Sampling Decisions

Questions that you can ask yourself to help you decide a sampling methodology is listed below.  What is most important is that you know your goal and scope of your project before you begin.  This will minimize the risk of under- or over-collection, collection of the wrong type of plant material, and the potential for unanticipated additional visitations to the plant population.

1.  What is the purpose for the collections?
   - Seed storage?, tissue culture living germplasm storage?, molecular research?, restoration propagation?
   - Where will the plant material collected be stored, propagated, or researched?

2.  Should the species be collected?
   - If the species of interest is rare or in areas that are difficult to access, is there analternative that can be used in its place?
   - If a cultivated source is available, can it be used in place of wild collected plant material?
   - Is there a legitimate need for a collection to be made?

3.  How many populations should be sampled per species?
   - How many populations are there?
   - Do I need to sample from every population and if not, which one will I sample from?
   - Are all of the populations accessible?
   - How will I impact the wild population(s) structure and surrounding area by my visitation.

4.  How many individuals should be sampled per population?
   - What do I know of the life history of the species (e.g. self incompatible or incompatible, plant variation within the population)?
   - What is the population size?
   - How many individuals would be considered representative of the population?

5.  How many propagules should be collected from each individual?
   - What kind(s) of propagules (seeds? cuttings?) will I collect?
   - What is the maximum amount of material I can remove before being detrimental to the individual plant and the dynamics of the wild

6.  Under what circumstances is a multiyear collection plan needed?
   - Propagation or storage attempt failed, and another collection trip is warranted as long as it does not negatively impact the natural
   - Only a very limited amount of plant material can be harvested at a time due to risk of harm to the plants or the dynamics of the plant

The risk of disease transmission of viral, fungal, or bacterial origin is a realistic possibility through the cutting implements used in collection of plant samples.  It is imperative that precautions be taken to ensure the integrity and overall health of the existing population and the surrounding flora as well as to maintain clean propagation stock material during collections.  While absolute elimination of all pathogens is impossible, sanitation protocols that minimize the risk of introducing serious foreign pathogens should be mandatory procedural requirements in any collection activity from wild plants.

Whenever possible, any plant samplings that require cutting into or off of a wild donor plant should be made with a new, unused blade.  This can be accomplished by using an implement such as a box knife fitted with a disposable razor blade.  The used blade can be changed before cutting the next sample. If using disposable blades are not suitable or available, decontamination of your cuttings tools (shears, pruners, knives) can still be accomplished through soaks in various cleaning products.  Read the manufacturer's label, material safety data sheet and application recommendations for proper usage and disposal.  The disinfestment soaks of tools require some time in solution, so it is best to work with several pairs at a time.  This way, you can have one to work with immediately and another soaking.

The described disinfestment treatments can significantly shorten the life of your tools. To prolong the life of your cutting tools, rinse in clean water, dry, and oil (e.g. Felco 980 spray) the blades at the end of each work period.

Some suggested disinfectants are:

1.  Chlorine Bleach solution: Make a 5-10% solution of household bleach.  Rinse tools with water to remove any visible debris or plant sap.  Soak rinsed tools in bleach solution for 5-10 minutes then rinse well with water.  Do not store pre-made solutions, always use a fresh batch of bleach solution made the day you do your cuttings.  Warning: Chlorine bleach is very corrosive to your tools.

2.  ZeroTol® is a broad-spectrum algaecide/fungicide formulated to kill active and dormant spores on contact.  ZeroTol is plant-safe, and can be used on tools, pots, trays, structures, concrete walkways, gravel/dirt walkways, stock tanks, and irrigation lines. For disinfestation of cutting tools, use a dilution of 1:300 or ½ fl. oz. per gallon of clean water.  Immerse cutting edges of tools for at least 10 minutes.  ZeroTol has a minimal amount of surfactant added in their formulation to improve the wetting action of the solution, but additional surfactant may be added if needed. Do not dry off and use the wet tool to make your cuttings.  Repeat the disinfection soak after use on each plant to kill and prevent transmission of plant disease organisms.  

3.  Consan® Triple Action 20 is a disinfectant, fungicide, microbicide/microbistat, sanitizer, virucide and algaecide for birdbaths, greenhouses, cutting tools, flower pots and algae covered hard surfaces.  Soak the cutting edges of plant tools in a solution of one teaspoon of Consan to one gallon of water for at least 10 minutes. Do not dry off and use the wet tool to make your cuttings.  Repeat the disinfection soak after use on each plant to kill and prevent transmission of plant disease organisms.  

4.  Miscellaneous Biocides: Some regular commercially available household cleaners might be useful as disinfectants for cutting tools or hard surfaces.  Read the manufacturer's label to see if the product is suitable for your specific needs.  For example, Proforce® from Ecolabs (can be found at Sam's Club, Sears and Amazon), is a one step disinfectant, cleaner, sanitizer, fungicide, mildewstat, virucide and deodorizer  Use at the recommended rate of 1 -2 oz per gallon of water.

5.  Flaming tools: An 85% ethyl alcohol dip followed by a 6-8 seconds flaming with a mini torch or Bunsen burner is sometimes used to clean cutting implements.  It is not recommended nor employed very often in field work due to the hazardous nature of this procedure.  This method is suited more for an environmental setting where the risk of starting a fire or causing injury by fire is controlled and minimized, such as in the greenhouse or propagation facility.

Before your collection trip, you should:

1. Familiarize yourself with the plant’s natural growth and reproduction habits to help determine the right time and stage to collect. 

2. Know what kind(s) of horticultural methods of propagation or storage you will have performed on the collected plant material, so that the right type, stage and quantity of propagation material is collected.

3. Compile the right type of collecting equipment and tools for harvesting, and packing material and containers to secure the plant material in once collected.

4. If you do not have one already, decide on a format as to how you will record your collection data.

In addition, you should keep in mind that the quality of the plant material harvested is directly dependant upon:

1. The health of the mother plant.  In general, unhealthy plants provide weak and/or diseased plant material and poor quality seed that are difficult to propagate.  When there is no alternate plant source, and propagules are removed from the plant, care must be taken to prevent causing further damage to the plant

2. The timing of the collection. Collection trips should be scheduled during the active vegetative growth period (if collecting vegetative material) or during the peak seed production period (if collecting mature seed) of the plant’s natural biological cycle.

3. Post-harvest handling.  Once collected, the plant propagules should be properly insulated and contained to safeguard and maintain the quality of the plant material during transport to the propagation and/or storage facility.