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MAT 0 0 CAY VA LUONG PHAN BON THJCH HOP CHO GIONG LUA KN2 NGUYEN CHUNG TAI YEN THANH
• Nguyen Van Hoan - Dai hoc Vlnh Nguyen Thi Huvng - Trung tarn Giong cay trongNgheAn LD^TVANDE
Gi6ng lua KN2 la giong lua thuan nang suat cao, da dupe TS. Nguyen Nhu Hai cun^ cong su tai Trung tam Khao kiem nghiem giong va san ph4m c^y trong Quoc gia nghien cun va chpn t£io thanh c6ng. D6 khai tMc tiem nang nang suat cua giong, can tiep tuc nghien cuu, thu nghiem cac bien phap ky thuat tham canh, trong do xac dinh mat dp va luong phan bon hop ly la bien phap )fy thuat quan trong. Viec b6 tri mat dp cay hpp ly nhSm tao ra mat dp quan the thich hop, tir do nang cao duoc hiSu qua quang hop va lam tang so b6ng tren mot don vi dien tich. \^Sc xac djnh liSu lupng phan bon thich hgp c6 vai tro quySt dinh tdi viSc nang cao cac yeu to cau thanh nang suSt cua cay lua, cung nhir kh^ nang chong chiu slu benh cua giSng. Xult phat tir yeu cau thuc tien do, de tai "Xac dinh mat do cay va luangphdn bon thich hap cho sdn xudt giong lua KN2 nguyen chung tai Yen Thanh - Nghe An " da dupe trien khai thuc hien. s
S 6 12/2014
II. DOI TlTONG, NOI DUNG VA PHlTOfNG PHAP NGHIEN CUtJ
1. Doi tvgng nghien cihi
- Giong lua KN2 la giong lua mod do nhom nghien cihi chpn tao giong lua cua Trung t ^ Khao kilm nghi?m giong, san ph&n cay trong va phan bon Qu6c gia chpn tao.
- Phan bon: Thi nghiem si> dung cac loai phan bon nhu sau:
+ Phan hiJu co: Phan chuong hoai muc.
+ Phan v6 co: PhSn UrS c6 ham lupng N la 46%;
Phan lan Van Dien co ham lupng PiOs la 15%; Phan Kali clorua co ham lupng K^O la 60%.
- Loai d4t dupe tien hanh nghien cmi trong d8 tai la dit thit nhe.
1. Noi dung nghien cihi
- Nghien cuu anh huong cua m£it dp cdy va t6 hop phan bon ^ n thai gian smh truong, chiSu cao cay cua giong lua KN2 trong vu xuan 2013.
- Nghien cuu anh huong cua mat do cly va t6 hop p h ^ bon den miic dp nhiem mot s6 loai siu benh hai chinh cua KN2 trong vu xuan 2013.
KH-CNNgheAn ^ '
HOATflONGKH-CN
- NghiSn ciiru anh huong cua mat do cay va to hop phan bon dSn cac ySu tS c4u thanh nang suat va nang suit cua KN2 Uong vu xuan 2013.
3. Dia diem va thoi pan nghien cuu - Tai xa Do Thanh - Yen Thanh - Nghe An.
-vii xuan 2013.
4. Phinmg phap nghiSn ciru a. Phmmgphdp bS tri thi nghiem
- Thi nghiem 2 nhan td, 3 Ito nhic lai (27 cong thiic), duoc b6 tri theo ki6u 6 Ion - 6 nho (Spit - plot), trong do:
+NhSn tS 6 Ion: Phan bon (P) g5m 3 cong thilc;
PI: 1 tin ph&i HCVS + 100kg N + 100kg PiOs + 70kgK2O
P2:1 tin phan HCVS + 110kg N + 100kg P2O5 + 80kg KjO
P3:1 ttophan HCVS + 120kgN+ 100kg P2O5 + 90kgK2O
+ Nhan 16 6 nho: Mat do (M), g6m 3 m\ic:
Ml: 45 khom/m' (15,6 x 14,2cm) M2: 50 kh6m/m' (15,6 x 12,8cm) M3: 55 kh6m/mM15,6 X 11,6cm)
- Dien tich 6 nho la 1 OmHchito rong 2m, chiSu dai 5m). T6ng dien tich toan bp thi nghiSm la 300m^
(khong kk phan each va hang bao v6).
