Table 7. Variables of the Gompertz equation for the disease progress curves of common spear rot / crown disease in several oil palm progenies.
Progeny Type of
symptom		 Gompertz Model Components˛
Variables
Yo B A r R
C9198 PCF (CSR) 0.013 4.343 0.227 0.32 0.98**
PCF\AF 0.027 3.612 0.04 0.7 0.61*
PCF+PCF\AF (CSR+CSR\CD) 0.04 3.219 0.24 0.28 0.98**
C9208 PCF\AF 0.013 4.343 0.04 0.09 0.74**
(Exp. 85-04)3 PCF+PCF\AF 0.013 4.343 0.093 0.09 0.80**
C9208 PCF\AF 0.008 4.828 0.025 0.12 0.68**
(Exp. 85-05) PCF+PCF\AF 0.008 4.828 0.117 0.09 0.78**
C9210 PCF 0.006 5.116 0.118 0.12 0.97**
PCF\AF 0.006 5.116 0.024 0.16 0.81**
PCF+PCF\AF 0.006 5.116 0.13 0.11 0.97**
C9650 PCF 0.012 4.423 0.185 0.23 0.99**
PCF\AF 0.049 3.016 0.333 0.18 0.97**
PCF+PCF\AF 0.062 2.781 0.333 0.23 0.95**
C9688 PCF 0.014 4.269 0.1 0.42 0.97**
PCF\AF 0.071 2.645 0.56 0.19 0.98**
PCF+PCF\AF 0.071 2.645 0.57 0.19 0.98**

1. CSR= common spear rot (no bent rachises CSR\CD= common spear rot associated to crown disease (bent rachises).

2. Yo= Gompertz; A= Yo= initial amount of disease; B= constant; A= asymptote; r= rate of disease increase).

3. Same progeny planted in two different experiments).

*: P= 0.05; **: P= 0.01.