Model simulasi penyakit busuk daun tanaman kentang
Research
Climate
User interface model simulasi penyakit busuk daun (late blight) pada tanaman kentang (Solanum tuberosum L
User interface model simulasi penyakit busuk daun (late blight) pada tanaman kentang (Solanum tuberosum L.) dibangun menggunakan Visual Basic 6.
Model ini membutuhkan input data cuaca (hujan, suhu minimum dan maksimum, kelembaban relatif dan lama penyinaran) harian selama setahun.
Terdapat dua opsi simulasi:
Perlakuan standar dengan penyemprotan fungisida setiap minggu
Bukan perlakuan standar
- Tanpa penyemprotan
- Dengan penyemprotan pada hari setelah tanam (HST): xx
Model simulasi ini mempunyai 3 sub model:
- Neraca air, yang akan menghasilkan informasi tentang fluktuasi kadar air tanah tersedia (mm/hari), evapotranspirasi aktual (mm/hari) dan intersepsi daun (mm/hari)
- Perkembangan, yang akan menghasilkan informasi tentang jumlah hari selama fase perkembangan (tanam-muncul tunas, vegetatif, pembentukan umbi, pengisian umbi dan pematangan umbi), thermal heat unit, dan proporsi alokasi biomassa (%).
- Pertumbuhan, yang akan menghasilkan informasi indeks luas daun (ILD/LAI), jumlah biomassa untuk daun, batang, akar, umbi dan total keseluruhan dalam ton/ha.
Hasil luaran akhir dari model simulasi ini adalah informasi peluang tanaman terinfeksi (%) dan intensitas serangan (%).
Penyusunan model ini dipimpin oleh:
Dr. Ir. Handoko | Laboratorium Meteorologi Pertanian IPB / Seameo BIOTROP
Kode sumber model, ditulis dalam Visual Basic 6.
NoteVisual Basic 6 - modul model simulasi
'++++++++++++++++++++++++++++++++++++++++++++++++++++
'Program simulasi penyakit busuk daun tanaman kentang
'++++++++++++++++++++++++++++++++++++++++++++++++++++
Public InputData As String
Public OutputData As String
Public Hst, hari, ch(1000), Tmin, Tmax, Td, Tave(1000), rh, ss, pi, wind, radiasi, lintang1, bujur1, RN, a2, b2, dlen
'variabel neraca air
Public Etm, Tsm, Tsa, Es, sd, wp, fc, swc, alpha, U, CEs1, CEs2, times, wdf
Public Fint ' intersepsi daun
Public Inf 'Infiltrasi
'Model Perkembangan
Public TU1 ' fase Plant - Emergence
Public TU2 ' Vegetative
Public TU3 ' Tuber inisiasi
Public TU4 ' Pengisian umbi
Public TU5 ' Pematangan umbi
Public THU, sp1, sp2, sp3, sp4, sp5, s1, s2, s3, s4, s5, Tb, sp, fs1, fs2, fs3, fs4, fs5
'Model Pertumbuhan
Public Sint
Public pA, pB, pU, pD 'proporsi daun
Public Kg 'koefisien respirasi pertumbuhan
Public Km 'koefisien respirasi pemeliharaan
Public Lue 'Light use efficiency
Public WD, WB, WA, WU, WT, dWD, dWB, dWA, dWU, dILD, ILD, kd, LMu(1000)
'Penyakit
Public embun, Tss, Hiv, dvILD
Public Scr 'Score Penyakit
Public HsTu ' Hari setelah tunas
Public HPr 'Hari Penyemprotan