- Khoang each giOa 2 Ito Ijp la 50em, giua 2 cang thiic la 30cm (giOa 2 Ito lap 1 va 2 e6 thj bo tri chung cung 1 bo).
- Gitta cac ISn lap va c4c 6 thi nghiem ti^nhanh dSp bo CO phu nilon ch6ng tran phan. Cac 6 gan b6 each bo t6i thieu 20cm.
b. Cac chi tieu theo doi
- Thoi gian sinh truong: la s6 ngay tir khi gieo ma dSn liic h?t chin (85% s6 hat tren bong da chiii).
dSn ch6p bfing cao nhit
- S6 b8ng/m' truoc thu khoang 2 ngay, dem 5 khom dai diSn/6(trir hang bia).
- S6 hat chicA6ng: truoc thu, lay iiglu nhien 10 bong chinh cua 10 bui dai dien/6 d6 dSm s6 hat chJc, tinh ty le hat lep. _ _
- Kh6i luong 1.000 hat: mSi lan lap lai lay 1.000 h?t phoi khS, cSn va ISy kSt qua trung binh cua 3 IJn lap lai.
- Nang su4t thuc thu: thu hoach rieng timg 6, phoi kho dat Sm d614%, lam sach va tinh nang suit thuc thu quy ra ta/ha.
- San benh: ghi nhan miic do nhilm va danh gia cho diSm theo quy ph?m khao nghiem gidng liia qu6c gia yh gia tri canh tac.
c. Quy trinh thi nghiem va cdc bifn phap ki thuat dp dfutg
Thuc hien theo quy pham 10 TNC 558, tien hanh d6ng nhfa tren tat ca cac 6 thi nghiem.
d-XaiysSlieu
S6 li$u diroc xii ly thSng ke bang Excell va phan tich kSt qua thi nghiem bang phln m ^ IRRIS- TART 5.0.
i n . KET QUA NGHIEN CUU
1. Anh hiroug ciia m^t do cay va lir9Tig phan bon den thofi gian sinh tmoBg va chiJu cao cay giong lua KN2
Thoi gian sinh tnrong cua cay lua la m6t dac trung di truy^n ciia giSng, tuy nhi^ thM gian sinh truong thay d6i tiiy theo diSu ki§n canh tac nhu miia vu, mat dp cAy, phan b6n... Ket qua nghien ciiu tir bang la cho thiy cac cong thiic co mat do va mfic phan bon khac nhau co su khac nhau ve thai gian sinh truong, tuy nhien sir chenh lech nay khSng dang kS (chi tir 1-2 ngay), dao dong tit 121-123 ngay.
- ChiSu cao cay: chon 5 cay dai dien/6, do tit goc
Bang la: Anh huvng ciia tuvng tSc m^t do c4y va lirong phan bon den thM gian sinh tnrong, chieu cao cay gl6ng lika KN2 XT
1 2 3 4 5 6 7 8 9
C8ng thii-c (M*P) PlMl P1M2 P1M3 P2M1 P2M2 P2M3 P3M1 P3M2 P3M3 LSDo.oi (M'P)
CV%
TGST(ngay) 121 122 121 121 121 122 122 122 123
Chieu cao cay (cm) 89,37 91,13 89,20 90,23 89,80 91,23 88,07 87,53 90,07 3,13 6.8
S6 12/2014- Tqp chi ™
KH-CN Ngihe An ' '
HOAIUUNOIVI-LIN
Kit qua Iheo doi cho thay: cbieu cao cay ciia cac c6ng thiic khac nhau, dao d6ng tu 87,53-91,23cm, troi^ do cao nh^t la cong thuc P2NG (91,23cm) va thip nhit la cong thiic P3M2 (87,53cm). Qua d6 cho th4y tuongtac giuamitt dp va lupng phan bon co anh
huong ro 6ka chieu cao cay cua giong lua KN2.
