Nitrogen has been associated to lettuce fresh weight accumulation. In this way, different bio stimulants formulations containing amino acids have been commercially offered although the yield increase has not been properly supported. The aim of this work was a) to quantify the changes in lettuce fresh weight accumulation and the physiological mechanism involved in plants sprayed with different amino acid solutions and (b) to characterize the responses to root restrictions under nursery with non-limited nitrogen supply. Our results showed that a foliar spray with different amino acids each alone or combined can change positively or negatively lettuce fresh-dry weight, total leaf area and photo assimilate partitioning under a nursery abiotic stress related to plug cell size. Although, exogenous amino acids supply can be suggested as signalling molecules, the presence of limited plug cell volume (288-plug cell tray) would be demanded for the use of more than a single one. On the other hand, although additive and antagonistic effects have been suggested, conclusive results needs for further experiments. | Foliar amino acids sprays on lettuce (Lactuca sativa L.) biomass accumulation
