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HOAT DONG NGHIEN ClIU DNG DUNG - TRIEN KHAI KHOA HOC CONG NGHE

Tom tat: Mot ngo (Sitophilus zeainais Motsehulsky) Id mpt lodi sdu hgi ehinh trong kho ngU cdc a Viet Nam vd bien phdp chit yeu de phdng chong ehiing

Id bien phdp hoa hoe. Cdy Neem (Azadirrachta India A. Juss) Id cdy trong bdn dia vd nhdp npi dugc trong chii yen ir cdc tinh Nam Trung bp

Viet Nam vcri dien tich hien nay Id 6.000 ha. Hdm lucrng ddu tu nhien ciia hgt Neem a Ninh Thudn Id 35,8 l/lOO kg nhdn hgt vd hdm lugng Azadirachtin trong ddu Neem tic nhien Id 2.058ppm.

Hai thuoc trie sdu thdo mpc SOY, SOD vd cde dgng nhU ddu ciia chiing Id SOY - EC vd SOD - EC de phong chong sdu mgt kho. Cde sdn phdm SOY - EC vd SOD - EC co hieu lice voi mot ngo rdt cao (100% sau 2 ngdy phun). Cde sdn phdm SOY, SOD co the duge xii ly cdc bao ehua ngo (sau khi xic ly hgt ngo bdng xong hai hodc xic ly nhiet vd dgt hieu lice tren 80% sau bdo qudn 6 thdng. Cde sdn phdm ndy rdt an todn v&i moi trucmg vcri LD.^ (chupt, duang mieng) > 10.000 mg/

kg vd du lugng Azadirachtin khong phdt hien duge trong hgt ngo dugc bdo bdo qudn bdng SOY, SO sau xu ly 15 ngdy. Do vdy, cdc sdn phdm dugc tgo ra tren eo the dugc sic dung de bdo qudn ngii cdc an todn vd hieu qud.

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Ik&^f^mifkikif^liUm

mi cmi Ufi up ISifaplk mais Mais kitklikimiiliAiPiilj^siii

Nguyen Trirtmg Thanh, Doan Thj Lirong, Nguyen Thi Thanh Thuy, Biii Xuan Thang - Vien Bao ve Thuc vat

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pt ngd duge xae dinh la ddi tugng gay hai chinh trong kho ngii ede d nude ta [5]. Viee bao quan ngii cdc trong nhieu nam qua chii yeu van dua vao bien phap ea ly va bien phap hda hge.

Tren the gidi, nhiing nam gan day ngudi ta da nghien cuu san xuat thudc thao mgc phdng chdng sau hai kho, dac biet la sir dung san pham tir cay Ciic sat trimg [2, 3]. Tuy nhien, cho den nay, rat it che pham thao mgc duge san xuat de bao quan kho ngu edc d nude ta.

Chi tinh rieng Ninh Thuan.

den nam 2010 da trdng tren 6.000 Cay Neem trong tai Phiro'c Dinh, ha Neem theo ke

Ninh Thuan. Anh: BBT hoach, trong do 2.500 ha da eho thu hoach va se phat trien manh trong cac nam tdi.

Hoat chat Azadiraehtint trong hat Neem ed tae dgng tdi sau hai dugc nhieu tae gia nghien cim.

Hien nay, cong nghe san xuat ehe pham thao mgc bao ve thyc vat ndi ehung, che pham bao quan ndng san tii eay Neem ndi rieng d nudc ta cdn rat sa khai [1 ]. Chiing ta can tap trung nghien ciiu

• "•

KHOA HOC & ^TbtngTIn

CONG NGHE

HOAT DONG NGHIEN Cl)U IJNG DUNG

- TRIEN icHAI KHOA HOC CONG NGHE

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de phat trien loai eay ban dia nay, khdng ehi gdp ph4n bao ve ndng san an toan ma cdn la ddn biy dl duy tri va thiic day phat trien eay Neem, gdp phan chdng sa mac hoa hang tram nghin ha dk viing ban khd han d nude ta.

* Ngi dung nghien ciru

1. Xae dinh lugng dau Neem hr nhien (bang ep ngugi nhan hat Neem trdng tai Ninh Thuan) va hdm lugng hogt chdt chinh Azadirachtin trong dau.

