ChT dao san x u i t B V T V - S d 3/2011
REP
S A PBOT
H O N GPhenacoccus manihoti Mat.-Ferr. MOT SINH VAT NGOAI LAI NGUY HI^M GAY HAI CAY SAN
Pham Van Lam, Ngo Tidn Dung Vien BVTV, Cue BVTV
Cdy s i n Manihot eseulenta Crantz ed trung tdm phdt sinh Id Nam My, du-gc di thyc tdi nhiiu nai trdn t h i gidi. Thi dy, cdy sdn du-ge di thyc tdi chdu Phi vdo khoang nhu-ng ndm 1500 (Neuenschwander et ai, 1990). Hiipn nay, cdy s i n Id cdy trdng quan trpng d nhiiu nu-dc thudc chdu My, chdu Phi vd chdu A.
Cay sin bj nhidu lodi sdu hgi tin cdng, O Nam My, cd gin 200 lodi chdn khdp (thudc 9 bd khde nhau) su- dyng cdy sin Idm nguIn thdc dn. 0 Brazil, cac lodi chdn khdp cd t h i gay thidt hai ndng suit sin cd tdi trdn 50% (Bellotti, 1990; Melo, 1990).
X u i t xu> cua loai rep sdp bot hdng Phenacoccus manihoti
Ndm 1973, mOt lodi rdp sdp bOt ngiu nhidn nhap ndi vdo hai nu-dc Congo vd Zaire, xdm nhidm edy s i n vd dd trd thdnh sdu hgi nguy hiem trdn cdy s i n d cdc nu-dc ndy. D i n ndm 1977, lodi rpp sdp bOt ndy du-ge Matile-Ferrero md ta Id lodi mdi eho khoa hpe vd ddt tdn Id Phenacoccus manihoti (Herren, 1990; Neuenschwander et al.,
1990). Lodi Phenacoccus manihoti thudc hp Pseudoeoccidae (Homoptera) vd ed tdn tilng Anh Id "cassava pink mealybug" Ten tieng Viet cua loai nay de nghj goi la "rep sap bot hong"
vi no thupc hg rep sap bpt Pseudoeoccidae va CO mau hbng.
Nhu-ng nghidn cd-u cua Vidn Ddu tranh Sinh hoc thuOc Lien hidp Anh (CIBC) vd cua Vidn Nghidn cd-u Ndng nghidp nhidt ddi quoc t l (IITA) trong ede nam 1977-1981 tgi Caribe, Venezuela, Guyanas, Ddng Bic Brazil, Nam Hoa Ky, Mehico, Trung My, Bic Colombia dd phdt hidn thiy mOt lodi rpp sdp bOt cd tridu ehd-ng gdy hgi gilng vdi trieu ohd-ng gdy hgi eua lodi rdp sdp bdt hong tgi chdu l^hi. Vi vdy, cdc nghien cd-u ndy bu-dc diu xdc djnh rdp sdp bdt gay hgi edy sin d ede vdng ndu trdn Id lodi rdp sdp bOt hong Phenacoccus manihoti. Tuy nhidn, do cd nhu-ng khde nhau nho ve d§c diem hinh thdi vd ban
chit lu-dng tfnh cua lodi rdp sdp bdt hgi cdy san d chdu My, ndn ndm 1981, Cox va Williams dd md ta vd ddt tdn cho lodi rdp sdp bpt hgi edy sin d chdu My Id lodi mdi cho khoa hpe vdi ten Id Phenacoccus hen-eni (Neuenschwander et al. 1990).
Culi cdng, vdp ndm 1981, nghidn ed-u cua Trung tdm Ndng nghidp nhipt ddi qudc t l (CIAT) da phdt hipn dygc lodi rdp sdp bdt hong Phenacoccus manihoti ed xuit xd- td- Paraguay. Nhu- vdy, lodi Phenacoccus manihoti du-ge md ta dgt tdn dya vdo mdu vdt thu trdn edy s i n d Congo vd Zaire, edn qud hyang ban xd- eua nd Id Paraguay (Bellotti;
1990; Neuenschwander ef a/. 1990).
