K thut trng nm rm (Volvariella volvacea) ti huyn Ch Mi An
Giang(02.06.2010, 03:10 pm GMT+7)
1. Gii thiu: Nm rm l loi nm c gi tr dinh dng cao v d trng i vi
iu kin kh hu nc ta. Ngun nguyn liu trng nm rm rt phong ph v a dng
nh: rm, bng, lc bnh, mt ca...Tuy nhin, trng bng rm l nguyn liu d tm
nht nc ta v gi c li r. Chnh ngh ny gip cho b con nng dn xa i, gim
ngho v gp phn n nh kinh t gia nh. 2. K thut trng nm rm: Tm tt quy
trnh trng nm rm (L Duy Thng, 2006)
To trang in
2.1 Chun b t trng: t trng nm rm l t ni thong mt, c th tn dng t
trng pha di vn cy, l ni trnh c gi la v nng gt, ma nhiu (Nu trng nm
ni c nng nhiu, c gi la m lp rm o mng th nm s b en) Xi nh t trc khi
trng nc thm nc tt, xt thuc tr mc hoc ri vi tr su hi v mm bnh. 2.2
Chun b v x l nguyn liu: a.Rm r:
Rm r mua v phi tin hnh rm thu c rm chn. Cch : ngi ta xp rm thnh
tng ng ngoi tri, phn ln b con thng ng ln gim chi ph mua bao nylon
ph gi nhit. Xp rm thnh tng lp, xong mi lp th tin hnh ri vi sng ri
ti nc ln v gim p n . Nc vi gip rm mau chn v lm gim pH trnh b chua s
lm hi n nm, ng thi cn gip tr c mm bnh c trong rm. ng cao chng 1m l
c.
Hnh 2: ng rm khong 10 ngy, s tay vo ng rm thy m nng th tr rm: tr
lp rm t trong ra ngoi, t di ln trn, c th gim p n thot nc chua ra
ngoi. Nu thiu nc th ti thm nc duy tr m cn thit. kim tra xem c thiu
nc hay khng, ta c th lm nh sau: rt 1 2 cng rm ra xon trn: + Nc nh
git t ch xon l d nc. + Nc ch rn m khng rt git l nc. + Khng thy nc
rn l thiu nc. Nu rm mua v l rm chn th rm chng 10 ngy l c th trng nm
c, nhng nu l rm mi sut th phi 25 ngy mi cht lng. Da theo kinh
nghim, khi nhn mu rm t vng sng chuyn sang vng sm v c chn ph hp th c
th cht m v meo. C th kim tra bng cch: ly ngu nhin vi cng rm cun ngn
tay v bt th. Nu quan st thy: + Cng rm t d dng th rm qu mc. + Cng rm
hi kh t l va cht nm.
+ Cng rm rt kh t th rm cha chn. Rm chn th tin hnh lm m nm: da
theo thi tit s lm 1, 2 hay 3 m. Nu tri lnh th lm 3 m tit kim o m v
din tch. Ma nng th lm 2 m. ng thi, tri lnh th lm m to hn gi nhit
tt, tri nng th m nh hn, lp rm mt mng hn v ti nc cng t hn thong kh v
thot nhit d dng hn.
Hnh 3: Cch xp m Thng ngi ta da theo din tch trng rm. Khng qu
nhiu v khng s dng th rm s h. 1 cng t vn th cn 20-30 cng t rm. b.
Meo ging: Bch meo chng 200 gram. Meo ging tt l meo mc trng, lan t
trn xung y bch, khng c mu xm, vng hay m en, t khng mc ri ni.
Hnh 5: Meo ging b nhim Khi meo mc trng ht c bch mi em s dng. Thi
gian bo qun bch meo t lc ra trng c bch l khong 7 ngy. Cho nn, lc
mua meo th nn mua khi t cn cha lan ht c bch, c th s dng t t. 2.3 Xp
m v v meo: Rm t chn th tin hnh xp m v meo. Cch xp m: Rm khng c di
nht nh v l rm sut, nn ngi ta thng cun rm thnh tng cun va phi ri xp
cc cun kht vi nhau.
Meo lan trng bch th ta em s dng: bch meo vo 1 ci thau, dng tay
bp ti ra, Ri meo dc theo m. Trung bnh 1 bch meo ri cho 2 mt ti ca
m. Ta ri u v ri gia m, khng ri qu dy v nm mc s nh. Sau y nh rm ln
trn. Thng 1 cng t s dng t 15 - 20 bch meo ging. 5 ngy sau khi v
meo, ta ph lp o rm ln m, ri mi ti nc. C th ha thuc phng tr su keo
vo nc ti v ti phun sng trong giai on ny (thuc ch ti vo lc ny, nu ti
ln nm lc su xut hin th gy ng c v cht nm) 2.4 Chm sc v ti n nm: Sau
khi ph o rm th ti nc hng ngy, ti phun sng trnh tn thng n meo nm, lc
no cng lm m rm duy tr m gip nm mc tt. Trong giai on nm ra qu th th
nm cn nh sng, sng sm lc mt tri mc c th phi nm 15 pht. Nhng trnh phi
nng gt v phi lu v s lm en nm Ti nc: Tri ma: b nm m c ma th khng cn
phi ti Tri nng: Sng hi nm th chiu ti phun sng Nu tri lnh lm nh hng
n m th c th ha thuc Marason vo nc ti lm m dng. 2.5 Thu hi nm: Nm rm
ln rt nhanh: 12 ngy sau khi v meo (tc l 5-7 ngy sau khi ph o m) th
c th bt u thu hoch nm. Thu hoch nm hng ngy, trong khong 15-20 ngy.
Hi nm vo lc sng sm trnh lm en nm. T dng bp, dng trng (dng meco) n
dng d u c hi, sau phn loi ra v bn ty theo loi. Nu nm mc thnh chm th
hi sao cho t l dng trng chim nhiu nht Gi bn: Gi nm rm dng bp, dng
trng dao ng khong 20.000 / kg. Nm d thng c mui s dng (nu mun dng nm
d ly bo t nm th vi ngy cho nm kh li ri mi tin hnh ly bo t lm ging -
meo). Khi gn ht t thu hoch, thy nm ra tha v nh th ngng thu hoch,
tin hnh x l lp m rm trng t mi. Rm s dng c th lm phn bn rt tt. Sau
khi thu dn rm c, tin hnh xi t v rc vi dit mm bnh. Sau mi trng t tip
theo. Lc ang thu hoch nm t trc l rm cho t sau vic trng c tin hnh
lin tc.
3. Bnh hi nm: Theo ngi dn a phng th trng nm rm thng t gp bnh hi.
Nng sut trng hay tht l do ging tt hay xu. Cc trng hp thng gp l: Tp
nhim m nm th loi b ch b tp nhim Rm mc nn c xut hin mc, nhng mc khng
hi nm, x l vi trong nn t v ti vi lc rm th t thy mc. Su keo thng xut
hin v n nm lc gn cui v thu hoch. Phng tr bng cch xt thuc lc v o m
(nh ni trn). 4. Cc yu t nh hng n nm rm:
Cc giai on pht trin
m ca khng kh (%) Cc tiu Ti u Cc i 30 15 40 35 42 40 80 80-90
NHIT (C)
nh sng
Ny mm bo t Tng trng ca h si t Khi s to qu th S pht trin ca qu
th
Khng cn Khng cn
20
30
35
80-90
Cn c nh hng n mu sc
28
30
35
80
nh hng ca cc yu t mi trng i vi nm rm 5. Kt lun: Trng nm rm l ngh
c vn u t thp, vng quay nhanh, thu li cao, cch trng d dng v t ri ro.
Do cn nhn rng b con nng dn c th ng dng rng ri, gp phn nng cao thu
nhp.
Ti liu tham kho:
L Duy Thng. 2006. K thut trng nm. Tp 1. Nui trng mt s nm n thng
dng Vit Nam. NXB Nng nghip
http://enews.agu.edu.vn/?act=VIEW&a=8885
Nm rm c th nui trng trong nh c khng ?Ngun: L DUY THNG - TRN VN
MINH
Nm rm cng vn c th trng trong nh nh cc loi nm trng khc. Nng sut c
th cn cao gp hai hoc gp ba ln so vi trng ngoi tri (v khng ch c iu
kin nhit v m , cng nh su bnh). Tuy nhin, do vic u t tng i tn km v
nht l cha c mt m hnh sn xut thuyt phc, nn t hp dn ngi trng. Mun nui
trng thnh cng nm rm trong nh cn ba yu t sau: a. Nguyn liu: Bao gm
loi nguyn liu, cch ch bin v phng php nui trng (khi, khay, v...) b.
