FACTORS AFFECTING PHOTOSYNTHETIC PRODUCTIVITY OF SWEET PEPPER AND TOMATOES GROWN IN CO₂-ENRICHED ATMOSPHERE

A long-term 75-day-exposure of sweet pepper and tomato plants to elevated CO₂ concentration (1 500 μl/l) led to adaptation changes in the photosynthetic apparatus which exhibited by slightly increased specific leaf mass (SLW) in both species.
In sweet pepper net photosynthetic rate (P_N) was significantly increased while in tomatoes the increase was non-significant under conditions of normal CO₂ concentration as compared to the plants from untreated atmosphere.

Removal of flowers and buds in sweet pepper (sterile var.) and deletion of artificial pollination in tomatoes (semisterile var.) resulted in leaf hypertrophy accompanied by increased SLW. As compared to the control plants with full fruit set (fertile var.) the differences in this character were much more pronounced in the plants grown in CO₂– enriched atmosphere than in normal atmosphere.
While P_N at 320 μl/1 CO₂ was lower in sterile pepper as compared to fertile controls having reached the higher value of the controls following CO₂ concentration increase up to 2 000 μl/l, the hypertrophic tomato leaves with incomplete fruit set (semisterile var.) showed increased P_N value both at 320 μl/l and 2 000 μl/1 CO₂ as compared with the controls.
This paid for both the species regardless of growing conditions (elevated or normal CO₂ concentration).

In sweet pepper fruit yield of the plants analyzed for photosynthetic activity was by 32 % or 47 % higher in CO₂-enriched atmosphere as compared to the controls.
The fertile and semisterile var. of tomatoes gave fruit yields higher by 36 % and 169 %, respectively than did the corresponding variant in the normal atmosphere.
Increased supply of assimilates in the semisterile variant grown in CO₂-enriched atmosphere compensated thus for the effect caused by artificial pollination of the trusses in normal atmosphere.

Symposium on CO2 Enrichment

J. Frydrych

https://doi.org/10.17660/ActaHortic.1984.162.31