o Ho Chi M i n h , tii giai

quyet nan chet cay tieu tren dao Phu Quoc vao t h d i gian dau cua nhQng

nam 1980 den giup cac t i n h mien Trung, Tay Nguyen va D o n g Nam Bp vao

nhufng nam 1990 Cac no lUc d o da g i u p tfch luy cac t h o n g t i n lien quan den

benh hai cay ho tieu Mat khac, cac tai lieu t h a m khao cung ho t r p cho cac

ket qua nghien cufu trinh bay t r o n g sach nay bao d a m ti'nh chi'nh xac va

khoa hpc

Cac tac gia bien soan sach nay chan t h a n h cam Pn sif d o n g g o p tu"

lieu va hinh anh m i n h hpa c6 gia tri khoa hpc cua sinh vien va hpc vien c6

ten t r o n g tai lieu t h a m khao va hinh anh cung cap bdi Cong t y Hoa nong

Hop Tri cho viec hoan thien cac npi d u n g Day la Ian xuat ban dau tien nen

khong tranh dUpc nhCng thieu sot, cac tac gia bien soan rat m o n g nhan

dupe su"dong g o p y kien cua ngadi dpc nham hoan thien sach t r o n g Ian tai

ban sau

Chan t h a n h cam o n

Tac gia

xii

I sd Li/ac CAY H6 Ti§u

Cay ho tieu dang dupe t r o n g la loai cay hai la m a m c6 ten khoa hpc

Piper nigrum L, 2n=52 hp Piperaceae dupe cho la m p t loai lai giu'a cac loai

hoang dai Piper wiglitiiva Piper galeatum, hoac Piper wightii va Piper

tricho-stachyon (Ravindran, 2000) Cay ho tieu dupe xem la "Vua cua cac loai gia vj"

con gpi la "vang den", diipc t r o n g nhieu d cac quoc gia nam gan xfch dao va

C O k h i hau nhiet d d i Hat tieu kho dUpc sCr d u n g nhu' m p t loai gia vj t r o n g

thUc p h a m , t i n h dau chiet xuat tii hat dUpc d u n g t r o n g chQa benh cho

ngUdi va c6 t r o n g t h a n h phan cua m p t so my p h a m

Hinh 1: Cac sdn pham sit dung tit hat ho tieu

A: Hat tieu den; B: Bot tieu den; C: Hat tieu trdng; D: Bot tieu trang; E: Hat tieu dong goi;

F: Tieu non Ci ctiua; G, H, I, K: Tieu dung lam gia vi trong ttiuc plidm ^

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 tieu dugfc cho la dOong Nam Chau

A vdi cac dang hoang dai tim thay trong rCfng nhiet ddi cua An 06, dao Java cua Indonesia Dang ho tieu du'ac trong tai Malaysia va Indonesia dUpc du

nhap vao the ky thuf nhat sau cong nguyen vao thdi cue thinh cua vuong

quoc Hindu 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 Nam tham gia vao thj tru'dng xuat khau, da thuc day su" phat trien ca dien tfch trong va quy mo

sin pham Su chuyen dich co cau cay trong va quy mo cong nghiep, djch

vu, va du lich da lam thu hep dien tfch vung tieu Phu Quoc, nhu'ng hinh thanh nhu'ng vung tieu mdi nhuChuSe Dich benh xly ra lien 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 VLTpt qua dien tfch da quy hoach, dem lai sin lupng tren 100.000 tan/nam, va xuat khau dat tren 14 ngan ti dong (nien vu 2012) va dang difpc trong tai 22 tinh thanh trong ca ni/dc

B^ng 1: Dien tfch trong cay ho tieu tren the gidi (hecta)

trong tieu (ha) hoach (ha)

Nang suat Udrc tinh (tan/ha) Shn lUqrng (tan)

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

dj t r o n g cac g i o n g ho t i e u d a o c t i e n d o a n la rat Idn g i u p c h o c o n g tac chpn loc g i o n g c6 nhieu trien v o n g va ben canh, n g u o n g o c g i o n g c u n g kho xac d j n h b d i s U t h f c h iTng cao cua cac g i o n g t r o n g nhieu v u n g dja ly

