NGHItN Clhl - TRAO Odl
K ^ QUA IVGm^IV CtU BUOC D A U
L DAT VAN DE
Trong nhO'ng ndm gan day, sy chuyen doi co cau miia vy vd vifc md rpng difn tich cdc giong lua Trung Quoc (ddc bift Id lua lai) dd ldm cho tinh hinh phdt sinh, phdt trien cua cdc loai sdu hgi dien biln phirc tgp, gay trd nggi khdng nhd vifc thdm canh tdng ndng suat. Trong dd, ray lung trdng {Sogatella furclfera Horvath) (Homoptera: Delphacidae) Id ddi tupng gay hgi nguy hilm cho sdn xudt liia chdu A ndi chung vd Vift Nam ndi rieng, ddc bift Id d cdc tinh phia Bdc. Bdi ngodi tdc hai tryc tilp, ray lung trdng cdn cd khd
ndng truyin mpt logi bfnh virus mdi Id bfnh virus liia liin spe den phuong Nam (Zhang etal., 2001).
d Vift Nam, bfnh virus lua liin spe den phuang Nam bdt dau xuat hifn tir vy miia ndm 2009 tren 20 tinh thupc khu vyc Dong bdng sdng Hong vd Bdc Trung Bp, trong dd tgi 16 tinh, bfnh ndy da xuat hifn gay hgi cd tren ngd (Vifn Bdo vf thyc vgt, 2009). Vy xudn ndm 2010, bfnh da nhanh chdng lan ra 28 tinh thupc khu vyc miln nui phia Bdc, Dong bang sdng Hong, Bdc vd Trung Trung Bp.
Trudc muc dp nguy hilm
• Nguyen Tuan L^c cua ray lung trdng, dd cd nhilu nghien cuu ve ddc dilm sinh hpc, sinh thdi ciing nhu bifn phdp phdng trir. Bdi vilt ndy tong hpp nhO'ng ket qud nghien cuu tren.
IL KlfcT QUA NGHIEN
ctru
\. Ddc diem sinh hpc ciia ray lung trdng
fl. Th&i gian phdt dftc, vdng d&i cua ray lurng trang
Tiln hdnh nudi ray lung trdng d cdc thdi gian cuoi thdng 4 din giua thdng 5, cuoi thdng 7 din giira thdng 8 vd cuoi thdng 9 din giua thdng 10 cho kit qua d Bdng 1.
Bang 1: Mpt so chi tieu sinh hpc cua ray limg trdng Chi tieu theo doi
Thdi gian triirng (ngdy) Thdi gian ray non (ngdy) Thdi gian trudc de (ngdy) Tuoi thp cua TT (ngdy) Thdi gian vdng ddi (ngdy) Khd ndng de trimg (trimg/cdi) Tylf cdp de(%)
Ty If dyc/cdi (%) Ty If CD/CN (%) Nhift dp TB ("C) Am dp TB (%)
Gid trf cdc chi tieu d cdc dpt nudi 4 - 22/7
5,46 + 0,77 12,1 + 1,57 3,78+1,01
7,6+1,7 21,2-23,4
57,4 45,0 49,0/51,0 24,4/75,6
30,2 85,5
20/9 -12/10 6,8 + 0,91 14,3 + 0,95 4,58 + 1,34
8,18 + 2,4 23,6 - 26,2
49,6 58,0 55,0/45,0
15,0/85,0 26,5 78,3
12/11 24/12 8,6+1,4 16,6+1,6 5.6+1,56 14,0 + 2,3 29,4-31,5
52,2 56,0 48,0/52,0 23,5/76,5
20,3 74,8 Ghi chu: TT: Trudng thdnh, CN: Cdnh ngdn, CD: Cdnh ddi, TB: Trung binh
Sd 3/2012 Thdng tin KH-CN Ngh$ An (22]
NGHllN CIIU - TRAO Odi
d trong khodng dilu kifn nhift dp 20,3-30,2°C vd am dp 74,8-85,5%, thdi gian phdt triln cdc pha cua ray lung trdng se keo dai khi d nhift dp thap vd riit ngdn khi d nhift dp cao: thdi gian trirng binh qudn 5,46-8,6 ngdy; thdi gian trudc de binh qudn 3,78-5,6 ngdy; thdi gian song ciia trudng thdnh Id 7,6- 14,0 ngdy; thdi gian vdng ddi Id 21,2-31,5 ngdy (Bdng 1).
