Tap chi Khoa hoc Cong rg^e \6PQ nghiep Viel Nam - So SII l4)/2020 duration m the ecological regions of the Red River Delta on the basis of 1500 kg HCVS + 70 kg P.O. + 70 kg K.O IS as follows: 70 - 80 Agrotain 46A' (Hai Duong. Thai Binh); 80 - 90 Agrotain 46A- {Nam Dinh); 90 Agrotain 46A (Ha Noi). The results of this smdy suggest that the appropriate amount of slow-release nitrogen fertilizer for rice production in the ecological sub-regions of the RRD will ensure productint)- while reducing fertilizer, improving production etficiency and protecting the environment.
Keywords; Rice ((Jrv-ii saliva L.), soil, fertilizer, Agrotein 46A- .N'gay nhan bai: 28/4/2020
N!;j; phan bi?n: 9/5/2020
XgUoi phan bien: PGS. TS. Nguyen Tri Hoan Ngay duyet dang: 20/5/2020
SO S A N H M O T S O CHi TIEU HOA LY VA THANH PHAN HOA HOC
TREN MAU HAT TIEU DEN T C PHU QUOC VA CUA, QUANG TRI
Hoang Quoc Tuan, Pham Ngpc Hflng T O M TAT
Muc dich chinh cfla nghien eflu nay la so sanh mpt sd chi tieu hda ly, thanh phan chat beo va tinh dau cua mau lieu den tfl hai vung Phu Qude va Cua, Quang Tri. Kel qua phan tich cho thay cd sfl khic biel ve thanh phan hda ly, chat beo va tinh dau cfla mau lieu gifla hai vflng. Trong dd, ham Iflong mdt so thanh phan linh dau chinh nhfl (r(im"-Caryophyllene eua mau lieu Cua, Quing Trj (32,85%) co xu hfldng cao hOn so vdi mau tieu Phu Quoc (28,03%), Him lfldng chal beo trong mau lieu Ciia. Quang Tn (6,92 mg/g) thap hdn so vdi mau tieu Phu Quoc (11,22 mg/g).
Cac chi tieu hoa ly nhfl protein, ham Iflong tro, do am khdng cd sfl khac biet gifla cac mau. Chi so LAB cho thay miu sic lieu Cua (L*a*b: 3,99" 1,35" 1,97) cd xu hfldng sang ban so vdi tieu Phu Qudc (L"a"b: 2,28* 1,37" 1.54)
Tfl khda: Tieu den, tmh dau, chat beo, Phu Qude, Cua I. DAT VAN DE
Hd tieu {Piper Nigrum L.) li cay cdng nghiep dai ngay, co gia tri kinh te va gia tri xuat khau cao, hing nam dem lai ngudn thu ngoai te Idn cho nfldc ta.
Hat tieu li mdt loai gia vi dfloc yeu thich tren toan the gidi. Cac so lieu thong ke cho thiy, Viet Nam la qudc gia xuat khau lieu hang dau the gidi. Sfl phat tnen ciia cic vung ho tieu trong nhflng nam qua da dong gdp rat Idn vao qua trinh phit trien kinh te xa hpi cua khu vflc nong thdn cd dien tich canh tic tieu, cii thien ding ke ddi song cua ngfldi dan (Hiep hpi Ho tieu Viet Nam, 2020). 6 nfldc ta, cay hd lieu dfldc trdng chu yeu d cac tinh mien Trung, Tay Nguyen va Nam Bg. Ket qui dieu tra cho thay cac giong tieu dfldc trdng nhieu d Ddng Nam Bd ehu yeu la giong Vinh Linh, mot dien tich nhd trdng gidng tieu Se, tieu Trung, tieu An Dp, con sdt lai mot vai vfldn trdng giong Lada Belangtoeng xen vdi cac giong khae. O Phu Qudc phan Idn dien tich trong gidng tieu Phu Qudc vi gidng tieu Ha Tien. Cf khu vvtc Tay Nguyen pho bien li gidng tieu Vinh Linh, 6 eae vfldn lieu gia cdn mdt vii vfldn trong cac gidng Se Md. Se Lpc Ninh, tieu Trung, tieu Trau, tieu Tien Sdn, Lada Belangtoeng, giong tieu An
Do chi mdi dfldc dfla vao trdng thfl trong vai nim gan diy. C( Quang Tn chu yeu giong lieu Vinh Linh vi giong tieu Se (tieu Cfla) (Nguyen Tang Tdn va ctv, 2016). Tuy nhien, do sfl khac biet vc dieu kien dia ly va phflong thflc canh tic nen dan den chat Ifldng vi thanh phan hda hpe cua tieu d cac vflng trong ed sfl khac biet. Do dd, trong nghien cflu nay, chflng toi tien hanh nghien cflu dinh gia sfl khac biet ve thanh phan hda hoc cfla tieu den tfl hai vflng tieu da cd chi dan dia ly va cd thflong hieu.