Nhiim danh gia dupfc anh huong cua tung yeu to mat dp va lupng phan bon rieng re den chieu cao cay, chung toi da t6ng hop dupe ket qua thS hien qua bai^ lb.
Bang lb: Anh hiromg cua tumg yeu to mat dg, phan bon t6i chilu cao cay cua giong KN2 Y l u t 6
Mat do cay (M)
Luong phan bon (?)
Cong thuc Ml M2 M3 LSDo,o5 (M)
CV%
PI P2 P3 LSDo,os (?)
CV%
Chieu cao cay (cm) 89,22- 89,49"
90,17' 1,78
9,4 8 9 9 1 * 90,42' 88,56'' 1,35 7,2
Cac mat dp khac nhau co chieu cao cay khac nhau khong co y nghIa a mux; a<0,05, chi dao dpi^
tCr 89,22-90,17cm, chung t6 mat dp cay khong anh huong nhieu den chieu cao cay.
Phan bon co anh huong Ion dSn chieu cao cay cua gifing lua KN2. Cac cong thurc phan bon khac nhau CO chi6u caj cay khac nhau co y i^hia 6 mute a<0,05. Trong do, cao nhat la cong thiic P2 dat 90,42cm va thip nhit la c6ng thiic PI dat 88,56cm.
2. Anh hirong cua mat d$ cay va lirgng phan bon den kha nang ch6ng ch|u sau benh cua giong KN2
Sau benh la mot trong nhung nguyen nhan hang diu gay anh huong xau dSn qua trinh sinh truong, phat trien cua cay lua, tir do anh huong tnic tiep den
nang suit va phSm chit lua gao. Do vay, trong ky thu^t tham canh lioa, c^n phai nam ro quy luat phat sinh, phat trien cua cac loai sau benh hai chinh, dong thoi thuong xuyen theo doi, kiem tra dong ru6ng dk kip thai phat hien va co nhiing bien phap xu ly thich hop.
Thoi tiet trong vu xuan 2013 dien bien cue ky phuc tap nen cac loai sau benh hai phat sinh va phat trien manh, gSy hai rat Ion cho cac tra liia cua toan vung. Trong do, b?nh dao 6n, kho van, sau cuon la va sau due than la nhftng doi tupng gay hai chinh cho cay liia. Dieu kien Ijuih o giai doan mupn cung lam giam kha nang chong chiu sau benh cua cay liia va tao dieu kien cho cac loai sau benh hai phat hien manh.
Bang 2. Muc d6 nhiem mgt so sau benh hai chinh va kha nang chong do cua giong KN2
XT 1 2 3 4 5 6 7 8 9
Cong thirc P l M l P1M2 P1M3 P2M1 P2M2 P2M3 P3M1 P3M2 P3M3
Cuon la (diem)
1 1 1 1 1 3 1-3
3 3
Due than (diem)
3 3 3 3 3 3 3 3 3
Kho van (diem)
1 1-3
3 1 3 3-5
3 3 5
Dao on (diem)
Ray nau (diem)
0 0 0 0 0 0 0 0 0
S6 12/2014 - Tgp chi
KH-CN Nehe A n [31
HOAT BONG KH-CN
Danh gia thi nghiem a cac giai doan de nhanh, lam dong, truoc tr6 va giai doan chin siia cho thay:
hdu het cac cong thiic deu hi nhilm sau cuon la a giai dogn de nhanh - lam dong. Trong do, cac cong thiic CO luong phan P3 (miic phan cao nhat) deu bi sau cuon la gay hai manh (diSm 3). Cac giong con lai nhiem 6 miic nhe (diem 1). Giai doan chin sua xuat hien mua rao ket hop vol nang nong 6a lam khi hau tai vung rat nong va am, tao dieu kien thuan led cho cac benh ve nam phat trien manh, dac biet la bSnh kho van. Trong thi nghiem, hau het cac cong thiic deu bi nhilm kho van. Cac cong thiic o meit do M3 (mat do day nhSt) bi nhiem kho van Bang 3a. Anh huong ciia den nang suat, cac yeu to cau
nSng nhit (diim 3-5). Cac giong con 1^ d£u hi nhilm 6 dilm 1 -3. Tit ca cac cong thiic d^u nhilm sau due than a miic trung bmh (diem 3), nhilm nh?