K thut : Chm sc, phng bnh c. Nh trng : Cu trc, trang b Trng nm rm
trong nh xut hin nc ta vo cui nhng nm 60 v u nhng nm 70. Tuy nhin,
cch trng n nay cha c ci tin bao nhiu, nguyn liu chnh vn l rm r v s
dng dn k nhiu tng. Qu trnh thanh trng nguyn liu v nh trng ch yu bng
hi nc nng. im yu ca phng php ny l nguyn liu v phng php thanh trng.
- Nguyn liu: Mc d, rm r l nguyn liu mang tnh truyn thng trong trng
nm rm, nhng cng l c cht cho nng sut km, nu khng mun ni l km nht, ng
thi th, cng knh v kh x l nht. Do , vi rm r, ngi trng kh trng nm rm
lu di trong cng nh trng, m khng b tp nhim. - Thanh trng: Phng php
thanh trng bng hi nc nng trong nh trng nm, hon ton khng ph hp vi iu
kin thc t nc ta. Vi nhng nh trng th s, mi trng khng m bo v trng
tuyt i, khi nng nhit bng hi nc nng (m v nng), s d thu ht ngun nhim
nm di, vi trng. Nguyn liu (c cht trng nm), sau khi kh trng, s nhanh
chng b nhim mc. u im ca phng php ny l: - Nguyn liu c lm mm ha bi vi
sinh vt hoc nm khc thnh c cht thch hp cho nm rm. - D b sung cc cht
dinh dng thch hp cho nm rm - D thanh trng, ch cn lm kh b mt (phi,
sy, t) - Nng sut nm tng i cao, trung bnh 22% (trng lng ti so nguyn
liu kh). Qui trnh trng nm rm trn mt ca c th tm tt :
im yu ca phng php ny l: - Nguyn liu l ph liu ( qua nui trng loi
nm khc), nn d ly nhim v cha cc sn phm khng li cho nm rm.
(*) Loi b nhng bch en, nhy nht hoc nhim mc... Qui trnh c th tm
tt nh sau:
(*) Meo ging cy im (nh trn rm), cch nhau 20 cm v cch ba 5 10cm.
u im ca loi nguyn liu ny l: cho nng sut nm cao (40 - 45% trng lng
ti so nguyn liu kh). Khuyt im ca loi nguyn liu ny l: nng cng khi x
l, nh lm m, x ti ( to thng thong)...
http://longdinh.com/default.asp?act=chitiet&ID=2600&catID=3
I. C IM CHUNG Tn gi Tn khoa hc Khu vc phn b Hnh thi qu th Nm rm
(straw mushroom) Volvariella volvacea (Bull. ex Fr.) Sing. Vng nhit
i v cn nhit i, c bit Chu . Tai nm pht trin qua hai giai on chnh:
dng bp v dng d. Khi cn non tai nm c bc trong lp v, c mu trng xm n
en. Tai nm trng thnh m mi bung ln cao. Cung c bao gc v khng vng c.
Gi th t nhin Rm r la nc, i khi trn c, l kh
Tai nm trng thnh c dng d, m xo rng, mt di m cu to bi nhng tm l
mng, gi l phin nm. Mi tai nm c khong 280 - 380 phin, xp st vo nhau
nh nan qut, khi u t trung tm (cung nm) ra ti ba mp. Phin khi cn non
c mu trng,
nhng khi tai nm trng thnh, phin chuyn sang mu hng tht, l mu ca
bo t chn. y l mt c im d nhn bit nht ca nm rm.
Dng nt
Dng trng
Dng ko di
Dng trng thnh
Hnh 1 : Cc giai on pht trin ca qu th nm rm
Hnh 2 : Hnh dng v cu to ca qu th nm rm Trn b mt ca phin hnh thnh
ccm hnh chy c ngun gc t cc u si nm phng ln. Mt trn chy hay m sinh
ra bn gai nhn, mi gai xut hin mt m bo t (basidiospore). Di knh hin
vi (phng i t 400 ln tr ln), ngi ta cn c th quan st thy cu trc ca bo
t nm rm. Bo t ny dng trng ct u, xung quanh c vch dy bao bc, tr chp
nh l du tch ni chng gn vo m. i khi ngi ta cn quan st thy nhng ht nh
mu hng tht trn h si t nm rm, chnh l cc hu bo t (chlamydospore) hay
cn gi l bo t mng dy. y l nhng bo t v tnh, phn bit vi bo t m l bo t
hu tnh. Hu bo t c hnh cu v l dng tim sinh ca nm. Nm rm l loi nm
nhit i v cn nhit i, nn nhit thch hp cho t nm tng trng v pht trin kh
cao (30 - 35oC), m khng kh t 80 - 90%, nh sng cho tai nm pht trin l
600 2000 lux. Ngoi ra, nguyn liu trng nm ch yu l rm r v cc ph liu
ca nng nghip. II. THI V TRNG NM RM Kh hu nc ta, nht l cc tnh pha
Nam, khng c ma ng ko di, m ch c hai ma ma, nng r rt, rt thch hp cho
trng nm rm quanh nm. Tuy nhin, do c im
v qui trnh, ngun nguyn liu v nhu cu th trng, m vic trng nm rm vn
cn mang tnh thi v. - Qui trnh trng nm rm hin nay ch yu ngoi tri, nn
vo nhng ma nghch, ma ma hoc nhng thng cui nm gi lnh, th vic chm sc
nm kh hn. V vy, nhng thi im ny s ngi trng gim xung, nh hng nhiu n
sn lng nm cho ch bin. - Ngun nguyn liu trng nm ph bin vn l rm r, nn
thng l thuc vo ma v. Sau thu hoch la, ngi nng dn mi c nguyn liu v
thi gian rnh ri trng nm. Kt qu sn lng nm cng tng gim theo. - nhng
vng, vic tiu th nm rm ch yu qua bn l trong dn, th nhu cu v gi c ln
xung ty thi im trong thng. Gi nm thng ln cao vo nhng ngy rm, n
chay... V vy, bn c gi cao, ngi trng nm phi canh cho nm ra ng vo cc
ngy trn. Do , mc d kh nng c th trng nm rm quanh nm, nhng thc t, vic
trng nm nc ta cn mang tnh thi v. y l vn cn khc phc gp phn cho cng
nghip ch bin nm xut khu pht trin. III. CHN A IM TRNG NM RM Vi phng
php trng ngoi tri, c th tn dng mi din tch xp m trng nm. M nm c th
cht dc li i, bi sn trng, trong vn, quanh nh, mt rung...C th tm tt
cch sp xp m nm rm theo thi tit v hng nng, gi qua m hnh hnh 3
Hnh 3 : M hnh sp xp m nm theo thi tit nng, gi
1/ Theo hng gi
2/ Theo hng nng
3/ Vo ma ma
4/ Vo ma lnh
Vic chn a im trng nm cn lin quan n nhiu yu t, nh thi tit, kh hu,
hng gi, hng nng ... Kinh nghim ca nhng ngi trng lu nm cho thy, nhng
m nm b gi thc vo hng, thng d b tht thu; ngc li, nhng m c nh nng tri
u trn khp chiu di s thu hi c kt qu hn. V vy, vic sp xp m nm thch hp
vi hng nng v hng gi l cn thit, va si m cho t, va trnh gi lm gim m
ca m. Ngoi ra, ty theo ma hoc thi tit, m chn mt bng tng ng cho vic
xp m. Ma ma nn chn nhng g cao, t ngp nc, hoc ln lip trnh ngp ng lm
cht t nm. Ma lnh tt nht nn chn nhng v tr thp, rnh cn, xp m. Mt vn
cng cn lu l iu kin i li ni trng nm, va tin cho vic vn chuyn nguyn
liu (rm r), va thun li cho chm sc. Gia cc m nn cha nhng li i t
30-40cm, khi dm p phi cc nm mc chn. Tt nht nn xp chiu di m thng gc
vi li i chnh. Trong trng hp do hng nng hoc hng gi, cn phi b tr m
song song vi li i chnh, th nn to mt li vo ct gia cc m. Qu trnh ch
bin nguyn liu, cng nh ti, chm sc nm, rt cn nc. Do , ni trng hoc xp
m khng nn xa ngun nc sch ( ti hoc trn nguyn liu). Ngoi cc yu t trn,
cn tm hiu khu vc nh trng nm, trong phi k n v sinh v cc ngun c th gy
nhim, nh rc, ao t, cng rnh, chung tri chn nui... Nn trnh xa cc ni
ny, v d xut hin cc mm bnh, cn trng, nm bnh hi nm. IV. CHUN B NGUYN
LIU CHO TRNG NM RM Do nm thng tm thy mc trn rm hoc r, nn quen gi l
nm rm. Tuy nhin, nm rm cng c th trng trn nhiu loi nguyn liu khc, nu
trong c thnh phn cht x (cellulose), nh: bng gn, b ma, lc bnh, b
chui kh, ay, mt s loi c kh.... Trong trng hp, mt ca hoai (mc) cng c
th lm nguyn liu cho trng nm rm. Rm r l nguyn liu ph bin dng trong
trng nm rm. Tuy nhin, nng sut nm trn rm r cha phi l cao so vi cc
loi nguyn liu khc. Ngay bn thn rm r cng ty loi, ty tnh trng, m cho
nng sut tng hoc gim. Qua nui trng, cho thy nng sut nm lin quan n
nguyn liu theo th t gim dn (>) sau: - Theo chng loi: rm r la np
> rm r la ma > rm r la ngn ngy. - Theo thnh phn cy la: t gc
ln ngn. - Theo ngun gc ca la trn t khc nhau: t ph sa > t bn phn
chung > t bn phn ho hc > t nhim phn > t nhim mn. - Theo
cch thu hoch: dng my phng > my sut > p tay. - Theo tnh trng
rm r: rm ma trc > rm mc (do ma nng) > rm mi thu hoch > rm
mc (do nm mc). S hin din ca vi lm mm nhanh nguyn liu, ng thi lm kim
ho mi trng, hn ch s sng ca vi khun, nm mc; ngoi ra, vi cng gip kh c
(nh gc Ca2+). Tuy nhin, trong nguyn liu cn ti, tt nht hn ch vic thm
vi, cho vi sinh vt (x khun, nm mc...) tham gia phn hy rm r c hiu
qu. Nguyn liu c x l theo s sau:
Rm r lm m bng cch nhn nc vi hoc ngm nc vi 48 gi v cht ng . ng
thng c b ngang khong 1,5m v cao 1,5m, cn di th ty . gia nhit ng c
th che ph ln mt lp nha (nylon). Thi gian ko di 5 n 10 ngy. Trong
thi gian , trung bnh ba ngy nn o trn mt ln l tt nht. Phn bn b sung
vo ng vo lc o trn, nu c nhiu ln o trn
V. XP M TrNG NM Vi cch trng ngoi tri hin nay, c hai kiu xp m: m
lung v m khi. 1. M lung Rm sau x l c xp thnh tng lp, thng ba hoc bn
lp. Mi lp va ti nc, va dm p, sau cy meo. Ging cy thnh tng im, cch
ba m t 5- 10cm v cch
nhau khong 20 cm (hnh 4).
