N G U Y E N N T I A N G A Y H I E N T U d N G V . \ N G L A , T H O I R t T R E N C A P H E V O I ( C O F F E A C A N E P H O R . 1 V A R . R O B U S T A )
V A B I E N P H A P P H O N G T R l T
T h e c a u s a l a g e n t s a n d c o n t r o l m e a s u r e s o f c o f f e e r o o t r o t d i s e a s e TrSn Kim Loang, Phan Quoc Sung,
Ha Thj Mao, Nguyen XuSn Hoa, Ta Thanh Nam, Nguygn Van Phi Hung,
Dao Thi Lan Hoa
Vien KHKT Nong Lam nghiep Tdy Nguyen
ABSTRACT
Since 1994, a yellow syndrom caused by root rot diseases h a s been observed on coffee planting areas of Central Highlands especially in Dak Lak province.
Nowadays, it is the most common and serious disease among t h e coffee root diseases in Dak Lak province. Feeder roots of mature coffee t r e e s are rotten resulting in yellowing leaves and die back. After up-rooting old coffee t r e e s or coffee root-rot infected t r e e s and replanting, almost taproots of replanted young coffee trees are also rotten. Most replanted coffee fields were infected by Pratylenchus coffeae. The percentage of infected coffee trees is 12 - 47% on average, t h e highest is 80%.
188 soil and root samples of coffee p l a n t i n g areas were collected for nematodes and fungi parasitic together with laying out an artificial inoculation in screen house.
Coffee root - lesion nematode, Pratylenchus coffeae, h a s been found the meun causal agent of coffee root-rot disease at a very high densities a n d frequency of occurrence (80 - 90%). This is t h e first time this nematode spieces h a s attacked on robusta cof- fee in Dak Lak province.
Data of suveying showed t h a t rotation after uprooting coffee trees is not effective on controlling nematode unless combined with deep plowing and collecting coffee roots. Many control measure such as soil treating, rotation, field sanitation, chemical are also applied after up-rooting coffee trees in a field experiment. The results showed t h a t field sanitation by deep plowing a n d collecting coffee roots are key measures for nematode control on r e p l a n t i n g coffee t r e e s . After sanitising, cereal crops or leguminous crops should be grovrai for rotation to suppress nematode densities in the soil.
1. Mof d a u
Ca phe vdi vdn la gid'ng cd k h a n a n g k h a n g tuyen t r u n g Pratylenchus coffeae cao hon ca phe che (Coffea arabica). Nhieu tac gia da de nghi dung ea phe vdi lam gdc ghep cho ca phe che de phdng t r d tuyen t r d n g Pratylenchus coffeae (Schieber,
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Ho
1971; Palanichamy, 1973; Kumar, 1984). Tuy n h i e n td n a m 1994, h i e n tugng v a n g la, thd'i re xua't hien phd bie'n va gay h a i n g h i e m trpng t r e n ca phe vdi tai Dak Lak. Trong n a m 1995, gan 400 h a ca phe dang cho qua p h a i bi t h a n h ly do trieu chdng v a n g la, thd'i re to. Cung trong n a m n a y t r e n 200 h a ca phe t r d n g lai deu bi vang la, thd'i re cpc. Ty le cay chet cd t h e len de'n 70 - 80%. C i c trieu chdng t r e n tuong t g n h d n g md ta ve sg gay h a i cua P. coffeae t r e n ca phe che tai Viet Nam va mpt so nude t r d n g ca phe t r e n t h e gidi cua Coste (1955), Palanichamy (1973), Phan Qud'e Sung (1976); Kumar (1984), Campos va cdng sg (1990). Tai Dak Lak, day la l a n dau tien xuat h i e n trieu chdng v a n g la, thd'i re t r e n ea phe vdi. Cho de'n nay da cd g a n lOOOha ca phe tai Dak Lak phai t h a n h ly va t r e n 500 h a ca phe dang bi gay h a i , trong dd cd t r e n lOOha bi h a i n a n g , cac dien tich n a y cd the se tiep tuc bi t h a n h ly trong thdi gian tdi.
2. V a t l i ^ u v a phu^oTng p h a p
- 188 mau dat va r i dugc lay tai cae vUdn ca phe vdi bi v a n g la, thd'i re tai T h a n h phd' Budn Ma Thudt va 4 huyen Krdng Ana, CuM'gar, Krdng Pak, Krdng Buk cua tinh Dak Lak de xac dinh t h a n h p h a n tuyen t r d n g va n a m ky sinh. Moi diem dieu tra lay it n h a t 30 mau.