Public Hpr1, HariSerangan
'Perlakuan
Public TanamStandar As Boolean
Public TanamJamur As Boolean 'Tanaman dikenai Jamur/non standar
Public TanamNoSemprot As Boolean
Public TanamSemprot As Boolean
Public jbk As Integer
'++++++++++
Public Sub HitungETP()
'Solar declination (degree):
d = -23.4 * Cos(2 * pi * (hari + 10) / 365)
'Daylength, dlen (hours):
sinld = Sin(lintang1 * pi / 180) * Sin(d * pi / 180)
cosld = Cos(lintang1 * pi / 180) * Cos(d * pi / 180)
sinb = Sin(-0.833 * pi / 180)
arg = (sinb - sinld) / cosld
arccos = Atn(-arg / Sqr(-arg * arg + 1)) + 2 * Atn(1)
dlen = 24 / pi * arccos
'Vapour pressure (mb):
TAve(hari) = (Tmin + Tmax) / 2
esat = 6.1078 * Exp(17.239 * TAve(hari) / (TAve(hari) + 237.3))
ea = rh * esat / 100
vpd = esat - ea
'Slope of vapour pressure (Pa/oC):
delta = 47.139 * Exp(0.055129 * TAve(hari))
'Albedo (unitless) :
albs = 0.05
albc = 0.25 * (0.23 - 0.05) * 2
alb = albs + albc
'S angot
sangot = 58.75 * (sinld + cosld)
'radiasi
radiasi = ((a2 + b2 * ss / dlen) * sangot)
'Long wave radiation (MJ/m2/d):
nN = (radiasi / sangot - 0.16) / 0.62
Rlw = 2 * (10 ^ -9) * ((TAve(hari) + 273) ^ 4) * (0.56 - 0.08 * Sqr(ea)) * (0.1 + 0.9 * nN)
'Net radiation (MJ/m2/d):
RN = (1 - alb) * radiasi - Rlw
'Aerodynamic function (MJ/(oC.m2.d)):
f1 = 0.64 * (1 + 0.54 * wind * 1000 / 3600)
'Energy limited evapotranspiration (mm):
'etp = 0.75 * (delta * Rn + f1 * vpd * 100) / ((delta + 66.1) * 2.454)
Etp = 0.75 * (delta * RN + f1 * vpd * 100) / ((delta + 66.1) * 3)
If Etp < 0 Then Etp = 0
'Evapotranspirasi Maksimum
Etm = Etp
End Sub
'++++++++++
Public Sub EvaporasiTanah()
'Kapasitas Intersepsi (fungsi dari ILD)
'Jika hujan = 0 diberikan irigasi sprinkle sebesar KL-KAT(n)
If ch(hari) <> 0 Then
Pair = ch(hari)
Else
Pair = fc - swc
End If
'Fint = 1.6481 * ILD ^ 2 + 0.3076
If ILD < 3 Then Fint = 0.4233 * ILD Else Fint = 1.27
If ch(hari) = 0 Then Fint = 0
If Fint > ch(hari) Then Fint = ch(hari)
'Infiltration (INF), mm :
Inf = Pair - Fint
'Tranpirasi maksimum, mm:
Tsm = Etm * (1 - Exp(-0.3 * ILD))
Esm = Etm - Tsm
p = Inf
If CEs1 >= U Then GoTo stage2
stage1:
If p >= CEs1 Then CEs1 = 0 Else CEs1 = CEs1 - p
cumes1:
CEs1 = CEs1 + Esm
If CEs1 < U Then Es = Esm Else GoTo transition
GoTo bufferevap
transition:
Es = Esm - 0.4 * (CEs1 - U)
CEs2 = 0.6 * (CEs1 - U)
times = (CEs2 / alpha) ^ 2
GoTo bufferevap
stage2:
If p >= CEs2 Then GoTo storm
times = times + 1
timeso = times - 1
Es = alpha * Sqr(times) - alpha * Sqr(timeso)
If p > 0 Then GoTo rained
If Es > Esm Then Es = Esm
cumes2:
CEs2 = CEs2 + Es - p
GoTo bufferevap
storm:
p = p - CEs2
CEs1 = U - p
If p > U Then CEs1 = 0
GoTo cumes1
rained:
Esx = 0.8 * p
If Esx <= Es Then Esx = Es + p
If Esx > Esm Then Esx = Esm