IL VAT LIEU VA PHlfflNG PHAP NGHIEN C0U 2.1. Vat lieu nghien cdu
Miu tieu den lfl vung tieu Phu Qudc vi tieu Cua Quang Tri.
2.2. PhUdng phap nghien cflu 2.2.1. PhUdngphdp lay vd chudn hi mdu
Mau dfldc lfla chgn ngau nhien tai 03 vfldn tieu tren moi dia phfldng. Tai moi dia phfldng dflpc iron lan lim mau chung de phan tich. Mau dflpc thu tip tai vfldn tieu tfl thing 2 tai Phu Qude vi thing 6 tai Quang Tri. Mau tieu dflpc che bien theo phflpng phap phPi say thfl cdng
' \'ien Cdng nghe Sinh hpc va Cdng nghe ThUc pham. Trfldng Dai hpc Bich Khoa Ha Noi
•^noahoc . i n ; .
2.2.2. PhUOng phdp phdn tich cdc cht tieu
Xae djnh protein tong -su bang phflong phap Kendal.
Xae dinh him Iflong iro khdng tan trong axit lheoH:VN 5484:2002 I ISO 930 1947]
- Xac dinh ham Iflpng tro tong sd theo TC\'N 7038:2002 (ISO 928:1997).
- Thdng sd CIF LAB dflpc xae dinh bang tbdng so do mau cua may quang pho do mau sic ColorLite SPH 860 (ColorLile/Dflc).
- Chat beo hat lieu dflpc thu nhan bing Shoxlet va phin lich bing CC'.MS. Cpt SPB 5Nis (30 m
« 0,32 mm x (1.25 pm). Chflong trinh nhiel: nhi^l dp dau lOOC; gifl Irong 1 phut, ting 20'C/phul len
\m (:, gifl I phflt, ling 2 'C/phfll len 2 5 0 1 . i;iu nhict
dp nay trong 1 phut (Al-Jasass FM and .-\l Ijsser .MS.
2012).
- Chflng cit tinh dau theo phflong phap Clcvenger Thinh phan tinh dau dflpc phan tich bing thiet bi GC/MS, Cpt SPB - 5MS I ^o m -0.32 mm -0,25 ^m), Chuong trinh nbt^t' nhi?t dti diu 40C,;. gifl trong 5 phflt, ling 11) (7phflt len 25i) t, . gifl d nhiel dd cudi
eung nay trung 1 phflt. Dieu ki?n MS ion ho.s MJU ^' the ion hda 70 ev, nhi?t dp duy tri 250" C. khi •"iJ^
la He tdc dp 0,5 ml/ phflt, tdc dp chid ddng i ^^' (Henr>k. H.L era/., 2015).
2.3. Thdi gian vi dja diem nghien cuu Nghien cflu dflpc thflc hi^n tfl thing l>2 den thang 6 nam 2019 tai Dai hpe Bich Khoa Ha Npi III. KET QUA \ A THAO 1 CAN
3.1. Cac chi tieu hda ly ciia tieu
Ket qua phan tich cho thay gii in do ani eua hai mau deu nam trong gidi han cho phep iheo rC\ N 7036 : 2008 vi khdng cd sfl khac bi?l gifl.i miu tieu Cuava Phu Quoc, lan Iflpt la 11.S3'V va !1.40".i.
Kel qua (bang I) cho thay ham Iflifng tro tdng trong hai mau tieu Cfla va tieu den Phu Qudc khdng ed khic biet nhieu. lan Iflpt la 4,53'\i va 4,51%. Theo nghien cuu cua Sruthy \a cdng tie vien (2013), cho thay him Iflpng tro cua mau tieu cua mpt so viing nhfl Kasagarod (5,09%,), Peruvannamuzhi (4,17'^'o) va Peehiparai (3,43"i)) khdng eo sU khac biet vdi mau tieu dflpc phan tich.