- Dat va rd dugc lay d dp sau 0 - 30cm. Mdi vUdn lay 5 m i u trdn lai t h a n h 1 m i u . - Nam duge nudi cay tren mdi trUdng PDA (Potato Dextrose Agar), WA (Water Agar), CLA (Carnation Leaf-piece Agar), tach don bao td va dinh danh theo Burgess (1994).
- Tuyen trung dugc ly trich b i n g phuong phap ngam r i (Fallis, 1943 &
Stermerding, 1964) va phUOng phap pheu Baerman (Hooper, 1986). Dinh danh tuyen trung theo: Mai, Mullin Peter (1996), Nguyen Ngpc Chau, N g u y i n Vd T h a n h (2000).
- Thi n g h i e m lay benh n h a n tao trong n h a lUdi: thgc h i e n t r e n cay ca phe eon d giai doan vUdn UOm cua 2 gid'ng; Robusta va Catimor (Coffea arabica var. cati- mor). Thi nghiem gdm 7 cdng thdc bd' tri theo khdi day du n g i u n h i e n (RCBD), mdi cdng thdc 30 cay, n h i c lai 3 lan.
Dat dugc say khd t r d n g d n h i e t dp ISO^C trong 30 phdt. Tuyen t r u n g duge lay nhiem d m a t so' 500 - 750 eon/kg dat. N a m duge cay t r e n mdi trUdng PDA va lay nhiem d m a t sd bao td >106/ml. Cay con duge tao vet thuong eO gidi b i n g each c i t dau re va duge n g a m vao dung dich n a m lay n h i i m trong 30 phut, dung dich n a m dugc trdn vao dat trUde khi cay cay con.
- Cae t h i nghiem t r e n ddng rupng duge bd tri theo khd'i day du ngau nhien, n h i c lai 3 - 4 l a n
3. K e t q u a v a t h a o l u a n 3. 1. Tri^u chiing
Dau tien, t r e n vUdn ca phe xua't hien mpt hay nhieu vung cay sinh trudng kem.
Tren ca phe kinh doanh, cac trieu chdng t r e n m a t dat rd n h a t la cay sinh trUdng cham lai (cay c i n cdi, it canh la), thieu dinh dudng (vang l i ) , heo khi thdi tiet ndng
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h a y khd, giam n a n g suat. Cac trieu chdng dudi dat gom: thd'i td" dau r i , re cd nhiJng vet t h a m den, he thdng re kem p h a t trien, d cay bi h a i nang, re thudng muc nat.
Hien tugng v a n g la thudng xuat hien gida mua mUa (thang 8, 9). Cay bi suy yeu dan sau nhieu n a m do he thd'ng re to bi huy hoai d i n de'n khd canh, rung l a v a chet. Benh p h a t t r i e n c h a m va p h a n bd cge bd theo tdng vung trong vUdn cay, day la trieu chufng de p h a n biet vdi trieu chdng vang la do thieu dinh dudng, cham sdc khdng tdt.
Hinh 1. Cay ca phe vol 7 nam tudi bi vang la do thdi ri td
Hinh 2. Trieu chdng thdi re to tren cay ca phe v6'i do tuyen trung Pratylenchus coffeae
\a • III in« 11
Hinh 3. Cay ca phe vdi 2_nam tudi bi vang li do thdi ri coc
Hinh 4. Trieu chdng thdi ri coc tren cay ci phe vdi do tuyen trung Pratylenchus coffeae
Tren ca phe trdng mdi va dUdi 3 n a m tudi, hien tugng v a n g la thudng xua't hien dau tien vao dau mda khd nam t h d 2, 3 sau khi trdng, d cae vUdn trdng lai tren nen dat cu cua cac vUdn ca phe gia cdi hoac da hi benh vang la, thd'i r i . Neu bi nang thi cay CO the vang la ngay td mua khd n a m trdng mdi. Trieu chdng chung la re coc bi thd'i den va ddt ngang, bd r i to gan m a t dat p h a t t r i e n m a n h . Trong mda mUa cay van xanh td't nhUng de'n dau mua khd, sau khi ddt mUa va ehUa tUdi nUdc, nhdng cay bi thd'i re cpc se the hien trieu chdng vang la va heo do thieu nUde va dinh dudng.
Do khdng cd re cpc nen eac cay nay d i bi nghieng khi cd gid to va ed the de dang dugc nhd len b i n g tay mac diu cay r a t x a n h td't trong mua mUa. Day la dac diem de p h a n biet cay b e n h va cay khdng benh trong mda mUa k h i cay chua vang la.
