KHOA HQC CdNG NGHE
TllVH HilMH GAY HAI CUA BEIVH RLJIVG LA IVIUA IVIIJA CAY CAO S U [Het/ea brasHiensi^ D VUIMG DOIMG IMAIVI BO
Dam Van Todn^' ^, Pham Quang Thu^
TOMTAT
Cay cao su {Hevea brasiliensis} la cay cong nghiep mang lai gia tri kinh t^ hang diu d viing Dong Nam b6.
Benh rung la miia mira cay cao su dupfc xac dinh la benh hai chinh va gay thiet hai dang ke cho cay cao su.
Nghien ciru tinh hinh gay hai cua benh rung la mua mua cay cao su lam co sd de nghien ciiu quan ly bfenh hieu qua. Ket qua nghien ciiu dien bien benh rung la miia mira cay cao su d viing Dong Nam bo cho thay, ti le bi benh va chi so benh 6 4 tinh a viing Dong Nam bg g6m Binh Phudc, Binh Duong, Dong Nai va Tay Ninh bat dau tang tii thang 5 va dat dinh vao thang 9 khi lucmg mua ti-ong nam la Idn nhat Ti le bi benh va chi sd benh giam dan tit thang 11 va khong thay xuat hien tir thang 1 den thang 4 hang nam, Ket qua nghien ciiu cung cho thay, cac gidng cao su tr6ng it viing Dong Nam bo c6 ti 1$ va chi so benh khong gidng nhau.
Cac dong RRIC121, RRIV2, RRIV115 va GTl co kha nang chdng chiu benh cao. O giai doan cay bdt dau dua vao khai thac nbira (tii 6-8 tudO, co ti le va chi sd benh cao hon cac lira tudi con lai va cay cao su U6ng tr^n ddt xam thudng co ti 1^ va chi sd benh cao hon so vdi cay tiong tien dat do bazan.
Tii khda: Benh rung la cao su, cay cao su, tilS bi benh, chi sd b$nh, nmg trong, gidng.
1.DATVAN0E
Cdy eao su {Hevea brasihensis), la mdt lodi cay than gd thudc hg Thau dau (Euphorblaceae), la cay da mue dich, cd gia tri kinh te cao. Trong nhiing nam gdn day, san lugng mu cao su khdng ngiing duge ndng cao nhd eai tidn ve gidng, ky thuat ndng nghidp, dien tich khai thae... Ndm 2017, didn tich trdng cao su toan qudc la 971.600 ha, trong do trdng d vung Ddng Nam bd la 540.300 ha. Mu cao su thien nhien xuat khau dat 1.395.000 tan, chiem fhi phan the gidi khoang 12%, chi sau Thai Lan va Indonesia.
Gia tri xuat khau tir cac san pham cao su va san pham gd cao su dat 4,85 ty do la My ndm 2016 va khoang 5 ty USD nam 2017 (Trin Thi Thuy Hoa, 2018). Trong nhiing nam gan day, dien tich cay cao su ngay mdt gia tang thi cay cao su ciing dang hi nhidu loai sau, benh hai tan cdng, ldm giam dang ke nang suat. Mdt trong nhiing benh quan trgng gdy thiet hai cho vudn cay cao su la benh rung la mua mua. Benh rung la mua mua gdy hai cho vudn cay eao su kmh doanh va kien thiet ca ban cung nhu vudn uom, nhung benh nang nhat d vudn cay cao su kinh doanh. Benh ldm giam 30-56% san lugng khi nhiim ndng. Tridu chiing dac trung la tren cudng la cd cue mu mau den hoac trang tai trung tdm vet
' Sd Khoa hpc va Cong nghe tinh Binh Phudc
^ Nghien ciru sinh Vien Khoa hoc Lam nghiep Viet Nam
^ Trung Cam Nghien ciru Bao ve rirng, Vien Khoa hoc Lam nghiep Viel Nam
benh. La bi rung cdn xanh gdm ca 3 la ehet va cudng.