2. Nghien cim tao mgt sd dgng ehe phdm phdng chong mot ngo tic ddu Neem tu nhien va danh gia hieu lye eua che pham ddi vdi mgt ngd.

3. Danh gia dp an todn ciia che phdm da chgn lgc (Du lugng, do dgc cap tinh).

* Thoi gian nghien cihi: tir nam 1/2009 den 12/2010

* Ket qua nghien ciru

1. Ket qua xae dinh ham lugng dau Neem va hoat chat Azadirachtin trong hat va la Neem nhap noi

Hien nay, gidng Neem nhap ngi ttr Xenegan duge trdng ehii yeu va rat thich hgp tai Nam Trung Bg. Qua Neem dugc thu thap tai khu rimg Neem Ninh Phudc, Ninh Thuan vao thang 6 nam 2009 tren eay Neem 10-13 nam tudi. Mgt sd hat Neem cting duge thu tti' cac cay Neem An Do de phan tich so sanh. Thdi diem thu hai la khi qua vira chin vang va chim thudng den an ciii va nha ra hat. Loai hat Neem Xenegan eu (thu hoach each luc xir ly 1 nam) va loai hat Neem An Do (eay Neem 7 nam tudi) duge tach chiet dau de so sanh.

/. /. Ket qud xdc dinh hdm luffiig dau Neem trong hgt Neem

Ham lugng dau thu duge trong nhan hat Neem bang phuang phap chiet dung mdi (n-hexane) va phuang phap ep ngugi trinh bay trong bang 1 cho thay ham lugng dau trong nhan hat Neem tai Ninh Thuan kha eao.Tuy san pham dau thu duge bang chiet dung mdi kha tinh khiet va ty le lugng dau thu dugc kha cao song van qua sir dung hoa chat (dung mdi) va ehi phi sir dyng dung mdi kha eao.

Bang 1. Ham lugng dau Neem chiet xuat dirge tir hat Neem giong Xenegan bang cac phuong phap khae nhau

(Neem trdng tgi Ninh Thudn, giong Xenegan tren 10 ndm tuoi, thu khi qud chin vdng - Phdn tieh tgi Vien BVTV, 2009)

Phuong phap thu dau Neem ty nhien

Lugng dau thu duge (lit dau /IOO kg nhan hat Neem)

Ep ngudi 35,8

Chiet n-hexane 39,0

Vdi phuong phap ep ngudi, dau Neem ty nhien edn ehiia mdt sd chat trong hat ke ea cac hoat chat sinh hgc nhu Azadirachtin, Nimbidin, Salanin,.... Day la mgt ket qua rat kha quan vi ehi phi ep dau ty nhien thap hon ban so vdi con dudng bang dung mdi.

1.2. Ket qud xdc dinh hdm luffng Azadirachtin trong cdc sdn pham tir cdy Neem

Kit qua phan tieh Azadirachtin bang may sac ky long Agiklent 1100 trong dich chiet nhan hat Neem va dau Neem ty nhien dugc ghi lai d bang 2. Nhu vay, ham lugng hoat chat Azadirachtin trong hat Neem trdng tai Ninh Thuan thudc loai kha so vdi Neem trdng d cac nirdc (3.000-6.000 ppm [6J).

Ham luang Azadirachtin trong dau Neem ty nliien tuong duang vdi ham lugng trong dau Neem ciia

Thing TiB

KHOA HOC & ( - 6 N C N C H L

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HOAT DONG NGHIlN Cl)U tfNG DUNG - TRIEN KHAI KHOA HOC CONG NGHt

Bang 2. Ham lugng Azadirachtin trong hat cay Neem va dau Neem tu nhien (Neem giong Xenegan tren 10 tuoi- Phdng Phdn tich, Vien BVTV 2009)

Ten mue

Ham lugng Azadirachtin (ppm)

Nhan hat Neem 4252

Dau Neem ty nhien 2058

2. Ket qua tao dang che pham trir mot hai kho ngu coc

Theo nhieu nghien eiru, eon dudng lay nhiem eiia mgt hai ngo trong kho bao gdm ea mgt lay nhiem tir ngoai ddng va mgt lay nhiem tir ndng san dang bi hai va ngay tai xung quanh kho [4, 9].