3.2. Tdc nhdn gdy hai
Ke't qua ly trich tuyen t r u n g cho t h a y Pratylenchus coffeae la loai tuyen trung chie'm Uu t h e trong cac loai tuyen t r d n g ky sinh cd t r o n g dat va re eua cay ca phe bi v a n g la, thd'i r i .
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B^ng 1. Thanh phan va mat so tuye'n trung ky sinh trong dat cua cac viTcfn ca phe kinh doanh co trieu chiJng vang la, fho'i r i tai Dak Lak (con/50g flat)
n
1 2 3 4 5 6 7 8
Thanh phan tuye'n trung
Pratylenchus coffeae Meloidogyne spp.
Tylenchus sp.
Rotylenchus sp.
Aphelenchus sp.
Helicotylenchus sp.
Tylenchorhynchus sp.
Xlphlnema sp.
Mat so trung binh
66 43 6 5 4 5 4 1
Mat so' cao nhat
544 296 56 56 64 40 16 16
Ty 1? hien dien tren tong so'tuyen trung (%)
15,63 10,20 1,51 1,14 0,85 1,14 0.85 0,05
Tan sua't xua't hien (%)
82,98 32,45 3,19 2,13 1,60 1,06 1,06 0,53
* Thdi gian dieu tra: thang 5/1999
Tren 80% so' m i u dat p h a n tich cd P. coffeae vdi m a t sd' t r u n g b i n h la 66 con/50g dat, m a t sd' cao n h a t len de'n 544 eon/SOg dat. Meloidogyne spp. la gid'ng tuyen trung cd m a t so' cung n h u mdc dp phd bie'n xep t h d 2 sau P. coffeae. Tuy n h i e n t a n suat xuat hien cua gid'ng nay cung chi khoang 32%, t h a p hon nhieu so vdi P. coffeae.
Cac gid'ng tuye'n t r u n g k h a c xuat h i e n vdi m a t so va t a n sua't r a t t h a p .
Trong khi dd, trong r i cay ea phe bi v a n g la, thdi r e . P. coffeae g i n n h u la loai tuye'n t r d n g ky sinh chie'm Uu t h e tuyet dd'i (Bang 2). Cd t r e n 90% so' mau dieu t r a cd P. coffeae, chie'm t r e n 48% tdng so tuye'n t r d n g cd trong r e , t r o n g khi ty le n a y d cac gid'ng khac khdng cao hOn 1%, ke ea MeloidogjTie spp. la gid'ng tuyen t r d n g thudng gay h a i n a n g t r e n ea phe vdi. M a t sd' trung binh eua P. coffeae trong re la 381 con/5g r i , m a t so cao n h a t len de'n 4.784 con/5g r i .
' Bing 2. Thanh phS^n va mat so'tuye'n trung ky sinh trong r i cua cac viTcfn ca phg kinh doanh cd trieu chu'ng vang la, thoi r i tai Dak Lak (con/5 g r i )
TT 1 2 3 4 5
Thanh phan tuye'n trung
Pratylenchus coffeae Meloidogyne spp.
Tylenchus sp.
Rotylenchus sp.
Helicotylenchus sp.
Mat so' trung binh
381 9 4 1 1
Mat so' cao nhat
4.784 184
64 40 24
Ty le hi?n dien tren tong so' tuye'n trung (%)
48,54 1,08 0,39 0,09 0,06
Tan sua't xua't hien (%J
92,02 14,89 10,64 5,31 2,66 Thdi gian dieu tra: thang 5/1999
Ngoai r a chung tdi eung n h a n tha'y cd sU k h a c biet r a t rd k h i p h a n tich m a t so tuyen trung P. coffeae t r o n g d a t va r i eac vUdn ea phe bi v a n g la thd'i r i va k h d n g bi vang la thd'i r i (Bang 3 va 4).
