Salmonella-Shigella plates. Salmonella-Shigella (SS) plates are used to detect bacterial contamination on raw meat. Salmonella-Shigella agar plates contain lactose, bile salts, ferric citrate, and neutral red.The bile salts select for Gram-negative bacteria.almonella-Shigella plates. Salmonella-Shigella (SS) plates are used to detect bacterial contamination on raw meat. Salmonella-Shigella agar plates contain lactose, bile salts, ferric citrate, and neutral red.
The best time to prune them is in early spring, just before they put on their growth spurt. You can do minor shaping and pruning at other times of year, too. Test Garden Tip: Save on holiday decorations by snipping a few branches for winter holiday greenery.
The best time of year to prune oak trees is from late fall until the end of March, when oak wilt disease is dormant and there is no risk of infection. If your oak tree is pruned at any other time of the year, some type of sealant should be applied to all pruning wounds to prevent oak wilt infection. Pruning paint is effective along with any latex paint. This same time period is also appropriate for trimming other species of trees, when insects and disease are dormant.