Mau tieu
Tieu Phfl Qude
Tieu Cua Ghi chii: Ih
Dd am
(%)
11,40
11.83 nghiem
i i n g 1. Chi tieu hoa ly eua lieu den Phii Quoc v
Ham lflpng tro tdng (%)
4.51 1.5'i /<tp 03 Idn.
H i m lupng tro khong tan trong axit (%)
0,9 11,45
Protein long sd
5.60 6,07
a Ciia, Quang T n Chi s(
2,28 3,99
d p mau LAB fl" b "
1,37 1,54 1,35 1,97
^Li d
6W aoc lOX lir 'iX- m x «00 22.10 MM Z600 2aO0 3000 Time [mini
Hinh 1. Sac kvddeiia iinh dau hat lieu den
TapchiKhoa hoc Cong none Nong nghiep Vie! Nam - _S j 5
Him Iflpng tro khdng tan trong axit phin tich
tfl mau lieu Cfla VA tieu den Phu Qudc lan Ifldt la 0,45% va 0.9%. Tro khdng tan trong axit li nhflng chat ban (dat, cat) Ian trong nguyen lieu va khdng tan trong axit HCI. Ket qua nghien cflu nay cho thay. ham Iflpng tro khdng tan trong axit cfla mau nghien cflu cao hdn nhieu lan so vdi mpt so mau tieu den tfl cic vung khac nhau cua An Dp, nhfl Kasagarod li 0,13%, d Peruvannamuzhi la 0,16%.
(Sruthie(fl/., 2013).
Ket qui phin tich cho thay, him Iflpng protein trong mau tieu Cfla va Phfl Qudc khdng co sfl khac biet Idn (Bing 1). So vdi mau tieu cfla An Dp (tfl 8,23 - 9,00%) mau tieu Cfla vi Phfl Qudc cd ham Iflpng protein thap hdn (Sruthi et ai, 2013).
Ket qua nghien cflu cho thay cic gia tri trung binh L', a', b" cua lieu Cua deu Idn hPn cfla lieu den Phfl Qudc. Theo phan bd mau trong khdng gian LAB, cho thay miu sic lieu Cua cd xu hfldng sing hdn so vdi tieu Phfl Quoc. Ket qua nay cd the tham khao de phat tnen phfldng phip phan biet ngudn ngoc cua hat tieu dfla tren mi mau sic.
3.2. Thanh phan chat heo ciia hat tieu Ket qua nghien cflu cho thay cd cd sfl khic bi?l ve thinh phan va him Iflpng axit beo trong hai mau tieu Cfla Quang Tri vi lieu den Phu Qudc. Ham tflpng axil Panmitic trong mau tieu den Phu Qudc (3,11 mg/g) Idn gap 1,62 lan so vdi mau tieu Cua (1,92 mg/g). Ham lflpng axit margaric khdng cd trong tieu Cua nhflng cd trong tieu den Phfl Qudc vdi bim lfldng thap 0,42 mg/g.
Hinh 2. Sic ky dd chat beo cfla hat lieu den Ham Iflpng axit stearic trong miu tieu den Phfl
Qudc (0,25 mg/g) cao gap 1,9 lan so vdi mau tieu Cfla (0,13 mg/g), Tong ham Ifldng axit beo no trong mau tieu Cua Quang Tri la (2,06 mg/g), trong mau tieu den Phfl Qudc (3,78 mg/g). Doi vdi axit beo khdng no, ket qua phan tich cho thay, ham lfldng axit a-linoleic trong mau tieu den Phu Qudc la (1,31 mg/g) gap 1,6 lan so vdi mau tieu Cfla Quing Tri (0,88 mg/g). Ham Iflong axit linoleic trong mau tieu den Phfl Qudc (4.44 mg/g) gap 1,44 lan so vdi tieu Cfla Quing Tri. Ham lflpng axit oleic trong tieu Phu Quoc (1,69 mg/g) gap 1,9 Ian so vdi tieu Cua Quing Tri. Nhfl vay tong him Iflpng axit beo khong no trong lieu den Phfl Quoc (7,42 mg/g) Idn hdn gap 1,5 lan so vdi tieu Cfla (4,S7 mg/g). Trong khi dd, long ham lflpng axil beo no trong mau tieu Cfla Quang Tri li (2,06 mg/g), trong miu tieu den Phfl Quoc (3,78 mg/g).