b. Khd ndng sinh sdn cda rdy
lung trdng
Tien hanh nudi ray lung trdng tren cdc giong liia khdc nhau cho thay khd ndng sinh sdn khdc nhau tuong doi rd n^t. Tren cdc giong Ilia nguon goc IRRI, ray lung trdng cd khd ndng sinh sdn thap, mdi con cdi chi de dupe 49,6- 57,4 trung (Bang 1). Tren cdc giong Ilia lai va liia thuan Trung Quoc, trudng thdnh cdi cd khd ndng d6 trimg va ty If tnimg nd cao hon. Cdc giong cd nguon goc
IRRI, ddc bift cdc giong mang gen khdng (nhu IR53386) khdng thich hpp cho ray lung trdng sinh trudng vd phdt triln. Thdi gian tiln de tning cua ray lung trdng Id 3 ngdy, de trimg tgp trung nhat vao thdi gian 6 ngay dau sau vu hda. Day la co sd dk tinh thdi gian phdng trir tot nhat cho mdi dpt ray, lay moc la thdi gian vu hda rp ciia ray trudng thdnh tren ddng rupng hodc ray trudng thdnh vao den rp.
Bdng 2: Vi tri de trumg ciia ray lung trdng d cdc giai doan sinh trvdng ciia cay liia
Giong lua
Bdc thom Bdc thom BC15 Tgp giao Bdc thom
Giai doan sinh trudng Mg 28 ngdy tudi
Cuoi de nhdnh Tro Trd Trd
So o truTig dieu tra (6)
557 65 183 384 168
Vj tri de triirng Gan chinh cua la
Soo 553 40 142 337 112
Ty If (%) 99,28 61,54 77,60 87,76 66,67
B?Ia Soo
4 25 41 47 56
T y l e ( % ) 0,72 38,46 22,40 12,24 33,33 c. Vi tri de trumg cua ray
lung trdng
Q giai dogn kit thuc de nhdnh, ty If 6 tning tren gan chinh Id cua giong liia Bdc thom thap nhat (61,54%). CJ giai dogn tro bdng, ty If d trung tren gdn chinh Id cua gidng Tgp giao cao hon so vdi gidng BC15, tuong ung Id 87,76% vd 77,60% (Bang 2).
Nhu vgy, vj tri de trdng cua ray lung trdng phy thupc chu yeu vdo giai dogn sinh trudng ciia cay liia: Khi liia d giai dogn mg, de nhdnh thi rdy lung trdng de chu ylu d md b? Id; Khi cay liia d giai dogn ldm ddng trd di, ray lung trdng de chu ylu tren gdn chinh Id liia.
d Chi tieu sinh hgc chinh cda ray lung trang cdnh ngan vd cdnh ddi
Doi vdi rdy lung trang, ty If ray dye thudng it hon ray cdi vd cdnh ngdn cung ludn it hon cdnh ddi khi dupe nudi d cdc mat dp vd giai dogn sinh trudng khdc nhau cua cay liia (Bdng 3 vd Bdng 4).
Bang 3: Mat do nuoi va ty If dang canh d ray Iimg trdng Mat do nuoi (con/khom)
1 5 10
Ty If canh ngan (%) 28,6
13,4 0
Ty If canh dai (%) 71,4
86,6 100
Sd 3/2012 Thdng tin KH-CN Nghf An (23]
NGHllN curu - TRAO 06l
Bang 4: Ty If dang cdnh vd giai doan sinh trvdng ciia liia Giai doan sinh trvdng ciia cay liia
De nhdnh
Dung cdi - Ldm ddng Tro - Chin
Ty If cdnh ngdn (%) 21,2
2,4 0
T^ If cdnh ddi (%) 78,8
97,6 100 6 nhift dp trung binh
31,7*'C vd am dp trung binh 65,8%, tuoi thp cua trudng thanh cdnh ngdn (13,22 ± 5,49 ngay) thap hon cd y nghTa so vdi tuoi thp ciia trudng thanh cdnh ddi (16,00 ± 5,64 ngay).