Dau cudng la hep xuc vdi chdi khdng cd mu va cac Id ehet d^ dang rdi ra khi ldc nhe. Tan la hi rung khdng ra lai ma phai den mua ra la sinh ly hang nam. Tren chdi xanh, ddm benh hinh ban due va cd mau ndu den, neu hi nang cd the ddn den ch^t chdi. Trai xanh gdn khd la giai doan mdn cam nhdt, vdt thdm mdu nau xuat hien tai phan dudi cua trai sau dd lan rdng todn bd. Trai hi benh thdi, khd lai va treo tren cay vdi nhiing dam nam man trang (Pattanakul va Langlois, 1975; Phan Thdnh Dung va cdng su, 2014; Nguydn Anh Nghia, 2016). Cac nghidn cuu vd hinh rung la miia mua cay cao su d Viet Nam da ghi nhan 2 loai nam Phytophthora palmivora vk Phytophthora botryosa la sinh vat gay benh chinh (Duong et al., 1998; Dang Vu Thanh etal., 2004). Nam 2016, ti-ong qud trinh nghien ciiu ve benh, thu thap mau dat va mdu la bi benh rung Id miia mua b cac tmh Ddng Nai, Binh Duong, Binh Phudc va Tdy Nmh, mdt sd loai nam khdc thudc ho Pythiaceae da phdn lap vd xac dinh gdm cac loai: Phytophthora heveae, Phytophthora nicotianae, Pythium sp. va Phytopythium sp. (Dam Van Toan etal, 2017).
Trong didu kien nude ta, benh xudt hien vdo nhirng thang mua ddm d vung dat dd Ddng Nam bd, Tay Nguyen va mien Trung (Nguyin Anh Nghia, 2016). Su thiet hai dd da lam giam dang ke den doanh tbu ciia cac doanh nghiep va anh hudng true tiep tdi ddi sdng cua ngudi trdng cao su. Quy md phat trien cao su ngay cang tang, ddng thdi tinh hmh
46 NONG NGHIEP VA PHAT TRIEN N 6 N G THON - KY 1 - THANG 11/2018
KHOA HOC CONG NGHE benh hai cung didn hien ngay cang phiic tap do yeu
td thdi tiet bat lgi, su dung gidng khdng thich hop...
Yi vdy, de ndng cao hidu qua kmh te cua cdy cao su thi viec nghien ciiu, xac dinh tinh hinh benh hai, dac diem phat sinh gdy hai de phdng trir benh la viec lam cdp thiet hien nay. Nghien ciiu nay trinh bay ket qua nghien ciiu tinh hinh gay hai ciia benh rung la miia mua cay cao su dviing Ddng Nam bd nam 2017.
2 . PHUDNG PHAP WHEN CUU
2.1. Nghien cihi di&n bi^n phdt smh, phdt tii^n ciia benh rung la mua mua d vimg Ddng Nam bg
Dieu tra didn bien phdt sinh, phat tri^n cua benh duoe tien hdnh tai 4 tinh: Binh Phudc (Ddng Phii, Phu Rieng, Chon Thdnh vd Tbi xa Ddng Xoai), Bmh Duong (Phu Giao, Ddu Tieng va Ban Bdng), Tdy Ninh (Duong Mmh Chdu, Tdn Chdu va Trang Bang) va Ddng Nai (Dinh Quan, Thdng Nhat vd Long Thanh). Dieu tra, thu thap sd lieu dinh ky 15 ngay/ldn vao mua mua va 30 ngay/ldn vao miia khd tir tiiang 01 nam 2016 den thang 12 nam 2017. Vide dieu tra tinh hinh gay hai cua benh rung la mua mua cdy cao su duge thue hien theo Tieu chuan Qudc gia TCQG 8928: 2013 va Quy trinh ky thuat cay cao su (2012) cua Tap doan Cdng nghidp Cao su Viet Nam, cu thd nhu sau: Tai mdi dia phuong, tien hanh didu tra 3 vudn cd dd tudi tir 8-10 tudi. Tai mdi vudn, thidt lap va dieu tra cd dinh tren 5 d tieu chuan duge hd tri theo dudng cheo gde, mdi d tidu chuan tien hanh dieu tra 30 cay de theo doi ehi tieu trong sudt thdi gian dieu tra didn bien. Cay hi benh dugc chia lam 6 cap nhu sau:
Cap benh 0 1 2 3 4 5
Tneu chimg
Cdy khoe, la, trdi tren cay xanh, khdng cd la rung
Rdt it trdi bi thdi; Id rung it Nhd hon V4 sd trai bi thdi, la rung it Tir V4 den it ban d sd trai hi thdi, la nmg nhidu
Tii 1/2 den it hon ^4 sd trdi bi thdi, la rung nhidu trai lap mdng tren mdt dat Tii % sd trai hi thdi, la rung nhieu trai Idp day tren mat ddt
Chi tieu tinh toan: Ti le hi hdnh (P %) va Chi sd bdnh (R%).
Ty le cdy hi benh hai duoe xdc dinh theo cdng
thirc: P % = —xlOO A^
Trong do: n: la so cay bi benh hai. N: la tong so cay dieu tra.
