KHOA HOC COHG NGHI

n g h i C n c u u k h A n A n g ltixig d u i m g c h £ p h A m CHITOSAIM OLIGOMER PHONE TRU BENH HAI THtlM

m o t s d C A Y T R O IV GNguyen Hdng Son1, Duong Vin Hpp2

t 6m t AtChitosan (c6n g<?i la oligo - sacarit) la mQt dang kitin d§ bi khu axetyl. Kitin la polyme sinh hoc co nhi£u trong thidn nhidn chi dung sau xenluloza. Vidt Nam c6 tiem ndng Ion vd xuat khiu tom. Hing n&m san lupng tdm trong nuoc c6 thd dat 250.000 tin, nhu vay lugng phu phim kitin uoc tinh c6 thd d?t 15000 tin.Dfty la ngu6n nguydn lidu c6 gid trj cho san xuit thuoc bao vd thvrc v$t dung cho canh tic ndng nghidp s?ch.Gin day trong chuong trinh hpp tac v6i D<u hpc liege, Vuong qu<5c Bi, Vidn Vi sinh v£t va C6ng nghd sinh hoc da nghidn cuu thanh cdng phuong phap san xuit chitosan oligomer bang con duong sinh hoc khi su dung enzym vi sinh vat la chitinaza va kitin deaxetylaza. Vidn da ph6i hpp voi Vidn Moi trudng Ndng nghidp nghidn cuu kha nang ung dung chitosan trong phdng tru dich h i trdn ddng rudng nham timg budc hoan thidn san phim a quy md san xuit ldn. Bai bao nay gidi thidu k£t qua nghidn cuu su dung chd phim chitosan oligomer cd dd pha loang 300 lin tuong duong ham lupng chitosan oligomer khoang 120 mg/lit trong phdng tru mdt so bdnh had trdn mdt sd cay trdng chinh nhu ca chua, dua chudt, dau an qui va bip cai.K& qua nghidn cuu cho thiy, hidu qua tru bdnh cua Chitosan phu thudc vao phuong phap va ndng dd su dung. Chitosan cd thd h^n chd rd rdt bdnh chdt eo cay con, bdnh hdo xanh vi khuin h?u ca chua va bdnh thdi nhun bip cai khi tudi thudc vao g6c c&y con. Hidu qua tru bdnh cao hon rd rdt so vdi chi phun chd phim trdn la cung nhu cao hon phuong phap phdng tru ma ndng dan dang ap dung la phun Validadn vao cay sau trdng 5 ngay. Trong ba bdnh trdn, hidu qua tru bdnh chdt eo cay con cua chi phim cao hon so vdi bdnh hdo xanh va thdi nhun bip cai. Khi chi phun ldn la, hidu qua tru cac bdnh chdt toan than nhu chit do cay con, hdo xanh ca chua hay thdi nhun bip cai thip hon rd rdt th$m chi khdng cd hidu qua nhung chitosan oligomer cd thd han chd tot bdnh hgi la nhu bdnh suong mai ca chua, phin tring dua chudt, gi sit d$u tr?ch. Hidu qua tru bdnh suong mai d?t cao nhit, sau dd ddn bdnh phin tring va thip nhit la bdnh gi sitTCr khda: Chitosan, b$nh hoi, ca chua, dua chufc bip cai, d$u trpch.

i . bAt v An b£

Li mot nuoc xuat khau tom dung thu 3 trdn the! gidi sau Trung Quoc, An Do, Vi£t Nam c6 nhi£u lpi thi trong vi|c khai thic kitin tu phu pham chi bien t6m. Dl tin dung nguon phu phim quy gii niy, Vidn Vi sinh vit vi Cdng ngh| sinh hpc (Dai hpc Qudc gia Hi Ndi) di phdi hpp vdi Vi£n M6i trudng Nong nghidp vi Trudng dai hpc liege cua Bi nghidn cuu su dgng enzim vi sinh vit cho sin xuit chitosan oligomer tir vd t6m dl lim thu6c BVTV. Phuong phip sinh hpc mdi san xuit chitosan oligomer c6 nhilu uu dilm hon cic phuong phip h6a hpc vi vit ly trong sin xuit chitosan oligomer trong nhilu nghidn cuu trudc diy vl tinh an toin cho ddi tupng ciy trdng, con ngudi vi mdi trudng sinh thii cho phit tridn nln ndng nghidp xanh. Kit qui nghidn

1 Vi$n Mdi tmdng Ndng nghidp2 Vi§n Vi sinh v#t vi Cdng ngh§ sinh hpc, D?i hpc Qu6c gia Hi Ndi

cuu dinh gii budc dau trong phdng thi nghidm cho thiy chi phim chitosan oligomer cd khi ning uc chi phit triln cua mdt so vi sinh vit giy b|nh thuc vit nhu Botrytis, Fusarium, Ralstonia vi ting khi ning kich khing cua thuc vit dupe dinh gii thdng qua hoat tinh enzym LOX ( lipoxygenaza).