2 Oac diem nong hoc cua cay ho tieu

Tai Viet Nam, cay ho tieu dUPc t r o n g tC/ Nghe An den Phu Quoc bao

g o m cac t i n h v u n g cao nguyen den v u n g ven bien Bac, N a m T r u n g bo Tuy theo g i o n g va ijch sCr canh tac, cay ho tieu da thich nghi v d i v u n g k h i hau nhiet d d i g i o mua d e n khong k h i lanh va am Udt, mua kho keo dai 4 - 5 thang, mUa nhieu den it maa, t r o n g t d i cao d p 800 met tren mat bien (Gia Lai), va t d i 19 d p vT Bac (Nghe An) Thich nghi vdi khi hau va t h d i tiet v u n g ven bien hinh t h a n h v u n g tieu c6 chat lupng cao nhU Phu Quoc, Ba Rja - Vung Tau

Nhiet d o thich h d p c h o cay tieu phat trien tCr 20 - 30°C, nhiet d o thap (10°C) va qua cao (40°C) deu anh h u d n g den sir phat trien cua cay, sa phan hoa m a m hoa, va t h d i gian chin cua trai Laang mUa tCr 2.000 - 3.000

m m , vdi am d p khong k h i tCr 60 - 70%, khong c6 gio bao Lupng nUdc t u d i vao mua kho cho cay tieu rat quan t r o n g vi day la t h d i gian cay tich ICiy chat kho vao hat va bat dau cho chu ky sinh trUdng mdi Anh sang tan xa thich hop c h o cay tieu sinh t r a d n g va phat trien, dac biet t r o n g giai doan sau trong va kien thiet co ban Nguon goc xuat xCrtCr v u n g rCrng nhiet ddi chufng

t o cay ho tieu thich nghi vdi dieu kien che b o n g , lUdng hufu co cao, va \ia am

nhung k h o n g chiu ung Cay ho tieu cd t h e t r o n g tren nhieu loai dat khac

nhau, C O cau dat anh h u d n g rat Idn den sufc phat trien cua cay Dat cd co cau

nang kho thoat nUdc, t h a n h phan cat nhieu kho giQ nUdc deu k h o n g thich

5

h o p cho cay ho tieu Oat c6 pH gan t r u n g

t i n h , t h a n h phan hQu cO cao, tang canh tac

tCr 80 - 100 cm, t h o a t niidc tot, deu thi'ch

h o p cho cay ho tieu phat trien

3 Dac diem hinh thai cay ho ti§u

5.1 Rivabgri

Cay ho tieu hinh t h a n h 2 loai re

chfnh, re l<hi sinh va re h u t dinh d a d n g

Rieng re coc, re cai, chi c6 khi t r o n g bang

hat

Re khi sinh phat sinh tai cac d o t

than chfnh, d o t canh cap 1 c6 nhiem vu neo

d o t than vao tru choai Viec neo bam se g i u p

d m h hinh tan cay, gia tang chieu cao, chieu

rong tan cay, va g i u p cac canh cap 1 phat

trien Oac diem re chi phat sinh nhieu tai

mat tiep giap v6i t r u choai, so re nhieu, it

phan chia va map chac

Re hut dinh d u d n g phat sinh tai cac

d o t than ngam, tai vet cat horn g i o n g , t a o

nen bp re g i u p cay hut d i n h d u d n g va nUdc

Re phat trien sau den 1 , 0 - 1 , 5 met va Ian

den ria tan la, tap t r u n g nhieu d d o sau tCr 20

- 50 m Ky thuat bon phan, tud\ va t u

goc anh h a d n g rat Idn den sii phan bo he re

t r o n g v u n g tan cay.Tuy nhien, h a d n g b o re

phat trien an sau x u o n g dat se g i u p cay

c h o n g chiu sUtan cong cua tuyen t r u n g va

nam gay benh, keo dai t u o i t h o cua cay tieu

3.2 Than va canh ho tieu

Than cay tieu 6uac phan biet b d i

mau sic, ki'ch thudc va sU phan canh Than

chinh phat trien len tren, bam chat vao t r u

choai, CO nguon goc tCf cay con hoac tu'

ngon canh tieu sau khi d o n day Choi nach

6

than phat trien t h e o dang tan d u Choi non c6 mau vang nhat den 66 d a m

tuy theo g i o n g va thdi gian sinh trUdng Giong Vinh Linh ngon non c6 mau (Jo nhat den vang nhat, g i o n g Lada Belantung c6 mau t f m nhat.Tuy nhien,