Chi sd bi benh binh quan duge tinh theo cdng
5
/_ni.vi
thuc: R{%)^^ xlOO N.V
Trong dd: R (%) la chi sd benh binh qudn. niia sd cdy hi hai d cap hai i. vi\a tri sd cua cap hai i, cd gia tri tii 0 den 5. A'^la tdng sd cdy didu tra. Ftri sd cap bi hai eao nhat (v=5).
2.2. Nghien eiiu tinh hinh gay hai cua bdnh rung Id mua mua ddi vdi cdc gidng eao su khdc nhau
Mdt sd gidng cao su trdng b vung Ddng Nam bd gdm: RRIV106, PB260, RRrvi24, RRIV205, RRIV115, BP235, VM515, PB86, RRIV2, RRIV215, RRIC121, PR107, RRIV4, RRIM600 va GTl. Dieu ti-a cdc vudn cay trdng cdc gidng cao su khac nhau d vimg Ddng Nam bd d giai doan 8-10 tudi tren ciing mot loai dat trdng la dat do bazan. Mdi gidng chon 5 vudn, mdi vudn dieu tra 5 d tieu chuan dugc bd tri theo dudng cheo gde, mdi d tidu chudn tien hdnh dieu tra 30 cdy.
Chi tieu theo doi gdm ti le hi benh (P %) va ehi sd benb(R%).
2.3. Nghidn cuu tinh hinh gdy hai eua bdnh rung Id mua mua a ckc loai dat trdng eao su khde nhau
Didu tra tinh hinh benh cua hai gidng cay cao su PB260 vd RRIV4 b giai doan tiidi tir 8-10 tiioi, ti-dng tren hai loai dat khac nhau gdm dat do bazan va dat xam. Mdi vimg dat dieu tra 5 vudn, mdi vudn dieu tra 5 d tieu chuan bd tri theo dudng cheo gde, mdi d tieu chuan tien hanh digu tra 30 cay. Chi tieu theo ddi gdm d le hi benh (P %) va chi sd benh (R %).
2.4. Nghidn ciiu tinh hinh gay hai cua bdnh rung Id miia mira d cac tudi cdy cao su khdc nhau
Dieu tra tinh hinh benh cua hai gidng cao su PB260 va RRIV4 tren cung mdt loai dat trdng la dat dd bazan d 4 giai doan sinh trudng khac nhau: giai doan <3 tudi. giai doan hi 3-5 tuoi, giai doan bdt dau khai thac mu (6-8 tiidi) va giai doan tii 9-14 tudi. Mdi giai doan didu tra 5 vudn, radi vudn didu tra 5 d tieu chuan bd tri theo dudng cheo goc, mdi d tieu chuan tien hanh dieu tra 30 cay. Chi tieu theo doi gdm ti le bi bdnh (P %) vd chi sd benh (R %).
NONG NGHIEP VA PHATTRIEN NONG THON - KY 1 - THANG 11/2018
KHOA HOC CONG NGHE
3. KET QUA NGHBV CUU VA THAU LUAN
3.1. Kdt qua di^u tra didn bidn bdnh rung Id miia mua cdy eao su d viing Ddng Nam bd
DiSu tra dien bien cua benh rung la mua mira eay cao su ddi vdi gidng PB260 trdng chii yeu d viing
Ddng Nam bd da dugc thue bien nhdm danh gia sat thuc trang tinh hinh benh qua cde tiidng trong nam 2017. Ket qua didu tra didn bien benh duge trinh bay d bang 1.
Thang 1 2 3 4 5 6 7 8 9 10 11 12 Fpr Lsd
Binh Phuoc P(%)
0"
0"
0"
0- 5,3' 10,7' 20,0"
26,7"
42,0=
37,3' 16,7'' 8,7'=
<0,001 3.831
R(%) 0- 0*
0"
gab 1,1"
3.1' 6,4"
9.6' IS.l' 16,7«
8,3=
2.F
<0,001 0,522
Binh Duong
?(%) 0- O"
0' 0' 4,7' 9,3' 18,6"
26,7"
38,7"
34,0' 16,7"
6,7'"
<0.001 2,817
R(%) 0' 0*
0"
0"
1,1"' 3,2"
11,2' 14.8' 16.9«
16,0'«
7,7"
2,0'"
<0,001 0,699
Tay Ninh P(%)
0- 0- 0*'
Q.I,
8,0"
11,5'"
16,5""
23,7"' 36,31!