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Bang 3. Mat so tuyen trung Pratylenchus cofi'eae trong da't cua cac viio'n ca phe voi trong giai doan kinh doanh b| va khong bj vang la, tho'i r i tai Oak Lak (con/50g dat)
Dia diem Vi?n KHKT NLN TN Cong ty ca phS 53 C5ng ty ca phe Phucic An Cong ty ca phg ThSng Lqi Cong ty ca ph§ Krflng Ana Nfing truing ca ph§ ChU Quynh
Trung binh So miu dieu tra
Vi/Gin vang !a, TB
20 87 51 53
Cao nh§'t
56 288 312 312
tho'i r§
TSXH (%)
66,7 100,0
60,0 75,6 45
Vir&n khong vang la, TB
4 20 21 12 0 0 9
Cao nhdt 16 96 80 56 0 0 96
90
thoi rfi ' JSXH_(%]_
33,3 33,3 33,3 40,0 0 0 23,3
* Thai gian dieu tra: thang 5/1999 ; t = 6,31 > t o.os = 1.98
Tai cung m o t dia diem dieu tra, 75% m i u dat cua cac vUdn v a n g la, thdi re cd sU h i e n dien eua tuye'n t r d n g P. eofeae vdi m a t sd' t r u n g b i n h t r e n 50 con/50g dat Trong khi dd, ed de'n 2 trong 6 dia diem k h d n g v a n g la, thd'i r i duoc dieu tra hoar toan k h d n g cd tuye'n t r d n g P. coffeae trong dat. U cac dia diem cdn lai P. coffeaf xua't h i e n vdi t a n sua't 33 - 40%, m a t so' t r u n g b i n h dudi 20 eon/SOg dat, thap hor nhieu so vdi cae vUdn hi vang la, thd'i r i .
B^ng 4. Mat so'tuye'n trung Pratylenchus coffeae trong rg cua cac vu'cfn ca phe voi trong giai doan kinh doanh bj va khong bj vang la, tho'i r i tai Dak Lak (con/5g r i )
Dja diem Vi§n KHKT NLN TN Cong ty ca phe 53 Cong ty ca phe Phudc An Cong ty ca phe Thang Lqi Cong ty ca phe Krong Ana Nong trudng ca phe ChU Quynh
Trung binh So m l u dieu tra
Vi/ofn vang la, tho'i r i TB
•643 625 271 513
Cao nhat
2.496 1.808 720 2.496
TSXH (%)
100,0 100,0 80,0 93,3 45
\l\iSi\ khfing vang la, thoi ri TB
0 15
1 39 2 10 11
Cao nhS't 0 72 80 192
56 80 192
TSXH (%) 0 33,3
6,7 60,0 20,0 40,0 26,7 90
Ghi chu: Thdi gian dieu tra: thang 5/1999 ; t = 15,59 < t o.os = 1,98
Tuye'n t r u n g P. coffeae xua't hien trong re cac vUdn bi v a n g la thdi r i vdi tar sua't t r e n 90%, r a t cao so vdi t a n sua't xua't h i e n d cae vUdn k h d n g bi vang la tho:
r i la 26,7%. M a t so trung binh cua tuye'n t r d n g P. coffeae t r o n g r i eac vUdn bi vanj la thd'i r i cao t r e n 45 lan cac vUdn k h d n g hi v a n g la thd'i r i .
So lieu dieu t r a cua Araya (1990) cho tha'y t r e n cac vUdn ca phe bi tuye'n trung ga) hai tai Turrialba Canton (Costa Rica) t a n sua't xuat hien cua Pratylenchus spp. 1^
36,7%, cao n h a t la 65%; tan sua't xuat hien cua Meloidogyne spp. la 68%, cao nhat U 89%. Vdi t a n xua't xua't hien nhU vay thi Meloidogyne spp. la loai tuye'n trdng chieir Uu the' trong cae vUdn ca phe tai Turrialba Canton. Neu so vdi cac ke't qua dieu tra cu£
chung tdi thi t a n sua't xua't hien cua P. coffeae tren cac vUdn benh tai Dak Lak ca(
tuong duong vdi t a n suat xua't hien eua Meloidogyne spp. tai Turrialba Canton.
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Ke't qua dieu t r a ve t h a n h p h a n va m a t sd tuye'n t r u n g ky sinh t r e n eac loai vUdn ca phe vd'i cho tha'y: t h a n h p h a n tuyen t r u n g ky sinh t r e n cae vudn ea phe k h d n g vang la, thd'i r i r a t phong phu vdi m a t sd k h d n g cao. Trong khi dd t r e n cac vUdn ca phe gia cdi va bi benh cd sU t a n g cao sd lugng tuye'n t r d n g P. coffeae trong r e . Thanh p h a n tuye'n t r d n g t r e n cac vUdn ca phe gia coi cung phong phu n h u t r e n ca phe khdng b e n h nhUng m a t sd P. coffeae va Meloidogyne spp. cao hon nhieu so vdi cac gid'ng k h a c , dac biet la P. coffeae.
Bang 5. Thanh phan va mat so'tuye'n trung ky sinh trong r i cac loai vu'cfn ca phe vo'i tai Dak Lak (con/5g r i )
n
1 2 3 4 5 6
Thanh phan tuye'n triing Pratylenchus coffeae Meloidogyne spp.
Tylenchus sp.
Rotylenchus sp.
Helicotylenchus sp.