CO sU thay doi mau sac cua ngon non tuy theo dia ly vung trong tieu

Re cay con giam canh

Re hut dinh dwdng

Hinh 4: Choi than non mau do nhat

Choi than non mau do nhat (A); 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 (canh cap 1)

Canh mang trai (canh dc)

Hinh 6: Cdc logi canh phdt trien tren cay ho tieu

- Canh vi/Ot: Dang canh moc thang phat trien len tren tao nen

l<hung tan cay Canh hdp vdi than chi'nh mot goc nho hon 45° bam vao tru

choai Hom giong tC/ canh vUpt se cho trai cham nhung cho nang suat cao

va thdi gian canh tac dai

- Canh laon: Hinh thanh tCrchoi sat goc, c6 long dai bo Ian tren mat

dat Hom giong tC/ canh luon cho trai cham nhUng nang suat cao

- Canh mang trai: Dang canh moc nghieng, canh ngan, khuc khuy,

long rat ngan, goc do phan canh idn Hom giong tCr canh mang trai cho

nang suat thap, mau gia coi, nhang mau cho trai

- Canh dinh: Dang canh phat trien tii phan dinh cua cay, long dai

moc ru xuong, ft dUpc dung lam hom giong (Phan Quoc Sung, 1998)

3.3 Dang la

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 hoa Dadi moi hoa la mot la bac rung sdm Xac dinh dac diem cua hoa cho moi giong la co sd xac dinh bien phap gia tang nang suat va dieu khien qua trinh thu phan tang so lupng trai/chum hoa

Hinh 8: Chum hoa va hoa ho tieu

3.5 Trai tieu

Trai tieu thuoc dang trai hach, hinh cau c6 dadng kfnii tu'4- 8 mm,

hau nhu khong c6 cuong Tuy theo giong va dieu kien canh 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 khi trai chin keo dai tC/ 8 - 10

thang, bao gom giai doan hinh thanh hoa va thu phan keo dai 1,0 - 1,5

thang, phat trien trai tLr4,0 - 5,5 thang, giai doan trai chin X\S 2,0 - 3,0 thang,

trai dat du'dng ki'nh toi da.Tuy theo 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 daoc goi nhu' benh chet nhanh, benh heo xanh, benh chay day, benh ba trau Khong tim thay"dau hieu"cua tac nhan gay benh ngoai dong ruong bang mat thUdng.Trieu chu'ng benh nhan dien qua si/heo ru tCrng phan hay toan cay v6i la mau xanh tai, dom nau den tren

la, trai non heo 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 than ngam Benh lam chet cay tieu hang loat, khong the kiem soat tai cac vung ho tieu tCr Nghe An den Phu Quoc, ti le cay chet len

den 100% Mac du 6\Sgc dau ta nghien cufu Xii nhufng nam 1980 den nay,

nhtfng nhufng hieu biet ve tac nhan gay benh van chua thanh he thong,

chaa CO bien phap phong trC/ hieu qua va mot phan vi nguon gene 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; B: Tai ban Id; C: Tai mep Id; D: Tai 2 mep Id, E: Tai dudi Id, F: Ld khong benh (Nguyen Than, 2004)

