Oh dear! It’s Oedema.

IMG_0690

Oedema on the young leaves in this begonia basket.

Oedema, that physiological disorder that appears during periods of low light and high humidity.  There’s been quite a bit of it reported in Ontario greenhouses this spring, and unfortunately it’s related to the long rainy (or snowy!) spring we’ve been having.  If you’ve noticed salt-like crystals, odd tumour-like growths or water-soaked spots on either side of your plant leaves this disorder might be the culprit.

The disorder affects a wide variety of greenhouse ornamentals.  It’s usually noticed in spring crops like sweet potato vine (ipomea), geranium, begonia and/or petunia. Continue reading “Oh dear! It’s Oedema.”

Advertisements

It’s “B” Season! Watch for Botrytis, Broad Mite and Burn.

Honeybee 2Although native bees and honeybees may just be starting to gather strength and are beginning to fly outside, other “B’s” have been of growing concern in the greenhouse for some time now.

These include common spring bedding crop problems like Botrytis cinera (aka grey mold), Broad mites, and leaf burn (from a variety of causes).

Keep reading for tips on how to manage these issues during this time of year.

Continue reading “It’s “B” Season! Watch for Botrytis, Broad Mite and Burn.”

Considerations for fine-tuning your fertilizer program

How do you typically fertilize floriculture crops in your greenhouse?  Based on how the plant performs? Maybe based on recommendations from your consultant or supplier?  Do you do it the way it’s always been done?  Do you know why it was always done that way? Continue reading “Considerations for fine-tuning your fertilizer program”

Demonstration Day – Best Management Practices for Outdoor Mum and Hydrangea Growers

Calling all outdoor chrysanthemum and hydrangea growers! Do you currently produce these crops outdoors during the summer months?  Would you like to learn more about how adjusting your fertilizer program could potentially lead to savings while maintaining the quality of the crop? How about learning about how to best manage your water and fertilizer program in an outdoor setting? Continue reading “Demonstration Day – Best Management Practices for Outdoor Mum and Hydrangea Growers”

Botrytis Bumming You Out?

BotrytisPrimula3

Botrytis spots on Primula petals.

With the intense period of rain we just had, and with MORE rain coming on Friday, it’s time to think about Botrytis control and prevention.  One of the most common and destructive diseases of greenhouse crops, outbreaks usually follow periods of cool, damp, cloudy weather.  Unfortunately, I can’t order up more sun for you, but I CAN suggest some management tactics.

 

Continue reading “Botrytis Bumming You Out?”

A Reminder about Fertilizer Injector Maintenance

Spring is here, and we know you’re busy!  Here’s a quick but very important refresher on fertilizer injector maintenance.  Ensure they’re working properly on a regular basis to avoid extra headaches.

How do I know if my injector is working properly?

Hopefully damage to foliage wasn’t your first sign things were a little off! Some things to remember:

  • The dilution ratio needed for each application should be known and adjusted as needed.
  • Remember that tracing dye in water-soluble fertilizers should never be used as an indicator of the actual strength of a fertilizer mixture.
  • If you are using multiple products or chemistries ensure they are compatible for tank mixing before running them through the injector.
  • If deviations greater than 5% from the expected setting occur, contact an irrigation specialist for assistance or repair. (But first, double check that math!)

Fertilizer injectors come in all shapes and sizes in the greenhouse.

There are two common methods to check if your injector is working as expected. Regular calibration is needed to ensure that an injector is operating properly. You should complete both methods listed here to ensure accuracy. Continue reading “A Reminder about Fertilizer Injector Maintenance”

Improperly ventilated heaters & ethylene damage

Spring is on its way, and with cold nights and warmer days we are seeing a common spring problem – poor air quality damage on spring bedding crops.  Symptoms, solutions and preventative measures are included in this 2017 update to a previous post.

Natural gas and propane are popular choices when it comes to heating a greenhouse.  The products of burning fuel are carbon dioxide (CO2) and water (H20); both compounds we know are good for your plants.  However, combustion is often (if not always) incomplete, and impurities such as carbon monoxide (CO), sulfur dioxide (SO2) and ethylene (C2H4) are also released leading to poor air quality if your heater is not properly vented.

Typically symptoms from ethylene damage and sulfur dioxide damage can been seen fairly quickly after exposure.

Figure 1. Signs of ethylene damage include leaf curling and epinasty, seen here in A) New Guinea Impatiens and B) lettuce seedlings.

In the short term (a few hours to a few days), ethylene damage results in leaf curling, epinasty (leaves bending downwards from the petiole) and flower drop.  If the stress continues over a Continue reading “Improperly ventilated heaters & ethylene damage”