Tylenchorhynchus sp.
Vircfn >
20 ndm 357
81 10 8 11
1
VUcfn 10 - 1 5 nam Khong benh
11
Benh 513
8 13 11 10 0
ViTcfn 1 - 3 nam tudi Khong benh
3 2 0 1 0 0
Benh 448
19 1 0 0 0
Mat so tuye'n t r u n g Meloidogyne spp. gida vUdn vang la va k h d n g v a n g la bie'n ddng khdng nhieu trong re. Chung tdi eung it tim tha'y trieu chdng sUng re do Meloidogyne spp. gay ra t r e n cac vUdn ca phe kien t h i e t co b a n t r d n g lai t r e n n e n dat cu. Hon n d a trieu chufng sUng r i do Meloidogyne spp. gay r a t r e n ca phe vdi tai Dak Lak ma chung tdi dieu t r a duoc h o a n t o a n k h a e h a n trieu chdng thd'i r i do Pratylenchus coffeae gay ra.
Ket qua p h a n lap n a m ky s i n h t r o n g b a n g 6 cho tha'y n a m chie'm Uu t h e t r o n g hau h e t cae m l u re cua vUdn la F u s a r i u m oxysporum ( t a n sua't xua't h i e n > 90%).
Trong khi dd F. solani la loai n a m cd t a n sua't xua't h i e n cao n h a t (67,8%.) t r e n cac loai vUdn dac b i e t la cac vUdn cd t r i e u c h d n g v a n g la, thd'i r e . Su h i e n d i e n vdi t a n sua't cao cua n a m F u s a r i u m solani t r o n g r i eac cay v a n g la cho tha'y rd hon sU phdi h g p eua loai n a m n a y vdi tuye'n t r u n g P . coffeae t r o n g viec gay thd'i re ca p h e .
Bing 6. Thanh phan va tan sua't xua't hien cua cac loai na'm ky sinh trong r i cay ca phe cua cac vi/cfn ca phe vo'i tai Dak Lak (%)
n
1 2 3 4 5
Thanh phin ni'm Fusanum oxysporum Fusanum solani Fusanum spp.
Rhizoctonia batatlcola Rhizoctonia solani
Vi/cfn vang Cay vang la
90,3 67,8 48,6 33,5 26,2
a, thd'i r i Cay kh5e
81,9 38,7 17,5 15,6 9,4
Vifdn khong vang la, thdi r i 83,3
25,0 18,3 16,7 0
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3.3. Kit qud Idy nhiim nhdn tao
Bang 7. Ty le cay con bj che't sau khi lay nhiim (%)
Cdng thi^c Dat l<hQ trung
Dat benh Lay R. batatlcola
LSy R. batatlcola + F oxysporum Lay F. oxysporum
LSy f! oxysporum + P. coffeae LSy P. coffeae
Sau 1 thang Robusta
1,1 12,2 3,3 10,0
6,7 4,4 2,2
Catimor 0 0 0 2,2 1,1 6,7 1,1
Sau 3 thang Robusta
3,3 e 13,3 d 34,4 b 76,7 a 23,3 c 36,7 b 6,7 e
Catimor 0 d 5,6 c 73,3 a 74,5 a
6,7 c 75,6 a 48,9 b
• Tren bang sd lieu, cac sd tren cung mOt cdt theo sau li cac chU cai gidng nhau ch! cic gia tn khong khac nhau theo trie nghiem da doan Duncan (DMRT) dp <0,05.
T r e n ca hai gid'ng ea phe, sau khi lay n h i i m 3 t h a n g , ty le che't cua cay con cao n h a t cd y n g h i a thd'ng ke d eac cdng thufc lay R. batatlcola + F. oxysporum va F.
oxysporum + P. coffeae. Cdng thdc d a t say cung ed m o t sd' cay che't n h u n g khi phan lap n a m t h i k h d n g tha'y cd sU h i e n dien eua cae loai n a m gay b e n h n h u cac cong thdc khae. Rieng dd'i vdi cac cdng thdc lay P. coffeae t h i cd sU k h a c nhau ro ret gida ca phe vdi va ca phe che. Ty le c a y c h e ' t t r e n ca phe che d cac cdng thdc co tuye'n t r d n g bao gid eung cao hon t r e n ca phe vdi d cung m o t cdng thdc lay nhiim.