11

Mo trieu churng va tac hai gay benh

Tren la: Dom nau den xuat hien vung 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 vao vi tri va dp cao cua cay, trieu

chufng thudng quan sat thay d la nam trong khoang 2 met cao cua cay, la

cua canh bo Ian tren mat dat bj benh nhieu hon tren cao

Hinh 11: Trieu chCfng benh do Phytophthora capsici gay ra tren 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 la non gay heo Id; E: Vet benh

dac trang tren choi non gay rung choi

12

Tren re: MuTc dp ton thi/ong re va dp sau vung re bi hai c6 lien quan

(jen trieu chufng phan tren mat dat cua cay ho tieu

+ Suxam nhiem qua re to den re chfnh se lam thoi phan than ngam g^n 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 mua kho nam sau khi he re bj huy hoai

13

Hinh 13: Cay ho tieu bj benh chet nhanh

A: Trieu chCtng Id vang nhgt toan cay la da'u hieu re nhiem benh; B: 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 sot Igi tren cay chodi va

lay Ian thanh cum tren vUcfn tieu

14

Tac nhan gay benh va dacjdiem gay benh

Tac nhan gay benh: Phytophthora palmivora var piperis;

Phytophthora palmivora MF4, tai Malaysia la Phytophthora botryosa, phytophthora parasitica var nicotianae (Varughese va Anuar, 1992), phytophthora capsici Leonian

P capsicidiuac xac dinh la nguyen nhan chi'nh gay benh chet nhanh

day tieu tai Indonesia (Manohara va cs, 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 dat theo thdi gian, c6 vUdn ty le cay benh len tdi 75%, ca biet c6 vUdn phai huy bo 100% cay tieu sau 4 - 7 nann cham soc

Nguyen Vinh TrUdng va cs (2006) da xac dinh hinh thdc sinh san hufu tinh cua P capsici la di tan A2, noan bao tCf hinh thanh nhu la bSng

chCrng cho sU duy tri nguon benh trong vadn ho tieu tai Quang Trj Nghien

cufu cua Ngo Vinh Vien va cs, (2007) xac dinh Phytophthora capsici la tac

nhan chi'nh gay benh chet nhanh, chet chann (thoi re) cay ho tieu tai Oak

Nong, 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 khac biet, nhonhatia 14 - 27 x 9 - 14 (am

va I6n nhat la 17 - 30 x 10 -16 |am Ki'ch thudc nuom tui bao tCf bien thien t(i

1,2 den 4,5 pm tuy theo mua mUa hay kho va dieu kien canh tac Kfch thu-dc

16 phong thi'ch hep tC/ 3,5 \im den 9,5 [xm, chieu dai cuong rung trung binh

71 Mm, CO khi dai den 127,0 |am Khong hinh thanh bao tCf vach 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 tren moi trUdng CRA, dudng kinh tan spi dat

15

85,4 m m ; 82,9 m m tren PGA va tren m o i t r u d n g khoai m i la 72,4 m m

P capsici tren ho tieu deu c6 kha nang phat trien trong khoang nhiet do tii

12 °C den 350C, nhang d 250C den 30°C la khoang nhiet do thfch hop nhat

d nhiet d o t h a p hon 12 °C, chi mot so ft mau phan lap vao mua kho 6 vudn

tieu t r o n g thuan phat trien NhUng d 35°C, rat ft mau phan lap ton tai, ngoai

tru' mau phan lap d vUdn tieu t r o n g xen cay ca phe tai D o n g Nai Dac diem

hinh thai va sa phat trien cua cac mau Phytophthora capsici phu thupc vao

yeu t o nhiet do TCr ]2K den IS^C toe d p phat trien cua t a n spi tren m o i

t r u d n g d i n h d u d n g cham, spi m a n h , mpc thua, mau trang nhat, k h o n g c6

sU xuat hien cua t u i bao tCr Nhiet d p 35°C he spi co cum lai, khong c6 sa

xuat hien cua t u i bao tCr, mau trang, xop, mpc b u n g tren mat moi trUdng

BSng 4: Mot so chi tieu so sanh hinh thai P capsici phan lap d vadn tieu

thuan va xen ca phe

C h i tieu tiieo doi Phytophthora or vaim xen Phytophthora d virorn thuan

(n = 12) ( n = 1 2 ) Bien thien T r u n g binh Bien thien Trung binh

Kich thirac tiii bao tir 15,3 - 27,8 X 21,6 X 12,7 15,3 - 26,8 X 21, 3 X 12,4

Kich thirac nuom tui 1,49 -3,87 2,69 1,66 -3,37 2,58

bao t u (nm)