d^o on (diim 1) va khdng bi ray nau gay hed.
3. Anh huong cua mat dd va luwng pfaSn bon d^n nang suat va cac y^u to cau thanh nang su^t cua gi^ng KN2
3.1. Anh huong cua tuffng tac mat dp va lu^g ph&n bon d^n nang suat, cdc yeu to cau thanh nang suit cua giong KN2
Ket qua theo doi su anh huong cua tuong tac mat dp va miic phan bon den cac yeu to cau thitnh nSng suSt cua giong liia KN2 dupe th6 hiSn qua bang 3a.
mat do cay va luffng phan bon thanh nang suat cua giong lua KN2 Luong
phan bon PI
P2
P3 Mat do
Ml M2 M3 Ml M2 M3 Ml M2 M3 LSDoo5(M*P)
cv%
So bong/m^
234,33"' 256,67*
260,67=' 228,33"
246,67"
253,00*
243,33'' 256,67*
275,33*
25,21 5,80
S8hat /bong 179,67' 180,10' 165,20' 178,30*
173,90*' 171,lO-'"
175,30*
171,50''«
161,30' 11,19
3,70
Xy le hat lep(%)
17,10' 18,80'"
18,50"
17,80' 19,30''' 20,10*
21,10*
22,10' 23,60' 2,02 5,90
PlOOO hat(g) 21,27 20,93 21,13 21,47 21,27 21,10 20,90 21,10 20,50 3,10 1,90
NSLX (ta/ha) 74,23 78,57 74,17 71,84 73,62 72,98 70,34 72,35 69,56
NSXX (ta/ha) 55,30*
58,10' 55,50*
54,90' 55,40' 54,40' 53,80' 53,40' 52,90' 3,10
3.3 So b6ng/m^ cvia cac c6ng thiic khac nhau co y
nghia d miic a<0,05, dao d6ng trong khoang 228,33-275,33 b6ng/m^, trong do, cao nhat 6 cong thiic P3M3 (275,33 bong/m^), thap nhfa 6 cong thiic P2M3 (228,33 bong/m^). Cong thiic khac nhau co s6 hat/bong khac nhau co y nghla 6 miic a<0,05, trong do, cao nhfa la c6ng thiic P1M2 (180,1 ha^bong) va PlMl (179,67 hatl^ong); thlp nhfa la cong thiic P3M3 (161,30 hatTjong) va P1M3 (165,20 hfit/bong). Ty le hjt lep ciia cac cong thiic dSu 6 miic trung binh, dao dong tir 17,1-23,6%, trong do thlp nhfa 6 cong thiic PlMl, P2M1 (17-18%) va sai khac c6 y nghla vi mat thong ke so voi cac c6ng thiic con S6 12/2014
lai vcd do tin ciiy o miic 95%. Cong thirc P3M3, P3M2 CO ty le hat lep cao nhfa, tirong ling 22,1%
va 23,6%.
Ket qua thi nghiem cho thiy trong cimg 1 giong voi cac mat dp cay va li^u luong piian bon khac nhau khong gay sai khac co y nghla vi mat thdng ke. Trong luong 1000 hat cua cac cong thiic trong thi nghiem dao dong tir 20,5-2l,47g.