26,3' 16,3""
7,7'"
<0,001 7,247
R(%) 0"
0- O"
0' 1,2' 3,5"
5,2"
8,4' 17,5' 15,3«
6,5"
1.9'
<0,001 0,8824
Dong Nai P(%)
0"
0"
0"
0' 5,3' 10,7"
20,0"
28.0"
35.3' 34,0' 18,0"
8,7""
<0,001 3,439
R(%) ty
o»
0" (f 1,2"
2,9"
6,4"
11,7"
16,8"
16,4' 6.4"
2,1'«
<0,001 1,304 Ghi chii: Trong ciing mot cdt, nhdng gii tii trung
thdngke theo tiie nghidm Duncan dmuc dp 0,05.
Qua didu ti-a cho thay, tii thang 1 den thang 4 hang nam la cac thang cay cao su thay la mdi, day ciing la nhiing thang miia khd, it mua, do am thap nen khdng thay benh xuat hien. Benh rung la mua mua bat ddu xuat hien khi thdi tiet ehuydn sang miia mua, bat ddu tii thang 5 hang nam, tijy nhien thdi gian nay rat it gap. Ti le va chi sd benh tang ddn khi lugng mua tang ddn tii thang 6, tiiang 7 va dat dinh diem vao thdng 9 (Binh Phudc dat dinh diem vdi ti le henh la 42,0% va chi sd benh la 18,1%, Binh Duong la 38,7% vd 16,9%, Tay Ninh la 36,3% va 17,5 va Ddng Nai la 35,3% vd 16,8%) khi lugng mua trung binh dat 650-750 mm, do am khdng khi vao khoang 88-95%.
Benh rung la mua mua bdt ddu giam tir thang 11, 12 trong ndm. Ket qua phdn tich thdng ke cung cho thay, ti le vd ehi sd benh giiia cac thang mua mua d vimg Ddng Nam bd (tii tiiang 5 ddn thang 11 hang ndm) cd su khac nhau rd ret. Nghien cuu cua Wastie (1973) tai An Dp, d vung Tdy Nam cua Thai Lan, phia Bac va phia Tay Malaysia, Mianma va d Sri Lanka cho thay, benh rung la mua mua thudng xudt hien trong thdi ky lugng mua Idn, keo dai, do am eao kdt hgp ed gid miia. O Thai Lan, benh rung la xuat bien
binh cung ky tu khdng khac bidt ed y nghia vd m$t vd Idy lan vao giai doan tii thdng 6 den tiidng 12 hang nam (Pattanakul va Langlois, 1975), d Sri Lanka tii thdng 5 ddn thang 10 Qayasing va Jayaratiie, 1996).
Str phat trien cua benh rung la miia mua cay cao su phu thudc chii yeu vao thdi tiet, dac biet la lugng mua va do am. Su xen ke giua thdi gian la udt do cd mua hoac cd suong vdi thdi gian la khd anh hudng den kha nang sinh bao hi cua nam gay benh. Cac sd lieu kh) hau ciia vung Ddng Nam bd cho thay cd mdi tuong quan thudn vdi dieu kien am do vd luong mua vdi su phat sinh va phat trien cua benh rung la miia mua. Ket qua nghien ciiu tuong tu nghien eiiu eua Phan Thanh Dung va cdng su (2014), Nguyin Anh Nghia (2016) va Chantarapratin etal (2001).
Ket qua nghien ciiu d bang 1 cung cho thay, ti \i va chi sd benh d 4 tinh viing Ddng Nam bd gdm Binh Phuoe, Bmh Duong. Tdy Nmh va Ddng Nai cung khdng gidng nhau. Trong 4 tinh thi Binh Phudc cd ti le va chi sd benh cao nhat (P% = 42.0%, R% = 18,1%
vao thdng 9), thap nhat la tinh Ddng Nai (P% = 35,3%, R% = 18,0% vao tiiang 9). Nguyen nhdn cd the la do Binh Phudc la tmh cd dia hinh cao, vdi dien tich ddi niii nhidu, do am khdng khi cao hon eac tinh cdn lai NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 11 /2018
KHOA HOC CdNG NGHE la dieu kien thuan lgi de nam benh smh trudng, phat
tridn. Ngoai ra, mtrc do dau tu va ky thuat canh tdc va phdng trir sdu benh cay cao su cua mdt bd phdn ngudi dan d Binh Phuoe, nhat la vimg sau vung xa, vimg ddng bao dan tdc cdn chua tdt dan den ty le vd chi sd benh cdn cao.
