Abstract

RODRIGUEZ, JORGE A.  and  PLAZA, GUIDO. Effect of hidroxy-carboxylic acids on the bio-regulation of stress caused by herbicides in tomato crops. rev.colomb.cienc.hortic. [online]. 2016, vol.10, n.1, pp.66-79. ISSN 2011-2173.  https://doi.org/10.17584/rcch.2016v10i1.4276.

Losing herbicide selectivity is a permanent risk in high-value crops, which is why it is important to have alternatives that mitigate the effect on the physiology of stressed crops. A greenhouse and a field experiment were performed to evaluate the behavior of hidroxy-carboxylic acids (HCA) as an organic bio-regulator in tomato plants that were treated with Metsulfuron-Metil and Metribuzine at regular and excessive doses. In the greenhouse experiment, the quantum efficiency (Fv/Fm), chlorophyll content, stomatal conductance and CO2 exchange were evaluated; in the field experiment, we evaluated the foliar area, root growth, net assimilation rate (NAR), relative growth rate (RGR) and yield. Statistically, the Metsulfuron-metil (regular and excessive rates) did not affect the chlorophyll content, but it decreased the quantum efficiency and CO2 exchange in 80% and 100% of the plants, which was alleviated by the bio-regulator application. During the first month after the application, the hidroxy-carboxylic acids did not have the decreased root growth that was seen after the Metsulfuron application, and aided in the recovery of the NAR and RGR, resulting in a better fruit set. The Metribuzine affected the CO₂ exchange significantly during 15 days after the application (daa) of treatments whereas the excessive dose application impacted the quantum efficiency for 7 daa and was responsible for leaf fall at 30 daa and 20% less production. All of the excessive Metribuzin dose injuries were mitigated by the bio-regulator application, reaching similar values as the control plants.

Keywords : Metsulfuron-Metil; Metribuzine; electron flux; ALS; Krebs cycle; Calvin cycle.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )