Protocol developed by
participants of the NE-1013 snap bean project.
For further information, contact:
Kent Burkey, Ph.D.
USDA-ARS Plant Science
NC State University
Raleigh, NC 27607
The following protocol is
based on a small plot approach so that multiple plantings are possible without
requiring significant land area.
- Use a rototiller or other available equipment to
prepare a seed bed free of weeds and debris.
- Slow-release fertilizer will be applied after
emergence as a side dress to discourage weed growth between rows.
- Each plot will be a single 3-meter (~10-ft) row.
- Row spacing of approximately 1-meter (flexible
to accommodate equipment and availability of plot land).
- Two adjacent rows will form an experimental
block containing the two snap bean lines.
- Each planting date will consist of 4
experimental blocks (8 rows).
- Randomly assign bean lines (e.g. S156 and R331)
to the rows within each 2-row block.
- Distinctive border plants (e.g. yellow wax
beans) are an option to separate sequential plots.
Planting and plant density:
- Manually prepare furrows approximately 2 cm
- Inoculate seeds with commercial preparation of
Rhizobium (e.g. Lipha Tech Company, 3101 W. Cluster Ave., Milwaukee, WI 53209, 1-800-558-1003; inoculum “D” for common bean). [Natural
Rhizobium populations are often not very effective, and it is unclear how
effective commercial preparations will be under our fertilization regime,
but for consistency each location should inoculate.]
- Hand-plant 60 inoculated seeds in each 3-meter
plot. Space as 30 sets of 2 seeds approximately 10 cm (~4 inches) apart.
- Water the seed bed immediately after planting to
enhance uniform germination, but do not water again until after emergence.
- After emergence, thin to 24 plants per 3-meter
plot…12 in each 1.5-meter subplot (see “Harvests”).
- Beginning 1 week after emergence, provide water
equivalent to 1 inch of rain per week by either natural rain events or
application using available equipment. Drip irrigation would be ideal; Raleigh is very happy with a landscaping irrigation
product called Netafim Techline. Based on a row width of 1 meter, 6.7
gallons of water per linear meter of row (or 20 gallons per 3 m row) is a
volume equivalent to 1 inch of rain over the 1 m2 area but
applied as a strip within each row. This is a contrived system, but we
need a standard approach. In addition, regions with high temperatures and
low humidity may have extremely high evapotranspiration rates that require
more water than other regions, so customized watering regimes will need to
be developed for individual locations.
- Incorporate a single application of slow release
fertilizer as a side dress at thinning (Scott’s Osmocote Plus, NPK 15-9-12 with micronutrients, 3-4 month release period).
30 g/plant x 24 plants = 720 g distributed evenly along each row and
incorporated by hoeing as part of the process of ridging up soil around the
- Remove weeds manually as required; rototiller
between rows, hand weeding within rows.
- Pest and pathogen problems will be unique to each location and should
be treated (and carefully documented) using recommended
chemicals/practices for the region. If root rot is a problem, some form of
soil sterilization made be required depending on severity of the problem
and other circumstances.
Harvests: Randomly assign 1.5-meter subplots for
mid-season and final harvests within each 3-meter plot
- Mid-season: Multiple harvests of “marketable”
pods from 10 of 12 plants in the mid season subplot (exclude plant #1 and
#12 that are considered border plants). Use visual estimate of pod
maturity to determine harvest date. Decided to use multiple fresh pod
harvests instead of a single “biomass” harvest in case pods develop at
different rates even though flowering will begin at the same time in S156
- Final: When >75% of pods are brown, harvest
10 of 12 plants in the final harvest subplot (exclude plant #1 and #12
that are considered border plants) for determination of final pod number
per plant. Dry pods to constant weight to determine pod yield, total seed
number and seed weight per plant, and average weight per seed.