SIP xam n h i i m va lay lan cua rep sap bot hdng P. manihoti d chau Phi
Sau vdi nam nhgp ndi vdo Congo vd Zaire, rpp iSdp bpt hong da trd thdnh sdu hgi chfnh trdn edy sin d chdu Phi. Rep sdp bdt tiong sinh san dan tinh vd Idy lan rdt nhanh. Td- hai nu-dc Congo vd Zaire bj xdm nhidm dau tidn vdo ndm 1973, rep sap bOt hong Idy lan sang Senegal-Gambia ndm 1976, NigefeBenin* ndm 1979, Sierra Leone, Malawi nam 1985. Dlnindm 1986, nd da xdm nhidm edy sin d 25 nu-de diiem 70% didn tich dai trong sdn dehdu Phi. Vdo ndm 1987 dd ghi nhdn rpp sdp bOt hing ed mdt d Tanzania, Mozambique. ROp sap bpt hong Idy lan trdn edy sin d chdu Phi vdi toe dO khoang 300 km/ndm. Din nam 1987 nd da xdm nhidm edy sin d 31/35 nyde thuOc dai trong sin d chdu Phi (Henen, 1990;
Neuenschwander etal.,^ 990).
Tac hai cua rep sap bot hdng P. manihoti v chau Phi
Tai chdu Phi, cdy sdn Id ky chd ty nhidn duy nhit cua rOp sdp bdt hong. ROp sdp bOt hong gdy tde hgi ndng ne cho cdy s i n . No t i n edng diim sinh tru-dng cua cdy s i n , gdy hien tu-gng chdn ngpn. Ngon chinh bj rOp sdp bdt hdng gdy hgi d i n d i n cdy sdn trd ndn Idn, Bj nhidm vdi mat dO cao, ddi khi gdy rung todn bO bd Id cua cdy s i n .
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ChT dgo san x u i t B V T V - S d 3/2011
ROp sdp bdt hong gdy hgi, Idm giam ndng suit eu sin d chdu Phi tdi 80-84% (Herren, 1990; Neuenschwander e^ a/., 1990).
Su* xam nhiim cda rep sap bot hdng P.
manihoti a tieu vung song Mekong
Cdy sin Id mdt trong cdc edy tring ehinh cua cdc nu-dc d tieu vdng sdng Mekong. Cdy sin trong d tieu vdng sdng Mekong nhim ddp d-ng mdt phin lyang thyc eho ngydi, thd-c dn cho gia sde vd nguydn lidu cho san xuit ndng lu-gng sinh hpe.
Tdi lidu HOi thao vd rdp'sdp bOt hong tgi Bangkok, Thdi Lan (tu- ngdy 31/5 din ngdy 2/6/2011) cho thiy rOp sdp bOt hdng P. manihoti Qa xam nhidm 2 nu-dc d tieu vdng sdng Mekong. Tgi Thdi Lan, lin diu tien rOp sdp bOt hing dygc ghi nhdn vdo euoi nam 2006. Din thdng 4/2008 diOn tfch sin d Thdi Lan bj nhidm rOp sdp bOt tipng Id 48.000 ha vd diOn tfch ndy tdng Idn 166.700 ha vdo thdng 5/2010. Tgi Canipuchia, mOt sd canh dong san d ede tinh bidn gidi vdi Thdi Lan dd ghi nhdn ed sii- hiOn diOn cua rdp sap bOt hing. Ndm 2009, didn tfch sin bj nhidm rdp sdp bdt hing u-dc khodng han 100 ha vd ndm 2010 khoang 137 ha.
