Features Fruit Production
Reducing transplant stress in field vegetables

June 1, 2010 – Field
vegetable growers have found that transplants are effective in decreasing seed
requirements and costs, reducing labour requirements for thinning and providing
more uniform planting density and accelerated crop development.

June 1, 2010 – Field
vegetable growers have found that transplants are effective in decreasing seed
requirements and costs, reducing labour requirements for thinning and providing
more uniform planting density and accelerated crop development.

“Earlier crop maturity
that is experienced when transplants are used means that growers will have an
extended harvest window,” says Robert Spencer, with Alberta Agriculture and
Rural Development. “An extended harvest means increased returns due, especially
when the grower also realizes improved yields and crop quality.”

For varieties that require
longer seasons, transplanting sets can make a huge difference, especially in
parts of Canada where the growing season is shorter.

“When transplanting,
reducing stress on the young plants is extremely important,” says Spencer.
“Growers should ensure that transplants have a good root system before they are
moved. This means that the plants are not transplanted until they are of the
appropriate age and size, are not too big or too old, as younger plants tend to
establish faster and experience less shock.”

Transplants must be
properly hardened off before being moved. Hardening off is a process designed
to allow plants to prepare and adjust to the harsher environmental conditions
outside of the greenhouse.

Hardening off may involve:

• allowing plants to dry out
  slightly
• reducing fertilizer
• placing in direct sunlight
  or outside during day
• reducing or increasing
  temperature for two to five days depending on planting conditions
• ensuring that transplants
  have root ball moisture topped up before planting

“Plant transplants at the
proper depth and firmly pack the soil around the root ball,” says Spencer.
“Plants should receive a dose of high phosphorus water-soluble fertilizer after
planting. It is important to water-in after planting as this ensures that there
is adequate moisture and soil to root contact.”

Care and caution at this
tender stage to avoid removing or damaging roots, can make a significant
difference in plant survival. Planting should take place on calm, cool,
overcast days as opposed to hot, dry and windy days. Failure to reduce
transplant stress can minimize the benefits that come from using transplants.