Do vay, cac ehe pham thao mpc tir cay Neem hudng tdi kha nang ngan ngira, tieu diet hoac xua dudi cac loai mpt hai kho. Sau khi thir nghiem hieu lyc va do dn dinh eua ehe pham, eae bude tao dang che pham tir dau Neem ty nhien duge tien hanh theo so do d hinh 1.

Hat Neem kho vai do am < 20%) lip nguoi thu dau tir nhien (loc de loai tap chat) B6 sung ; + Chk chk on dinh NEPI (0,1 %)a

1

+ Ch§t trg luc SPYR (2,5%) hoac INDE (0,05%)

• Chat nhu hoa (RPOL: 5%) neu la dang diing de phun

Khu§y dgu 2000 vong/ phiit (30 phut) SOD

I

(Trg luc la INDE)

T

SOY-EC (Trg lyc la SPYR ^

CO chat nhjj hoa)

T

SOY (Trg luc la SPYR)

T

SOD-EC (Trg luc la INDE + c6

chat nhii hoa)

T

Dong vao chai mau va bao quan nai mat va anh sang ySu Hinh 1. So 36 tao dang ehl pham SOY (SOY-EC) va SOD (SOD-EC)

Hinh 2. Sac ky d6 phan tich mau dau Neem tu nhien

16

KHOA HOC & ^{Thing Tin} CONG NGHE

HOAT DONG NGHIEN Cl)U IJNG DUNG

- TRIEN icHAI KHOA HOC CONG NGHE

E l

mgt tae gia An Dp la 1950 ppm [10].

3.3. Ket qua danh gia hieu luc ciia cac che pham dugc tao dang

3.3.1. Ket qua xae dinh hieu luc trii- mot kho ciia cac che pham Neem dang nhu dau (bang 3) Bang 3 trinh bay hieu lyc trir mgt kho ciia hai ehe pham tii' dau Neem ty nhien la SOD-EC, SOY-EC cho thay: Hai che pham nay ed hieu qua rat eao khi phun trii' mgt dang bam quanh cac vat lieu ehira luong thye va quanh kho (dat hieu lye 100% sau phun 2 ngay).

Bang 3. Hieu luc cua cac che pham Neem dang nhu dau ddi vdi mot ngo (S. zeamais) (Vien BVTV. 10/2010)

Cdng thiic

SOD-EC SOY-EC Ddi chirng

Mgt dieu tra dugc 1 NSP

145 217 189

2 NSP 136 198 172

Ty le mgt chet I N S P

82,3 88.4 6,3

2 NSP 100 100 8,7

Hieu lyc (%) 1 NSP

81,1 87,6

-

2 NSP 100 100 - (NSP = ngay sau phun)

3.3.2. Khi sd' dung che phdm Neem bdo qudn ngo

Thi nghiem duge tien hanh vdi eae eong thire khae nhau cho ket qua dugc trinh bay trong bang 4 cho thay:

+ Viec xic ly nhiet hodc hod chdt xong hai thudn liiy cho hieu qua vdi mgt ehi eho hieu qua eao sau 2 thang xir ly. Den thang thir 3, hieu lyc chdng mgt chi cdn thap hon 75%, can phai xir iy tiep theo.

+ Cach xir ly trpn che phdm SOY, SOD true tiep vdi ngo chua qua xic ly nhiet cting chi cho hieu qua eao sau 2 thang va mot phdt trien sau 3 thang trd di... Nguyen nhan vi mgt sd mgt da nam trong hat ngd khdng tiep xiic vdi thudc cd kha nang sdng sdt va tiep tyc phat trien ve sau.

Cach xir ly trgn che phdm SOY. SOD true tiep voi ngo dd qua xic ly nhiet eho hieu qud phong chong mgt cao tren 84% sau 6 thang.

+ Cach. phun hodc quet mat ngodi mat bao dyng ngd (da qua xir ly nhiet) bang SOY (SOY-EC neu phun). SOD (SOD-EC neu la phun) va lam lap lai sau 3 thang bao quan eho hieu qua bao quan ngd dat 81.9 - 82,6%). Cach nay don gian va de img dung vdi ndng dan va hat ngd khdng can dinh chat bao quan.