3.2. K^t qua di^u tra tinh hinh gay benh rung Id cdy cao su cua cdc gidng cao su d vimg Ddng Nam bd
Ket qua dieu tra cho thay cdc ddng vd tinh cao su trong giai doan khai thdc ddu bi nhiem benh rung la miia mua vdi ede miic do khac nhau, ket qua the hien dbang 2.
Bang 2. Tinh hinh benh ryng Id miia mua cua mOt sd gcaosutrdngffvun
Thii tu
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Dong vo tinh cao su RRIC121 RRIV215 GTl VM515 RRrV124
RRIV2 RB235 RRIV115
RRrV4 RRIV205
PB260 RRIV106
PR107 PB86 REIM600
Fpr Lsd
g Ddng Nam bO (nam 2 P%
26,0»
30,0"' 30,7"' 31,3"'"
32,0'""
33,3'"""
35,3"""
35.3'"""
35,3'=""
36.7'""
37,3""
38,6"
44,7' 44,8' 48,3'
<0,001 5,142
R%
14,4'"
15,1'""
13,1"' 15,1'""
16,4'"
11,5"
16,9""
14,9'""
17.5"
15,1'""
16,9""
17,1'"
24,4' 23,1"
26,3'
<0,001 2,374 Ghi chu: tiong cimg mdt cot, nhung gia tri trung binh cdng ky tu khdng khae biet cd y nghia ve mat thdng kd theo tiie nghidm Duncan dmuc dp 0,05.
Bang 2 cho thay, eac ddng vd tinh bien dang trdng d vung Ddng Nam bg ed kha nang khang benh rung la mua mua khdc nhau rd ret. Mdt sd loai bi benh ndng nhu PR107, RRIM600, PB86 vdi ti le bi bdnh dao ddng tir 44,7% ddn 48.3% va ehi sd benh dao ddng tii 24,4 - 26,3%. Cdc gidng hi benh trung binh nhu: RRIC121, RRIV2, RRIV115, GTl cd ti Id bi benh dao ddng tir 26,0% ddn 35,3%, chi sd benh khoang tir 11,5% ddn 16,9%. Khdng cd loai nao khang hoan toan vdi benh rung la mua mua. Anon (1986) da dua mot
sd gidng cao su vao thir nghiem. Ke't qua cho thay mdt sd ddng cd kha ndng de khang lai bdnh do nam Phytophthora b Ddng Nam A gdm RRIM712, PR255, PR261 va GTl. Mdt sd ddng trudc day dugc trdng phd bidn d Ddng Nam A da dugc phdt hien mdn cam vdi benh rung la mua mua do nam Phytophthora gdm RRIM600 va PR107. Ket qua nghien ciiu eho ket qua tuong tu cua Kajomchaiyakol (1977, 1980) nhimg khae vdi nghien eiiu eua Phan Thanh Dung vd cdng su (2014) eho rdng gidng GTl mdn cam vdi benh rung la miia mua.
3.3. Kdt qua didu ti-a tinh hinh bdnh rung Id mtia mua cdy cao su d edc giai doan tudi khdc nhau
Su phat sinh va gay hai cua benh rung la miia mua b cac vudn cao su cd do tudi khdc nhau da duoe didu tra tren 2 ddng vd tinh PB260 va RRIV4, ket qua didu tra dugc trinh bay d bang 3.
Bang 3. Tinh hinh bdnh rung la raiia mua df dg tudi khdc nhau cua cdy cao su d vimg Ddng Nam bd
g)idu ti-a ndm 2017, trdn ddt xdm) Thii
tu 1 2 3 4
Tuoi cay Duoi 3 tudi Til 3-5
tudi Tir 6-8
tudi Tir 9-14
tudi Fpr Lsd
Dong vo tinh PB260 P%
5,3"
10,7' 37,3"
33,3"
<0,001 4,298
R%
1,2"
2,9' 16,9"
16,4'
<0,001 1,489
Ddng vo tinh RRIV4 P%
5,1"
12,0' 36,7' 34,0'
<0,001 5,609
R%
1,6"
3,3"
16,4' 15,9'
<0,001 1,832 Ghi chu: tiong eung mdt cdt, nhdng gii tii trung binh ciing ky tu khdng khae biet ed y nghia vd mat thdngke theo tiic nghidm Duncan dmuc dp 0,05.