Kit qui nghidn cuu trong phdng thi nghi|m dinh gii hi|u qua khing vi sinh vit trdn 4 loai rau d cic muc dp pha loing khic nhau (1/100, 1/300 vi 1/500) cho thiy hi|u qui cao nhit cd thi d?t dupe khi phun d ndng dd 1/100 vi 1/300. Tai dd pha loing niy, ndng dd kitin, chitosan oligomer tdng sd uoc tinh khoang 120 mg/1 vi lupng duong khu tuong ung (NAG) khoing 4 mg/1. Cic kit qui nghidn cuu cua thi gidi v! su dung chitosan oligomer dl tru b|nh cho ciy trdng cung chi ra ring ndng dd hi£u qui cua chi phim rit khic nhau ddi vdi timg lo?i ciy vi b$nh. Ghaouth E. L vi cdng sy (1994) [3] cho bilt khi su dpng d ndng dd 0,4 mg/1, chitosan

•s

NONG NGHllP vA PHAT TRiIn NONG TH O N -K Y1 + 2 -THANG 2/2014 25

KHOA HOC COHG NGHt

oligomer cho hidu qui rO r t doi voi bdnh do nim Pythium spp. gay ra doi voi dua chudt Bell va cpng sir [1] lai nhan thiy, hidu qua khang bdnh do Fusarium spp. trdn can tay chi thuc su r6 rdt khi kdt hpp phun va tuoi true tidp vao goc a nong do chitosan cao tai 30 g/1. Trdn at, Kim va cong sir (1997) bao cio, hidu qua khang bdnh do nam Phytophthora chi thuc su cao khi su dung chitosan a nong do 2 g/1 theo phuong phap tuoi vao goc nhung voi bdnh do nam Botrytis gay ra, E. L. Ghaouth va cdng su (1997) lai phai su dung chitosan a nong dp10 g/1 [4, 5). Doi vdi ca chua, E. L Ghaouth cho bidt hi u qua khang bdnh do nim Fusarium gay ra c6 thd dat kha rd rdt a nong dd 12,5 g/1 [3]. Nhung nghidn cuu khac cua Benhamou (1997) lai thiy su dung chitosan a nong dp thip (1 g/1) cung cho lai hidu qua khang Fusarium trdn c i chua kha r6 rdt O nong dd thip (0,1-6,4 mg/1), Bhaskara (2000) [2] cung nh3n thiy rd kha nang bao vd ca chua cua chitosan khang lai bdnh do nim Altemaria gay ra.

O nuoc ta, Bp Nong nghidp va Phat tridn nong thon cung da cip giiy phdp cho su dung chd phim chitosan oligomer nhu mpt lorn thudc bao vd thuc vat voi tdn thuong mai la Rizasa 3DD va Tramy 2 SL co nong dd chitosan oligomer 3-5%. Cac san phim nay hidn dang dupe nhap khiu tu nuoc ngoai va da chung minh c6 hidu qua rd rdt trong phong tru bdnh hai. Nghidn cuu cua chung t6i la nghidn cuu dau tidn vd san xuit vi thu nghidm chd phim kitin, chitosan oligomer dugc san xuit bang phuong phap sinh hpc nham muc dich ung dung cho san xuit thuc pham sach. Ket qua thu nghidm budc dau cho thiy tridn vpng r6 rdt cua chd phim so v6i cic thuoc bao vd thuc vat hoa hpc.

Dd g6p phin thuc day kha nang ung dung chd phim chitosan oligomer trong phong tru bdnh h?d cay trong, da tidn hanh nghidn cuu kha nang uc chd mot so bdnh do vi sinh v$t trdn mpt so loai rau tai vimg san xuit rau an toin khu vuc Ha Noi.

2. WAT LfU, NOi DUNG VA PHUONG PHAP NGHEN CUII2.1. vat lidu nghidn cuuChd phim chitosan dupe san xuit tu vo tom cua

theo cong nghd su dung emzim vi sinh vat; cac v$t lidu trien khai thuc nghidm dong ruong trdn cay ca chua, dua chupt bap cai vi dau tr ch.

22. Ndi dung nghidn cuuDinh gia hidu qua ph6ng tru bdnh hai cua

chitosan trdn ciy c i chua, dua chupt bap cai va d$u an qua;

Xac djnh ky thuat su dung phii hpp ddi voi timg doi tupng bdnh hai chu ydu trdn timg cay trdng.