K i c h thuac l6 phong 4,63 -7,78 5,65 4,20 -6,86 5,41

thich tui bao tir (nm)

K i c h thuac chieu dai 27,5 - 104,5 70,2 31,8 - 118,5 71,4

cuong rung tiii bao tir

(urn)

Dang lai A2 va A l A2 1

(Theo Nguyen Thi Huang vdcs, 2013)

Dac diem gay benh:

P. capsici CO the gay trieu chifng chet cay ho tieu 6 thang tuoi khi

nhiem 10^ d p n g bao tCr/ml t r o n g 20 - 30 ngay d dieu kien am d p cao D p n g

bao tCr la n g u o n lay nhiem nguy hiem, t r o n g vong 4 g i d sau khi p h o n g thfch

tii tui bao tCr cac d p n g bao tCf co kha nang xam nhap vao m o la, dinh re non,

va vet t h a p n g tren than, choi non, m d dau cho chu ky gay benh D p n g bao

tCf chi p h o n g thich t r o n g dieu kien am d p k h o n g khi cao, nhiet dp thap, mUa

nhe, t r o n g gipt nadc Mua kho, he spi va t u i bao tCr la n g u o n gay benh cho

re ho tieu Nguon benh ti'ch luy giam dan t h e o chieu sau, t h a d n g tii t r u

choai den mep tan la va sau den 30 c m la v u n g n g u o n P capsici hien dien

t r o n g mua kho (bang 5) 6 d p sau nay, he re hut dinh d a o n g cua cay ho tieu

16

tap t r u n g nhieu va tuyen t r u n g ky sinh re hien dien p h o n g p h u Che d p t\Jd'\

hay am d p dat v u n g re la yeu t o tac d p n g d e n siJ t o n tai va d a y tri n g u o n benh t r o n g 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)

T i 1^ (%) mau la bj nhiem P capsici trong

mau dat

T i If

trung binh (%)

Do sau lay mau dat (cm) T r u tieu 1 Try tieu 2 T r u tieu 3

T i If

trung binh (%)

P capsici luon t o n tai dadi tan cay tieu, mat so trong phan goc cay

tieu luon cao h p n vung dat giufa hang cay tieu (bang 6), va vao mua kho

P capsici khong hien dien giCa cac hang cay tieu Tran Thi HUdng va cs

(2013) da xac dinh P capsici tap trung d giCifa hang tieu 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 d o can tao cac mUPng thoat nadc tot, nham cat nguon benh lay Ian va phat tan t r o n g mua mUa Cay t r o n g xen, n h a 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 mau la tieu diing 6e "bay P capsici"

trong dat, nhiet dp phong sau 4 ngay

17

BSng 6: SLTtich luy n g u o n P capsici trong mua kho va maa d hai mo hinh

t r o n g ho tieu nam 2007 (TranThj HUdng, 2009)

thuin

Trong xen Trong

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 p h o n g trCr da duoc ap

d u n g Trieu chufng cay tieu chet

hang loat t h a d n g xay ra vao mua

kho, dudi dieu kien nhiet do cao,

boc thoat hai nUdc nhieu, d o he

re bj h u thoi nen cay nhanh

chong tan lui Trong mua mUa,

hien t a o n g cay chet xay ra khi

iUdng mira va so ngay mUa dat

cao nhat t r o n g nam Cay t h a d n g

chet tCfng phan, hoac it nhanh,

rung la, rung d o t hang loat d

phan tren cao cua cay.Tuy nhien,

kieu gay benh cua P. capsici tren

cay ho tieu la "tap trung", nghia la

khong ngau nhien, cay benh

xuat hien quanh n g u o n benh Hinh16: Trieu chCfng "teo top" ca chum

ban dau tao t h a n h v u n g benh trditieuxanh la ddu hieu nhgn bietcay

(Anandaraj, 2000) Thdi gian Ci bibenh chet nhanh, I(h6ng the phuc hoi

benh, tfnh tCr luc P. capsici xam Lifuy, cayl<li6ng biberili vdichCim trdi

nhiem t h a n h cong vao m o 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, d o t than non, va re to, P capsici