Es = Esx
GoTo cumes2
bufferevap:
If swc < 0.5 * wp Then Es = 0
If swc >= fc Then Es = Esm
End Sub
'++++++++++
Public Sub Transpirasi()
'Relative Extractable Water (rew, unitless):
Swccrit = wp + 0.4 * (fc - wp)
rew = (swc - wp) / (Swccrit - wp)
If swc <= wp Then rew = 0
If swc > fc Then rew = 1
' Menghitung perubahan kedalaman perakaran (mm)
' If s >= 0 Then
If TAve(hari) > 7 Then drdepth = 2.2 * (TAve(hari) - 7) Else drdepth = 0
' Else
' drdepth = 0
' End If
rdepth = rdepth + drdepth
If rdepth > sd Then rdepth = sd
'Actual transpiration (mm) :
Tsa = Tsm * rew * rdepth / sd
If Tsa > Tsm Then Tsa = Tsm
If Tsm > 0 Then wdf = Tsa / Tsm Else wdf = 0
End Sub
'++++++++++
Public Sub neraca_air()
swc = swc + Inf - Es - Tsa
If swc > fc Then GoTo runoff
perc = 0
GoTo bufferwbal
runoff:
runoff = swc - fc
swc = fc
bufferwbal:
If swc < 0 Then swc = 0
End Sub
'++++++++++
Public Sub Inisialisasi()
'Neraca air
sd = 400 'mm kedalaman perakaran
wp = 0.13 * sd ' wilting point
fc = 0.5 * sd ' field capacity
swc = fc ' soil water content
alpha = 5.08
U = 12
CEs1 = U
CEs2 = 0
times = 0
Es = 0
'Model Perkembangan
TU1 = 214 ' (0-160) fase Plant - Emergence
TU2 = 228 ' (160-330) Vegetative
TU3 = 147 ' (330-440) Tuber inisiasi
TU4 = 481 ' (440-800) Pengisian umbi
TU5 = 268 ' (800-1000) Pematangan umbi
Tb = 7
sp1 = 0.16
sp2 = 0.17
sp3 = 0.11
sp4 = 0.36
sp5 = 0.2
'Model pertumbuhan
Km = 0.0108 '0.015 'padi
Lue = 0.035
kd = 0.35 'Koefisien pemadaman
Kg = 0.13 ' 0.14 padi
WU = 80 '20 gram/biji (berat basah) * 20% tanam:40000 tan/ha
WB = 0
WA = 0
WD = 0
WT = 0
End Sub
'++++++++++
Public Sub Perkembangan()
'Suhu rata-rata diambil pada saat perhitungan ETP
'fase tanam-emergence
THU = THU + (TAve(hari) - Tb)
If sp >= 0.8 Then GoTo fase5
If sp >= 0.44 Then GoTo fase4
If sp >= 0.33 Then GoTo fase3
If sp >= 0.16 Then GoTo fase2
fase1:
If TAve(hari) > Tb Then s1 = s1 + sp1 * (TAve(hari) - Tb) / TU1
fs1 = fs1 + 1
If s1 > sp1 Then
s1 = sp1
ILD = 0.0323
Else
GoTo hitung_sp
End If
fase2:
If TAve(hari) > Tb Then s2 = s2 + sp2 * (TAve(hari) - Tb) / TU2
fs2 = fs2 + 1
If s2 > sp2 Then
s2 = sp2
Else
GoTo hitung_sp
End If
fase3:
If TAve(hari) > Tb Then s3 = s3 + sp3 * (TAve(hari) - Tb) / TU3
fs3 = fs3 + 1
If s3 > sp3 Then
s3 = sp3
Else
GoTo hitung_sp
End If
fase4:
If TAve(hari) > Tb Then s4 = s4 + sp4 * (TAve(hari) - Tb) / TU4
fs4 = fs4 + 1
If s4 > sp4 Then
s4 = sp4
Else
GoTo hitung_sp
End If
fase5:
If TAve(hari) > Tb Then s5 = s5 + sp5 * (TAve(hari) - Tb) / TU5
fs5 = fs5 + 1
If s5 > sp5 Then
s5 = sp5
Else
GoTo hitung_sp
End If
hitung_sp:
sp = s1 + s2 + s3 + s4 + s5
End Sub
'++++++++++
Public Sub Pertumbuhan()
'proporsi biomass
pD = 0.852 * Exp(-4.0748 * sp) 'x '0.9871 * Exp(-5.6564 * sp)
