Onion thrips (Thrips tabaci) are an increasing pest of greenhouse ornamentals, strawberries, vegetables, and even cannabis. Why is this, and what can growers do about it?
To learn more about this emerging pest, register for the latest GrowON webinar – a webinar series JUST for covered crops!
Onion thrips (Thrips tabaci) are an increasing pest of greenhouse ornamentals, strawberries, vegetables, and even cannabis. Why is this, and what can growers do about it?
To learn more about this emerging pest, register for the latest GrowON webinar – a webinar series JUST for covered crops!
Every year, factors like increased cloud cover, rain, poor ventilation, and lack of accessible chemicals can leave growers struggling to control Botrytis cinerea (otherwise known as grey mould) in their crops. Our next GrowON webinar speaker has spent an entire PhD trying to bring you better solutions to an old problem: battling Botrytis.
Read on for more details on the speaker and how to register.
Continue reading “REMINDER TO REGISTER: Webinar on Battling Botrytis THIS THURSDAY”Every year, factors like increased cloud cover, rain, poor ventilation, and lack of accessible chemicals can leave growers struggling to control Botrytis cinerea (otherwise known as grey mould) in their crops. Our next GrowON webinar speaker has spent an entire PhD trying to bring you better solutions to an old problem: battling Botrytis.
Read on for more details on the speaker and how to register.
Continue reading “GrowON 2022 Webinar Series: Battling Botrytis in Covered Crops.”
As much as we all hate thrips, there are, frankly, worse problems to have. And it’s name is Leafminer. These flies cause just about the ugliest damage we see in floriculture (Fig. 1), and they have incredible pesticide-resistance capabilities. Outbreaks seem to go in cycles, and I’ve had quite a few gerbera and mum crops come across my desk with leafminer this past 2 weeks.
This post covers chemical options (BawHawHawHa!!! Oh… Sorry… I’ll get myself under control now) and non-chemical options for leafminer, as well as how their control fits into the big picture in greenhouse IPM programs.
Happy spring! With the season in full swing, we know that growers are busy this month. I read an interesting article on the effects of supplemental LED lighting in bedding plants this week, and I’ve summarized it here with the key messages at the bottom of this post. It seems like an appropriate article for the season, especially if you are starting to think ahead to how you might improve production for the 2017 spring season.
Much of the LED lighting research done in ornamental plants has focused on finding the best wavelengths for plant production. This can vary based on the plant being grown, and the qualities desired. Before we dive into the study, let’s review some of the reasons why you might consider LED lights from a plant production standpoint. Continue reading “Supplemental Lighting Options for Bedding Plant Seedling Production”
I’ve had a handful of calls in the past few weeks asking me to identify poor air quality damage on spring bedding crops. Even if you have never had problems, the following is a good refresher on why proper maintenance of greenhouse heating systems is important.
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.
These impurities can leave your crop looking a bit down (Literally! It’s called epinasty, see more below), and it can happen in as little as 24 hours. Continue reading “A Burning Question: Ethylene and Sulfur Dioxide Damage in the Greenhouse”
The ice storm that passed through Ontario late last week may have disrupted more than just your travel plans. If your power went out, and your generator didn’t kick on right away your greenhouse might have dipped in temperature overnight, leading to possible cold or chilling injury. Continue reading “Recognizing Cold Injury”
Effective biocontrol programs for western flower thrips often use multiple natural enemies. These include predatory mites like N. cucumeris or A. swirskii, but also generalist predators like Atheta and Orius, which can feed on mite eggs and nymphs.
So, how can you make sure your generalist predators aren’t just eating all your predatory mites, instead of your thrips? Continue reading “Snack attack: how to help prevent your thrips bios from eating one another”
By Sarah Jandricic and Chevonne Carlow
It’s that time of year again, when baskets of Million Bells (Calibrachoa) are going up in the greenhouse. Here’s how to deal with and prevent some of their most common issues.
Iron deficiency in Calibrachoa. The resulting yellowing can look similar to symptoms caused by black root rot or nitrogen deficiency.
From a nutritional standpoint, the best thing you can is keep the pH of your calibrachoa in its ideal range; between 5.5 and 6.0. A pH higher than this can inhibit nutrient uptake, especially micronutrients such as iron.
Iron deficiency can be difficult to distinguish from other issues (like Black Root Rot – see below), but typically leads to yellowing of new growth. Leaves may only show chlorosis between the veins, or it may be spread throughout the leaf. This is different from nitrogen deficiency where yellowing occurs in the oldest leaves. If iron deficiency occurs, adding a chelated form of iron is best for uptake.
Million bells are also highly susceptible to Black Root Rot (Thielaviopsis) – I’ve seen this take out a good chunk of a crop. Symptoms include:
Prevention is worth a pound of cure with this disease, as it is difficult to eradicate once established. Important steps to take include:
If already established, rotated applications of Senator and Medallion may limit Black Root Rot, but are unlikely to cure it.
Lastly, Million Bells are highly attractive to aphids. With baskets hung up in the greenhouse, they can be “out of sight, out of mind”, but regular monitoring is needed to prevent large aphid outbreaks. Place sticky cards directly in baskets, and routinely check plant material for aphid cast skins and honeydew.
Once aphids are detected (and they will be!), applications of Beleaf (flonicamid), Enstar (kinoprene) or Endeavor (pymetrozine) will usually take care of them. However, be aware that all of these insecticides take around 4-5 days to start causing aphid death.
