The effect of different irrigation water depth applications and the atmosphere enrichment with CO2 was evaluated. The experiment was carried out with sweet pepper (cultivar Mayata) in two similar plastic greenhouses in Piracicaba, Brazil. In one of them, CO2 was applied with irrigation water, increasing the CO2 concentration in the atmosphere to 800 mmolCO2/mol and in the other greenhouse the irrigation water was not enriched with CO2. In each greenhouse four irrigation water depths were applied, corresponding to 60; 80; 100 and 120% of a reduced pan evaporation (RPA), in a complete randomized block design with ten replications. The CO2 was injected into irrigation pipeline during a period of 40 minutes. Fruits were harvested from ten selected plants, after 90 days of transplanting, evaluating fruit number, length, diameter, pulp thickness, weight and yield (kg/ha). The effect of different irrigation water depths was observed for length, pulp thickness and fruit number per plant in the greenhouse with CO2 application. In the greenhouse with CO2 enrichment and irrigation water depths corresponding to 100% of RPA, differences were observed in length, pulp thickness, fruits numbers per plant and yield of 7.0%, 4.5%, 35.0% and 38.4%, respectively. On the other hand, in the greenhouse without CO2 application, different water depth applications did not affect any parameter. All analyzed parameters presented better results in the greenhouse with CO2 enrichment, except for the fruit pulp thickness. The CO2 application in the plastic greenhouse resulted in increased length, diameter, fruit number per plant, weight and yield of 12.4%, 11.9%, 21.4%, 20.0% and 51,3%, respectively.
Capsicum annuum L.; carbon dioxide; yield; evapotranspiration; drip irrigation; fruit characteristics
