Vergara - 1976 - Physiological and morphological adaptability of ri

TEI\{PER.~\'IT.TRE AND LIGHT. REPRODUCTIVE GR('J\\='TH AND RIPENING 205
Actual qmin yield lg/mz)
500
500 —
400 —
O
I
300 — r = O53
° n= n32
.0 Y3 ) I00
200 —
O
I
|QQ I I | I
I00 200 300 400 500 600
Estimated groin yield {g/mzl
14. Correlation diagram between actual and estimated
grain yield. Grain yield [gfmet 1961b? data. 22 prefectures.
Excludes values of grain yield lower than 100
gfmi. Nlodektype IV. four stages.
The model of type IV was represented by a reciprocal equation with the
climatic factors at several stages, Thih model can elucidate the climatic effect to
some extent. because ofthe reciprocal equation.
Now. we discuss whether the simplified reciprocal equation including climatic
factors at tu-‘o stages represents the prettious climatic effect.
1/ 1' = b,/t, + bltfsl + bJr, + bity/s, + c (S)
where n. s1: climatic factors at previous stage, and t1. s1: factors at sequent
stage.
Y is obtained from eq. 5 as follows:
l‘ = 1
bl/rl + ban/st + lh/r, + 5,1,1 + c
_
rlsitm
beans; + bgftflisl + bgisirl + bgisqg + crisins; (6)
To determine the temperature response at stape 2. eq. (6) is differentiated b) r1;
d}-"d,_ = ’1l3|:3:(bs>3':
"
174111)
_
(— blsltts, + bgtfltzs, + b,t,.r,lz + Innsltf + ctlsqtzsQl (7)
then. optimum temperature (thy-J!)
is obtained as follows:
bu... = VSibi/b. (3)