Trdn sin d Ldo,. Tmng Quoc chu-a ghi nhdn thiy rOp sdp |3pt hong. 0 ViOt Nam chu-a cd edng bd chfnh thd-c ndo dd ghi nhdn cd sy hidn dien cua rdp sdp bOt hong tren.cdy sin. Tuy nhidn, hai dgi bieu dy hOi thao din td- CIAT phdt bilu da phdt hidn thiy rOp sap bOt hong tgi ydng trpng sin Ddng Nam BO.
Nghidn ed-u cua Thdi Lan cho thiy trong didu kiOn nhit djnh, rOp sdp bOt hong cd the ehuyin sang sing tren cdc lOc non cua cdy eao su. Nhu- vOy, tdc hgi kinh t l do rep sdp bOt hong gay ra se cdn Idn han nhiiu doi vdi cdc nyde d tieu vdng sdng Mekong ed trong cdy eao su.
Hinh 1. Rdp sdp bOt hong trdn Id cdy s i n
Hinh 2. Ngpn edy sdn bj nhidm rep sap bOt hdng
(Ngudn anh: Pham Van Lim, Chonburi, Thai Lan, ngay 01/06/2011)
Thay Idi kit lugn
ROp sdp bOt hong Phenacoccus manihoti Id mOt djch hgi ngogi lai xdm lin nguy hiem tren cdy sin d dai trdng s i n eua chdu Phi. Loai djch hai ngogi lai ndy dd xdm nhidm cdy s i n trdng d Thai Lan vd Campuchia thuOc tilu vdng sdng Mekong.
Ngoai cdy s i n , trong dieu kidn nhit dinh, rOp sdp bOt hong ed the t i n edng lOe non cua cdy cao su.
Hom gilng Id mOt trong ede du-dng Idy lan eua rOp sdp bOt hong. Vi vdy, can lu-u y vipe trao doi hom giong san d vdng bidn gidi vdi Campuchia.
Den nay chu-a co mpt nghien ed-u chuyen nao v l sdu benh hgi s i n d VjOt Nam. Vide diiu tra xac dinh sy hidn didn eua rep sdp bOt hdng ndi rieng vd diiu tra ea ban, nghidn ed-u bidn phdp phdng chIng sdu bpnh chfnh hgi s i n theo hu-dng tong hgp ndi Chung dang Id ddi hoi c i p bdeh cua san xuit sin d nyde ta. De nghj Bd Ndng nghidp vd PTNT xem xdt duyOt bo sung kinh phi vd giao eho ViOn Bao vO thyc vdt thyc hidn nhipm vy ndy.
TAI LIEU THAM K H A O
Bellotti A.C., 1990. A review of control strategies for four important cassava pests in the Americas. Integrated Pest Management for
Tropical root and tuber crops (Eds. Hahn S.K., Caveness F.E.). IITA, Ibadan, Nigeria: 58-65.
Herren H.R., 1990. The Africa-wide biological control program. Integrated Pest Management for Tropical root and tuber crops (Eds. Hahn S.K., Caveness F.E.). IITA, Ibadan, Nigeria: 33-41.
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Trao d i i thong tin va kinh nghiem B V T V - S d 3/2011
Melo Q.M.S. ,1990. /\rthropOd pests associated with cassava in Brazil. Integrated Pest Management for Tropical root and tuber crops (Eds. Hahn S.K., Caveness F.E.). IITA, Ibadan, Nigeria: 132-138.
Neuenschwander P., W.N.O. Hammond,1990.
Biological control of the cassava mealybug, Phenacoccus manihoti, in Africa: Review of field studies. Integrated Pest Management for Tropical root and tuber crops (Eds. Hahn S.K., Caveness F.E.). IITA, Ibadan, Nigeria: 42-50.
