There is no standardized protocol to select Trichoderma against trunk disease pathogens in grapevine. This study describes a protocol to select Trichoderma isolates for protecting the pruning wounds of grapevine against Lasiodiplodia theobromae. Thus, four assays were performed: (1) in vitro antagonism of Trichoderma isolates, molecularly identified, to control L. theobromae; (2) in vitro effect of grapevine fungicides on the conidia of the antagonists; (3) capability of Trichoderma to survive and endophytically penetrate in grapevine canes; and (4) efficiency of Trichoderma and fungicides to protect the pruning wounds of grapevine shoots against L. theobromae. T. asperelloides (02/03), T. koningiopsis (09/02), and T. asperellum (01/13) were the best antagonists for L. theobromae. The conidia of the three isolates were affected only by tebuconazole, with the first two fungi being the most tolerant to the fungicides. The Trichoderma isolates survived on the cane tip for 15 days, but only T. asperelloides (02/03) penetrated endophytically 4 cm in the cane and showed preventive and curative capability to control L. theobromae, with similar efficiency as that of the fungicides in both the periods tested post inoculation. These four assays are suggested to select Trichoderma against L. theobromae or other trunk disease pathogens.

The ground pearl, Eurhizococcus brasiliensis (Wille) (Hemiptera: Margarodidae), is the most important grapevine pest in Brazil. Its seasonal occurrence and distribution on the roots of the different development stages were determined to allow better monitoring of this insect and better targeting of its vulnerable life stages. Yellow cysts (after the first nymphal moult) showed the lowest density in October, followed by a gradual increase towards August. White cysts (cysts with enclosed pre-pupal males or females) occurred from August to December, with a peak in November. Mobile females (adult females emerging from the white cysts) were found from August to December, with a peak in August. Parthenogenetic females that remain in the ruptured white cysts for egg laying were present from August to April, with a peak in November. Mobile nymphs (first instar) were also found from August to April, with a peak in December. Yellow cysts were most abundant at depths of 0 to 25 cm. The horizontal survey showed that cysts occurred mostly on the trunk below the ground (trunk of the rootstock), and that almost all occurred in an area of 20 cm width around the trunk. These results provide important information for better monitoring of this pest and to develop better methods for and timing of chemical control.