2.3. Phuong phap nghidn cuuNC dupe tidn hanh trdn dong rupng theo kidu

didn hep, nhac lai 3 lan. Cac o TN dugc xip xdp theo phuong phap khoi ngau nhidn hoan toan (Randomized complete block design - RCB). Didn tich o TN la 20 m2. TN gom 11 cong thuc, trong d6 co 3 cong thuc tuoi thuoc vao goc sau trong + phun dinh ky 15 ngay/ lan kd tir sau khi trong a n6ng dp 1/500,1/300 va 1/100; 3 cong thuc phun thuoc ldn la djnh ky 15 ngay/ lin va 3 cong thuc phun thuoc ldn la djnh ky 10 ngay/ lan kd tir sau khi trong cung v6i 3 nong dp trdn; c6ng thuc ddi chung khdng su dung chitosan va khdng su dung thuoc BVTV khac; ddi chung su dung thudc theo ndng dan. Lupng dung dich thudc tuoi vao goc la 800 lit/ ha va lupng phun ldn la la 500 lit/ha.

Didu tra, danh gii: didu tra djnh ky 10 ngay/ lin dd danh gia muc dp nhidm bdnh, tir dd tinh hidu qui trir bdnh cua cac cdng thuc thi nghidm. Phuong phap didu tra theo tidu chuin nginh. Tinh ty Id bdnh (TLB) va chi sd bdnh (CSB); hidu dinh hidu qui phdng trir bdnh theo cdng thuc Abbot (ddi vdi TN ddng rupng khi ty Id bdnh trudc phun ddng nhit).

S. KET QlU NGHEN CUU

3.1. Hidu qui trir bdnh cua chitosan trdn cay ci chua

3.1.1. Hieu qua trir benh chet eo cay con h$i ca chua

O cac cong thuc tudi chitosan vao goc, hidu qua trir bdnh cd thd dat tir 55,88 ddn 79,41% a 10 ngay sau trdng (NST) ; 64,15 ddn 86,79% a 20 NST va 72,37 ddn 89,47% 30 NST tuy theo ndng dd thudc su dung, cao hon giam rd rdt so vdi khi chi phun ldn la. Ty Id bdnh a ca 3 cdng thuc phun thuoc djnh ky 15 ngay/ lin khdng cd su sai khac rd rdt so vdi ddi chung, nghla la vide phun thudc ldn la theo chu ky 15 ngay/ lin khdng cd kha nang han chd bdnh hai. Cic cdng thuc phun thudc dinh ky 10 ngay/ lan tuy cd hidu qua phdng trir bdnh thap han cac cdng thuc tuoi thudc vao goc (chi dat 42,11% ddn 63,1% sau trong 30 ngay) nhung cao hon rd rdt so vdi cac cdng thuc phun djnh ky 15 ngay/ lin (Bing 1).

Dd trir bdnh chdt eo cay con, ngay or diu vu ndng dan da phun 1 lin bang thudc Validacin 5SL, 3 lit/ha vao gdc sau khi trdng 5 ngay, hidu lye trir bdnh 1at

26 N6 NG NGHIEP va PHAT TRIEN NdNG TH6 N - KY 1 + 2 - THANG 2/201

KHOA HOC COHG NGHt

cao nhit 11 46,05% sau trdng 30 ngiy, tuong duong vdi chitosan dinh ky 10 ngay/ lan 6 n6ng dd 1/300 va c6ng thuc phun chitosan djnh ky 10 ngay/ ldn d nong 1/100 cung nhu thip hon so vdi cac cong thuc tuoi dO 1/500 vi thip hon rd rdt so vdi cic cong thuc phun chitosan vio goc (Bang 1).

Bing 1. Ty 1$ bdnh hai vi hidu lye phdng tru cua chitosan ddi vdi bdnh chdt do c!y con d chua

Cdng thucTi Id bdnh (%) Hidu lye phdng trir (%)

10NST 20 NST 30 NST 10NST 20 NST 30 NSTChitosan - 1/500 - tudi vio gdc + phun dinh ky 15 ngiy/ lin 4,17b 5,28c 5,83b 55,88 64,15 72,37

Chitosan - 1/300 - tudi vio gdc + phun dinh ky 15 ngiy/ lin 3,89b 4,72b 3,89a 58,82 67,92 81,58

Chitosan -1/100 - tudi vio gdc + phun dinh ky 15 ngiy/ lin 1,94a 1,94a 2,22a 79,41 86,79 89,47

Chitosan - 1/500 - phun dinh ky 15 ngiy/ lin 9,44d 13,89g 19,72e 0,00 5,66 6,58

Chitosan - 1/300 - phun dinh ky 15 ngiy/ lin 9,17d 13,89g 19,17e 2,94 5,66 9,21

Chitosan - 1/100 - phun dinh ky 15 ngiy/ lin 8,61d 13,33g 18,33e 8,84 9,43 13,16

Chitosan - 1/500 - phun djnh ky 10 ngiy/ lin 6,94c 9,44ef 12,22d 26,47 35,85 42,11

Chitosan - 1/300 - phun dinh ky 10 ngiy/ lin 6,39c 7,78e 9,17c 32,35 47,17 56,58Chitosan - 1/100 - phun dinh ky 10 ngiy/ lin 5,83c 6,67d 7,78c 38,24 54,72 63,16Ddi chung phun thudc theo ndng din (Validacin 5SL, 3 lit/ha) 6,67c 8,89e ll,39d 29,41 39,62 46,05

