Photosynthetic measurements in lettuce submitted to different agroindustrial residue composting

Claudiana Moura dos Santos, Laurício Endres, Tâmara Claudia de Araújo Gomes, Cleber Júnior Jadoski, Luis Antonio do Nascimento, Emanuelle Dias dos Santos

Abstract


This work was developed with the objective of evaluate effects of different organic composts on the photosynthesis, gas exchange, chlorophyll fluorescence in lettuce grown under nursery conditions. The experiment was accomplished following a randomized design, with 14 treatments and four replications. Using the following treatments: T1 to T6 (sugarcane based substrates), T7 to T12 (coconut based substrates), T13 (manure) and T14 (mineral fertilization). The following parameters were evaluated: photosynthesis rate, respiration, stomata conductance, the ratio of internal to external CO2 concentrations (Ci /Ca), the efficiency of water use (A/E) and carboxylation efficiency (A/Ci), chlorophyll concentrations, maximum quantum yield of photosystem II (Fv/Fm). The plants of lettuce grewn with mineral fertilization and manure showed higher values of stomatal conductance. The treatments with sugarcane based substrates showed higher rates of photosynthesis, transpiration, carboxylation efficiency and chlorophyll content, indicating that the better photosynthetic capacity when grown on these substrates.


Keywords


Gas exchange; chlorophyll fluorescence; organic composts



DOI: https://doi.org/10.5777/paet.v3i3.1269