Nang suat ly thuySt phan anh tiSm nang nang suat cua gi6ng, la co so cho viec xay dung cac bien phap ky thuat nhjm nang cao nang suit thuc thu cua mot gi6ng. Nang suit ly thuyfa gi6ng KN2 dao dong til 69,56-78,57 ta/ha, trong do cao nhat 6 cong thirc P1M2, thip nhit 6 cong thiic P3M3.
Tgp chi Ml KH-CN Nglie An
HOAT BONG KH-CN Qua bang 3a cho thay: Cac cong thiic khac nhau
thi NSTT khac nhau co y ngiua 6 muc a<0,05, trong do cao nhat 6 cong thiic P1M2 (58,4 ta/ha), cao hon khong co y nghia ve mat thong ke so voi cac cong thiic PlMl, P1M3. Cac cong thiic con lai d^u CO nang suat thip hon va tuong duong nhau ve mat thong ke, dao dong tir 52,9-54,9 ta/ha.
3.2. Anh hu&ng ciia timg yeu to (mat dp cay, lupng phan bon) den nang suat vd cdc yeu to cau thanh nang suat
Xet yeu to mat dp anh huong toi cac yeu to cau
thanh nang suat va nang suat cua giong KN2 cho thiy: mat do cay khac nhau co so bong/m^ khac nhau CO y nghia a miic a<0,05, trong do mat dp cay M2, M3 CO so bong/m^ Ion hon mat do cay Ml. Mat dp cay Ml, M2 cho so hat/bong cao nhit sai khac CO y nghia so voi mat dp M3. Nhu vay, khi mat dp tang, s6 bong/m^ tang nhung s6 hat/bong giam va ngupc lai. Ty le lep bien dong tu 18,67- 20,73%, cao nhit o mat dp M3 va thap nhat a mat dp Ml. Su khac nhau giua cac mat dp cay ve ty le hat lep co y nghia ve mat thong ke 6 miic dp tin cay 95%.
Bang 3b: Anh huong cua tung yeu to (mat do cay, luvng phan bon) den nang su^t, cac yen to cau thanh nang suat cua giong liia KN2 Chi tieu
Mat dp cay
Ml M2 M3
LSDo.05
cv%
Luong phan bon PI P2 P3 LSDo.os
cv%
So bong/m^
235,33' 253,33' 263,00' 14,70
2,60 250,56' 242,67' 258,44' 22,45
4,00 S6 hat/bong
177,76' 175,17' 165,87' 7,07 1,80 174,99' 174,43' 169,37' 12,75
3,30
Xy le lep
(%)
18,67' 20,07' 20,73"
0,45 0,90 18,13' 19,07' 22,27"
1,36 3,00
PlOOO hat (g) 21,21 21,10 20,91
21,11 21,28 20,83
NSLX (ta/ha) 72,47 74,84 72,31
75,78 72,89 70,89
NSXX (ta/ha) 54,67"
55,63' 54,27' 1,47 1,20 56,30' 54,90*
53,37' 1,98 1,60 Khoi luong 1.000 hat dao dong tir 20,91-
21,21g. Mat do cay cang thua thi khoi luong 1.000 hat cang cao. Tuy nhien, miic dp chenh lech giiia cac cong thiic la khong dang ki.