Ddi chung khdng phun thudc 9,44d 14,72g 21,lief . . j

CV0Q 12,7 22J 24,4LSD (5%) 1,92 1,48 1,923.1.2. HiSu qua tru binh heo xanh vikhuan hai ci

chuaHdo xanh vi khuan la bdnh rit khd tru nhung ch£

phim chitosan da chung to kha ning phdng trir khi cao vdi bdnh niy. Khi tudi thudc vio goc, hidu qui tru bdnh cd thd d$t tdi 85,0% or nong dd 1/100; 80% d nong d0 1/300 vi 68,75% d ndng dd 1/500. Khi phun ten la, tuy hidu qui tru bdnh dat thip hon nhung ndu phun dinh ky10 ngiy/ lined thd han chd tdi da61,25% ty 10 bdnh hai (khi phun d ndng dd 1/100). Khi phun vdi tin suit thip hon (15 ngiy/ lin) vi phun 10 ngiy/ lin nhung d ndng d0 thip hon, hidu qui tru bdnh giam rd rdt

3.1.3. Hi$u qua tru binh suong mai hai c i chuaHidu qui trir bdnh suong mai c i chua cua

chitosan cung khi rd ring, d$c bidt cic cdng thuc

phun thudc dinh ky trdn li ddu cd thd phit huy hidu qui tuong duong cdng thuc tudi thudc vio goc + phun ldn li. Do dd chi sd bdnh d cic cdng thuc phun dinh k trdn II vi cdng thuc tudi vio goc + phim dinh ky ldn li khdng cd su sai khic rd rdt khi su dgng d cung ndng dd- Didu dd cd nghia li vide tudi thudc vio gdc khdng cd y nghia han chd bdnh suong mai.

Kdt qui d bing 3 cung cho thiy, hidu qui cua chitosan phu thudc rd rdt vio ndng dd phun vi tin suit phun. Cic cdng thuc phun dinh ky 10 ngiy/ lin ddu cho hidu qui cao hon rd rdt so vdi cic cdng thuc phun 15 ngiy/ lin dcung ndng dd, th|m chi khi phun d ndng dd 1/300 hay 1/500, cic cdng thuc phun dinh ky 10 ngiy/ lin dl cd thd cho hidu qui trir bdnh tuong duong vdi cdng thuc phun d ndng dd 1/100 hay 1/300 cua cdng thuc phun dinh ky 15 ngiy/ lin. Khi

NdNG NGHliP VA PHAt TRli-N NONG THON - KY 1 + 2 - THANG 2/2014 27

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n6ng dO phun cao hon, hi£u luc cua thuoc cung tang hoc dSc hi u nhu Boocdo luan phi£n vdi Ridominrd r£t n£n hi£u qua dat rit cao, tuong duong vdi c6ng thuc

CT cong thuc phun tru theo nong dan phai do phun chitosan dinh ky 10 ngay/ lan 6 nong dd 1/100phun thu6c dinh ky 7 ngiy/ ldn bang cdc thuoc h6a (Bang 2).

Bang 2. Chi sd b£nh hai vi hi u luc trir b^nh suong mai hai c i chua cua chitosan

Cdng thucChi sSb^nh sau trdng (X) Hi£u luc trirb£ah sau trdng 00

30 NST 40 NST 50 NST 60 NST30NST 40 NST 50 NST 60NSTChitosan -1/500 - tudi vio goc + phun dinh ky 15 ngiy/ lin 6,57d 10,17c 12,35d 16,30e 36,2 42,6 472 43,4

Chitosan - 1/300 - tudi vio goc + phun 3inh ky 15 ngiy/ lin 4,34bc 6,84bc 8,83b 11,66c 57,8 61,4 62,2 59,5

Chitosan -1/100 - tudi vio goc + phun 3inh ky 15 ngiy/ lin 3,20b 4,96b 6,92ab 9,13ab 68,9 72,0 70,4 68,3

Chitosan - 1/500 - phun dinh ky 15 ngiy/lan 6,59d 10,34c 12,46d 16,45e 35,9 41,6 46,7 42,9

Chitosan - 1/300 - phun dinh ky 15 igiy/ lan 4,61bc 7,24bc 9,41b 12,42cd 55,2 59,1 59,8 56,9

Chitosan - 1/100 - phun dinh ky 15 ngiy/ lan 3,40b 6,00b 9,07b 11,43c 66,9 66,1 612 60,3

Chitosan - 1/500 - phun dinh ky 10 ngiy/ lan 4,71bc 7,44bc 10,61c 14,Old 54,3 58,0 54,6 51,4

Chitosan - 1/300 - phun dinh ky 10 ngiy/ lan 3,98b 5,83b 8,82b 11,31c 61,3 67,1 62,3 60,7

Chitosan - 1/100 - phun dinh ky 10 ngiy/ lan 1,35a 2,95a 5,70a 7,34a 86,9 83,3 75,6 74,5