Ket qua nghien cihi d bang 3 cho thay, benh rung la miia mua gay hai d tdt ca eae giai doan sinh trudng ciia cay, ti le va chi sd benh d cae giai doan khac nhau rd ret. O giai doan dudi 3 tudi benh hai nhe vdi ti le va chi sd benh la 5,3% va 1,2% tren ddng PB260. Cdn tren ddng RRIV4, ti le va chi sd benh giai doan nay la 5,1% va 1,6%. Giai doan nay cay chua giao tan, vudn cay thdng thoang, do am vudn cay thudng thap. Hon nira trong giai doan nay tan eay thap, cac bien phap phdng tru benh dugc thuc hien dk dang, viec phun thudc phdng trir eac loai benh duoc thuc
KHOA HOC CONG NGHfi hien tdt hon va dat hiiu qua.
Ket qua dieu tra eho thay, cay cao su bi benh rung la miia mua cao khi cay bdt dau budc vao khai thac mu (6-8 tudO, giai doan nay ti le va chi sd benh cao hon cac giai doan khac, vdi ti le vd chi sd benh la 37,3% va 16,9% ti-dn ddng PB260. Cdn ti-en ddng RRIV4, ti le va chi sd benh giai doan nay la 36,7% va 16,4%. Trong thdi ky nay cay bi benh cao cd the do giai doan ndy cay cao su da giao tan, luong boi nude bi giii lai dudi tan lam do am vudn cay ludn cao, la didu kien de nam benh phat sinh, phat ti*ien. Hon nira giai doan nay tan cdy da cao, dung eu phun thudc phdng tni benh chua du chieu cao dd phdng trir tren nggn, do vay ngudn benh khdng duac phdng trir triet de. Ngoai ra, giai doan mdi dua vao khai thac, cay cao su hi nhidm benh nang hon giai doan trude vd ca giai doan khai thac dn dinh cd th^ do khi bat dau khai thac, sinh ly cay cao su ehua thich nghi vdi su tac ddng tir ben ngoai, lam gidm sire de khang eua cay. Hon nira, vdi vudn cay cao su tieu dien, do ngudi ddn khi trdng cao su chu ydu la tu phat, khdng theo quy hoach, viec lira chgn gidng khdng dam bao tieu chuan ky thuat. Vdn de cao mii va ky thuat cao khi cay budc vao thdi ky khai thac thudng khdng dap ling dugc yeu cdu ddt ra dan den tmh trang pha buy mat cao, la dieu kien thuan loi de sau benh lay lan, phdt tnen. Viec tan dung khai thac tnet de nhu ehe do eao qua day, md mieng cao qud sdm khi cay chua du tieu chuan dua vao khai thac (cay dii tieu chudn dua vao khai thdc khi chu vi vong thdn do cdch mat dat Im phai dat tir 50 cm trd len; dd day vd dat ti-en 6 mm) cOng la nguyen nhdn lam cho vudn eay sinh trudng vd phdt tnen kem, nang suat vudn cay thap, khdng on dinh, gidm chu ky khai thdc va tudi thg vudn cdy. Ket qua nghien cim tuong tu' nghien cim eua Phan Thanh Dung va cdng su nam 2014 vd Nguydn Anh Nghia nam 2016.
3.4. K^t qua didu tra tinh hinh b^nh rung Id miia mua cdy cao su d cde loai d^t trdng khdc nhau
Ci viing Ddng Nam bd, ly Ie cay cao su duoc trdng tren loai dat dd bazan va dat xam chiem ty le Idn nhat. Tren dat dd bazan, eay cao su trdng thua (thudng la 7 X 3m), dat xam trong day hon (thudng la 6 X 3m). Ket qua dieu tra tren ddng vd tinh PB260 giai doan 6-8 tudi cho thay ty le va miic dp bi benh d hai loai dat nay khdng gidng nhau. DiSu tra dugc tien hanh tren ddt xam tai huyen Ddng Phu va tren dat dd tai huyen Phu Rieng tinh Binh Phudc. Kdt qua duoe
trinh bay tai bang 4.
Bang 4. Miie dO nhidm benh rung Id miia mua a cdc didu kien ddt trdng khdc nhau cua cdy cao su a vimg
Ddng Nam bd Thir
tu 1 2
Loai dat Dat dd bazan Dat xam Fpr Lsd
Dong vo tinh RRIV4 P%
31,3 33,4 0,062 2,130
R%
13,7 15,2 0,036 0,782
Ddng vo tinh PB260 P%
35,3 38,0 0,252 4,98
R%
14,7 16,1 0,134 0,879 Ghi chii: tiong cung mdt cot, nhdng gii tri trung binh cdng ky tu khdng khic bidt cd y nghia ve mat thdngke theo tiic nghidm Duncan dmuc dp 0,05.
