Leaf nutrients concentration on 'Tabasco' pepper due to the application of CO₂ by irrigation

We verified the effect of different doses of carbon dioxide (CO₂), supplied via drip irrigation in the concentration of macronutrients and micronutrients in the leaves of 'Tabasco' pepper (Capsicum frutescens). The treatments consisted initially of four levels of CO₂ (0, 206.6, 309.9 and 413.2 kg/ha) before pruning the plants, and then four more doses of CO₂ (0, 245.4, 368.0 and 490.7 kg/ha) after pruning, respectively T1, T2, T3 and T4. The analysis of nutrient concentration was determined in leaves at 189, 350 and 432 days after transplanting (DAT). There was a significant linear effect (p<0.05) for rates of CO₂ on concentrations of N, Fe, Mn and for Zn there was a quadratic effect (p<0.05) at 187 DAT. With respect to the concentration of Ca, there was a significant linear effect (p<0.01) at 484 DAT. The N concentration in leaves at 187 DAT increased depending on the CO₂ levels. The concentration of Fe decreased depending on the CO₂ levels. Identical behavior was observed on Mn at 189 DAT. The concentration of Zn decreased on treatments T2 and T3, with an increase on T4 compared to control. We concluded that CO₂ had a significant effect on the levels of N, Fe, Mn and Zn at 187 DAT and 484 DAT to Ca. The CO₂ caused an increase on the concentration of N (59.5 g/kg) and Zn (97 mg/kg) on 'Tabasco' pepper leaves compared to the control values with 49.3 g/kg and 86 mg/kg for values of N and Zn, respectively. The concentration of Fe (230 mg/kg) Mn (235 mg/kg) and Ca (13.8 g/kg) decreased in the leaves as compared to control, with values of 235 mg/kg, 308 mg/kg and 26.4 g/kg for Fe, Mn and Ca, respectively.

Capsicum frutescens; trickle irrigation; carbon dioxide.