Hnh 4 : V tr cy meo ging ln m nm
Hnh 5 : Xp m nm v cy meo ging nm rm Ty c im tng loi nguyn liu, m
c cch xp m khc nhau: - Nguyn liu dng l rm cng di (la ma): thng b li
thnh tng b (ng knh khong 10-15cm). Cc b rm c xon nh na vng v b gp
li (ni ch xon). Sau , xp st vo nhau thnh hai dy i xng, vi u b gp
hng ra hai bn. Vi cch lm ny nn m c th rng t nm dn su tc (50 - 60cm)
(Hnh 6). hai u ca m, cc b rm c xp thnh hnh nan qut, gi cho phn bn
trn khng b xung. Lp trc xp xong l cy meo v xp n lp k tip. Lp sau
phi tht vo 5 10 cm, so vi lp trc, trnh ra hai bn.
Hnh 6 : Cch xp m vi rm cng di - Nguyn liu dng l rm cng ngn: c th
b hoc khng. Trng hp b thnh b, khng cn b gp v xp thnh hai dy (nh rm
cng di), m ch cn xp mt dy v t (ct) cho gn hai u. Vi cch ny m nm c b
ngang trung bnh l bn tc (40cm) (Hnh 7) v khng phi lm hai u m.
Hnh 7 : Cch xp m vi rm cng ngn - Nguyn liu l gc r : xp so le
nhau sao cho phn gc hng ra hai bn, nhng ch lm thnh mt dy (nh trng
hp rm cng ngn). B ngang m nm cng khong 40 cm. - Nguyn liu rm r qua
my sut (b ri, ti): lm theo kiu rm cng ngn (khng b) hoc nhi khun (m
khi).
Hnh 8 : Xp m nm rm ng bng sng Cu Long 2. M khi S dng khun. Khun
c dng hnh thang y ct, hai mt h. Chiu ngang t 40 - 50
cm, chiu di t 60 - 120 cm, cao 40 cm (hnh 9). Khun thng lm bng
g, i khi bng tn v g.
Hnh 9 : Khun dng trong trng nm Nguyn liu c nhi vo khun thnh tng
lp dy mt tc (10 cm), sau , cy ging. Meo ging cng cy thnh cm, nh
phng php xp m th cng. Chiu cao m ty theo ma, nh ma lnh, cht m cao
(nhiu lp hn); ngc li ma nng, cht m thp (t lp hn). Tuy nhin, cc tnh
pha Nam, kh hu tng i n ha (khng nng cng khng lnh lm), nn ch cn xp
ba lp rm hoc r l c. Sau khi cht xong, thng phi phi m mt n hai nng,
trnh b mt m b qu t, d pht sinh mc hoc nm di. Phng php trng nc ta cn
thm giai on t m, bng cch ri rm vn sut chiu di m v t, vast trng b mt
ca m, va cung cp khong cho nm. Ngoi ra, ngi ta cn cho rng, khi xp
m, do phi dm p v ti nc, t nm b lnh, cn t m, si m meo nm bn trong.
VI. CHM SC V TI N NM
Sau t m, do phi ti nc dp la, nn phi m khong hai n ba nng cho kh
b mt (trnh mc hoc nhim tp) v tip theo l lm o m. Ao m l phn bao ph
bn ngoi, nhm che chn bt nh sng v gi m cng nh m cho m nm. Ph bin hin
nay thng dng rm r, bn li thnh tm hoc khng, ph ln m nm. Rm ph tt nht
nn lm hai lp: lp mng ch yu l rm vn, lt (m) trong; lp dy, rm tt hn,
che ch ngoi. Vo ma lnh hay ma ma, ngi ta cn dng nylon y thm ln lp
lt (Hnh 10). Nh o m, t nm c iu kin tng trng tt hn, to nhiu sinh khi
(lng t nm), chun
b cho vic hnh thnh qu th hay tai nm. V vy, giai on ny cn gi l
giai on nui t.
Trong giai on nui t, vn gi m cho m nm rt quan trng. Do , cn thng
xuyn theo di nhit . Nhit o bng nhit k, t su vo bn hng m, khong 2/3,
hoc c th dng tay p st thnh m kim tra. Nhit trong m lun phi gi trn
35oC, nu xung thp, c th m b thiu m (nc) hoc thi tit lnh. - M nm
thiu m l do rm cha ngm nc hon ton khi xp m hoc chn m (cc b rm) khng
cht. C th sa bng cch chn li cho cht hn - Thi tit lnh, nht l v m, cn
che y m nm k hn (o m dy hn hoc thm lp nylon nh ni trn). Trong thi
gian t, hn ch ti nc, v nm di d pht trin, nh hng n nm trng. Nhng vo
nhng thng nng gt, m nm b mt nhiu nc hoc nhit trong m tng cao, nn ti
nc nn xung quanh m, h nhit v b sung m cho m. Thng thng n ngy th by,
sau khi xp m, t nm rm bt u xut hin v an thnh mng nhn bn hng m hoc
ngi thy mi meo nm rm. y l thi im ti n nm. Lc ny, lng nc ti nhiu hn
v u khp mt m nm. Nc s lm gim nhit , kch thch t nm kt qu th. giai on
ny, cn ly bt o m cho thong kh v mi sng khong 8 - 9 gi, nn phi m trn
di nng 20 - 30 pht. Nh nh sng cc n nm s pht trin tt hn. Sau ti nc v
y o m li. Nm rm ln rt nhanh. Thi gian thu hoch mt t nm ch ko di t 3
- 4 ngy, nhiu nht vo ngy th 2 v 3, cn ngy u v cui thng khng ng k.
Nm thu dng cu (nt ln), gi c lu hn, nhng nng sut gim. Ngc li, dng ko
di, th nng sut tng, nhng tai nm mau n (bung d), thi gian bo qun
ngn. Tt nht l thu hi nm dng trng. Sau khi thu hoch t 1, nu mun tip
tc thu hi t 2 hoc t 3, phi tip tc t tr li (thng l 5 - 6 ngy) v sau
ti n nm (nh t 1). Mt m nm c th thu nhiu t, nhng nhng t sau nm gim,
nn kinh doanh, ngi trng ch thu hai hoc ba t l thu dn, x l t v nui
trng mi. Tm li, chm sc nm cn lu mt s im sau: - giai on nui t (m
si): khng nn ti nhiu nc v gi m m. - giai on ti n nm : tng m (nhng
khng lm m ng nc, t nm d cht
v ngp);thng kh cho nm h hp; chiu sng tai nm pht trin bnh thng.
