Abstract

MIGUEL-ZARATE, Norma; AYALA-GARAY, Oscar J.; SANCHEZ-DEL CASTILLO, Felipe  and  MAGDALENO-VILLAR, J. Jesús. The use of plant growth retardants in tomato (Solanum lycopersicum L.) seedlings. Rev. Chapingo Ser.Hortic [online]. 2021, vol.27, n.3, pp.157-169.  Epub Jan 31, 2022. ISSN 2007-4034.  https://doi.org/10.5154/r.rchsh.2021.01.003.

An alternative tomato production system consists of establishing three short crop cycles per year and managed with a high population density (9 plants·m-2) and early blunting. For this purpose, it is necessary to extend the seedbed phase until two months. The aim of this study was to evaluate the effect of three growth retardants (Uniconazole, Paclobutrazol and Propiconazole) on the quality of DRD 8537 commercial hybrid tomato seedlings, with one or two applications (at 25 and 50 days after sowing [das]) and two doses per retardant (low and high). Plant height, stem diameter, and number of leaves were evaluated at 31, 49 and 66 das. In addition, the leaf area, fresh weight, and dry matter content of the plants were evaluated at 66 das. The retardants affected height, diameter, fresh weight, and dry matter. The number of applications had no significant effect, and the high dose reduced height and leaf area. The retardants allowed extending seedling time on the seedbed until two months without affecting plant quality. Paclobutrazol was the retardant with the best response in terms of reducing height and leaf area, resulting in more compact seedlings.

Keywords : intensive cultivation; growth retardant; seedbed; cycle reduction; triazoles.