Trong khi sir dung bien phap xdng hoi bang Phosphin ket hgp phun dau Neem tren bao dyng thdc tai Phillipines. sau 8 thang hieu lye ddi vdi cac loai mgt giam cd 60-70 % so vdi ddi chirng [7].

Nhu vay. hieu qua phdng chdng mgt kho ciia eae che pham tii' dau Neem cd hieu lyc kha cao va dai hon han viec xir ly nhiet va xir ly hda chat (thudng chi keo dai hicu luc chap nhan duge trong 2 thang).

KHOA HOC &

TMngTIn

CONG NGHE

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M HOAT DONG NGHIEN CliU llNG DUNG J - TRIEN KHAI KHOA HOC CONG NGHE

Bang 4. Hieu luc phong chong mot hai ngo cua cac che pham moi tao ra

(Vien Bao ve thye vat, thang 1- thang 7/2010)

Stt Cdng thirc

XLN

HL(%) XLHC

HL(%)

SOY(T)-XLN

HL(%)

SOY(T)-KXLN HL (%)

SOD(T)-XLN

HL(%)

SOD(T)-KXLN HL(%)

SOY(Q)-XLN

HL(%)

SOD(Q)-XLN

HL (%) DCI

Mat do mpt sdng trung binh (eon/ 1 kg) sau xu ly 1 thang

1,2 97,2

2,6 94,0

0,0 100,0

10.2 76,4

0,0 100,0

9,8 77,3

0,0 100,0

0,0 100,0

43,2

2 thang 34,6 92,6

45,4 90,3

2,6 99,4

112,6 75,9

3 "' 99,3

80,6

n,7

4,2 99,1

8,2 98,2 467.0

3 thang 118,8^

74,6

146.4'"

68.7

7,8^

98,3

234,8^

49,8

5,8' 98,8

180,4' 61,4

10,8' 97,7

12.4' 97,3 467.6'

4 thang 112,4

65,6

168,2 48,6

18,4 94,4

123,6 62,2

16,4 95,0

204,4 37.5

28,6 91,3

30,8 90,6 327,2

5 thang 164,8

49,9

216,8 34,1

32,8 90,0

142,2 56,8

26,8 91,8

134,6 59:1

34.6 89,5

42.2 87,2 328.8

6 thang 200,6^''

28,5

220,6"^

21,4

42,6' 84,8

120,4^' 57,1

38,4' 86,3

146,8"

47,7

48,2' 82,8

50.8' 81,9

280,6^

- KXLN. XLN = Kliong va ed xu ly nhiet trude khi xir ly che pliSm Neem; -XLHC = Xir ly xdng hai bang hoa chat Phostoxin theo lidu khuyin eao; -SOY(T). SOD(T) = Phun va trpn tuong img eae chi pham SOY va SOD vdi ngo; - SOY(Q), SOD(Q) = Quet hoac phun ddu mat ngoai bao dyng ngd tuang

^m Thing Tin

•8 • KHOA HOC &

CONG NGHE

HOAT DONG NGHIEN COU O N G DUNG

-TRIEN KHAI KHOA HOC CONG NGHE a

ung eae ehe pham SOY va SOD; - HL = Hieu lyc so vdi ddi ehung.

3.4. Ket qua danh gia do an toan cua san phdm bao quan ngu coc tir cay Neem

3.4.1. Ket qud xdc djnh du lugng cua hogt chat Azadirachtin trong nong sdn

Mau ngd ed nguy ea mat an toan nhat la trpn trye tiep SOY, SOD vao hat ngd. Lay mau sau xir ly 15 ngay, sir dyng phuong phap phan tich du lupng Azadirachtin tren may HPLC 1100 (Chiit bdng MeOH Cpt C18, He dung moi MeOH/Hp=65/35, dong 0,5 ml/inn; Buoc song: 217 nm, thai gian:

15 mn). Ket qua phan tieh eho thay boat chat Azadirachtin khdng phat hien thay trong ea hai mau xirlySOYvaSOD.

