Use of Fungicides and Biological Controls in the Suppression of Fusarium Crown and Root Rot of Asparagus Under Greenhouse and Growth Chamber Conditions

Abstract

Growth chamber, greenhouse, and field experiments were conducted with fungicides and biological control agents, including nonpathogenic isolates of Fusarium oxysporum, to test their ability to control disease caused by F. oxysporum f. sp. asparagi and F. proliferatum. In greenhouse studies with asparagus seedlings in soil, Trichoderma harzianum strain T-22, benomyl, and fludioxonil treatments increased root weight and decreased root disease compared with the infested control when a low level of F. oxysporum f. sp. asparagi and F. proliferatum was used. The fungicide fludioxonil limited plant death caused by Fusarium spp. at high inoculum levels, whereas T. harzianum strain T-22 was not effective. Nonpathogenic isolates of F. oxysporum were effective in limiting Fusarium disease on asparagus seedlings in culture tubes, although isolates differed in their ability to control disease caused by F. oxysporum f. sp. asparagi and F. proliferatum. In greenhouse studies, no significant differences in plant death were found between asparagus plants growing in media infested with F. oxysporum f. sp. asparagi and F. proliferatum and left untreated, and those treated with nonpathogenic F. oxysporum. The efficacy of fungicides and biological control products to control Fusarium crown and root rot under commercial field conditions could not be evaluated due to low disease pressure.

Organic amendments conditions on the control of Fusarium crown and root rot of asparagus caused by three Fusarium spp.

“…On the other hand, the lower severity of root symptoms caused by isolate Fp3, as compared to Fo5 and Fs2 (except for incubation of substrate amended with PPM-2% at 30ºC) is likely due to poor survival of F. proliferatum in bare soils, as this species does not produce chlamydospores; therefore the initial inoculum density was lower for this than for the two other species tested (Elmer et al, 1996;Elmer, 2001). This is in agreement with previous results (Reid et al, 2002) that showed a low root severity (20%) using F. proliferatum at 1.3 × 10 4 CFU/g (similar to that in our experiments). For the other treatments, however, we found much lower root severity values than the un-amended control.…”

Isolation and characterization of Fusarium oxysporum, a wilt causing fungus, for its pathogenic and non-pathogenic nature in tomato (Solanum lycopersicum)

“…), gerbera (Gerbera jamesonii Hook. ), basil (Ocimum basilicum L.), asparagus (Asparagus officinalis L.), eggplant (Solanum melongena L.), carnation (Dianthus canyophyllus L.), watermelon (Citrullus lanatus), tomato (Solanum lycopersicum L.), (Minuto et al, 1995ab;Larkin and Fravel, 1999;He et al, 2002;Reid et al, 2002;Silva and Wagner, 2005) and colonize the plant rhizosphere and roots without inducing any symptoms (Benhamou and Garand, 2001). The non-pathogenic antagonistic F. oxysporum have the same characteristics as pathogenic except that they are not disease causing and hence are important because these organisms can sustain up to the crop duration.…”

Efecto de Trichoderma harzianum y compost sobre el crecimiento de plántulas de Pinus radiata en vivero

“…Los beneficios obtenidos varían según las condiciones ambientales y con la asociación particular de las especies involucradas (Trappe 1977, Bledsoe 1992. En general, las plántulas ectomicorrizadas poseen una mejor adaptación al estrés hídrico (Duddridge et al 1980, Boyd et al 1986, Reid et al 2002 y una mayor supervivencia en las plantaciones (Wright 1957, 1971, Castellano y Molina 1989. No obstante lo anterior, hongos no micorrícicos pueden estimular el crecimiento de plantas cultivadas (Rabeendran et al 2000), éste es el caso de Trichoderma harzianum (Rifai) (Deuteromycetes).…”