So trung de trung binh cua
mpt trudng thanh cdnh ddi cao hon cd y nghTa so vdi so trung de trung binh cua mpt trudng thdnh canh ngdn (tuong ung Id 100,09 ± 57,23 vd 88,78 ± 59,44 trung/cdi), nhung trung do ca hai dgng hinh cdnh ddi va cdnh ngdn di deu cd ty If
nd cao, khdc nhau khdng cd y nghTa, tuong ung Id 95,64% va 96,11% (Bdne 5). Nhu vgy, trong quan the ray lung trdng, vai trd cua dgng hinh cdnh dai quan trpng hon dgng hinh cdnh ngdn (dilu ndy trai ngupc so vdi ray nau).
Bang 5: Mpt so chi tieu sinh hpc ciia ray lung trdng cdnh ngdn vd cdnh dai Chi tieu
So lupng trimg de (trimg/cdi) Ty If trimg nd (%)
Tudi thp trudng thdnh cdi (ngdy) Nhift dp trung binh (°C)
Am dp trung binh (%)
Ray cdnh ngdn 88,78 ± 59,44
(23 208) 96,11 13,22 ±5,49
31,7 65,8
Ray cdnh dai 100,09 + 57,23
(18-184) 95,64 16,00 + 5,64
31,7 65,8 Ghi chii: So trong ngoac don Id phgm vi biln dpng
2. Mpt so bifn phap phong t r d
a. Hifu luc cua thuoc xir ly hgt giong trong phong trir rdy lurng trdng a giai dogn lua non
Thi nghifm thuoc Enaldo 40FS xu ly hgt giong lua (vdi lilu lupng 40-60 ml/60kg hgt gidng liia gieo dl cdy Iha) dupe tiln hdnh trong nhd ludi tgi Vifn Bao vf thyc vat cho hifu qud rat cao. Ray trudng thdnh thd vdo khay mg 10 n^dy tudi cd xu ly hat giong bdng Enaldo 40FS bj chet tren 80%
sau 1 ngdy thd vd tren 90% sau 3 ngdy thd. Thi nghifm vdi mg
15 ngdy tudi cd xu ly hat giong bdng Enaldo 40FS cho thdy rdy
trudng thdnh chit 80% sau 3 ngdy thd.
b. Hifu luc cua mgt so logi thuoc ddi v&i rdy lung trang trong giai dogn liia de nhdnh tro
Tiln hdnh thu nghifm 16 logi thuoc doi vdi ray lung trdng trong giai dogn liia de nhdnh den trudc tro, kit qud cho thay: Cdc thuoc Elsin
lOEC, Oshin 20WP, Penalty gold 50EC vd Dantotsu
16WSG cd hifu lyc hon 90%
sau 5 ngdy; Cdc thuoc Bassa 50EC, Alika lOEC cd hifu lyc tren 80% sau 5 ngdy; Cdc thuoc Confidor lOOSL, Chess 50WG cd hifu lyc tren 70% sau 5
ngdy. Cdc thuoc Sutin 5EC, Elincol 12ME, Oncol 25WP cd hifu lyc tren 60% sau 5 ngay;
Cdc thuoc Regent 800WG, Metarhizium anisopliae. Butyl
lOWP, Exin 4.5HP cd hifu lyc thap sau 5 ngdy (Bdng 6).
Trong giai dogn liia de nhdnh din trudc trd, phdi chpn cdc thuoc vua cd tdc dung tiep xiic, vua cd hifu lyc keo dai nhu: Elsin lOEC, Oshin 20WP, Dantotsu 16WSG. Cdc thudc ndy sau 3 ngdy diu cd hifu lyc khd cao vd cd hifu qud keo dai nen su dyng rdt tot cho giai dogn ndy dl trd trudng thdnh ray lung trdng di tru din rupng non.
