Compatibility of Trichoderma isolates with pesticides used in lettuce crop

Abstract

Keywords: Sclerotinia minor , Sclerotinia sclerotiorum, Trichoderma asperellum, Trichoderma asperelloides, Lactuca sativa, controle biológico, controle químico.Lettuce drop, caused by Sclerotinia sclerotiorum and S. minor, is considered one of the most important diseases that affect this crop in Brazil (21); it is also widespread worldwide, causing considerable losses in lettuce crops (22).This disease causes wilting and collapse of lettuce heads in infested fields where weather conditions favorable for its development, such as mild temperatures and high humidity, prevail (13, 28). The main difference between S. sclerotiorum and S. minor is that the latter forms a white mycelium with several small black sclerotia (0.5 to 3 mm diameter), while S. sclerotiorum forms fewer and larger sclerotia, irregular in size, on the lettuce heads (28).The management of lettuce drop is usually obtained by integrating Lettuce drop, caused by Sclerotinia minor and S. sclerotiorum, is one of the most important diseases that affect lettuce crop in Brazil. In previous studies, isolates of Trichoderma asperellum (IBLF 897, IBLF 904 and IBLF 914) and T. asperelloides (IBLF 908) were selected for the biocontrol of this disease. In this subsequent study, the compatibility of these isolates with pesticides used in lettuce crop in Brazil was evaluated. Initially, the mycelial growth of isolates was evaluated in culture medium plus pesticides. Then, the effect of pesticides on the parasitism of T. asperelloides isolate IBLF 914 in baits and sclerotia of S. minor and S. sclerotiorum, as well as on the survival of lettuce seedlings, was evaluated in gerboxes after application on baits and sclerotia of the antagonist with pesticides at their respective commercial doses.

Evaluation of a Newly Identified Endophytic Fungus, Trichoderma phayaoense for Plant Growth Promotion and Biological Control of Gummy Stem Blight and Wilt of Muskmelon

“…In this study, T. phayaoense could tolerate the selected fungicide (metalaxyl) in the field at recommended dosages. Similar to our results, previous studies have shown that T. atroviride, T. harzianum , T. koningii , and T. pseudokoningii have been acknowledged for their ability to tolerate fungicides, herbicides, and insecticides ( Khan and Shahzad, 2007 ; Chaparro et al, 2011 ; Singh et al, 2012 ; Bhale and Rajkonda, 2015 ; da Silva et al, 2018 ). Additionally, the biocontrol agents of T. harzianum and T. virens could tolerate different insecticide compounds and could display varying degrees of tolerance ( Wedajo, 2015 ).…”

Determination of effects of some fungicides used in hazelnut growing areas against Trichoderma species

“…In the previous studies, several fungicides including prochloraz, guazatine, cyprodinil, fludioxonil, azoxystrobin, metalaxyl+mancozeb, metalaxyl+copper oxide, copper hydroxide, copper sulphate and copper oxide were found to be more effective to conidial germination of Trichoderma spp. (Roberti et al 2006;Marcellin et al 2018;Silva et al 2018).…”

Trichodermaas a Biocontrol Agent againstSclerotiniaStem Rot or White Mold on Soybeans in Brazil: Usage and Technology

“…The ai fluazinam (alone or associated to thiophanate-methyl) and carbendazim (C) drastically reduced viability of Trichoderma strains (up to complete inhibition of spore germination). In vitro assays report insensitivity of T. harzianum, T. stromaticum, and T. atroviride to procymidone [59][60][61] suggesting its simultaneous use with Trichoderma species for the control of S. sclerotiorum in tomato [62] and lettuce [63]. Other research demonstrate that thiophanate-methyl is compatible to many strains of Trichoderma spp., whereas carbendazim and fluazinam are extremely toxic [64][65], supporting our findings.…”