MtfiU QUA COA M 6 HINH TU0\ NU'OC TI^T KIEM K^T H O P VQI
BIEN PHAP BA GIAM BA TANG TRONG SAN XUAT LUA (y NGHE AN
Nguyin T u i n Loc, Pham Thj Hdng Trung tim Bio vd thue vit vOng khu 4
1. Dat v i n d l
Nyde ed vai trd quan trphg bde nhit trong san xuit Ida, nhu-ng tydi nu-dc theo tOp qudn (tydi ngdp, tu-di nhieu l i n /vy) eua ndng ddn mang lgi hidu qua khdng cao, gdy hidn tygng Idng phi nu-dc d mOt sd giai dogn edy Ida khdng can t h i i t Tydi nu-de hgp ly, khoa hoc nhim tilt kiOm lu-gng nu-dc niiu-ng vdn dam bao cung c i p du eho cdy Ida vdo nhd-ng giai ddign ein thiit nhit md cdy Ida ddi hoi! Tu-di nu-dc khoa hpe tgo diiu kiOn cho bO r l Ida phdt triln m$nh, dn sdu xuong cdc ting d i t phfa du-di ldm cho cdy Ida ed-ng cdp, khde han, chIng ehju dygc sdu bOnh hgi cung nhu- cac yeu t l b i t Igi cua thdi tilt vd cho ndng suit eao han. Tydi nu-dc khoa hpe: "ydt khd" xen ke da du-gc Vidn Ida Quoc t l (IRRI) ehd-ng minh vd d-ng dyng thdnh cdng d mOt so nyde. O Trung Quie, thyc hipn "tydi nyde khoa hpe" da giam du-gc chi phi fydi nu-dc, giam ehi phi BVTV, tdng ndng suit Idi, tdng hiOu qua kinh
t l . Vy Ddng Xudn 2005-2006, md hinh "tu-di nyde tilt kiOm" k i t hgp "ba giam ba tahg" d tinh An Giang, trdn diOn tich hdng chyc ha dd tilt kiOm tiln nyde tu-di, giam lu-gng gilng Ida gieo sg, tdng ndng suit Ida td- 3-8 tg/ha.
Vdi nhO-ng vdng ed thdi tilt khic nghiOt, ning ndng vd khd hgn kdo ddi, tinh trgng khan hiim nyde ngpt, nyde tydi cho Ida t h y d h | xuydn x i y ra nhy vdng khu IV, viOc tydi nu-dc khoa hpe, tilt kiOm cho Ida cdng c i p bdeh hgri.
D l thuylt phyc vd khuyin edo ndng ddn trong Ida trong vdng dp dyng tiln bp ndy, ndm 200Q, Trung tdm Bao vO thyc vdt vdng khd IV dd M n hdnh thd- nghiOm md hinh: "Nghidn ^Cru Crng dung bidn phip tudi nude tidt kidm kdt hgp vdi bign phip ba glim ba ting ddn sin xuit IQa d Ngh$An".
2. Mot s6 k i t qua mo hinh ap dung
2.1. So liri tudi nude vi phiyi rupng
k
TT 1 2
Bang 1. So lan tu-di niipp-G va so ian phoi rupng trong vy Dong xuan va Chi tieu
S6 lan tu-di nu-o-c (lin) So lan pho-i ruOng (lin) My-c nu-dc ngam so mpt rupng (cm)
Mo hinh DX
6,0 2,0 15-20
HT 5,0 4,0 15-20
He thu (2006) Dii chd-ng
ex
10,0 1,0
HT 8,0 1,0
So vdi DC DX
-4,0 -1,0
HT -3,0 -3,0
Vu Ddng Xudn 2006, » = d i u - giO-a vy (sau cay dd-ng odi) trdi Ignh, dm u, mya phdn keo dai, khdng nang, ndn khdng phai dygc ruOng. Td-
giai dogn Ida Idm ddng - chin thu hogeh, gid tdy nam ning ndng x u i t hiOn, it mya, ndn dd dp dyng dygc c h l dO tydi "Ndng - LO - Phai" xen ke
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