Bang 4 cho thdy, ti Id vd chi sd benh rung la mua mua cay cao su trdng tren dat xam eao hon trong tren dat dd. Vdi gidng cao su PB260, ti le va chi sd bdnh ti-en dat xdm lan luot la 38,0% vd 16,1%, trong khi trdn dat dd ty le nay la 35,3% va 14,7%. Tuong tir nhu vdy, gidng RRIV4 khi trdng trdn hai loai dat nay thi miic do va ty le bi benh tren dat xdm cao bon tien dat do vdi ty le hi benh va chi sd benh d ca hai nen dat lan lugt la 33,4% va 15,2% tren dat xam vd 31,3%
va 13,7% tren dat dd.
Trong qua trinh dieu tra thue te cho thay, mdt sd dia phuong d viing Ddng Nam bd nhu tai huyen Ddng Phu. Phu Rieng tinh Bmh Phudc, huyen Phu Giao, Bau Bang tinh Binh Duong, huyen Duong Minh Chau tinh Tdy Ninh, nhieu dien tich dat d vimg dat thap tning kem thoat nude, mue nude ngam cao, thdm chi mdt phan dien tich dat trdng lua cung dupe ngudi dan cai tao de tdn dung trdng cao su. Ngoai ra, cao su cdn duoe trong d mdt sd khu vuc cd dia hinh phuc tap, do ddc cao, khdng c6 thiet kd he thdng chdng xdi mdn nhu thiet ke vudn trong theo dirdng ddng miic, bd bao, tham tiiuc vat. Didu nay ddn den viec khd dp dung cac bien phap ea gidi hda trong san xuat, viec thu hoach mu, cham sdc vudn eay cung gap nhidu khd khan. Rieng ddi vdi khu vuc nay, cay cao su sinh trudng va phdt trien kem, ndng suat mu tiiap, kha nang chdng chiu benh va didu kidn ngo?i canh hat loi ciia cay cao su rat han che. Nghien ciiu cd ket qua tuong tii nghidn ciiu cua Anon (1973) eho rdng, ndu mat do trdng cay cao su Idn ban 500 cay/ha va dat co do thoat nude kem, ngheo chat dmh dudng thudng bi benh do nam Phytophtiiora cao ban.
50 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 11/2018
KHOA HOC CONG NGHE Nhu vdy, de phdt trien cdy eao su mdt each bdn
vimg, trude khi trdng nhdt thiet phai tinh den cdc ydu td han che cua dat de cd bien phdp khdc phuc kip thdi. Vdi nhung vimg dat xam, can chii y trdng vdi mat dd vira phai, khdng qua day, can bd sung chdt dinh dudng cho ddt, nhat la cac chat hiiu ca de tang do phi cho dat. Ddi vdi dat trdng cd do doe eao, can thuc hien bien phdp canh tdc hgp ly nhu thiet ke dudng ddng miic, bang eay xanh chdng xdi mdn nhdm phat huy mdt each tdt nhdt hieu qua su dung dat.
4. KETLUAN
Benh rung la mua mua cdy eao su bdt ddu xuat hien tir thang 5 d 4 tinh cua vimg Ddng Nam bd gdm:
Binh Phuoc, Binh Duong, Tdy Ninh va Ddng Nai, ti le va chi sd benh tang ddn va dat dinh diem vdo thdng 9, benh giam ddn tir thang 11 va khdng thay xuat hien tir thdng 1 den thdng 4 hdng nam.
Kha nang khdng benh rung la miia mua d cac gidng cao su duoe trdng d vimg Ddng Nam bd khac nhau rd ret. Gidng RRIC121, RRIV2, RRIV115, GTl cd kha nang chdng ehiu bdnh tdt, cac gidng cao su RRIM600, PR107, PB86 bi nhiem benh kha nang.
6 giai doan cay bat dau dua vao khai thac (tu' 6-8 tudi), cdy cao su cd ti le va chi sd benh rung la mua mua cao hon cde liia tudi cdn lai va eay cao su trdng trdn dat xdm thudng cd ti le va chi sd benh cao ban so vdi cay trdng tren dat dd bazan.
l A l UEU THAM KHAU
1. Anon, 1986. RRIM planting recommendations. Planters Bulletin of Rubber Research Institute of Malaysia, 186,4-22.
2. Chantarapratin, U., Pattanakul, P., Changreung, N., Rojanasujit, A , Romreunsukarom, P., & Ramlee, A. (2001). Rubber diseases survey on large scale clone trail (pp. 1-52). Research Report.
Rubber Research Institute Thailand.
