In pecans, the determination of the time the different phases of fruit growth begins and the time period at which they are completed is very important, with the purpose of planning the best orchard management. However, these phases occur in different dates in the different pecans productive regions, and even in the same area, differences are recorded from one year to another, different environmental conditions.
A study was carried out during seven years (1988‑1994) to know the fruit growth and development phases of Western pecans, comparing at the same time the accuracy of days, degree‑days and evapotranspiration in the prediction of these phases.
It was found that: Free‑nucleate endosperm, ovary wall lignification and kernel filling started at 66, 89 and 97 days after stigma receptivity.
To determine the time at which the different fruit phases started the prediction though evapotranspiration, was higher than degree‑days and days.