Doi chung phun thuoc theo ndng dan (Boocdo luan phi£n vdi Rhidomin) 1,33a 2,94a 4,61a 6,08a 87,1 83,4 80,3 78,9

Doi chung khdng phun thuoc 10,29e 17,72d 23,38e 28,81f - - - •

CV(%) 17,42 19,87 22,43 20,64LSD (5%) 1,12 1,56 1,68 2,023.2. Hi£u qui tru b£nh cua chitosan trtn c&y dua 3.2.1. Hieu qua tru binh ch it eo ciy con hai dua

chuQt chudtBing 3. Ty 1$ b^nh h?i vi hi£u lye trir b£nh ch£t ho ciy con trtn dua chudt cua chitosan

Cdng thucTil£b£nh 06) Hi£u lye phdng tru (X)

10 ngiy sau

tr6ng

20 ngiy sau

trong

30 ngiy sau

trong

10 ngiy sau

tr6ng

20 ngiy sau tr6ng

30 ngiy sau

trdngChitosan -1/500 - tudi vio goc + phun dinh ky 15 ngiy/ lin 3,89b 5,00b 6,39c 53,33 64,00 71,95

Chitosan -1/300 - tudi vio goc + phun dinh ky 15 ngiy/ lin 3,33b 4,44b 4,17b 60,00 68,00 81,7

Chitosan -1/100 - tudi vio goc + 1,94a 1,67a 1,67a 76,67 88,00 92,68

28 N6 NG NGHlfP VA PHAT TRIEN N6 NG THdN - K* 1 + 2 - THANG 2/2l 4

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phun djnh ky 15 ngdy/ ldnChitosan -1/500 - phun dinh ky 15 ngdy/ ldn 8,33e 13,06e 21,39g 0,00 6,00 6,10

Chitosan -1/300 - phun dinh ky 15 ngdy/ ldn 8,06e 13,06e 20,83g 3,33 6,00 8,54

Chitosan -1/100 - phun djnh ky 15 ngdy/ lan 7,78e 12,78e 20,00g 6,67 8,00 12,20

Chitosan -1/500 - phun djnh ky 10 ngdy/ ldn 5,83d 9,17d 13,06f 30,00 34,00 42,68

Chitosan -1/300 - phun dinh ky 10 ngdy/ ldn 5,56c 7,50c 10,00e 33,33 46,00 56,10

Chitosan -1/100 - phun dinh ky 10 ngdy/ ldn 5,00c 6,39c 8,33d 40,00 54,00 63,41

Ddi chung phun thudc theo n6ng dan (Validacin 5SL, 3 lit/ha) 5,83d 8,61cd 12,22f 30,00 38,00 46,34

Ddi chung khdng phun thudc 8,33e 13,89e 22,78h - - -

CV(%) 11,24 20,18 17,66LSD (5%) 0,75 1,31 1,62

Kdt qui d bang 3 cho thdy, cdc c6ng thuc tuoi ldn Id ddu c6 hidu qua trir bdnh, do d6 ty 1$ bdnh dduchitosan vao goc cho hidu qua cao hon r6 rdt so vdi giam r6 rdt so voi doi chung a tat ca cdc cdng thucchi phun ldn Id d cung nong do. Cong thuc dat hidu thi nghidm. Hidu qua trir bdnh cao nhdt c6 thd dat tdiqud cao nhat la tuoi thuoc vao goc + phun djnh ky 15 78,77%.ngdy/ ldn 6 nong dp 1/100 (92,68% sau trong 30 Trong cdc cong thuc thi nghidm, cdc c6ng thucngdy). Trong khi d6 ndu khdng tudi thuoc vao gdc ma phim dinh ky 10 ngay/ ldn cd hidu qua cao hon rd rdtchi phun ldn Id dinh ky 15 ngdy/ ldn, hidu qud chi dat so vdi cdc cdng thuc phun 15 ngay/ ldn. Khi tdn sudt12,20%, phun dinh ky 10 ngdy/ lan dat 56,1%. phun dinh ky nhu nhau (15 ngay/ ldn), hidu qua cua

Tuong ty TN vdi cd chua, d cdng thuc phdng trir cdc cdng thuc tudi vao goc + phun ldn Id khdng cd sutheo dan da phun Validacin vao gdc vdo 5 ngdy sau khac bidt ro rdt so vdi chi phun ldn Id d cirng nong do,tr6ng, do d6 hidu qud giam bdnh cung khd cao, dat nhu vay bidn phap tudi vdo gdc khdng anh hudngtuong duong cdng thuc phun dinh ky chitosan 10 nhidu tdi kha nang phdng trir bdnh phdn trdng.ngdy/ ldn d ndng do 1/300 den 1/100 tuy timg giai doan sinh trudng cua cay (Bang 3).