Cac thi nghiem lay n h a n tao tuye'n trung tren 3 gid'ng ea phe che (Coffea arabica), ca phe vdi (Coffea canephora) va ca phe mit (Coffea exeelsa) eua Kumar (1979) cho tha'y ca phe vdi cd t i n h chd'ng chiu cao n h a t vdi tuye'n t r u n g Pratylenchus coffeae, ke de'n la ca phe mit va ca phe che. Tac gia cung tha'y r a n g vdi so luong tuyen t r u n g P. coffeae tid 500 - 5.000 con trong r i t h i cay con 40 n g a y tud'i va 120 ngay tudi hi gay h a i n a n g trong khi cae cay 1 n a m tudi chd'ng chiu ducfc.
3.4. Mot so kit qud phong trii trin dong ruong 3.4.1. Ve sinh dong rugng vd ludn canh
Luan canh la bien p h a p duoc d a n h gia la cd hieu qua cao t h r o n g phong trif tuye'n trdng. De ed eO sd xac dinh loai cay t r o n g ed t h e luan canh vdi cay ca phe de phdng t r d tuye'n t r d n g P. coffeae chung tdi da dieu t r a t h a n h p h a n tuye'n trung trong r i mot sd' cay lUOng thUc va dau dd t h u d n g dugc t r d n g xen t r o n g vUdn ca phe.
Bang 8. Thanh phan va mat do tuye'n trung throng r i mgt so' cay trdng tren cac vi/ofn ca phe bj tho'i r i do tuye'n trung P. coffeae (con/5g r i )
n
1 2 3 4 5 6
Thanh phan tuye'n trung Pratylenchus coffeae P. brachyurus Pratylenchus spp.
Meloidogyne spp.
Helicotylenchus sp.
Rotylenchus sp.
Lua 0 32
0 24
0 0
Ngd 0 342
0 24 0 0
san
0 0 320
40 0 0
Lac 0 12 32 8 0 0
Oau xanh 0 0 88
8 0 0
Oau den 0 0 315
23 0 24
Mudng hoa vang
0 0 4 7 24 0
Muong den 0 0 21 51 69 0 Ghi chu: Muong hoa vang: Crotalaria striata Muong den: Cassia siamea
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Cac sd lieu trong bang 8 cho t h a y cd the dung cac cay Ida, ngd, san, lac, dau xanh, dau den, mudng hoa vang, mudng den de luan canh trUdc khi t r d n g lai ca phe. Tuy nhien, trong thUc te san xua't neu chi ap dung mot bien phap luan canh thi khd cd the trdng lai ca phe sau 2 - 3 n a m . Ke't qua n a y dugc t r i n h bay trong Bang 9.
Bang 9. Tinh hinh benh tho'i r i do tuye'n trung P. coffeae tren cac dien tfch trong lai tren dat da nho bo ca phe trong cac dieu kien chuan bj dat khac nhau
Ky thuat canh tac Luan
canh Khong 1 nam 2 nam 3 nam
Cay sau, gom r i
Khong Khong Khong 3 lan
Dien tich trong lai tren fla't cu (ha)
323 92 88 21
Dien tfch benh ha
323 92 88 1.5
% 100 100 100 7
% cay che't Trung
binh 40 20 25 10
Thap nhat
7 5 10
5
Cao nhat
80 25 40 15
Bien p h a p luan canh h a n che sU gay h a i cua tuye'n t r u n g qua viec lam giam 50%
cay chet t r e n vUdn sau k h i t r d n g lai so vdi k h d n g luan canh. Tuy n h i e n , neu chi ap dung mot bien p h a p luan canh thi hieu qua t h a p hon so vdi luan canh ke't hgp vdi cay sau (40 - 50cm) va thu gom r i khi chuan bi dat t r d n g lai. Bien p h a p thu gom r i la mot khau quan t r o n g de loai bdt ngudn tuye'n t r d n g trong d a t t r d n g ca phe.
Trdng tuye'n t r d n g P. coffeae thudng t d n tai trong cac t a n dU thUc vat, n h a t la r i cay, sau khi khdng cdn cay ky chu (Campos va cdng sU, 1990). Ke't qua dieu t r a cho tha'y viec ke't hop 2 bien p h a p luan canh va cay sau thu gom re da cho ke't qua r a t kha quan, chi ed 7% vUdn t r d n g lai bi b e n h , vdi ty le cay che't la 10%. Day la ty le cd the chap n h a n duge dd'i vdi cac vUdn ca phe t r d n g mdi. Kumar (1984) tai An Do cung da de nghi ap dung bien p h a p cay, xdi, phoi dat sau khi nhd va ddt cac cay bi tuye'n t r u n g gay hai.