VII. NUI TRNG NM RM TRONG NH Nm rm cng vn c th trng trong nh nh cc
loi nm trng khc. Nng sut c th cn cao gp hai hoc gp ba ln so vi trng
ngoi tri (v khng ch c iu kin nhit v m , cng nh su bnh). Tuy nhin,
do vic u t tng i tn km v nht l cha c mt m hnh sn xut thuyt phc, nn
t hp dn ngi trng. Mun nui trng thnh cng nm rm trong nh cn ba yu t
sau: a/ Nguyn liu: bao gm loi nguyn liu, cch ch bin v phng php nui
trng (khi, khay, v...) b/ K thut : chm sc, phng bnh c/ Nh trng : cu
trc, trang b 1. S dng rm r Rm r sau khi lm m v ng nh trn, vt ro,
cho vo khun g kch thc (20 x 30 x 15) cm nn cht. Khi rm nn xong c ly
ra, gi bng cc tm nha (nylon) v dng dy buc cht. Cc gi rm c th hp kh
trng bng hi nc 95oC trong 4 gi hoc khng. Meo nm rm c b vn v cy vo
hai u ca gi.
Hnh 11 : Khun v gi rm trng nm rm Cc gi rm c xp chng ln nhau gi m
cho t nm n lan Sau 7 n 10 ngy, t nm mc ph hu nh ton b khi rm l thi
im chun b chuyn sang nh trng. Trong nh trng, cc khi rm c lt bao
ngoi v xp chng ln nhau thnh nhiu lp. Sau ti n nm bng cch phun sng
vo cc khi rm v gi m nh trng trong khong 80 -90%. Thng sau khi ti t
3-4 ngy nm bt u kt n. im yu ca phng php ny l nguyn liu v phng php
thanh trng. - Nguyn liu: mc d, rm r l nguyn liu mang tnh truyn thng
trong trng nm rm, nhng cng l c cht cho nng sut km, nu khng mun ni l
km nht, ng thi th, cng knh v kh x l nht. Do , vi rm r, ngi trng kh
trng nm rm lu di trong cng nh trng, m khng b tp nhim. - Thanh trng:
phng php thanh trng bng hi nc nng trong nh trng nm, hon ton khng ph
hp vi iu kin thc t nc ta. Vi nhng nh trng th s, mi
trng khng m bo v trng tuyt i, khi nng nhit bng hi nc nng (m v
nng), s d thu ht ngun nhim nm di, vi trng. Nguyn liu (c cht trng
nm), sau khi kh trng, s nhanh chng b nhim mc. 2. S dng mt ca thi T
nhng l do trn, mc d nhiu ni c gng thc hin vic trng nm rm trong nh,
nhng u khng em li hiu qu, hoc do b tp nhim hoc do u t qu tn km. Vi
nhng nghin cu gn y cho thy, c th s dng ngun mt ca thi (trong trng
nm mo, bo ng...) hoc nhng mt ca g mm hoai, lm nguyn liu cho trng nm
rm trong nh. u im ca phng php ny l: - Nguyn liu c lm mm ho bi vi
sinh vt hoc nm khc thnh c cht thch hp cho nm rm. - D b sung cc cht
dinh dng thch hp cho nm rm - D thanh trng, ch cn lm kh b mt (phi,
sy, t) - Nng sut nm tng i cao, trung bnh 22% (trng lng ti so nguyn
liu kh). im yu ca phng php ny l: - Nguyn liu l ph liu ( qua nui
trng loi nm khc), nn d ly nhim v cha cc tp cht khng li cho nm rm. -
Qui trnh nui trng c ko di thi gian hn, do phi lm mm mt ca bng cch
nui trng thm mt loi nm khc hoc phi hoai nguyn liu cho ph hp vi nhu
cu nm rm. Tuy nhin, pht trin cng nghip trng nm rm, th y l ngun
nguyn liu tng i kh thi nht.
Qui trnh trng nm rm trn mt ca c th tm tt :
Vn quan trng phng php ny thnh cng l m bo dinh dng v v trng nguyn
liu. V dinh dng, ngoi vic kh c v lm cht t nm c bng nc vi, cn phi b
sung thm dinh dng cn thit cho nm rm. Dinh dng dng cho nm, gm ngun m
v khong. Ngun m c th l phn chung ( hoai), tuy nhin thun tin thng
dng phn ho hc, nh ur, DAP, N-P-K, SA... V v trng, phng php n gin,
nhng rt hiu qu, l phi kh b mt m nm. Vi cch ny, nm mc cng nh nm di
hu nh khng cn iu kin pht trin. 3. S dng bng thi Mt loi nguyn liu
khc c th dng trng nm rm trong nh rt tt, l bng thi. Bng thi l ph liu
ca cng nghip dt, nn cng l ngun nguyn liu tng i di do nc ta. u im ca
loi nguyn liu ny l: cho nng sut nm cao (40- 45% trng lng ti so
nguyn liu kh). Khuyt im ca loi nguyn liu ny l: nng cng khi x l, nh
lm m, x ti ( to thng thong)... Qui trnh c th tm tt nh sau:
VIII. BNH TRONG TRNG NM RM Cng nh vt nui v cy trng, nm rm c th b
nhiu bnh. Bnh nm rm c th chia lm hai loi: bnh sinh l v bnh nhim. 1.
Bnh sinh l Nm rm l loi nm rt nhy cm vi mi trng, bao gm nhit , nh
sng, nc ti, dng kh (oxy) v thn kh (carbonic)... - Nhit : nh hng rt
ln n s tng trng (ra t) v pht trin (ra qu th) ca nm rm (bng 3). Do ,
ging nm rm (t nm) bo qun trong t lnh (12 - 15oC) trong 48 gi, em cy
chuyn khng kh nng mc li nh cc ging nm khc.Trong lc nm kt n hoc qu
th ang hnh thnh, nhit thay i t ngt (ln hoc xung), nm s cht hng lot.
- Anh sng : i vi nm rm, nh sng rt cn giai on t hnh cu sang hnh
trng. giai on ny, nu thiu nh sng qu th s c mu trng hay mu xm.
Vitamin E s gim hon ton, Vitamin D khng c, sc t melanin (sc t en)
khng hnh thnh. Tuy nhin, khi cng nh sng gi lin tc t 2500 lux tr ln
trong 4 gi, nm cht 100%. - Nc ti : chi phi ton b hot ng sng ca nm.
Ngoi vn d nc hoc thiu nc, th tnh cht ca tng loi nc rt quan trng (nc
phn, nc mn, nc nhim bn v vi sinh hoc ho hc...). T nm b nc phn s mc
chm, tha v u si t s cong li, tai nm ti bng nc phn s d hnh, to dng
bng ci hoc cht non. Nc nhim mn cn lm cho s tng trng v pht trin ca
nm rm cng kh khn hn. T nm i mu, ri bng, qu th khng hnh thnh c. Bng
3 : nh hng ca nhit ln nm rm
THNH PHN
NHIT
KIU BIU HIN
40 oC T NM (ln hn hay bng 40 )
t nm mc chm v tha dn ri cht
15oC (nh hn hay bng 15 )
t ngng tng trng v khng mc li c
25 oC QU TH (nh hn hay bng 25 )
qu th hay tai nm khng to thnh c
25 - 28 oC
tai nm b d hnh
35 oC (ln hn hay bng 35 )
nm mau trng thnh (sm bung d)
2. Bnh nhim mc v nm di.
Trong qu trnh nui , m nm thng b nhim tp bi nm
Nm mc c mc xanh (Verticillium fungicola), mc cam (Neurospora
spp.), mc thch cao (Scopulariopsis fimicola), nm trng c (Sclerotium
rolfsii)... Mc nhim nh: phi kh mt m (mt nng), dng nc vi 0,5- 1% ti
ln vt bnh. Trng hp bnh thch cao, c th x l bng vi bt CaO, thuc tm
(KMnO4) hoc acid acetic 40%. Mc nng: s dng cc thuc dit mc, nh
Bennomyl (Benlate-C) 0,1%, Zineb (Tritofboral) 7% hoc Validacin 3%
(cho bnh trng c)... Trc khi nm rm xut hin, thng thy nm di pht trin
mnh, ph bin l nm gi (Coprinus sp.). iu kin nm di mc l: mi trng
(nguyn liu) hi d m (> 70%), giu m (ur) v hi acid ( 5 ). Do , cn
trnh to iu kin tt cho nm di, bng cch hn ch cc nguyn nhn trn. Ngoi
ra, nm cn b mt s loi cn trng, nh: rui, mt g, b nhy, cun chiu, kin,
gin, tuyn trng... tn cng. Bin php tt nht phng nga l x l nn t trc
khi
trng, nh ti nc, xi nh, rc vi bt, xt thuc dit rui mui.... Phi rm
(dng lm o m) 2 3 nng. Khi ti n nm, rc vi hoc tro xung quanh m (nu
trng di t). Bnh xy ra thng gim nng sut v gy tht thu cho ngi trng.