3.2.2. Hiiu qui tnrbenh phan tring hai dua chudt Cdc cdng thuc tudi chitosan vdo dat + phun dinh

ky ldn Id cung nhu cdc cdng thuc chi phun dinh kyBdng 4. Ty Id bdnh hai vd hidu luc trir bdnh chdt eo cdy con cua chitosan trdn d$u tr ch

3.3. Hidu qud trir bdnh cua chitosan trdn d$u tr?ch

3.3.1. Hieu qua tru binh chit eo ciy con h$i diu trach

Cdng thuc Hid bdnh (%) Hidu yc phdmr trir (%)10 NST 20 NST 30 NST 10NST 20 NST 30 NST

Chitosan -1/500 - tudi vao gdc + phun dinh ky 15 ngay/ ldn 3,61b 4,17b 4,72b 56,66 65,08 72,59Chitosan -1/300 - tudi vdo gdc + phun dinh ky 15 ngay/ ldn 3,33b 3,89b 4,33b 60,02 67,42 74,85Chitosan -1/100 - tudi vdo gdc + phim d)nh ky 15 ngdy/ lin 1,94a 2,67a 3,33a 76,71 77,64 80,66Chitosan - 1/500 - phun dinh ky 15 8,33e 11,lie 15,83eg 0,00 6,98 8,06

N6NG NGHltP VA PHAT TRlf:N N6NG TH6N-KY 1 + 2 -THANG 2/2014 29

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ngay/ lanChitosan - 1/300 - phun dmh ky 15 ngay/ lan

8,06e 11,lie 15,28f 3,33 6,98 11,29

Chitosan - 1/100 - phun dinh ky 15 ngay/ lan 7,78e 10,83e 14,72f 6,67 9,30 14,52

Chitosan - 1/500 - phun dinh ky 10 ngay/ lin 5,83cd 7,78d 10,00e 30,00 34,88 41,94

Chitosan - 1/300 - phun dinh ky 10 ngay/lin 5,56c 6,39c 7,78d 33,33 46,51 54,84

Chitosan - 1/100 - phun dinh ky 10 ngay/ lin 5,00c 5,56c 6,39c 40,00 53,49 62,90

Doi chung phun thuoc theo ndng dan (Validacin 5SL, 3 lit/ha) 6,llcd 7,50d 9,17e 26,67 37,21 46,77

Doi chung khdng phun thudc 8,33e ll,94e 17,22hCV(%) 13,33 15,78 19,05LSD (5%) 0,71 0,92 0,86Tuong tu hi£u qua trir bdnh chdt eo d y con tr£n

d chua va dua chupt doi vdi dau trach d c cong thuc khong tuoi thudc vao goc nhung phun ten la voi tan suat cao hon (10 ngay/ lin) tuy c6 hidu qua trir bdnh khong cao bang cac cdng thuc tudi thuoc vao gdc 6 cung nong dp nhung ddu cd hidu qua trir bdnh rd rdt hai cdng thuc phun ndng dd 1/100 va 1/300 khdng cd sy sai khac vd hteu qua trir bdnh nhung ddu cao hon rd rdt so vdi cdng thuc phun dr ndng dd 1/500. Hidu luc trir b£nh cua 2 cdng thuc nay cung kha cao (54,84 ddn 62,90% vao 30 ngay sau trong) - Bang 4.

3.3.2. Hiiu qui trir bdnh g i s it hai dau trachSo vdi hteu qua trir cac bdnh trdn la khac nhu

bdnh suong mai ca chua va bdnh phin tring hai dua chudt, hidu qua trir bdnh gi sit trdn dau trach cua chitosan dat thip hon. Hidu qua cao nhit khi phun vdi tin suit 10 ngay/ lin (dat tu 57,97 ddn 69,03% vao 70 ngay sau trong), thip hon cdng thuc phdng trir theo dan (d?t 75,07%). Trong thi nghidm nay, cdng thuc phdng tru theo dan dupe ap dung phun theo ddi tupng dich h?i khi xuit hidn phd bidn (tuc chi so hai xap xi 10%) bang cic thudc hda hoc thudc ho?t chit Propiconazole vl Difenoconazole.

Cic cdng thuc phun vdi tin suit 15 ngay/ lin cd hidu qui thip hon rd rdt so vdi cdng thuc phun 10 ngiy/ lin. Khi kdt hgp giua tudi thudc vao gdc va phun ten la, hidu qui d?t cao hon. Khi chi phun ldn 11 vdi tin suit 15 ngiy/ lin, hidu qua trir bdnh khi phun b cdc ndng dd khic nhau khdng cd sy sai khic rd rdt nhung khi kdt hyp vdi tudi thudc vio gdc thi hidu

qua khi su dung b ndng dd 1/ 100 cao hon rd rdt so vdi 1/ 300 va 1/ 500. Khi ndng dd cang cao, hidu qui cua thudc cang cao, nhung hidu qui cung chi dat cao nhit la 55,26% vao 70 ngay sau trdng.