3.4.2. Cdc bien phdp xic ly ddt
B^ng 10. Ty le cay ca phe vo'i che't do tho'i r i khi trdng lai tren dat cu (%)
TT 1 2 3 4 5 6
Cdng thiJc
Doi chLfng Xu ly vol
XL/ ly voi + dot hd Thudc hoa hoc (HH) Xu ly vol + ddt hd + HH Ca phe vdi ghep ca phe mit
Trung binh
Sau 18 tha Khdng cay sau,
gom r i 31,2 a 36,5 a 32,3 a 8,1 b 7.9 b 19,1 ab 22,5
ng trd'ng Co cay sau,
gom r i 14,0 ab
1.5 b 3.6 ab
7,8 ab 1,5 b 21,8 a
8,4
Sau 30 thanq trdng Khdng cay sau,
gom r i 75,0 a 81,3 a 75,0 a 56,1 ab 35,0 b 25,0 b
57,9
Cd cay sau, gom r i
23,4 a 6,5 ab 6,6 ab 8,8 ab 4,1 b
28,1 a 12,9 t = 6,43 > to,o5 = 2,23 t = 8,01 > to.os = 2,23
Ghi chu: - Dia diem thi nghiem: Cong ty ca phe EaPol< (CuM'Gar, Oak Lak) - Trong thang 6/1996
- Thudc hoa hoc: Viben C 50 BTN (0,5 %) + Furadan 10 H (30 g/hd)
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Thi nghiem dugc thUc hien t r e n 2 n e n dat cd va khdng cd cay sau, thu gom re. Ke't qua trong bang 10 cho tha'y, ty le cay chet cua dien tich cd cay sau, thu gom re thap hon cd y nghia thd'ng ke so vdi dien tich khdng cay sau, thu gom re. Ngay ea d cong thdc dd'i chdng, ty le cay che't t r e n 2 n e n dat nay eung k h a c nhau. Ty le cay che't cua cdng thdc dd'i chdng d diem khdng cay sau, thu gom r i cao gap 3 lan so vdi diem cd cay sau, thu gom r i . Sau 30 t h a n g trdng, trong khi cae cdng thufc d diem khong cay sau, thu gom r i deu t a n g n h a n h ty le cay che't t h i cae cdng thdc dugc xd ly dat (cdng thdc 2, 3, 4, 5) d diem cd cay sau, thu gom r i hau n h u k h d n g t a n g dang ke.
Cdng thdc dung cay ghep vdi gdc ghep la ca phe m i t (Coffea exeelsa Chev.) co ty le cay che't tUOng dd'i cao d ca 2 dia diem.
Theo ddi m a t do tuye'n t r u n g P. coffeae sau 24 t h a n g t r o n g (Bang 11), chdng toi n h a n tha'y mac dau k h d n g luan canh nhUng bien p h a p cay sau, thu gom re da lam giam d a n g ke ngudn tuye'n t r u n g P. coffeae. T a t ea eac cdng thdc t r e n n e n dat co cay sau, thu gom r i deu ed m a t do tuye'n t r u n g P. coffeae t h a p hon cd y nghia thdng ke so vdi khi t r d n g t r e n n e n dat khdng cay sau, thu gom r e .
Bang 1 1 . Mat dp tuye'n trung P. coffeae trong r i cay ca phe sau 24 thang trdng lai tren nen dat da trdng ca phe (con/5g r i )
TT 1 2 3 4 5 6
Cdng thii'c Ddi chiing
XLT ly vol
Xlf ly vol + ddt hd Thudc hoa hpc (HH) XLf ly vol + ddt hd + HH Ca phe vdi ghep ca phe mit
Trung binh
Khdng cay sau, thu gom r i 288
608 256 236 229 254 312
Co cay sau, thu gom r i 90
32 60 48 40 40 50 t = 4,79 > tflos = 2,23
Sau 4 nam trdng lai vUdn cay d diem ed cay sau, thu gom re vdn phat trien td't va hit dau cho qua trong khi tai diem khdng cay sau, thu gom re vUdn cay da chet gan het va rat Id dd nen da phai nhd bd. Nang sua't eua vUdn cay cd cay sau, thu gom re dat tren 1,8 tan. Day la mot nang sua't khdng thap dd'i vdi mot vUdn ca phe bat dau cho qua.
Nang sua't cua eac cdng thdc dugc xuf ly dat trUdc khi trong dat 1,9 - 2,0 t a n nhan/ha, oO vdi dd'i chdng khdng xd ly dat chi cd 1,7 t a n nhanTha. Cdng thdc trong cay ghep gdc ea phe mit cd ty le cay che't cao nen nang sua't cung thap hon cae cdng thdc khac.