Do , cng hn ch bnh c tt, th ngi trng cng thu li cao. Mun vy cn c
bin php phng tr tng hp, nh: Bng 4 : Cc bin php phng nga trong nui
trng nm rm
Bin php
Cch lm
X l k nn t
- Phi nng, ti nc, xi, rc thuc... - nh k phi thay i nn t, ct ngun
bnh
X l nguyn liu
- Trnh s dng nguyn liu mc, hm... - m bo m, pH thch hp.
X l o m
- Chn rm kh, sch - Phi hai n ba nng, trc khi s dng y m nm
Gi m m
- Lun gi m nhit 32 - 35oC - Tri lnh ph thm o m, tri nng ly
bt.
Phng bnh
- Theo di thng xuyn pht hin bnh - Dit ngay ngun bnh trnh ly lan
- Dn v sinh v xt thuc sau mi t trng
IX. VN BO QUN V TIU TH NM RM RA SAO ? Dng thng phm ca nm rm ch
yu l dng bp (cu hoc trng) v nm thng bn ra ch di dng ti, nn ngi trng
phi hi sm (3 - 6 gi sng, mt s ni cn hi vo bui chiu).Nu nhng ni c c
s ch bin nm hoc gn ch, th vn n gin hn, nhng i vi nhng ni xa ngun
tiu th, th tht s gy kh khn cho ngi trng. Nm rm ti c th gi thi gian
di (4 ngy), nu nhit 10 - 15oC. Nm c cho vo dng c cha, nh thng g hoc
st tre (c lt li nha), bo qun bng kh ( sn xut ti Vit nam).
Ngoi ra, ngi ta cn c th gi nm dng mui (nm mui). Nm c chn (lut)
10 - 15 pht trong nc si (thm 1% mui + acid citric c pH = 3). Vt ra
lm ngui nhanh, trnh nm b chn tip. Sau , xp vo dng c cha v p vi mui
ht. Sau 12 gi, vt ra, ra sch mui bm ngoi, cho tip vo dng c cha khc
v ngp vi nc mui 20 - 23 . giai on ny, nu nc ngm b c, phi thay nc
mui khc, trnh nhim trng v mc. Thi gian bo qun nh vy c vi thng.
Trong trng hp bt kh khng hoc c yu cu, ngi ta cn ch bin nm dng kh
(nm kh). Nm rm bp thng kh phi hoc sy hn cc loi nm khc, nhanh kh,
phi ch i tai nm. Nm sy bao gi cng gi c mi v v mu sc tt hn phi nng.
Nhit sy nn bt u 60oC trong 2 gi, sau gi 50oC v ko di trong 8 gi. Nm
kh cui cng ch cn khong 10% nm ti (10 kg nm ti cho 1 kg nm kh). Nm
kh tt, nu trong bao kn c th gi c nm. L Duy Thng i hc Khoa Hc T nhin
TP. HCM
Thi v trng Nm Nm rm c th trng c quanh nm. Ma ng Xun, gip Tt
Nguyn n, c gi lnh th phi chn gi, gi m v lm m nm ln hn. Ma ma cn lm
mi che hoc t rm dy hn gim m, lm nn m cao trnh ngp ng. nhng ni c
nhiu gi, gi mnh cn lm ro chn gi, b tr cc m nm thng gc vi hng gi.
Chun b rm Cch rm thnh ng Cch ny p dng c cho c rm ti v kh. Cc bc tin
hnh: Rm c cht thnh ng, chiu rng 1,5-2m, chiu di 4-8m. Khi cht ng, c
mi lp rm cao 20-30cm ti nc cho rm thm u v dng chn dm cho d, tip tc
cht cc lp tip theo cho n khi ng rm c chiu cao 1,3-1,5m. Sau ly
nylon, rm kh hoc l chui t chung quanh gi m v gi nhit. Vi ngy sau
khi , nhit trong ng ln cao khong 60- 70oC. Nhit s lm cht cc mm nm
di v phn hy mt phn cht hu c trong rm r, gip cho nm rm d hp thu cht
dinh dng, pht trin thun li sau ny. Sau khi rm t 1012 ngy, khi ng rm
xp xung, chiu cao khong 0,8-1,0m. Lc ny c th em rm cht ra lung. Cch
x l nc vi trc khi Cch ny c p dng cho rm, r kh. Rm, r c nhng vo nc
vi, pha vi t l 3 kg vi cho 100 lt nc. Ngm rm va ngp. Mc ch dit nm
tp, ty ra cht phn, cht mn trong rm r. Thi gian ngm trong nc vi t
20-30 pht, sau vt ra, ro nc, cht thnh ng vi chiu rng 1,5-2m, chiu
di
4-8m. Cn dm nh cho d, ly nylon, rm hoc l chui t quanh gi m v gi
nhit. Thi gian 5-6 ngy: Trong thi gian u, sau khi cht ng 2-3 ngy,
tr rm mt ln. Nu rm qu t, cn gim bt dng c y bn ngoi. Nu rm b kh, cn
b sung thm nc vi vi t l 3 kg vi cho 100 lt nc, ti va . n ngy th 5-6
kim tra li ng rm. Rm t, khi vt vi cng thy c nc nh vi git l tt
nht.Rm iu kin cht nm phi t yu cu: - Rm r mm hn. - C mu vng ti. - C
mi thm c trng ca rm r khi ln men. Chn meo ging L khu quan trng c nh
hng rt ln n nng sut trng nm. Chn meo ging tt, ng tui, khng nhim tp
khun s cho nng sut cao v cht lng nm tt. Tiu chun bch meo tt Si t nm
mu trng trong, m np bch c mi tng t nh nm rm. T nm pht trin u khp mt
trong bch meo. (Ring mt s meo ging, khi t trng thnh, bt u kt t li
thnh nhng ht mu nu vn cho nng sut tt). Mt bch meo ging nng trung
bnh 120g, c th gieo trn m nm rng 0,5m, cao 0,40,5m, chiu di lip
4-5m. Ch khi chn meo ging Khng chn s dng bch meo c m mu nu, en, vng
cam v b nhim nm di. Khng chn bch meo pha di y bch b t, b nho v c mi
hi chua. Xp m & rc meo gingLy rm trong ng D b lp rm ngoi mt ng
. Ly rm bn trong mang i xp m trng nm, c gng xp ht trong ngy phn rm
d lp y khi . Cht m nm Cch 1: Ri mt lp rm ln mt lip, tip ti nc. Dng
tay d dt sao cho c chiu rng theo mt lip khong 50cm, chiu cao 20cm.
Ri meo ging dc hai bn lung, cch mp lung 5-7cm. Tip tc lp li thao tc
trn cho lp rm th 2, th 3... Nu ba lp th pha trn khng ri men ging,
ch ri rm kh dy 4-5 cm. Ti nc d dt, vut mt ngoi cho m lng, gn. Vut m
khng gn, mt ngoi m khng lng khi thu hoch nm s lm h cc n nm nh, lm
gim nng sut. Cch 2: Rm sau khi chn c cun thnh tng b, ng knh
15-20cm, chiu di t 45-50cm, xp d dt tng lp. Sau mi lp rm, ri meo dc
hai bn lung, cch mp lung 5-7cm, tip tc xp nh trn cho lp rm th 2, th
3... Nu ch ba lp th pha trn ch ri rm kh dy 4-5cm, ti nc d dt, vut
mt ngoi cho m lng, gn. Lu : Ty theo ma, thay i dy khi y m cho thch
hp. Ma nng: T rm mng thot nhit. Ma ma, ma lnh: T rm dy gi nhit v
chng thm nc. Chm sc v thu hoch: Chm sc m nm i vi nm rm, khng cn dng
phn bn g thm. V rm r khi phn hy cung cp dinh dng cho cy nm pht
trin.
