Hello Jin Yun,
Aloha! I am not very familiar with the potato model, but after a quick
look at it the genetic coefficients seem to be as follows:
G2 - a leaf area expansion rate in degree days
G3 - potential tuber growth rate
G4 - does not seem to be used in the model
PD - an index that supresses tuber growth during the period
that immediately follows tuber induction
P2 - an index that relates photoperiod response to tuber initiation
TC - an upper critical temperature for tuber intitiation
To make GENCALC calculate genetic coefficients for potato, you will need
to add the following lines in the GCRULES.FLE file:
*PTSUB96 1 POTATO
5 P2 1/00*00 0.1 2.0 9 0.4 0.8 TUBER INDUC.
6 TC 1/00*00 0.5 2.0 9 15.0 22.0 TUBER INDUC.
1 G2 6/00*00 50.0 800.0 9 1800. 2200. TUBER+TOP WT
2 G3 4/00*00 0.5 200.0 9 22.0 25.0 TUBER DRY WT
4 PD 4/00*00 0.1 100.0 9 0.7 1.0 TUBER DRY WT
*PTSUB96 2 POTATO
5 P2 1/00*00 0.1 2.0 9 0.4 0.8 TUBER INDUC.
6 TC 1/00*00 0.5 2.0 9 15.0 22.0 TUBER INDUC.
*PTSUB96 3 POTATO
1 G2 6/00*00 50.0 800.0 9 1800. 2200. TUBER+TOP WT
2 G3 4/00*00 0.5 200.0 9 22.0 25.0 TUBER DRY WT
4 PD 4/00*00 0.1 100.0 9 0.7 1.0 TUBER DRY WT
You may manipulate the rules and the order of the rules. You may want to
delete the rule that defines TC. When I ran GENCALC on the data sets
in DSSAT, the value for TC always went to the minimum or maximum without
affecting the tuber induction date. This may be a result of air
temperature being near 15 C, nearly optimum for tuber initiation and the
lower limit for TC.
You will also need data for tuber dry weight, tuber + top dry weight, and
date of tuber induction in the averages file (*.PTA).
The last thing you will need is a new GENCON.EXE. I will email this to
you. The current GENCON.EXE cannot handle the very large genetic
coeffient G2.
If you have questions, please let me know ([log in to unmask]).
Good luck.
Sincerely,
Richard Ogoshi
On Mon, 14 Jul 1997, Jin-Il, Yun wrote:
> Hello,
>
> I am trying to find genetic coefficients of some potato cultivars in Korea
> using GenCalc. There is neither explanation on G2, G3, G4, PD, P2, and TC
> of potato in DSSAT manual nor rules for potato in GCRULES file. Is there
> any way to run GenCalc for potato? I am using DSSAT version 3.0.
> Jin I. Yun, Ph.D
> Associate Professor, Agricultural Climatology
> Faculty of Life Science and Natural Resources
> Kyung Hee University
> Suwon 449-701,Korea
> Tel 82-331-280-2608
> Fax 82-331-281-4966
> e-mail : [log in to unmask]
>
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