4. Ket l u a n va de n g h i
4.1. Tuye'n t r u n g Pratylenchus coffeae la tac n h a n chinh gay h i e n tugng vang la, thd'i r i t r e n ca phe vd'i tai Dak Lak.
4.2. Fusarium solani la loai n a m chinh phdi h g p gay h a i vdi tuye'n t r u n g P. cof- feae dua den trieu chdng thd'i r i va gay che't cho ca p h e vd'i.
4.3. Bien p h a p cay sau k e t hgp vdi ve sinh ddng rugng nhU thu gom va dot ri sau khi nhd bd cac \Tidn cay hi vang la, thd'i re do tuye'n t r d n g Pratylenchus coffeae la bien p h a p quyet dinh sU t h a n h cdng khi t r d n g lai ea phe t r e n d a t cd.
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4.4. Luan canh la bien phap can thiet de han che ngudn tuyen trung trong dat trUdc khi trdng lai. Luan canh neu duge phdi hgp vdi bien phap cay sau, thu gom re se lam tang hieu qua phdng trd tuye'n trung. Cac cay luong thuc nhu Ida, ngd, sSn va cay phan xanh, dau dd thudng duoc khuyen cao trong xen trong vUdn ca phe nhu dau xanh, lac, dau den, mudng hoa vang deu cd the diong de luan canh vdi ca phe de phdng trd tuye'n tning P. coffeae.
4.5. Cac bien phap xd ly dat bkng thud'c hda hgc, dot hd, bdn vdi chi gdp phan lam tang hieu qua phdng trd trong dieu kien dat da dugc luan canh, cay sau va thu gom r i .
4.6. De nghi bd sung cae bien p h a p c a n h tae sau trong quy t r i n h t r d n g ca phe:
Sau khi nhd bd eac vUdn ca phe gia cdi va eac vUdn bi vang la, thd'i re do tuye'n trdng P. coffeae can p h a i cay sau it n h a t 2 lan, thu gom va dd't h e t re cdn lai t r e n vUdn sau dd luan canh vdi cae cay t r d n g k h a c trong 2- 3 n a m . TrUdc khi trdng lai nen cay sau va thu gom re 1 l a n n d a de loai bd t r i e t de ngudn r i cu trong dat.
TAI LIEU THAM KHAO
1. Burgess L.W., Summerell B.A., Bullock S., Gott K.P., Backhouse D. (1994), Laboratory manual for Fusarium research. University of Sydney, 133 pages.
2. Campos V.P., Sivapalan P., G n a n a p r a g a s a m N.C. (1990), "Nematode parasites of coffee, cocoa and tea". P l a n t p a r a s i t e nematodes in subtropical and tropical agriculture, CAB i n t e r n a t i o n a l institute of parasitology, pp. 387 - 430.
3. N g u y i n Nggc Chau, N g u y i n VQ T h a n h (2000), "Tuye'n t r u n g ky sinh thUc vat", Ddng vat chi Viet Nam, NXB Khoa hgc va ky t h u a t . H a Ndi, pp. 167 - 175.
4. Coste R. (1955) , Les cafeiers et les cafes dans le monde, P a r i s , pp. 206 - 217.
5. Hooper D.J. (1986), "Extraction of free-living stages from soil". Laboratory methods for work m i t h plant and soil nematodes, London, pp. 5 - 30.
6. Hooper D.J. (1986), "Extraction of nematodes from plant naterial". Laboratory methods for work m i t h plant and soil nematodes, London, pp. 51 - 58.
7. Kumar A.C. (1979), "Relative tolerance or susceptibility of Arabica, Robusta and Exeelsa coffees to Pratylenchus coffeae ", A compendium of coffee research in India, Central coffee research institute, India, pp. 202.
8. Kumar A.C. (1984), 'The symptoms and diagnosis of the disorder, 'Spreading dechne' (Cannoncadoo dieback) with a note on spread and control of the causal agent, Pratylenchus coffeae"., Joumal of coffee research, Indian, pp. 156 - 159.
9. Mai W.F, Mulhn P e t e r G. (1996), P l a n t - parasitic nematodes- A pictorial key to genera, Cornell University P r e s s , USA, pp. 94 - 95.
10. Palanichamy K. (1973), "Nematode problems of coffee in India", Indian 11. Shieber E. (1971), "The nematode problems of coffee in Guatemala", Nematropics, (1), pp. 17.
12. P h a n Qudc Sung (1976), Mgt sd ke't qua bUdc dau ve b e n h tuye'n t r d n g cua cay ca phe che d vung Phu Quy Nghe An, T r a m nghien cdu cay nhiet ddi Phu Qui.
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