Theo di nhit v m l khu quan trng nht trong qu trnh sn xut. m l
yu t hng u, v m gip qu trnh phn hy rm r thun li t s to nhit trong m
nm. Nu m d, tha nc: Nhit s gim, m nm b lnh. Nu m thiu, m b kh nhit
tng. Gi m thch hp: Khi kim tra m nm, rt mt nm (khong 15-20 cng) rm
gia lung, bp cht trong lng bn tay, nc hi rn qua k tay l va. Nu nc
khng rn qua k tay l kh, phi ti nc. Nu thy nc chy qua k tay thnh git
l d nc, phi ngng ti nc v ngy phi d o m cho nc bc hi. Trong ma ma
phi lm mi che sau khi d o m. iu chnh nhit bng cch ti nc v y m: Khi
kim tra m nm, thy nhit tng, rm thiu nc cn dng thng vi sen ti cho m
nm. Trnh dng vi nc mnh s lm h nhng si t v nm nh. Nu ch tng nhit m
khng thiu nc, phi gim rm o b t thay bng rm kh gim sc nng v thot bt
nhit. Khi kim tra m nm thy nhit gim, m b lnh: Ngng ti nc, d bt o m,
mi che nng... gip m hp thu c nhiu nng. Nu l ma ma, cn dng nylon,
mng ph nng nghip (y pha en ln trn) m nm gi nhit, tng nhit bn trong.
o rm o m: Sau khi cht m 5-8 ngy, d rm o ra, xc cho ti v y tr li cho
m nm. Cn phi o o m trnh t nm n lan ra ngoi, khng to c nm. Thu hi nm
rm Sau khi rm 10-14 ngy c th thu hoch: thi gian thu hi nm, ty loi
meo v cch . Nm ra r vo ngy th 12-15; sau 7-8 ngy ra tip t 2 v thu
hi trong 3-4 ngy th kt thc v trng nm ( 25-30 ngy). Thi im hi nm:
Thu hi mi ngy 2 ln. Ln th 1 vo sng sm trc 6 gi. Thu hi ln th 2 vo
khong 14-15 gi chiu. Chn nm tiu chun hi: Nm rm pht trin lin tc v
nhiu cy dnh vo nhau. Cn phi chn la hi nhng cy cn bp, hi nhn u. Cch
hi, xoay nh cy nm, tch ra khi m. Khng nn st chn nm trn m, v phn chn
nm khi thi ra, s lm h cc n nm k bn. Sau khi hi xong, y k o m li.
Thi gian thu hoch nm thng 7-10 ngy. Nng sut trung bnh 1,5kg nm ti
trn 1m lip nm. Nm sau khi thu hi cn tiu th ngay trong 2-3 gi. Nu
mun ngy hm sau cn bo qun nhit t 10-150C.
K thut trng v ch bin nm rm (Volvariella volvacea)[ Cp nht vo ngy
(19/04/2011) ] - [ S ln xem: 1812 ]
1. c tnh sinh hc: Nm rm c tn khoa hc Volvariella volvacea gm
nhiu loi khc nhau, c loi mu xm trng, xm, xm en, kch thc ng knh cy
nm ln, nh ty thuc tng loi. cc quc gia vng nhit i rt thch hp v nhit
nm rm sinh trng v pht trin. Nhit thch hp nm pht trin t 30-32oC; m
nguyn liu (c cht) 65-70%; m khng kh 80%; pH = 7, thong kh. Nm rm s
dng dinh dng cellulose trc tip t nguyn liu trng. c im hnh thi: Bao
gc (volva): Di v cao lc nh, bao ly tai nm. Khi tai nm trng thnh, n
ch cn li phn trm ly phn gc chn cung nm, bao nm l h si t nm cha sc t
melanin to ra mu en bao gc. m nht ty thuc vo nh sng. nh sng cng
nhiu th bao gc cng en. Cung nm: L b h si xp, xp theo kiu vng trn ng
tm. Khi cn non th mm v gin. Nhng khi gi x cng v kh b gy. M nm: Hnh
nn, cng c melanin, nhng nht dn t trung tm ra ra mp. Chu k sng: Qu
trnh to thnh qu th nm rm gm 6 giai on: - Giai on u inh ghim
(Pichead: n nm). - Giai on hnh nt nh (tiny button). - Giai on hnh
nt (button). - Giai on hnh trng (egg). - Giai on hnh chung
(clogation: ko di). - Giai on trng thnh (nature: n xe). Chu k sinh
trng v pht trin ca nm rm rt nhanh chng. T lc trng n khi thu hoch ch
sau 10-12 ngy. Nhng ngy u chng nh nh ht tm c mu trng (giai on inh
ghim), 2-3 ngy sau ln rt nhanh bng ht ng, qu to, qu trng (giai on
hnh trng), lc trng thnh (giai on pht tn bo t) trng ging nh mt chic
d, c cu to thnh cc phn hon chnh. Nguyn liu v thi v nui trng: Hu ht
cc ph thi ca ngnh nng nghip giu cht cellulose u c th l nguyn liu
trng nm. nc ta, cc tnh min Nam (t Nng tr vo) trng nm rm hu nh quanh
nm. Cc tnh pha Bc bt u trng t 15-4 n 15-10 dng lch l thun li.
2. X l nguyn liu: Rm r c lm t trong nc vi (3,5kg vi ha vi 1.000
lt nc), vun ng, 2-3 ngy o mt ln, tip 2-3 ngy l c. Thi gian ko di
4-6 ngy. Nguyn liu qu t (khi vt vi cng rm c nc chy thnh dng) cn tri
rng ra phi mi em trng. Rm r t (khi vt vi cng rm c nc chy thnh git)
l tt nht. Nu kh qu cn b sung thm nc khi o ng . 3. ng m cy ging: t
khun (c th vun thnh lung khng dng khun) theo din tch hin c sao cho
thun li khi i li, chm sc nm v tit kim din tch. Chiu ngang mt m t
0,3-0,4 mt, chiu cao t 0,35 0,4. Tri mt lp rm r vo khun dy 10-12cm.
Cy mt lp ging vin xung quanh cch mp khun 4-5cm. Tip tc lm nh vy 3
lp. Lp trn cng tri rng u khp trn b mt (lp th 4). Lng ging cy cho
1,2m m khong 200-250g. Mi lp ging cy xong dng tay n cht, nht l xung
quanh lm thnh m. Trung bnh mt tn rm r kh trng c trn di 90-100 mt m
nm. 4. Chm sc m nm cy ging: Ty thuc a im trng trong nh hay ngoi tri
(sn bi, di tn cy, ng rung,) m cch thc chm sc s khc nhau. a. Trng
trong nh: Sau 3-5 ngy u khng cn ti nc, nhng ngy tip theo quan st b
mt m nm thy rm r kh cn phun nh nc trc tip xung quanh. Ch phi ti nc
kho, nu ti mnh (ht nc ln) d lm si nm tn thng, nh hng ti nng sut v
lc ny si nm pht trin ra tn pha ngoi thnh m. n ngy th 7-8 bt u xut
hin nm con (giai on ra qu), 3-4 ngy sau nm ln nhanh to bng qu to,
qu trng, vi gi sau nm c th s n d. Nm ra mt dy, kch thc ln cn ti 2-3
lt nc cho mt ngy. Lng nc ti mt ln rt t (0,1 lt cho 1,2 mt m/ngy).
Nu ti qu nhiu nm d b thi chn v cht ngay t lc cn nh. b. Trng ngoi
tri: ng m nm ngoi tri thng b cc t ma ln, nng nng lm h hng, v th cn
che ph thm mt lp rm r kh trn b mt m nm. Lp rm r ny cn tt, xp theo
mt chiu, ph theo kiu lp mi nh. Chiu dy 4-5 cm. Tt c cc b mt ca nhng
m mp ngoi khu vc trng cng cn che ph bng lp rm ph o, kim tra nu thy
m nm b kh c th ti trc tip ln lp o ph nhiu ln trong ngy, sao cho lp
rm pha ngoi ca m nm khng b mt nc. trnh ma v tin cho vic chm sc m
nm, c th cm cc cc tre, hoc an thnh chic lng cch mt m nm 10-15cm,
pha ngoi bc mt lp nylon, pha trn cng ph rm r kh cng tt. Nhit m nm
trong nhng ngy u khong 38-40oC l tt nht. Vic ti nc tng t nh vi nm
trng trong nh.
