Selection of genetically diverse Trichoderma spp. isolates for suppression of Phytophthora capsici on bell pepper.

Environmentally compatible control measures are needed for suppression of Phytophthora capsici on pepper. Twenty-three isolates of Trichoderma were screened for suppression of a mixture of 4 genetically distinct isolates of this pathogen on bell pepper (Capsicum anuum) in greenhouse pot assays. Of these 23 isolates, GL12, GL13, and Th23 provided significant suppression of P.

Genetic and Biological Diversity of Trichoderma stromaticum, a Mycoparasite of the Cacao Witches'-Broom Pathogen.

ABSTRACT The witches'-broom disease, caused by the basidiomycete Crinipellis perniciosa, is the most limiting factor for cacao cultivation in Brazil. Trichoderma stromaticum is a mycoparasite of the witches'-broom pathogen of cacao that is currently being applied in the field to manage the disease in Bahia State, Brazil. In this work, molecular and traditional methods were used to study the genetic and biological diversity of this mycoparasite.

NEP1 orthologs encoding necrosis and ethylene inducing proteins exist as a multigene family in Phytophthora megakarya, causal agent of black pod disease on cacao.

Phvytophthora megakarya is a devastating oomycete pathogen that causes black pod disease in cacao. Phytophthora species produce a protein that has a similar sequence to the necrosis and ethylene inducing protein (Nep1) of Fusarium oxysporum. Multiple copies of NEP1 orthologs (PmegNEP) have been identified in P.

Developmental expression of stress response genes in Theobroma cacao leaves and their response to Nep1 treatment and a compatible infection by Phytophthora megakarya.

Developmental expression of stress response genes in Theobroma cacao leaves and their response to Nep1 and a compatible infection by Phytophthora megakarya were studied. Ten genes were selected to represent genes involved in defense (TcCaf-1, TcGlu1,3, TcChiB, TcCou-1, and TcPer-1), gene regulation (TcWRKY-1 and TcORFX-1), cell wall development (TcCou-1, TcPer-1, and TcGlu-1), or energy production (TcLhca-1 and TcrbcS). Leaf development was separated into unexpanded (UE), young red (YR), immature green (IG), and mature green (MG).

Effect of Formulated Plant Extracts and Oils on Population Density of Phytophthora nicotianae in Soil and Control of Phytophthora Blight in the Greenhouse.

Formulated plant extracts and oils were investigated for control of diseases caused by Phytophthora spp. Soil infested with chlamydospores of Phytophthora nicotianae was treated by incorporating 1, 5, and 10% aqueous emulsions of formulations containing clove oil, neem oil, pepper extract and mustard oil, cassia extract, synthetic cinnamon oil, or the fungicide metalaxyl. Population densities of P.

Effect of Botanical Extracts on the Population Density of Fusarium oxysporum in Soil and Control of Fusarium Wilt in the Greenhouse.

Several commercial formulations of botanical extracts and essential oils are being investigated as possible alternatives to soil fumigation for control of Fusarium wilt diseases. Soil infested with Fusarium oxysporum f. sp.