Phytohormones in organic fertilizers influence β-carotene concentration and marketable yield of lettuce (Lactuca sativa)

A. Sukor, F.S.M. Amer, J. Vanamala, J.G. Davis
Lettuce (Lactuca sativa) is a commonly consumed vegetable, due to its nutritive value, including β-carotene, a precursor to vitamin A. Nitrogenous fertilizers have been shown to impact a crop’s ability to accumulate β-carotene in plant tissue. This study aimed to evaluate the effect of organic fertilizer types on β-carotene concentration and marketable yield of lettuce. A two-year field study was conducted at the Colorado State University Horticulture Research Center, Fort Collins, CO. Fertilizers (blood meal, feather meal, fish emulsion, cyano-fertilizer) were applied at 56 kg N ha‑1. Fish emulsion and cyano-fertilizer were supplied in four split applications through drip irrigation, while the blood meal and feather meal were subsurface banded before planting. All fertilizer treatments in 2013 increased β-carotene concentration in leaf tissue compared with the control, while only fish emulsion recorded significantly higher β-carotene concentration in 2014. The indole-3-acetic acid (IAA) applied in the fish emulsion treatment may have led to increased β-carotene concentrations. IAA application was positively correlated with β-carotene concentration in 2013 (r=0.49; P=0.0083) and 2014 (r=0.53, P=0.0029). A significant negative correlation (r=-0.7565, P=0.0044) was found between marketable yield and β-carotene concentration in leaf tissue in 2014. High salicylic acid application in the cyano-fertilizer treatment may explain the higher total leaf area of this treatment compared with other fertilizers. IAA application in the fertilizers was positively correlated with β-carotene concentration in lettuce. Further research is needed to determine the mechanism through which this impact occurs.
Sukor, A., Amer, F.S.M., Vanamala, J. and Davis, J.G. (2022). Phytohormones in organic fertilizers influence β-carotene concentration and marketable yield of lettuce (Lactuca sativa). Acta Hortic. 1348, 15-22
DOI: 10.17660/ActaHortic.2022.1348.2
https://doi.org/10.17660/ActaHortic.2022.1348.2
blood meal, feather meal, fish emulsion, cyano-fertilizer, indole-3-acetic acid, salicylic acid
English
1348_2
15-22

Acta Horticulturae