pB = 0.6599 * Exp(-3.7117 * sp) ' x '0.3652 * Exp(-4.5512 * sp)
pA = 0.7517 * Exp(-5.2305 * sp) 'x '0.2922 * Exp(-5.6926 * sp)
pU = 1 - pA - pD - pB
'Menduga ILD
sla = (-0.0139 * (sp ^ 2)) + (0.0189 * sp) - 0.0025 ' ha/kg
If sla < 0 Then sla = 0
dILD = 0.6 * sla * dWD
ILD = ILD + dILD
'Perhitungan hari setelah tunas
If HsTu <= 0 Then
If ILD > 0 Then HsTu = HsTu + 1
Else
HsTu = HsTu + 1
End If
'======================================================================
'Penyakit (infeksi jamur akan mengurangi ILD jika indeks Tss >=80%)
If TanamJamur = True Then
'Penyemprotan
If TanamSemprot = True Then HPr = Val(Hpr1)
If TanamNoSemprot = True Then HPr = 1000
If Hst < HPr Then
If Hiv < 1 Then
If Tss >= 80 Then
Hiv = Hiv + 1
HariSerangan = Hst
dvILD = 0.0012 * (Hiv ^ 1.6122)
ILD = ILD * (1 - dvILD)
End If
Else
Hiv = Hiv + 1
dvILD = 0.0012 * (Hiv ^ 1.6122)
ILD = ILD * (1 - dvILD)
If ILD <= 0 Then ILD = 0
End If
Else
Hiv = 0
dvILD = 0
End If
Else
If jbk = 0 Then
If Tss >= 80 Then
jbk = 1
HariSerangan = Hst
End If
End If
End If
'===================================================================
'Intercepted radiation (MJ/m2/d) :
RR = 140 * dlen * 3600 / 10 ^ 6
Sint = radiasi * (1 - Exp(-kd * ILD))
If Sint > RR Then Sint = RR
'Potential gross dry matter production (kg/ha/d) :
GDMp = Lue * Sint * 10 ^ 4
'Actual gross dry matter production (kg/ha/d) :
GDMa = (1 - Kg) * GDMp * wdf
'Respirasi Pemeliharaan (kg/ha/d):
Q10 = 2 ^ ((TAve(hari) - 20) / 10)
RmD = Km * Q10 * WD
RmB = Km * Q10 * WB
RmA = Km * Q10 * WA
RmU = Km * Q10 * WU
'Pembagian biomasa :
dWD = (pD * GDMa - RmD)
dWB = (pB * GDMa - RmB)
dWA = (pA * GDMa - RmA)
dWU = (pU * GDMa - RmU)
If Hst <= 30 And Hst < 45 Then
bmax1 = 4 * 40
If dWU > bmax1 Then dWU = bmax1
End If
If Hst >= 45 Then 'And Hst <= 60 Then
bmax2 = 3.76 * 40
If dWU > bmax2 Then dWU = bmax2
End If
WD = WD + dWD
WB = WB + dWB
WA = WA + dWA
WU = WU + dWU
WT = WD + WB + WA + WU
End Sub
'++++++++++
Public Sub Penyakit()
'syarat spora (ss)
Tss = 0
If ILD >= 0.5 Then
'syarat intersep (ss1)
If Fint > 0 Then ss1 = 1 Else ss1 = 0
'syarat embun (ss2)
If Td > Tmin Then ss2 = 1 Else ss2 = 0
'syarat Suhu Minimum (ss3)
If Tmin > 11 Then ss3 = 1 Else ss3 = 0
'syarat suhu maksimum (ss4)
If Tmax >= 24 And Tmax <= 26 Then ss4 = 1 Else ss4 = 0
'syarat kelembababan
If rh > 90 Then ss5 = 1 Else ss5 = 0
'total ss
End If
If hari >= 7 Then
Tch = 0
STave = 0
For i = 0 To 7
Tch = Tch + ch(hari - i)
If ch(hari - i) > 0 Then Hch = Hch + 1
STave = STave + TAve(hari - i)
Next i
ST = STave / 7
If Tch >= 38 And Hch >= 4 Then
If ST <= 24 Then
ss6 = 1
Else
ss6 = 0
End If
End If
End If
Tss = ((ss1 + ss2 + ss3 + ss4 + ss5 + ss6) / 6) * 100
Scr = (dvILD / 1.0237) * 100 'persen
End Sub