3. 4. 2. Xdc dinh LD.^ cua che phdm Neem Ket qua thi nghiem ve xae dinh dp dpc cap tinh ciia SOY va SOD vdi chupt bach eho thay:

Sau khi cho nudt thudc d eae lieu 1.000, 2.000, 5.000, 7.000 va 10.000 (mg/kg) chupt sdng binh thudng 100% sau 1 ngay xir ly. Do do LD^^ ciia hai che pham tren vdi chupt (qua mieng) deu ldn hon 10.000 mg/kg va eae thudc nay thupc nhdm rat it dpc (nlidm IV theo quy dinh eiia WHO)

K£T LUAN

1. Hat cua eay Neem gidng Xenegan trdng dugc 9-10 nam nay d Ninh Thuan ed hdm lugng ddu khd cao (39,0 L dau chiet xuat bang dung mdi va 35,8 L do ep ngugi/100 kg nhan hat).

2. Ham lugng hoat chat cd y nghia nhat trong viee san xuat thudc thao mgc trir dieh hai Azadirachtin trong eay Neem 10 tudi o Ninh Thuan thupc logi eao so vdi d eae nod khae tren the gidi (4.252 ppm ddi vdi hat Neem gidng Xenegan).

Ham lugng Azadirachtin Pong ddu Neem tic nhien (ep ngugi) la 2058 ppm.

3. Da tao dugc hai che pham tii' dau Neem ty nliien la SOY va SOD ed hieu lyc hrir mgt kho tren 90% sau 4 thang, tren 80%o sau 6 thang khi phun hoac quet mat ngoai bao ehira ngd bao quan (xii' ly nhiet trudc khi bao quan). Cac ehe pham tren duge nhu hda (SOY-EC, SOD-EC) ed thd

phun trir mpt ngd tryc tiep (phun ve sinh kho) vdi hieu lyc trii' mpt ngo eao (100% sau phun 2 ngay) 4. Cac che pham nay rat an todn vdi moi truang, thupc nhdm rat it dpc (LD^^ qua mieng vdi chupt > 10.000 mg/kg) va sau hai tuan xir ly da khdng cdn tdn du hoat chat trong ndng san ke ca khi phun trye tiep. Cd the hoan thien cdng nghe de san xuat cac ehe pham thao mpc tir dau Neem de bao quan ngd hieu qua va an toan.

TAI LIEU THAM KHAO

1. Akou-Edi, D. (1984). Effects of Neem Seed Powder and Oil on Tribolium confusum and Sitophilus zeamais. ZFA Entomologic 103: 208-213.

2. Gabriele S. (2000). Natural Crop Protection in the Tropics. Magraf Verlag.376 pp.

3. Jaeobson, M (1986). Neem Tree: Natural Resistencepar Excellence. In "Natural Resistenee of Plants to Insects". American Chemical Society Symposium Series No. 296. ACS, Washington, D. C. 220-232.

4. Knowel D. A. (Editor) (1998). Chemistiy and Technology of Agrochemical Formulations.

Kluwer Academic Publishers. Dordrecht/ Boston/

London.

5. Nguyen Duy Trang, Nguyen Thi Me va nnk (2000). Nghien cuv sic dung mpt so lodi cdy co tinh dpc de ldm thuoc trie sdu a phia Bdc Vet Nam. Vien Bao ve thue vat. Tuyen tap cdng trinh Nghien ciiu Bao vd thuc vat (1996-2000). NXB Nong nghiep, trang: 255-268.

6. Ruskin F. R. (Editor) (1992). Neem. A tree for Solving Global Problems. National Academy

Press. Washington, D.C, 1992.

7. Saxena R.C., Kidiavai E.L. (1997). Neem Seed Extract Spray Applications as Low-Cost Inputs for Management of the Flower Thrips in the CoCPea

Crop. Phytoparasitiea 25(2): 99-110. (NO)

8. Singh R. R (2000). Neem for Pest Management. How to Grow and Use. Indian Agricultiu-al Research Institute, New Dellii -

110012, India. 36 pp.

9. Yu Qude Trung (1981). Sdu hai ndng .san trong kho vd phong trii: NXB Ndng nghiep. 372p.

10. v^ovw.neemuses. com

KHOA HOC &

TMng Tin

CONG NGHE

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