3.4. Hidu qui trir b$nh cua chitosan trtn cli bip3.4.1. Hiiu qui tru binh chSt eo d y con hoi d i

bipCung nhu hidu qui trir bdnh chdt eo d y con

trdn d c d y trong khac, hidu qui trir bdnh trdn bip d i kha rd rdt Hidu qua dat cao nhit khi ap Hung bidn phap tudi thuoc ngay sau trdng (bidn ddng tu71,22 ddn 83,47% sau trdng 70 ngiy).

Khi chi phun ten la, hidu qui tru bdnh cung giam rd rdt dac bidt khi phun theo chu ky 15 ngiy/ lin. Hidu qua phong trir cung it cd sy sai giua d c nong dp phun. Khi rut ngin tin suit phun mring10 ngay/ lin, hidu qui tang rO rdt so vdi phun 15 ngay/ lin va cd sy sai khac rd rdt giua d c cAng thuc phun dr d c ndng dd khac nhau. Hidu qua cua chitosan khi phun ldn la 10 ngay/ lin rfmg can hon cdng thuc phdng trir theo din 11 phun Validacin vdo 5 ngiy sau trdng.

3.4.2. Hiiu qui tru binh thdi nhQn bip d i cua chitosan

Kdt qui thi nghidm t?i bang 5 cho thiy, d c cdng thuc phun chitosan ddu cd tic dyng h?n chd hfoh rd rdt, giam ty Id bip bi h i t£r 5,31 ddn 78,00% phy thudc vio ndng dd thudc phun vd phuong phip su dyng. Cdc cdng thuc tudi thudc vdo gdc cho hidu qui cao nhit (64,39% ddn 78,00% khi thu ho ch - tuc 90

N6NG NGHIfP VA PHAT TRIEN N6NG THdN - KY 1 + 2 - THANG 2/20U

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ngiy sau trdng), cao han rd r£t so v6i cic cdng thuc khing sinh Validacin vio goc dd trir bdnh ch£t eo ciy chi phun ldn li vi cdng thuc ph6ng trir theo ndng con a dau vu). din (chi phun thudc trir nim bdnh vi phun thudc

Bing 5. Ty Id bdnh hgi vi hidu lye trir bdnh thdi nhdn bip cai cua chitosan(TN tpiDdngAnh, HANQivyxui

I•<51£

Cdng thucTi Id bdnh (%) Hidu lyc p

(%:hdng trir

80 NST 90 NST 80 NST 90 NSTChitosan -1/500 - tudi vao gdc + phun djnh ky 15 ngiy/ lin 7,50b 7,83b 55,88 64,39Chitosan -1/300 - tudi vio gdc + phun dinh ky 15 ngay/ lin 7,00b 7,00b 58,82 68,18Chitosan -1/100 - tudi vio gdc + phun djnh ky 15 ngiy/ lin 3,67a 4,83a 78,43 78,00Chitosan -1/500 - phun dinh ky 15 ngay/ lan 16,67e 20,83e 1,96 5,31Chitosan -1/300 - phun dinh ky 15 ngiy/ lan 16,33e 20,83e 3,92 5,31Chitosan -1/100 - phun dinh ky 15 ngay/ lin 16,00e 20,17e 5,88 8,33Chitosan -1/500 - phun dinh ky 10 ngiy/ lin 12,20d 14,50d 29,41 34,91Chitosan -1/300 - phun djnh ky 10 ngiy/ lin 11,17c 11,83c 34,31 46,12Chitosan -1/100 - phun djnh ky 10 ngiy/ lin 10,00c 10,00c 41,18 54,55Ddi chung phun thudc theo ndng din (Validacin 5SL, 3 lit/ha) 12,17d 13,50d 28,43 38,66Ddi chung khdng phun thudc 17,00e 22,00e - -

CV(%) 15,23 11,76LSD (5%) 2,12 1,89

4. Kfl LIMN ldn li vdi tin suit 10 ngiy/ Uin, hidu qui trir bdnh

Chitosan co hidu qui phdng trir rd rdt doi vdi cic bdnh h?i chu y&i Wn cic ciy rau dai didn. Hidu qui trir bdnh phu thuoc vio ciy trong, phuong phip vi ndng dd su dyng. Khi tuoi vio gdc ciy, chitosan cd thd h n chd rd r£t bdnh chdt eo ciy con (hidu qui trdn ci chua dat 89,47%, dua chudt dat 92,68%, diu trach 80,66% vi bip cai dat 84,43%), bdnh hdo xanh vi khuin hai c i chua (85,00%) vi bdnh thoi nhun bip cai (79,00%). Hidu qui tru cic bdnh niy khi tudi thudc vio gdc cao hon rd rdt so vdi chi phun chitosan trdn li cung nhu cao hon phuong phip phdng trir mi ndng din dang ip dung li phun Validacin vio ciy sau trong5 ngiy. Vdi hidu qui dd chi can su dung chitosan d n6ng dO 1/300 li phu hop d£ trir bdnh chdt eo ciy con, cdn khi trir bdnh hdo xanh vi khuin hoic thoi nhun bip cii thi phai su dung a nong dd 1/100.