Bing 2. Thinh phan chat beo trong miu lieu den
Ten t h a n h phain
Panmitic Margaric Stearic a-Linoleic(ALA) Linoleic(LA) Oleic
H a m liigrng (mg/g) Tieu den Qudng Tri
1,92 0,00 0,13 0,88 3,09 0,90 6,92
Tieu den Phii Quoc
3,11 0,42 0,25 1,31 4,44 1,69 )J,22
So vdi ket qui nghien cflu Tieu An Do cho
thay tieu den Quang tri thap hdn va tieu Phu quoc
cao hdn doi vdi ham Ifldng axil beo long cua cac
vung Kasagarod 10,34 mg/g; d Peruvannamuzhi li
10,02 mg/g; d Peehiparai la 8,88 mg/g (Dr. J. Pion
etai, 1990).Tap chi f' . •
3 . 3 . T h a n h p h a n t i n h d a u c u a hat t i e u Kcl q u a p h a n tich c h o thay, mpt sd t h a n h phan l i n h d i u c h i n h i r o n g hat tieu cua tieu %'ung Cua, Q u a n g Tr) cd xu hfldng c a o h d n so ven m a u tieu Phu Q u d c ( B i n g 3). T h a n h p h a n (rjfii-Carj'ophyllene l i t h i n h p h a n c h i n h cd t r o n g t m h d a u h^t tieu chiem lan Iflpt la 3:.S5"„ v i 28,03".. rrflnj-Car>ophyllene da dflpc chflng m i n h la m o t chat cd hoat tinh sinh hpc cao, ed t i c d u n g k h i n g k h u a n tot. Ngoai ra con cd tac d u n g g i i i stress, c h o n g t r a m c a m % A giai rUdu (Pinho-da-Silva L. et ai, 2012).
L i m o n e n e chiem ti I? 11.47'\, trong m a u tieu Phu Q u d c , va I4,45'\i trong m a u tieu Cfla. Q u i n g Tn, L i m o n e n e hoat d p n g n g i n ngfla u n g thfl va k h i n g u v i c i c chal chuyen hda ciia n d axil perillie. axit dihydroperillic, u r o l e r p e n o l va l i m o n e n e 1.2-diol cd t h e fle che sfl p h i t trien khdi u (Alan D. etai. 2012)
Bang 3. Thanh phan tinh dau trong hat tieu
I STT Thanh p h a n
Phu Quoc
(%)
Cua.
Q u a n g Trj
(%)
1 a-Thujene 2 a-Pinene 3 Sabincne 4 )3-Pinene 5 /i M\icene 6 a-Phellandrcne 7 6-3-Carene 8 a-Terpinene 9 p-Cymene
1,32 1.01 3,35 4.04 ,-,(-) fi,S/
6,66 5,69 2,22 1,11 2,47 2,22 12.03 Sti' u,sy
(),S9 1.12 0.44 1.45 14,45 1,21
13 0,12 0.19
0,69 10 ^-Phellandrene 1.69 11 Limonene 11.47 12 }'-Terpinene 0,88
/rrim-Sabinene hydrate
14 Linalool 0,59 15 cS-Elemene 1.21 0,48 16 /^Elemene 1.25 0,88 18 trjn.-,-Caryophyllene 25,03 32.85 19 a-Caryophyllene 1.88 1,52 20 Germacrene D 0.:S 0,41 21 /^-Setinene 1.52 1,11 22 a-Sehncne 1.46 1,05
(iVn chii: 'Ihiinh phdn tinh theo % dien tich sdc ky do.
I h a n h p h a n Sabinene t r o n g m i u tieu Cu •, - n*''^' S 51 "b \'a m a u tieu Phfl Q u o c Ii 7,44%. Tron.. KHI dd, t h a n h p h a n 6-3 C a r e n e t r o n g m a u ti^u Phu Q - ' ^ '•'^'•' h d n so v0i m a u Ueu Q u i n g Trj, lan lupt l i 12.03%^-'
> S"'e. Theo n g h i e n eflu cua Nguyen T h a n h Hu^ ^'^
cdng t i e n e n (2012), h i m Iflpng rra;is-Car\ ophyllf "^
trong m a u tieu t h u m u a tai C a n T h d chiem e^ao nhat, 27,03%, tiep d e n l i L i m o n e n e , chiem 15-4/'^' va .y-3-Carene c h i e m 14,03 % t r o n g nuiu tieu p h i n tich.
