Sensitivity of hyperparasitic fungi to alternative products for use in the control of papaya black spot

Abstract

The use of more than one control technique can maximize the reduction of the damages caused by the fungus Asperisporium caricae causal agent of the black spot in the papaya crop. The objective of this work was to evaluate the sensitivity of the fungi Hansfordia pulvinata and Acremonium spp. to alternative products with potential for use in the control of the black-spotted ptarmigan. Three isolates of Acremonium spp. (A-598, A-602 and A-617) and an isolate of H. pulvinata (H-611) were grown in BDA medium containing Agro-Mos  , Bion  , Ecolife  , Hortifospk  , Matriz G  , Vitaphol  separately. The Amistar 500WG  fungicide was used as a positive control and pure BDA as a negative control. The toxicity of the tested products was determined based on the values of the biological index, derived from the means of mycelial growth, sporulation and germination of conidia, in each experimental unit. In this way it was possible to select the products classified as compatible for all isolates, and to test them in vivo. In the greenhouse, only the isolates and isolates with selected products, were applied in papaya plants with foliar symptoms of black-spotted. The incidence of leaves with hyperparasites and the percentage of black-painted lesions colonized by the tested isolates were evaluated. Thus, the H-611 isolate proved to be compatible with most of the alternative products tested, except with Hortifos  . Bion  and Matrix  products were compatible with all tested isolates and could be used in conjunction with Acremonium spp. and H. pulvinata to control the papaya black spot, since these products did not present toxicity on the hyperparasitic fungi.

Perception of fungi by farmers in the Cerrado

“…It was observed that conventional farmers had a greater understanding of what fungi are, as they could identify fungi as being harmful to crops. This is because many are phytopathogenic to a great diversity of cultivable species and of economic importance (Dean et al 2012, Vivas et al, 2020. These farmers know more about the species of fungi that cause diseases in different productions and the methods of combating them, usually through the use of pesticides or other chemical compounds.…”

“…Maubl. (Ascomycota: Mycosphaerellaceae) that causes the black-spot in the papaya crops (Vivas et al, 2020). The production of biofertilizers by capturing fungi from the soil is also a viable alternative recognized by these farmers.…”

Prospection of genotypes resistant to black spot in half‐sib families of papaya

“…Other works evaluated severity, incidence, and AUPDC on papaya black spot used to alternative products to disease control; however, the more economical method to disease control is resistance genetics (Vivas et al., 2021). The Golden cultivar (susceptible control) and Maradol (resistant control) were overcome by half‐sib families in this work, showing the resistance potential of the genotypes (Pirovani et al., 2021).…”

Evaluating the Utility of Simplicillium lanosoniveum, a Hyperparasitic Fungus of Puccinia graminis f. sp. tritici, as a Biological Control Agent against Wheat Stem Rust

“…Hyperparasitic fungi are widespread in natural ecosystems and commonly parasitize filamentous fungi [ 5 ]. These fungi might provide promising alternatives to chemical fungicides for the control of fungal diseases in plants [ 6 ]. They have thus received much research attention from botanists for their potential to be used as biocontrol agents against plant pathogens.…”

“…However, the application of nonselective fungicides can lead to a disease more difficult to manage [ 9 ]. In addition, the heavy use of fungicides can have deleterious effects on the environment, along with animals and humans [ 6 ]. Here, the utility of hyperparasitic fungi for the control of Pgt infection is evaluated.…”