Khi thu hi ht nm t 1 cn nht sch tt c cc gc nm v cy nm nh cn st
li, dng nilon ph li cho n khi nm ra th g b. Ngng 3-4 ngy sau ti tr
li nh ban u, tip thu t 2. Sn lng nm thu hi tp trung n 70-80% trong
t u, t 2 cn li 1525%. 5. Cch thu hi nm: K t lc trng n khi hi ht t 1
khong 15-17 ngy. Nm ra r vo ngy th 12 n 15. Sau 7-8 ngy ra tip t 2
v hi trong 3-4 ngy th kt thc mt t nui trng (tng thi gian 25-30
ngy). Dn v sinh sch s, ti nc vi 3-4 ngy li trng t tip. Hi nm cn
giai on hnh trng (trc khi nm n d) l tt nht, m bo cht lng v nng sut
cao. Trng hp nm mc tp trung thnh cm, ta c th tch nhng cy ln hi trc,
nu kh tch th hi c cm (c to, nh u hi ht). Mt ngy, hi nm 2-3 ln. Nhng
ngy nng nng, nhit khng kh cao, nm pht trin rt nhanh, v vy ngi hi nm
phi quan st k, khi nm hi nhn u l hi c ri. Nng sut nm dao ng t
12-20% so vi nguyn liu kh (mt tn rm r cho thu hoch khong 120-200kg
nm ti). Nng sut nm cao hay thp ty thuc vo cht lng ging nm, k thut
nui trng v yu t kh hu. 6. Su bnh v cch phng chng: Trong qu trnh
trng nm rm thng c mt s su bnh hi nm: - Nm di (nm mc) do m nguyn liu
qu cao. Loi ny khng gy hi nhng cnh tranh dinh dng ca nm rm, cn iu
chnh m nguyn liu lc em trng, hn ch ti khi chm sc. - Cc loi nm mc
(mc xanh, vng, en,). Loi ny nguy him, nguyn nhn c th do nguyn liu b
nhim bnh t trc. Nh xng v sinh khng sch s, khu vc nui trng m thp,
trng nm nhiu ln, Cn loi b nhng m b bnh ra xa khu vc nui trng thm ch
em chn su hoc t ngn chn ngun bnh ly lan. Vic dng cc ha cht phun trc
tip ln m nm t c hiu qu, tt nht l phng nga trc. - Cn trng ph hoi
(chut, gin, kin, mi,) chng gm nhm si v cy nm, o hang, lm xo trn m
nm, n ging nm va cy xong, Dng thuc by chut, gin, kin, ti khu vc nui
trng nm. 7. Cch ch bin nm rm: Khi hi nm xong, nm rm vn tip tc pht
trin, nu thm vi ting sau, t giai on hnh trng c th b n , v vy cn tiu
th nhanh trong 3-4 gi ng h. Dng c ng nm cn thong, khng qu nhiu nm
(chiu cao dng c ti a 25cm). Mun nm qua ngy th bo qun nhit 10-150C.
T lc hi n tay ngi s dng trong khong thi gian 2-3 gi l tt nht. Nm rm
l loi thc phm rt ngon, c hm lng m cao, giu cc axit amin, cht khong
v cc vitamin. Ch bin nm thnh nhiu mn n khc nhau: nm xo, canh nm,
cho nm, sp nm, a. Ch bin nm mui xut khu
Th trng tiu th nm mui hin nay cng rt a dng. Nm mui nguyn qu, sau
phn loi theo kch c ng knh nm to, nm nh khc nhau. Hoc nm phi bc v
bao ri phn loi, Trc khi ch bin nm mui, ngi sn xut cn bit r yu cu ca
khch hng t mua loi no. Cch mui nh sau: - un nc si, th nm ti vo chn,
dng v tre nn cho nm chm trong nc, un to la cho si li cng nhanh cng
tt. si 5-7 pht, vt nm ra th vo chu nc lnh, thay nc nhiu ln ti khi
mt tay l c (c th vi nc chy lin tc) m bo nm rn chc, nm ra r ro nc. -
Cho nm chn vo ti nilon khng thng, chum vi hoc can nha, c mt lp nm,
mt lp mui theo t l 1kg nm + 0,3kg mui kh nh ht + 0,2 lt dung dch
mui bo ha. - Khi nm y cc dng c cn ph thm mt lp mui kh trn b mt n
chm nm trong nc mui trnh nm mc pht trin. Nu lu 1-2 thng tr ln cn
cho thm 3-4kg axit citric cho 1 tn nm. Thi gian mui c 15 ngy, nm s
n nh v cht lng, lc tin hnh phn loi hoc bc v nm. Nm mui m bo cht lng
tt l: khng b vng mc, mi thm d chu, nng mui t 230 B, pH = 4. Cy nm
rn chc, khng gip nt. Khng ln cc tp cht khc, mu dung dch mui trong
sut. T l nm mui so vi nm ti t khong 60-70%. b. Nm sy kh: Thi nm
thnh lt mng (kiu lt sn) hoc nguyn qu nm nt bao em phi nng (nu tri
nng to) hoc sy nhit : 40-450C n khi nm kh gin. m bo m cn li 13% cho
vo ti nilon buc kn, nm kh c mu hi vng trng rt p. Nm kh xut khu v
tiu th ni a. Trung bnh 10kg nm ti em phi, sy kh cho ra 1,1kg nm kh.
Hin nay, Trung tm Nghin cu ng dng v Dch v Khoa hc Cng ngh Tin Giang
phn lp c mt s chng nm rm c phm cht tt, nng sut cao v n nh (nng sut
bnh qun t 18-20% so vi nguyn liu a vo nui trng). Cc ging nm rm ny
hin c Trung tm cung cp ri cho b con trng nm trong tnh v cc tnh ln
cn. Cc vn lin quan v ging v k thut nui trng nm rm c th lin h vi
Trung tm ti a ch s 555 ng p Bc phng 5 TP. M Tho tnh Tin Giang, in
thoi (073) 857576. TI LIU THAM KHO 1) Nguyn Ln Dng (2004), Cng ngh
nui trng nm, Nh xut bn Nng nghip. 2) Nguyn Hu ng, inh Xun Linh,
Nguyn Th Sn, Zani Federico (2003), Nm n c s khoa hc v cng ngh nui
trng, Nh xut bn Nng nghip.
Nm rm l loi nm kh quen thuc vi nhn dn ta. Nm thng mc trn nguyn
liu ph bin l rm nn c tn chung l nm rm (Straw mushrooom), tn khoa hc
l Volvariella volvacea. Nm rm l loi d trng, mau thu hoch, cho kinh
t cao. C mi tn rm ra trng nm ni chung tr chi ph trong thi gian 15
20 ngy c th li t 500.000 700.000 ng. B sau khi trng nm ch bin thnh
phn sinh hc cao cp. Ngoi ra, b nm cn dng nui trn t, ly trn nui gia
cm, gia sc v tm, c.
1. THI V TRNG: Nm rm c th trng c quanh nm, tuy nhin ty theo iu
kin thi tit m chng ta p dng cc bin php khc nhau khc phc tnh trng bt
li. Nu thng gip Tt, c gi lnh th phi che k, gi m v lm m to hn. Nu vo
ma ma phi lm mi che cho m nm hoc rm dy hn, lm nn m cao hn trnh ngp
ng. nhng ni c gi mnh, phi lm ro chn gi, ng thi b tr m nm thng gc vi
hng gi. 2. CHUN B A IM: C th cht rm nhiu ni nh: t rung, trong vn
cy, chung quanh nh,c th trn nn t, gch, xi mng trn k. Ngay c trong
nh, trong bc nylon. Chn a im sao cho bng phng, cao ro khng b ngp
ng, sch s v nht l gn ng vn chuyn rm r, gn nc ti tin vic chm sc, thu
hoch v chuyn ch. Chun b t trc khi trng: nu t trng v nht l vo ma ma,
ta nn x rnh c nhng lip rng 60 80cm, cao khong 10cm, dc v hai m, nm
cht mt lip, mc ch sao cho thot nc khi ti, khng b ngp ng khi ti. 3.
VT LIU DNG CHT NM: Ngi ta c th dng nhiu vt liu khc nhau trng nm rm
nh: rm r, b ma, thn v l chui, lc bnh, bng gn. Nhng thng ta hay dng
rm r. Cht nm bng rm, la ma hoc thn nng, la t hoc la np u dng c c. C
th dng rm mi sut cn ti hoc rm r kh, min ng mc nt ( bin thnh mu nu
en) s cho nng sut khng cao. * Phng php rm: Phng php c p dng vi tt c
cc loi rm r c th dng rm ti hoc rm kh. Rm c cht thnh ng rng khong
1,5 2m, di t nht 1,5m. Cht mt lp rm b cao khong 2 3 tc (b sung dinh
dng 0,5 1% ur, 1% vi) ti nc cho tht t v dng chn dm cho d. Cht lp th
hai dy khong 3 tc, ti nc v dm d nh trn. Tip tc lp th 3, th 4 cui
cng ng c chiu cao khong 1,5m. Mc ch ti tng lp cho nc thm u trong
rm. Vi ngy sau khi , nhit trong ng ln cao 60 70 oC, lm cho nm di
cht i v phn hy mt phn cht hu c lm cho t nm rm d hp th cht dinh dng.