3. Dang Vu Thanh, Ngo Vmh Vien and Andre Drenth (2004). Phytophthora diseases in Vietnam.
Diversity and Management of Phytophthora in Southeast Aisa, 83-89.
4. Dam Van Toan, Dang Nhu Quynh, Nguyen Minh Chi, Thomas Jung, Marilia Horta Jung, Ana Perez-Sierra, Helen Rees and Pham Quang Thu (2017). Biological characteristics of Pythiaceae species isolated from soil of Hevea brasiliensis
plantations m the Soutii of Vietnam. Stii meeting lUFRO Working party 7.02.09 Phytophtiiora in Forests and Natural Ecosystems in Vietnam (Sapa,
Vietnam).
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(1997). Diseases and pests of Hevea brasiliensis m Vietnam. Symposium on natural rubber {Hevea brasiliensis): Vol. 2 - physiology & exploitation and crop protection & planting methods sessions, Ho Chi Minh city, Vietiiam, 14-15 October 1997, 80-91.
6. Duong, N. H., Thanh, H. N., Yen, N, T and Dung, P. T. (1998). Diseases and pests of Hevea Brasiliensis in Vietnam. In: Symposium on Natural Rubber {Hevea brasihensi^, 2, 80-91.
7. Jayasingbe, C. K and Jayaratne, A. H. R.
(1996). Phytophthora epidemic possibihty of management using resistant clone. Journal of Natural Rubber Research Institute of Sri Lanka, 77, 66-67.
8. Nguydn Anb Nghia (2016). Phdng ti-j benh trdn cao su: Benh rung Id mua mua.
http://tapchieaosu. vn ngay 05/08/2016.
9. Pattanakul, C. and Langlois, S. J. C. (1975).
Present situation oi selection at Rubber Research Centre Thailand. Rubber Research Institute of Thailand, No. 84,17 p.
10. Phan Thanh Diing, Nguydn Anh Nghia, Trdn Anh Pha, Nguydn Ddn Hieu (2014). Tai lieu tap huan ky thuat bao vd thuc vat cay cao su. Vien Nghidn cim Cao su Viet Nam, 120 trang.
11. Kajomchaiyakol, P. (1977). Survey of Phytophthora diseases in 1976. Thai Journal of Agricultural Science, 10, 427436.
12. Kajomchaiyakol, P, (1980). Diseases and pests of rubber in Thailand, 1979. Rubber Journal 1, 12-29.
13. Tap doan Cdng nghiep Cao su Viet Nam (2012). Quy trinh ky thuat cay cao su, 153 trang.
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Dau dn nganh cao su Viet Nam tren the gidi.
bttp://tapehieaosu. vn. ngiy 12/Q2/2Q18.
KHOA HOC C 6 N G NGHl
16. Wastie, R.L. (1973). Influence of weatiier on brasiliensis in Malaysia. Journal of tiie Rubber the incidence of Phytophthora leaf all of Hevea Research Institute ofMalaya,23{S), 381-390.
SmJATION OF PHYTOPHTHORA LEAF FALL DISEASE OF RUBBER (Hevea brasiliensis) IN SOUTH EAST VIETNAM
Dam Van Toan, Pham Quang Thu Summary
Rubber tree {Hevea brasiliensis) is the leading tropical crop of economic value in the South East of Vietnam. Phytophlhora leaf fall disease is identified as a major disease and causes significant damage to rubber tree plantations. The disease incidence and severity of Phytophthora leaf fall disease was studied to assist with the effective management of the disease. Results of the study showed that the disease incidence and disease seventy m four provinces: Binh Phuoc, Binh Duong, Dong Nai and Tay Ninh, started increasing from May and peaked in September when the rainfall in the area was highest Disease incidence and severity have been declining since November and symptoms of disease were not observed from January to .^ril. The results also show that the rubber varieties planted in the South East region have different levels of disease resistance, in which RRIC121, RRrV2, RRTVllS and GTl are the most disease resistant vaneties. Disease incidence and seventy are highest m the plantations at early stages of latex exploitation (6-8 years) compared lo other stages. The rubber plantation planted in gray soil showing higher disease incidence and seventy than those grown on basalt red soil.
Keywords: Hevea brasihensis, Phytophthora leaf fall disease, disease incidence, disease seventy, plantation, varieties.
Ngudi phan bidn: TS. Hd Minh Thanh Ngay nhdn bdi: 14/9/2018 Ngdy thdng qua phan bidn: 16/10/2018 Ngdy duy^t ddng: 23/10/2018
52 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 11 /2018
