Plant growth regulators (PGRs) may have an important role in regulating both yield and fruit quality dur-ing the production of sweet pepper in controlled-environment greenhouses, but the uncertainly of results
– due to the specificity of the plant response – could limit their use and potential benefits. Therefore,
weinvestigated the effect of the foliar spraying of abcisic acid (ABA), gibberellic acid (GA
3
) and indole-3-acetic acid (IAA) on fruit colour, concentrations of carbohydrates, ions and amino acids, plant growth
and total fruit yield. Although yield was decreased by the GA3 and ABA treatments, GA3 augmented plant
height and the levels of tyrosine, phosphate, sulphate, iron and phosphorus while decreasing the amounts
of glucose and fructose. The foliar applications of IAA did not produce any change when compared with
the control plants, while plants treated with ABA had decreased levels of sucrose but higher levels of iron.
GA3
, applied fortnightly, produced a significant improvement in the fruit quality of sweet pepper but did
not significantly increase total yield. Further studies will be necessary to determine the best GA3
concen-tration and frequency of application, to obtain greater benefits for human consumption this important
crop