Four genotypes of ‘desi’ and two of ‘kabuli’ chickpea (Cicer arietinum) were sown at six locations in Australia on various dates between 1986 and 1988, giving 22 combinations of site and sowing date with diverse photothermal environments. Times from sowing to first flowering (f) varied from 30 to 162 d, mean pre-flowering temperatures from 10.8° to 29.3°C and mean photoperiods from 11.3 to 15.6 h d−1. There was no evidence that any observation had been obtained in photoperiods shorter than the ceiling photoperiod (Pcc) or longer than the critical photoperiod (Pc). This suggests that, in typical agricultural environments, chickpea crops experience photoperiods (P) which should satisfy the condition Pcce < P < Pc. In one ‘kabuli’ and two ‘desi’ genotypes, 1/f was influenced by both temperature and photoperiod. The coefficient of determination (R2) for a linear, additive rate of development model ranged from 0.74 to 0.80, with no significant difference in either temperature sensitivity or photoperiod sensitivity among these three genotypes. In the remaining three genotypes, no significant response to temperature was detected between 10.8° and 29.2°C, so rate of progress to flowering was influenced solely by photoperiod. There was no significant difference in the sensitivity of 1/f to P among these three genotypes. The linear, additive rate model found here to be so satisfactory as a predictive tool for phenology, is also shown to have much wider general application.
Predicción del liempo de floración