Sau 3 - 4 ngy o mt ln, o rm r t di ln trn, trn xung di, ngoi vo
trong, trong ra ngoi cho u. Khi ng xp xung (sau 10 12 ngy) ta c th
ko rm ra cht m. 4. XP M NM: Cch xp rm : d b lp rm mt ngoi ng , mang
rm bn trong xp m nm v c gng xp ht trong ngy. Cch cht m nm: ri vi x
l nn trc khi xp m, ly rm cun trn nh ci gi v dng ng p thnh lung chiu
cao khong 20cm, rng 30 - 40cm ri mt ng meo gia dc theo m. Tip tc ri
rm cht lp th hai. Ring lp th hai cao khong 15cm, ti nc, d dt ri ri
lp meo th hai. (c th cht 2 3 lp rm, ty theo ma: ma nng cht thp, ma
lnh cht cao. C mi lp rm dy 15 20cm th ri mt lp meo). trn cng ph mt
lp rm mng khong 5cm ti nc d dt, vut mt ngoi m cho lng v dng tay nht
tng cng
rm ri vi bn ngoi xung y m (nu mt ngoi m khng lng v khng d dt,
sau ny khi thu hoch s lm h cc n nm nh, nng sut thp). Hng ngy theo
di ti nc v 4 -5 ngy sau dng rm kh ri ti khp ton b mt ngoi ca m, to
thnh o m dy 10 - 15cm (ma lnh, ma ma, cht xong ph rm ngay v ph rm
dy hn ma nng). 5. CHN GING MEO: Vic chn ging meo rt quan trng. V
meo tt, ng tui, khng nhim tp khun s cho nng sut nm cao v cht lng nm
tt. Meo tt c nhng si t nm (khun ti) mu trng trong, mi tng t nh nm
rm, t nm pht trin u v kn bch meo. Nu bch meo c nhng m mu xanh, en,
vng cam l nhim nm di, khng nn s dng. Khng chn bch meo c y bch t,
nho v c mi hi chua. Mt bch meo ging (khong 120g) c th cp c 2 2,5m m
(tnh theo chiu di m). 6. CHM SC V THU HOCH: * Chm sc: Chm sc nm rm
trong thi gian t quan trng nht l theo di m v nhit . Trong m l yu t
hng u, v m s to nn nhit thch hp cho t nm. Nu m d th m s lnh v m
thiu nhit ca m tng lm cho t chm pht trin. Theo di m trong m bng cch
dng tay rt mt m rm gia m, nm cht trong lng bn tay, nc hi rn ra k
tay l va, nu nc khng rn ra l kh, ta phi ti thm nc. Ti bn ngoi o m,
c pha trn m v hai bn hng m. Nu nm cht thy nc chy ra thnh git l d nc
th ngng ti ngy v d o m ra cho nc bc i. iu chnh m ca m bng cch ti
nc. Ti nc phi dng thng ti vi bp sen c tia nh, v git nc mnh d lm h
nhng t nm v n nm nh. Theo di nhit c th s dng nhit k c su vo lp rm
th hai v ngp khong 2/3 nhit k. Sau 3 5 pht ly ra xem. Nu nhit ca m
khong 33 37oC l t. iu kin nui trng nm rm c th tm tt nh sau: Yu t
Nhit m pH Nui t nm Khong bin thin Ti thch 15 40 oC 35 2oC 60 70% 70
2% 67 6,5 Ra qu th Khong bin thin Ti thch 20 25 oC 32 2oC 80 90% 80
2% 67 6,5
Sau khi cht m nm, t ngy th 6 8, mi ngy o lp rm o mt ln trnh t nm
n lan ra lp rm o, khng to c nm. Cch o rm o: d lp rm o ra, xc cho ti
v y li. T 9 10 ngy sau khi cht cc n nm mu trng bng u inh ghim xut
hin hai bn hng m, ngy sau n nm chuyn sang mu nu v bt u ln nhanh. Tu
theo tng thi tit, trung bnh khong 10 15 ngy sau khi cy meo l c th
hi nm c.
* Thu hi nm: Khi hi la cc nm bp hi nhn u (gn nt bao) hi trc,
xoay nh tay tch g ra khi m, khng nn st li chn nm b t trn m, v phn
ny khi thi ra s lm h cc n nm k bn, thu hoch xong y k o m li. Thi
gian thu hoch ko di khong 7 12 ngy. Trung bnh c 1m (tnh theo chiu
di m nm) hi c 1 2,5 kg nm ti (ty theo cht lng rm, meo ging, chiu
cao m cht). Thng nng dn c tp qun hi sm t rng sng & vo bui chiu
(mi ngy thu hai ln). Sau khi thu hi t 1, ta ngng ti 01 ngy, sau chm
sc tip tc nh lc u. Ngi trng c th bn thm ur hoc cc cht dinh dng. Ur
ti b sung cho nm vo thi im nm bt u kt n ( t 1 & 2), nng s dng
trong khong 1 3% o nn ti vo lc nm dng inh ghim hoc nt v thng phun
ti vo sng sm l tt nht. V nng sut l thuyt: cao nht l 15% (s kg nm ti
trn 100kg rm kh). Tuy nhin, thc t nui trng i tr nng sut trung bnh
cn thp hn nhiu, dao ng trong khong 5 10%. Ngoi ra, nng sut cn tu
theo cht lng rm, meo ging, chiu cao m cht, ....).
,
khu vc BSCL ni chung, trng nm trn rm l ngh c t lu. Ngh ny ph hp
vi iu kin ca hu ht gia nh nng dn v mau em li hiu qu. V th, nhng nm
gn y ngh trng nm rm khng ngng pht trin v thc s tr thnh mt ngh cho
thu nhp kh i vi nng dn. Theo kinh nghim mt s nng dn trng thnh cng
th khi trng nm rm cn lu cc im sau: 1. Chn a im trng: Nm rm c th
trng nhiu trn nn t khc nhau nh t rung, ry, vn cy, hoc trong nh nhng
phi thot nc tt, khng b ng. Ni trng t chu nh hng ca gi mnh. 2. Chn
nguyn liu trng: Nguyn liu tt khng mc nt, khng b nhim phn hoc b ngp
nc thi en. 3. Chn meo ging: Phi chn meo ging tt, t cht lng. Meo
ging l mt trong nhng yu t quan trng quyt nh nng sut v phm cht nm .
Meo tt s c mi ca nm rm v cc t nm mu trng, trong mc u khp bch. Bch
meo km cht lng c mi hi, chua, y bch b ng nc v thng c m mu vng hay
xanh en. 4. Nc ti: Cc ngun nc sch nh: nc sng, mng , nc ging
khoan,Trnh ti bng nc nhim phn mn hoc b hi thi. 5. rm: Rm trc khi
cht (ging) v meo cn phi . Cch : ri rm tng lp mng, va ti va dm cho d
n khi thnh ng cao khong 1,5 m, rng 1,5 2 m, chiu di ty theo lng rm
mun lm v mt bng cho php. C th y ng, bng nilon. Lm cch ny va s dng
ht lng rm , khng phi b lp ngoi, va t tn thi gian . Thi gian ty thm
hc ca rm. Khi thy cng rm mm nhn, c mu vng sm l uc. 6. Lm ging, v
meo: Rm sau khi , cht ging nh ging khoai rng 4 5 tc, cao khong 3
tc, di ty . Ri u hai hng meo cch ra ging 1 tc. Ri, ph ln lp rm dy 3
5 cm cho kn meo va phi. Sau , ri 1 lp rm o dy khong 10 cm gi m v bo
v ging nm. Nu c, trc khi y lp rm c th t ging va v sinh va cung cp
mt phn dinh dng cho nm. Ma ma, sau khi v meo nn lm ngay o m. 7. Chm
sc:
- Thng xuyn theo di nhit v m ca ging nm. Nhit thch hp gia ging
khong 35 45oC (hi nng tay) l c. Nu cao hn hoc thp hn phi can thip
ngay. Nu nhit cao hn 40oC, bt lp o m gim nhit . - Kim tra m bng cch
rt mt nm rm t trong ging, nm cht li, nu nc ch rn ra k ngn m khng nh
git l m khng cn ti; nu nc nh thnh git l th, cn bt o m (lc tri mt)
nc bc hi bt, nu khng thy nc rn ra l thiu, cn ti ngay. - Khi thnh m
c t ging (khong 6 7 ngy sau khi v meo) th tin hnh ti n nm. Ti u khp
lung bng thng vi c bp sen git mn. Khi n nm pht trin ln, nn ti t li
v ti lc chiu mt.
Uh