Kel q u i n g h i e n cflu P h a n N h i t M i n h \ J e p n g t i c vien (2006) eho thay c u a / t - C a r y o p h y l l e n e (20.31^>J, chiem ti le cao n h a t t r o n g t h a n h p h a n tinh d a u c u a lieu Chfl se. Gia Lai. T r o n g k h i dd, mau lieu Phii Q u d e va Cua chi cd d d n g p h i n a - C a r y o p h ) llcne vdi li 1^ lan lupt la 1,88% v i 1,52%. So s i n h t h a n h p h a n p-Pinene, cho thay m a u tieu tfl Phfl Q u d c va Ciia eao h d n so vdi mau tieu cfla vflng Chfl Se, t i n h Gia Lai (1.86%).
Kcl qua phan tich t h a n h p h a n linh d a u nay c h o thiy, sfl khac bi(?t ve v u n g t r o n g cd the d a n d e n sfl khac biet ve t h i n h p h a n v i ti le gifla c i c t h i n h p h a n tinh dau. Sfl k h i c biet ve h a m Iflpng cac loai t i n h d a u se i n h hfldng den gia tri cua hat tieu.
1\' KET LUAN
Nghien cflu bfldc d a u eho thay cd sfl k h a c biet gifla m i u tieu eiia hai vflng n i y . T r o n g d o , ket q u a p h i n tich cho thay, m p t so t h a n h p h a n t i n h d a u chinh irong hat tieu cfla lieu v u n g Cfla, Q u a n g Trj (Sabinene, 8,51%; L i m o n e n e , 14,45%) cd xu h f l d n g cao h p n so vdi m i u lieu Phu Q u d c (Sabinene, 7,44%;
Limonene, 11,47%). H a m Iflpng chat b e o t r o n g m a u tieu Cua. Q u a n g Tri (6,92 m g / g ) t h a p h d n so vdi m a u tieu Phfl Q u d c (11,22 mg/g), Cac chi tieu h d a ly nhU protein, ham Iflpng tro, d p am k h d n g cd sfl k h a c biet gifla cac mau. Chi sd LAB cho thay m i u sac tieu Cfla ( L ' a ' b : 3,99' 1,35*^1,97} ed xu hfldng sang h p n so vdi tieu Phu Quoc ( L ' a ' b : 2 , 2 8 - l , 3 7 " l , 5 4 ) . C a c t h o n g tin ve sfl khac biet gifla cac m a u cd the sfl d u n g t h a m k h i o de x i e thflc xuat xfl cfla s i n p h a m . TAI LIEU THAM KHAO
Hiep hpi Ho tieu Viet N a m , 2020. Bdo cdo tht iruong ho tieu 2019 & du dodn 2020, ngay truy cap 21 ,'02/2020.
Dia ehi. http://ptexim.com.vn/test-post-pd!/
N'guyen Thanh Hue, T r i n h M i n h K h a n g , Nj^ y^n Tan Hoang Sun va Nguyen Thi Bich T b u \ . n 2012 Khao sal ihanh phan hda hpc v i boat ti khimi;
VI smh vat cua tinh dau gflng (zingiber 'iun,il' roscoe) va tinh dau tieu Piper nigrum L ,,p ,, Khoa hoc - TrUdng Dqi hoc Cdn Thd, 21a 1 ,J3
T"J nghiep Viet Nam - P h a n N h a l .Minh. Mai T h i n h Chi, Phimg Van T r u n g ,
Biii Trpng Dat v i Nguyin Ngpc H a n h , 2006. khao sit thanh p h i n hda hpc cua tinh dau tieu {Piper nigrum L.) chiet xuat bing phflong phap carbon dioxide long sieu tdi han. Tqp chi Khoa hoc - TrUdng Dai hgc Cdn Thd 2006: 6, 97-102
T C \ N 5484:2002. Tieu chuan Viet Nam ve Gia vi - Xae dinh tro khdng tan trong axit.