chi can 4 - 1 0 ngay da gay chay la, chet choi, rung d o t than, va cay 6 thang tuoi se chet sau 30 ngay bj xam nhiem (Nguyen Than, 2004) D o n g bao tCr la nguon xam nhiem chfnh t r o n g mua mUa gay ra trieu chCrng benh rat nhanh tren la, trai, ngpn non, va d o t t h a n , t r o n g khi he spi va bao tCrco the la n g u o n xam nhiem vao re cay t r o n g mua kho khi am d p v u n g re phu hop

DUa vao so cay benh t r o n g v a d n c6 the d u doan vj tri n g u o n benh ton tai va d u d o a n trinh trang benh cua v a d n sau nhieu nam NhUvay, bien phap"c6 lap" n g u o n benh ban dau se g i u p giam n g u o n benh tich luy va lay Ian t r o n g v a d n va giQa cac v a d n ho tieu

2 Benh v a n g la

Mo ta trieu chuTng va tac hai cua benh

Benh xuat hien rai rac tren v a d n , mang t i n h cue bp Cay benh c6 la vang t a phan d a d i len tren tru tieu, canh la thaa, khong cd hoac rat it canh non va canh mpc vapt, so canh mang trai ft, so trai tren c h u m tieu it Re bi u sang, ft re t o va t h a d n g bi h a t h o i muc nat Cay benh rat de nhan biet t r o n g vadn Trieu chang vang la rat g i o n g trieu c h a n g thieu d i n h d a d n g cua cay, tuy nhien cay k h d n g hoac ft phuc hoi sau khi bdn phan va t h a d n g trieu chang vang ngay cang nang t h e m Benh lam t a n g chi phf p h d n g t r a n h a n g

t h a d n g it hieu qua, cay se chet dan sau m o t vai nam cho trai

Hinh 17: Hoi chihig vang Id

19

Hinh 18: Hoi chCfng vang Id

Tac nhan gay benh 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

ngay 14 sau chung va den 28 ngay toan bo la cay bj vang Nam xam nhiem qua vet thaong cua re khi trong mdi, khi xdi xao bon phan, qua vet thaong do tuyen trung tao ra va u benh trong thdi gian ft nhat 15 ngay gay thoi den tang phan re, pha vd tQng phan

mo mach dan, gay bien mau he mach lam cay suy

nhuac dan den vang la Nhieu nghien cdu cho rang tuyen trung la tac nhan tao vet thaong cho Fusarium

spp xam nhiem.Trieu chQng vang la doi khi do rep ky sinh tren re tao ra, rep chi'ch hut dinh dadng lam cay

kiet sdc vdi la vang nhat, giam sdc song Cay benh

thadng xuat hien vao mua kho va thadng khong gay chet hoac chet cham, sa lay nhiem ta tatao nen vung benh cue bo; mot den mot vai cay gan ke c6 trieu chang benh Nguyen nhan gay vang la thadng kho xac dinh chinh xac, c6 nhieu tac nhan hien dien dong thdi tren cay benh, vi vay"hoi chQng vang Ia"c6 the daoc goi cho trieu chQng vang la cay ho tieu hien nay

Ttian bi ttioi den

do Fusarium va tieu bao tCf Dai bao ttf

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 hlnh thanh Hoi chufng vang la cay tieu c6 lien quan

den miJc dp re bi ton thaong do su ky sinh cua tuyen trung Trieu chufng

sung re thudng do tuyen trung noi ky sinh gay ra, hoac chi la vet tham nau

- nau den tren re do tuyen trung ngoai ky sinh tao ra

Tac nhan gay benh va dac diem gay benh

Cac mau dat va re ho tieu thu tai Vinh Linh, Gia Linh, va Cam Lo

-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, Hemicycliophora, Hirschmanniella,

