Abstract
The photosynthesis of cocoa ( Theobroma cacao Linn.) as influenced by light, temperature and vapour pressure deficit (VPD) was studied in the field. Net photosynthetic rate ( P N), transpiration rate and stomatal conductance showed significant seasonal variations. P N was highest during periods of low evaporative demand (low VPD). Diurnal patterns of these parameters indicated transient midday water deficits which reduced P N. Optimum temperature for P N was 31–33°C and light saturation occurred at 400 μmol m −2s −1. The CO 2 compensation concentration was 100 ppm. Droughttolerant accessions maintained higher leaf water potential than drought-susceptible types in dry months. There was no significant difference in P N between tolerant and susceptible accession types.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have