EFFECTS OF LIGHT AND TEMPERATURE ON POTENTIAL APPLE PRODUCTION

To improve estimations of fruit yield, the relationship between weather and canopy photosynthesis needs to be quantified.
This relationship has been examined by simulating potential apple production under different weather conditions.
Daily gross and net photosynthesis were calculated using solar radiation input, seasonal canopy light interception, and mean daily temperature.
Maintenance respiration was calculated per organ.
Assimilate allocation to leaves, fruit, roots, and woody above-ground organs during the season was derived from empirical data.
In seasons with ‘good’ weather, fruit production could easily be 25% higher than that under ‘bad’ conditions.
High temperatures in spring were found to promote fruit production, which was due to increased gross photosynthesis.
Later in the season, however, high temperatures were unfavourable, which was explained by maintenance respiration, increasing from 15% of gross photosynthesis shortly after bloom to 50–60% just before harvest.

IV International Symposium on Computer Modelling in Fruit Research and Orchard Management

P. S. Wagenmakers

https://doi.org/10.17660/ActaHortic.1996.416.23