T C \ ' N 7036:2008. Tieu ehuan Viet Nam ve Hat tieu den (Piper nigrum L.). Quy djnh ky thuat, TCVN 7038:2002. Tieu chuan Viet Nam Gia vj & Xic
djnh tro tdng so.
Nguyen Tang Tdn v i ctv., 2016. Gidng ho lieu, ngay truy cap 29-04-2016. Dia chi: http://iasvn.org/chuyen- muc/Giong-Ho-Tieu-8195.html.
Al-)asass FM, Al-Jasser MS., 2012, Chemical composition and fatty acid content of some spices and herbs under Saudi Arabia conditions. Scientific World Journal 2012:859892, 1-5.
Alan D. Kaye M D , A d a m M. Kaye P b a r m D , M i n e r a l , V i t a m i n , a n d Herbal S u p p l e m e n t s , 2012, FASCP, FCpha, in Anesthesia and Uncommon Diseases (Sixth Edition),
Comparison of physicochemical parameters and chemical composition of black peppers from Phu Quoc and from Cua, Quang Tri province
Hoang Quoc Tuan, Pham Ngoc Hung Abstract
The main purpose of this study was to compare some physicochemical parameters, fat and essential oil in samples of pepper from two regions of Phu Quoc and Cua, Q u a n g T n province The analytical results showed that there are differences in physicochemical parameters, fat and essential oil of two pepper samples In particular, the content of some main essential oil components such as Ir«HS-Caryophyllene of Cua, Quang Tri samples (32.85%) tended lo be higher than that of Phu Quoc (28.03%). The fat content in the pepper sample of Cua (6,92 mg/g) was lower than that of Phu Quoc (11,22 mg/g), Physicochemical parameters such as protein, ash content, humidity had no differences between two samples. LAB index showed that the color of Cua pepper ( L ' a ' b : 3,99'1,35* 1,97) tended to be brighter than Phu Quoc pepper ( L ' a ' b : 2,28'1,37'1,54)
Keywords: Black pepper, fat, essential od, Phu Quoc, Cua
H e n r y k , H.J., A n n a , G., 2015. Analysis of black pepper volatiles by solid phase microextraction-gas chromatography: A comparison of lerpenes profiles with hydrodistillation. /. Chromatogr. A. 141S 200-209
Pinho-da-Silva L I , Mendes-Maia PV, Tedfilo T M , Barbosa R, Ceccatto VM, Coelho-de-Souza AN, Santos C r u z J, Leal-Cardoso JH., 2012. Trans- Caryophyllene. a natural sesquiterpene, causes trachealsmoothmusclerelaxationthroughblockadeof voltage-dependent Ca^' channels. Molecules. 17 (10):
11965-11977.
P i o n J., Rodriguez-Feo G., Borges P., Rosado A., 1990. Chemistry and sensory properties of black pepper oil {Piper nigrum L ). / Food/Nahrung, 34 (6):
555-560.
Sruthi D., T. John Zachariah, N . K. Leela a n d K.
Jayarajan, 2013. Correlation between chemical profiles of black pepper (Piper nigrum L ) van Panniyur-1 eoUecled from different locations. Journal of Medicinal Plants Research. Vol, 7(31), pp, 2349-2357.
Ngay n h a n bai: 28/4/2020 Ngay p h a n bien: 11/5/2020
Ngfldi p h a n bien: TS. Phan T h a n h Binh Ngay duyet d i n g : 20/5/2020
D A N H G I A , C H O N L O C C A C G I O N G M A N G TAY M d i NHAP NOI
TAI NINH THUAN
Nguyen \'an Son', Tran Thi Thao', Phan Cong Kien', Trinh Thi \'an Anh', Vd Thi Xuan Trang', Vu Thj Dung' TOM T A T
Danh gii k h i nang sinh trfldng va nang suit mang eua 10 gidng mang tay mdi nhap ndi tfl My. Ha Lan, Dflc v i Thai Lan lai Ninh Thuin tfl thing 9 nam 2018 den t h i n g 2 nam 2020, Thi nghiem dflOc bd tri theo phflong phap khdi day du ngau nhien (CRBD), lip lai 3 lin. Ket q u i cho thay d i chpn dflpc 2 gidng cd nang suat cao v i thich nghi vdi ' \'i?n Nghien cflu Bdng va Phat trien Ndng nghiep Nha Hd