Khi chi phun ldn li, hidu qua tru cic bdnh chdt toin thin nhu chdt eo ciy con, hdo xanh c i chua hay thdi nhun bip cii thap hon rd rdt thim chi khdng cd hi£u qui nhung chitosan cd thd han chd tot bdnh h?i li nhu bdnh suong mai c i chua, phin tring dua chuQt, gi sit diu tr?ch. Hidu qui trir bdnh trdn li thip hon bdnh h?d toin thin (tru bdnh suong mai d?t 74,5%, phin tring li 78,77% vi ri sit li 69,03%). Khi phun trir

cao hon khi phun 15 ngiy/ lin vi ndng dd thudc cung can cao hon.

6. NGH|

Can tidp tuc nghidn cuu sin xuit cic dgng chitosan dd phu hyp vdi muc dich ung dyng trong dit nhu tao dang hat, byt dd cd thd trdn vdi phin chuong, phin hoi hpc khi su dung.

Nhi nude cin ho try du in sin xuit thu nghidm, tir dd dau tu diy chuydn cdng nghd dd sin xuit chitosan quy md ldn nhim tin dung nguSn phu pham vd tom, cua trong chd bidn thuy san, gdp phin ting nguon thu cho ngudi sin xuit vi gdp phin bio vd mdi trudng.

tju i4 u h u m kh Ao

1. Bell A. A., Hubbard J. C., Liu L, 1988. Effects of Chitin and Chitosan on the incidence and severity of Fusarium yellows of celery. Plant Diseases. 82(3): 322-328.

2. Bhaskara Reddy M. V., Angers P., Castaigne F., Arul J., 2000. Chitosan effects on blackmold rot and pathogenic factors produced by

M fV is n g h iEp VA PHAT TRlffN NONG TH O N -KYI + 2 -THANG 2/2014 31

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Altemaria alternate in postharvest tomatoes. J. Amer. Soc. Hort Sci. 125(6): 742-747.

3. El Ghaouth A., Arul J., Wilson C., Benhamou N., 1997. Biochemical and cytochemical aspects of the interactions of chitosan and Botrytis cinerea in bell pepper fruit Plant Diseases. 86(6): 121-128.

4. El Ghaouth A, Arul J., Wilson C.t Benhamou N., 1994. Ultrastructural and cytochemical aspects of the effect of chitosan on decay of bell pepper fruit Physiological and Molecular Plant Pathology. 44:417-432.

5. Kim K. D., Nemec S., Musson G., 1997. Effects of composts and soil amendments on soil microflora and Phytopthora root and crown rot of bell pepper. Crop Protection. 16(2): 165-172.

POTENTIAL CONTROL OF CHITOSAN OLIGOMER ON SOME PLANT DISEASES ONVEGETABLES IN VIETNAM

Nguyen Hong Son1, Duong Van HopSummary

Chitosan oligomer, an natural oligo - saccharide is a de-acetyl substance of chitin which is the second avaiable abundant by-product in nature followed cellulose biomass. In nature, chitosan is mainly obtained from the hard outer skeleton of shellfish, including crab, lobster, and shrimp. It is used for medicine. As shrimp exporting country, Vietnam has promising potentiality to produce chitosan from by-product (about 15,000 tons chitin a year). Under the collaboration with Liege University, Belgium, the Institute of Microbiology and Biotechnology, a member institute under Vietnam National University, Hanoi has been successful in bio- converting chitin to chitosan-oligomer by microbial enzymes ( chitinase and deacetylase). To develop commercialization of product the institute has been cooperated with the Institute for Agriculture Environment evaluating the potentiality of product to control vaious diseases on vegetable. This paper will report some recent findings on potential use of chitosan-oligomer as biocontrol substance for some major vegetable diseases. It was found that when aplying the product diluted by 1/300 of chitosan oligomer, equipvelent with 120 mg active ingredient/lit the product performed high potentility to control major soil bom diseases such as damming off, bacterial wilt rod, blight powdery midew, rust on various crops such as tomato; cucumber; cabbage and bean scouts. By drenching into the root chitosan showed higher control effect to damming off, bacterial wilt and rod disease whereas the foliar aplication could provide better control on blight, powdery midew and rust The bio-efficacy depended on crops, application method, dosage and target disease. The highest control can be reached with damming off diseases (ranged from 83.43 to 92.68%), followed by bacterial wilt (85.00%), cabbage rod (78.00%), powdery midew (78.77%), blight (74.50%) and rust (69.03%).Key words: Chitosan, diseases, tomato, cucumber, cabbage, legume.

Ngudi phin bi£n: GS.TS. Nguy£n Van Tu£t Ngiy nhin bii: 18/12/2013 Ngiy thdng qua phin bi£n: 17/01/2014 Ngiy duy$t ding: 24/01/2014

32 NONG NGHlf P VA PHAT TRIEN NdNG TH d N -K Y 1 + 2 - THANG 2/2C