Biological alternatives combined with Naphthaleneacetic Acid (NA) for the management of Plasmodiophora brassicae Woronin in cauliflower (Brassica oleracea L. var. Botrytis)

Abstract

Introduction— Club root can cause yield losses in crucifers between 70% to 80% and it is a serious problem of crucifers in Colombia.

Objective— To evaluate biological alternatives combined with Naphthaleneacetic Acid (NA) for the management of P. brassicae in cauliflower under the conditions of the municipality of Mutiscua.

Methodology— A randomized block experimental design with six treatments and three replications was established in a cauliflower culture, comparing commercial products based on the antagonist microorganisms Trichoderma harzianum, Bacillus subtilis and Burkholderia cepacia + NA, NA alone, a treatment with lime as a production standard and a whiteness. Ten plants were evaluated per experimental unit; height, stem diameter, number of leaves and incidence and severity of the disease. Finally, with the results obtained, a cost benefit analysis was developed.

Results— The results showed that the applications of the biological products T. harzianum and B. subtilis combined with the growth regulator NA, although they do not curatively control the disease, reduce it when applied preventively. The cost-benefit ratio was more favorable for T. harzianum + NA, followed by lime. Although with low effectiveness, lime treatment was the cheapest alternative.

Conclusions— Trichoderma harziaanum + NA, as applied in the experiment, and lime constitute non-chemical alternatives feasible for use by farmers for disease management.