Sd 3/2012 Thdng tin KH-CN Nghf An (24]
NGHllN CIJU - TRAO o6l
Bang 6: Hieu lyc ciia mpt so lo^i thuoc doi vdi ray lung trdng (Nghi Lpc, Nghf An, 2010) Loai thuoc diing
Actara 25WG Alika lOEC Bassa 50EC Butyl lOWP Chess 50WG Confidor lOOSL Dantotsu 16WSG Elincol 12ME Elsin lOEC Exin 4.5HP Oncol 25WP Oshin 20WP Regent 800WG Penalty gold 50EC Sutin 5EC
Metarhizium anisopliae
Lu'O'ng diing (g, ml/ha)
80 500 1200 1000 500 500 100 500 500 750 750 100 80 1200
500 20.000
Hifu lire sau phun (%) 1 ngay
35,0 52,6 61,3 9,2 28,2 43,5 45,4 34,4 64,5 2,3 33,2 48,6 24,2 69,3 30,6 3,2
3 ngdy 58,3 83,2 81,3 22,5 53,2 68,2 81,7 57,6 89,6 5,2 54,5 88,3 49,5 81,2 57,4 18,6
5 ngay 71,6 87,2 89,0 44,6 72,0 76,2 90,0 68,0 93,2 7,8 63,4 91,0 56,3 90,2 68,2 47,9
7 ngdy 70,8 84,2 83,5 71,6 71,6 74,2 87,4 64,3 91,2 8,3 62,4 87,5 52,6 89,4 66,3 57,1 Trong dilu kifn khdng xdc
djnh dupe mat dp ray lung trang mang bfnh, de hgn che sy truyen bfnh virus liia liin spe den cua rdy lung trdng thi tot nhat nen chpn cdc thudc cd hifu qud tu 80-90% dk diing tren dong rupng. Khdng nen su dyng cdc thudc cd hifu lyc thap khi ray lung trdng bimg phdt djch.
c. Hieu luc cua mgt so logi thuoc sinh hgc doi v&i rdy lung trdng tren dong rugng
Trong dieu kifn thdi tiet nam 2010 ludn khd hgn nen vifc thu nghifm thudc sinh hpc do Vifn Bdo vf thyc vat vd Vifn Liia O Mdn sdn xudt khdng dgt hifu qud cao. De tdng hifu lyc ciia thuoc sinh hpc, trong thi nghifm da pha
them chdt sieu trp lyc Enomil 30L vdi lupng diing 200 ml/ha.
Khi dirng don le, hifu lyc sau 3 ngay chi dgt 16,8-18,4% va sau 14 ngdy hifu lyc cao nhat cung chi dgt 41,5-43,2%. Khi kit hpp vdi chat sieu trp lyc Enomil 30L, hifu lyc sau 3 ngdy tdng len 23,1-24,6% vd sau 14 ngdy hifu lyc tang len 59,4-61,3% (Bdng 7).
Bang 7: Hieu qua cua thuoc sinh hpc tren dong rupng (Nghi Lpc, Nghf An, vu mua 2010) Cong thdc
Metarhizium I (Vifn Bdo vf thyc vat) Metarhizium II (Vifn Liia 6 Mdn) Metarhizium I + Enomil 30L Metarhizium II + Enomil 30L
Lurpng dung (kg/ha)
20 3 20 + 0,2
3 + 0,2
Hifu lyc sau phun (%) 3 ngay
16,8 18,4 23,1 24,6
7 ngay 36,6 39,3 57,1 59,7
14 ngay 41,5 43,2 59,4 61,3
21 ngay 39,6 40,3 52,1 55,3
Sd 3/2012 Thdng tin KH-CN Ngh$ An (25]
N G H I C N C I J U
- TRAO O d l
Ket qua thii nghi?m t^i Ngh? An cho thay, sii dyng thuoc sinh hpc trir ray lung tring tgi cac vung kho hgn, ning n6ng thi hi^u qua khong cao, nhat la khi c6 djch thi vi?c dung thuoc sinh hpc Igi cang phai thgn trgng nhim tranh vi?c truyen b?nh cua ray doi vdi cay liia. Theo Heinrichs (1979), doi vdi cdc vung trong lua nhi?t ddi, bi?n phap chu yeu de ph6ng trir ray nau la dung giong khdng va thuoc trir sau. Cho den thdi diem hi|n tgi khi ma giong khang chua co de sur dyng rpng rai trong san xuat thi sir dyng thuoc trir sau vin Id bi?n phdp chu yeu de dap tit djch ray hgi lua. Vi$c chgn Ipc cdc logi thuoc va phuang phap sir dung CO hi^u qua la rit can thiet cho vifc phong trir ray hgi ilia. De tru ray lung tring, da thii nghi?m mgt so logi thuoc phun theo 2 giai dogn sinh trudng cua cay liia (de nhanh trudc tro va tro chin). Thuoc dugc phun khi dieu tra mat dg ray den nguang phong trir. Ket qua thi nghifm tgi Ngh? An cho thiy dB phong trir riy lung tring c6 hi$u qua can tuan thu nguyen tac 4 diing.
ChQn thuoc dung: Giai dogn tir de nhanh den trudc tro, phai chgn thuoc c6 2 tdc dgng vira ngi hip (luu dan) vira tiep xiic mgnh nhu Elsin
lOEC, Oshin 20WG, Dantotsu 16WSG... Giai dogn ngam sua - chin, cay liia hip thu kem, nlu tren rugng c6 ray non tudi Idn va trudng thanh > 50% thi phai dung thuoc CO tac dyng vira tiep xiic mgnh vira luu din nhu Elsin lOEC hoac cac thuoc c6 tdc dyng tiep xiic mgnh nhu
Penalty gold 50EC ho$c Alika lOEC cOng vdi chat bdm dinh Enomil SOL.
- Sir dyng diing lieu lu</ng va nong d^: Neu trSn rugng ray non chu yeu Id tuoi 1-3 vdi mgt dg > 20 con/kh6m thi diing thuoc theo dung nong dg khuyen cao. Neu tren rugng c6 riy non tuoi Idn vdi mgt dg > 100 con/kh6m thi tang nong dg thuoc len 1,5 Ian vd phai phun dii nude de thuoc phii deu tren cdy lua.
Phun dung luc: Neu mgt dg ray non tuoi 1-3 tir 10-15 con/kh6m thi diing thuoc dieu hoa sinh trudng con triing Butyl lOWP kit hgp chit bdm dinh Enomil SOL. Neu mgt dg > 20 con/kh6m thi dimg thuoc Chess 50WG kit hgp thuoc Bassa 50EC.
Diing ky thugt: Khi d giai dogn lua de nhanh trudc tro, diing thuoc co 2 tac dgng vira ngi hap vira tiep xiic va phai phun udt deu tren toan bg cay liia. Khi d giai dogn lua gia, cay hap thu kem, phai re liia, bam tryc tiep bing bam c6 dp suit mgnh va tia nho vao goc liia nai ray lung tring sinh song.
Trong thdi ky lua dang tro bong, phai mdu thi khong dugc phun trir ray vi luc ndy liia rit man cam vdi thuoc, neu mgt dg qua cao thi phai re liia de phun tryc tiep vao goc, khong dugc phun len bong lua dang tro.
III. K £ T L U A N
6 dieu ki$n nhift dg 27,S-29,S°C vd im dg 80,7- 89,0%, pha riy non ciia riy lung tring co 5 tuoi. Thdi gian tuoi 1 vd tuoi S hai dai han cdc tuoi 2, 3 vd 4 mgt chut, thdi gian cd pha riy non keo dai 12-13 ngay. Thdi gian
tiln d6 triirng Id S-4 ngay vd thdi gian v5ng ddi Id 23-27 ngdy. Trudng thdnh song dugc 7-14 ngdy.
Cdc giong lua c6 dnh hudng den khd ning sinh san cua ray lung tring. Ray lung tring c6 khd nSng sinh san cao nhit khi dugc song tren giong lua c6 nguon goc Trung Quoc vd khong thich hgp vdi cdc giong lua c6 nguon goc IRRI (d$c bi?t giong mang gen khdng). Trong vy xuan d mien Bic (nhi^t dg vd am dg trung binh Id 24,7°C va 64,8%), riy lung tring co thdi gian de triirng kio ddi tdi 16 ngdy, nhung triirng dugc de tgp trung vao 6 ngdy dau, sau do so trirng de dugc giam dan.
Nhiing triirng de vao niira dau thdi gian de triing co ty le nd cao.
De ngin ch^n co hi^u qua vi?c ray lung trang truyen b^nh virus lua liin sgc den trong thdi gian cay liia non, cin phdi xii ly hgt giong bang thuoc Cruiser Plus 312.5FS va Enaldo 40FS. Cay liia d giai dogn de nhdnh den trudc tri, d l di?t ray lung tring xam nhgp vao rugng phai diing cac thuoc c6 tdc dyng luu dan va tilp xuc nhu Elsin lOEC, Oshin 20WG, Dantotsu
16WSG. Neu mgt dg ray non cao thi CO the dung cdc logi thuoc dieu hoa sinh trudng c6n triing nhu Butyl lOWP hoV thuoc Chess 50WG cgng them chit bdm dinh Enomil SOL d l tSng hieu qua cua thuoc. Thuoc sinh hgc co hieu lye d miic trung binh vdi riy lung tring, nen khi co djch khong khuyen cdo sii dyng.
Khi khong co djch, nen dung tir liira 2 de nim phdt trien gay b?nh cho riy khd tot./.
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