At the core of most clichés is a source of wisdom and nip it in the bud’ is no exception. When it comes to plant disease management, including those caused by bacterial and fungal pathogens, the key to success is to literally nip it in the bud – remove and/or inhibit the source of inoculum. To achieve this as the weather becomes more accommodating to plant pathogens (increased temperature and humidity), a few crucial strategies are necessary:

1. Regularly scouting for anomalies – circular, angular or ‘mushy’ leafspots and/or ‘fuzzy’ fungal fruiting bodies (Peronospora), wilting/crinkling (Rhizoctonia spp.), discoloration of leaves, or defoliation – will help to identify early onset of disease outbreaks.
2. Ensuring a sufficient ‘dry-down’ cycle between irrigation events (these include rain and supplemental irrigation events) will ensure that leaves and flowers do not remain wet for extended periods and most importantly, overnight. Leaves and flowers should be allowed to dry-down between irrigation events to discourage development of plant diseases such as Botrytis and Cercospora spp. Many commercial nurseries do not irrigate after 2:00 pm, and try to minimize overhead irrigation as much as possible, relying on spaghetti-tubing or flood-irrigation methods.
3. Establishing good air circulation with adequate spacing between plants is crucial for helping to keep pathogen populations low and preventing disease spread among plants. Fans can be used to help improve air circulation in areas where plants are densely aggregated.
4. Improved water quality is also key for ensuring that water-borne pathogens (e.g. Pseudomonas ) are not introduced to plants via irrigation water or systems. Large nursery operations rely on using peroxide to treat both circulated and re-circulated irrigation water.
5. Removing the source of inoculum by culling infected plants goes a long way to saving healthy plants, thereby nipping the problem in the bud before it gets too cost prohibitive or nigh impossible to control. Pesticides may not always be an option as pesticide resistance becomes increasingly more common due to overuse/misuse.

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