Hoplolai-mus, Meloidodera, Meloidogyne, Pratylenchus, Scutellonemo, Trichodorus,

Trophonema, Tylenchorhynchus, va Xiphinema Tai vung ho tieu Tan Lam

-Quang Tri, c6 4 loai tuyen trung gay benh nguy hiem la Meloidogyne

incognita, Rotylenchulus reniformis, Xiphinema americanum, Paratrichodorus

namus (Nguyen Ngoc Chau, 1995) Nghien cufu cua Phan Thanh San (2004)

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 7: Phan Crng cua mot so cay chi thi vdi Meloidogyne spp phan lap tCr

re nhieu giong ho tieu khac nhau trong thi nghiem chung benh (Phan

Thanh Son, 2004)

Nguon So biroii/gram re tiroi cua cac cay chi thi

Meloidogyne Bong Dau Thuoc la 6t Du-a hau Ca chua

Khao sat tren nhCfng mau re tCr nhieu vung trong ho tieu khac nhau,

Nguyen Van Ngoc (2004) da xac dinh Meloidogyne spp ky sinh tren 100%

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mau re cua tat ca cac giong ho tieu dang canh tac, rieng Tylenchulus hien

dien pho bien d vung 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 re cay ho tieu cung hien dien nhieu loai tuyen trung ngoai ky sinh va npi ky sinh, trong do

Rotylenchulus reniformis, Meloidogyne incognita, Meloidogyne arenaria, va Tylenchulus semipenetrans la loai tuyen trung ky sinh c6 djnh gay hai cho re

ho tieu va hien dien pho bien trong cac vung tieu tCr Quang Tri den Binh PhUdc, Ba Rja - Vung Tau Mat so tuyen trung lien quan khong rp rang vdi hpi chufng benh vang la, tuy nhien cay bi benh vang la cp he re cSn cpi, nhieu u budu, dau re npn bi tham den va muc nat tCrng phan

Tuyen trung lupn hien dien trpng vung re hp tieu va tap trung nhieu tu" do sau 5 den 40 cm, vi re la noi cung cap dinh dudng cho tuyen trung Cay 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 trien cap nhat va luc tuyen trung tap trung vap vung re nhieu nhat

Tuyen trung nhanh chdng tiep can va xam nhiem vap re npn sau khi cay dupe trpng va thiet lap quan the vdi nhieu the he cung tpn tai Tuy

nhien ca cau dat, ngudn hufu co, vi sinh vat dpi khang hpac ky sinh cd anh hudng den dan sp tuyen trung Tuyen trung re cay hp tieu it dinh c\J d tang

<Jat 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

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Bang 8: Mat so tuyen trung Meloidogyne spp va Tylenchulus sp trong vung

re ho tieu

Dja diem Giong (ten thu-ecng gpi) Mat so Meloidogyne Mat so Tylenchulus sp

dieu tra (so miu re phan tich) spp (con/lg re) (con/1 g re)

Trung Cao nhat Trung binh Cao nhat binh

Ba Rja - Vinh Linh (n = 7) 285 334 388 414

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 Dat) Pennijur - 1 (n = 8) 305 394 269 437

Lada belangtung (n=10) 144 206 223 283 Dong Nai VTnh Linh (n = 5) 108 206 12 20

(Long Sc la nho (n = 3) 117 146 102 146

Khanh) Sc la Ion (n = 4) 186 266 252 354

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

-Binh Phudc Vinh Linh (n= 16) 179 230 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

-(Thanh Dire Se la nho (n = 5) 226 286 0

Go Dau) Se la lorn (n = 5) 139 306 0

-Se ba chia (n = 5) 159 276 0

-Tieu trau (n = 5) 206 260 0

-Lam Dong VTnh Linh (n = 4) 373 496 0

Bao Loc) Phu Qu6c (n = 4) 181 255 0

Tieu trau (n = 5) 238 355 0 Dak Lak VTnh Linh (n = 5) 263 340 0 -

Cu Jut, Tieu se (n = 5) 326 376 0

-Cu Mgar) Tieu trau (n= 10) 354 410 0

-Binh Thuan VTnh Linh (n = 5) 403 480 0

-(Due Linh) Tieu se (n= 10) 333 410 0

-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 (n = 5) 424 460 0

-(Trich ketqud nghien citu cua Nguyen Van Ngoc, 2004)