Nang suat ly thuyet va nang suat thuc thu dat cao nhit 6 mat dp M2 tuong ling 74,85 ta/ha va 55,63 ta/ha, nang suat thip nhit 6 mat dp M3 tuong ling 72,31 va 54,27 ta/ha
Xet yeu to lirpng phan bon anh huong din cac yeu to cau thanh nang suat va nang suit cua gi6ng KN2 cho thiy: Lupng phan bon a miic P3 va PI cho s6 bong/m' cao nhit, dat 258,44 va 250,56 b6ng/in^ va sai khac co y nghia ve mat th6ng ke so voi miic P2, chi dat 242,67 bong/m^. S6 hat/bong cao nhit a mac P1, P2, hrong ling 174,99 va 174,43 hat/bong va sai khac co y nghla vi mat thdng ke so voi miic P3 chi dat 169,37 hat/bong a dp tin cay o miic 95%. Ty le lep thap nhit o, miic phan bon PI S6 12/2014
(18,13%), P2 (19,07%) va cao nhfa a miic P3 (22,27%). Miic phan bon PI va P2 co ty le lep sai khac CO y nghia ve mat th6ng ke so voi miic phan P3. Cac miic bon phan khac nhau khong lam biSn dong nhiSu trong lupng 1.000 hat cua gidng KN2, dao dpng tit 20,83-2i ,28g. Lucmg bon phan PI cho nang suat ly thuyet va nang suat thuc thu cao nhit, tuong ling 75,78 va 56,30 ta/ha, thip nhfa la lupng bon phan P3 dat 70,89 va 53,37 ta/ha.
IV. KEX LUAN VA KIEN NGHI 1. Ket luam
- Cac cong thiic co thoi gian smh truong chenh lech nhau 1-2 ngay, cac cong thiic bon phan nhi6u hon thi keo dai thai gian sinh truong hon cac cong thiic bon thap.
- Ve chiSu cao cay: cac cong thiic mjit dp va lupng phan bon khac nhau c6 anh huong toi chieu cao cay cuoi cimg. Cac cong thiic co lupng phan
Tgp chi . , , KH-CNNgheAn ' '
HOATDONG KH-CN
bon thip va mat dp day co chieu cao cay cao hon so voi cac cong thiic co lupng phan bon cao vao mat dp thua. Xet anh huong cua tin^ nhan t6 d6n chieu cao cay cu6i cung tlu yeu to mat dp anh huong khong dang k^, y§u t6 lupng phan bon co anh huong ro ret toi chi tieu nay. Chi8u cao cay tang khi tang luong phan bon tm miic (1 tan phan HCVS + UOkg N + 100kg PzOs + 80kg K2O).
Sau do ti8p tuc tang lupng phan bon thi chieu cao cay lai giam xu6ng.
- Kha nang ch6ng chiu sau benh: Cac cong thiic CO mat d6 ciy cao (M2, M3) kk hop voi bon lupng phSn bdn cao (P2, P3) nhiem sau benh nang hon so voi cac cong thiic co mat dp cay thip (Ml, M2), cong thiic bon phan thip (PI).
Cac cong thiic ciy theo mat do M3P3 nhiem sau benh nang nhat.
- Ve nang suat: Trong 2 yeu to thi nghiem thi yfiu to lupng phan bon la yeu to co anh huong Ion den cac yeu to cau thanh nang suat va nSng suit gi6ng KN2. Va cong thiic P1M2, cSy voi mat dp 50 khom/m^ cay 1 danh a lupng p h ^ bon 1 tin phan HCVS + 100kg N + lo'okg P2OS + 70kg K2O cho nSng suat cao nhat la 58,10 ta/ha.
2. Kien nghi
Ap dung quy trinh san xuat KN2 nguyen chung tai Nghe An: cay 1 danh voi mat dp cay M2 = 50 khom/m^ va lupng phan bon PI (1 tan phan HCVS + 100kg N ' + 100kg P2O5 + 70kg K2O)./.
Tai li£u tham khao
1. BOi Dinh Dinh (1995), Y^u id dinh du&ng hgn chi nang suat cay trong va chien luge quan ly dmh ditang de phat trien nong nghiep bin vung, D6 t^i KN - 01 - 10, Nxb Nong nghi?p, H4 N6i.
2. hiii Huy Ddp (1980), Cay liia Vi4t Nam. Nxb Khoa hpc \h KJ thu§t, Hk Noi.
3. Bach Trung Hung va cs (1995), "Nghien cuu cdc yeu to anh huong den nang suat lua a 2 xa vung dSng
bSng song Hong", trong sach Nong nghiep vung dong bang song Hong trong th&i gian cdi each hien nay, Vi?n Khoa hoc Ky thuat nong nghifp Vi^t Nam, Nxb N6ng nghiep, Ha Npi, tr. 58-89.
4. Do Thi The, 2004, Nghien cuu anh huong cua lieu Iw^g phan dam va mpt so danh cay den sinh truong, phat trien va nang suat giong lua VL20, Luan vSn Thac sy nong nghi?p, Tnrimg Dai hoc N6ng nghilp H^ N^i
5. D^o The Tuin (1980), Sinh ly rugng lua co nSng suat cao, Nxb Nong nghiep. Ha Noi.
S 6 12/2014
I. DAT VAN BE
Ca h6ng my (Sciaenops ocellatus) la doi tupng nuoi mdi, co t6c dp sinh truong nhanh, thit tiiom ngon, giau gia tri dinh du6ng nen dupe thi tnrong trong va ngoai nuoc ua chupng. Ben canh d6, ca co kha nang thich nghi voi nhieu dieu kien bat Ipi ciia moi truong s6ng, dac biet la nhift dp thip, trong khi cac d6i tupng ca biln khac khong the nuoi dupe. Vi vay, ca h6ng my dang duoc chpn nuoi kha ph6 biln 6 cac viing ven bien Quang Ninh, Hai Phong, Nam Dinh, NghS An [5,6]. Khi nghe nuoi ca hong m^ phat triln thi nhu e^u tu thuc tiln 1^ can c6 nguon ca giSng du v^ s6 lupng, dam bao ve chit lupng.
Hien nay, trong uong ca giong va nuoi ca hong my thuong phim thi thiic an su dung chu yeu la ca tap [2,5]. Tuy nhien do nguon Ipi ca tap ngoai tu nhien ngay cang khan hi6m cho nen nguoi nuoi ho^
toan bi dpng nguon thiic an cho ca. Ngoai ra, viec sir dung thiic an ca tap rat de gay 6 nhiem moi truong ao nuoi nen kho co the phat trien nghe uong nuoi ca hong my b quy mo Ion. M6t s5 vung nuoi co bo sung thSm thiic an tu che nhim tan diang nguon nguyen lieu dia phuong nhung thanh phan i^yen liSu chua on dinh nen hieu qua san xu^t ciing nhu chit lupng ca giong chua cao. Truoc thuc te do, viec tim ra loai thiic an phu hpp gop phin neing cao ty le s6ng va t6c dp tang truong cho ca hong m5^ giai doan ca giSng la rat can thiet va co y nghia nhSm cung cip ca giong CO chat lupng tot cho cac vung nuoi ca thuong pham.
n . PHlTONG PHAP NGHIEN ClTU 1. Boi tirffng nghien cihi
Ca hong my (Sciaenops ocellatus) giai ca dogn giong CO chi6u dai trung binh 4,07 cm/con, khii lupng trung binh: l,62g/con, khoe manh.
2. Vat li^u nghien cihi
- Thiic an thi nghiem g6m 3 cong thiic (CT) dupe sir dung nhu sau:
CTl: 100% ca tap.
CT2: Thiic an tu chi (bot ca 50%, bpt dSu nanh 35%, cam gao 10%, premix vitamin 2%, premix khoang 3%).
CT3: Thiic an cong nghiep cho ca (CP9950 cua Cong ty CP voi protein 35%, chit beo 1,4%, dp §m 11%, nang lugmg 2.860 kcal/kg, chit xo 6%).
- Dung cu, thilt bi nghien ciiu: giai luoi, can tieu ly, thuoc do...
Tqpchi [6]
KH-CNNgheAn