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Re thuoc Id c6 budu tuyen trung

Re cay dt c6 bUdu tuyen trung

Re bong vai 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

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Hinh 22: SUdinh ci/cua Hfleloidogyne spp trong ri ho tieu

A: Budu va ton thMng tqi bUdu; B: Dinh atcua con cdi tri/dng thanh Meloidogyne

trong bUdu va sU bien dang 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 t h o n g t h u d n g n g u d i t r o n g d u n g p h a o n g phap

giam canh de nhan g i o n g t r o n g t r o n g nridi va t r o n g thay the nhufng cay tieu

chet t r o n g v a d n O a c d i e m phan hoa canh nhanh cua cay va sutac d p n g cat

tia tao tan hang nam da lam lay nhiem vi rut t h e o kieu ngau nhien gia tang

mure d p nhiem benh tren d o n g rupng Benh xuat hien tC/vUdn u o m den sau

khi t r p n g va t r p n g supt t h d i gian spng cua cay v6i trieu chufng benh tren ca

cay hpac m p t phan cay, vai canh hpac m p t it la khp phat hien va xCr ly

Trieu chufng benh do vi rut gay ra

O o m hoa la: Be mat la cp cac d p m nhp mau vang nhat tdi vang dam vdi

nhieu vet hpai tCr, la npn khi nhiem nang se bi bien mau, m e p la quan, g p n

spng Nhin tpan bp cay van phat trien binh thu'crng Trieu chufng t h u d n g

thay d la banh te cua nhanh tieu, va p h p bien tren cac v u n g hp tieu

Vang la gan x a n h : d la npn va la gia Oau tien la cac vet kham hinh trpn

mau vang nhat nam npi tiep nhau dpc t h e p gan chinh cua la (trieu chufng

nay thay nhieu d la npn) Khi benh nang, vet benh nga mau vang dam Ian

het ca phan t h i t la tap t h a n h vet vang t r p n g khi gan chfnh van cpn xanh

Mep la q u a n , gPn spng, CP nhieu vet hpai tCr Nhin tpan bp, cay van phat

trien binh t h a d n g , n h a n g nhanh t h i ngan k h p n g v a p n dai

Vang la Kham la La nho Caykhde

Hinh 25a: Cac dang benh do vi rut gay ra

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La nh6 bien d a n g : Hau het la npn C P kich

thu^cfc nhp k h p n g binh t h u d n g , c h o p la cong xuong, be mat la nhan n h u m , loi lom, c6 nhieu vet kham, d o m Ngpn npn bi chun lai, cay sinh trUdng cham hpac lun vang ca cay Dpi khi

trpng cung m p t cay chi CP m p t phan hay m p t vai nhanh tieu CP trieu chtTng benh, CP it c h u m

trai, sp t r a i / c h u m ft, hat rat nhp

Vang la: Phan vang la phan gi6i han giufa cac

gan chinh cua la, k h p n g phan biet rp rang giQa vung benh va khpng benh, la khpng bien dang Trieu chCrng t h a d n g thay d la banh te va

la gia Trieu churng benh g i p n g n h u cay thieu Khamxoan la

dinh d a d n g

D o m v a n g nhat: T h a d n g thay d la gia, tren mat la cp nhieu vet d d m nhp

mau vang, d a d n g kinh khpang 1 - 3 m m , vet benh k h p n g hpai tCr, k h p n g mat di, la khpng bj bien dang Cay phat trien binh t h a d n g

Kham x a n h : Gan la xanh, bien dang d mep la, CP nhieu vet xanh dam Ipi

jpm tren mat la, la xpan cupn vap phfa t r p n g Nhanh phat trien yeu, c h u m

trai thaa, sp t r a i / c h u m ft SP vdi cay tieu khpng b e n h

I

La nho, xoan lun, kham

Hinh 25b: Cac dang benh do vi rut gay ra

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