Bringing growers in the USA together with essential horticulture products from all over the world.
CULTIVATE'22 is HERE!
After two years, we are happy to announce the return of our annual
PTH Customer Appreciation Night! It is our chance to get together and thank you for your continuing support. Join us for a night of celebration for our amazing community! We cannot wait to see you there! When: July 17th at 5:30 PM Where: Wolfs Ridge Brewing - The Hickory Room 215 N. 4th Street Columbus, OH 
It's the most exciting time of the year! Cultivate '22 is this month, and we are making this edition extra special for you! We cannot wait to show you what we have been working on. From July 16 to July 19, come and meet our team at booth #1903!
|
As in years past, the Hort Americas Happy Hour will be a great event to kick off Cultivate and connect with industry leaders. Register here and meet us on Sunday, July 17th
Join Bruno D’Amico, Global Product Manager, Horticulture, for an educational seminar on the proper hanging and mounting of Arize horticulture lighting, from GE Current, a Daintree company. Your free registration also includes lunch. Click on the image above to register.
|
research shows 14% yield increase
"Intra-canopy lighting is an additional tool to improve productivity with the same footprint"
What tools can help growers boost yields without increasing energy consumption or monthly bills? It might just be intra-canopy lighting. New research conducted by Leo Marcelis, his team at Wageningen UR, and researchers of Current shows that intra-canopy LED lighting, even when light input is the same, can increase yields by 14%.
"Essentially, intra-canopy lighting provides localized light for an under-illuminated part of the plant canopy. The plant has an under-utilized architecture which intra-canopy lighting now allows to be an energy source for the plant", says Leo Marcelis with Wageningen UR, who conducted the article in collaboration with lighting company Current. For the study, their new Arize® Integral ICL fixture was used, which directs an optimized light spectrum across a wide, 120-degree angle from both sides of the fixture.
The trial's goal was to simply compare LED toplight to two (2) other treatments that used differing ratios of LED toplight to LED intra-canopy lighting. The premise of the experiment was to determine where best to deploy light for tomato yields. "In other words, to find where a photon has its greatest light use efficiency for tomato production," says Leo.
The trial's goal was to simply compare LED toplight to two (2) other treatments that used differing ratios of LED toplight to LED intra-canopy lighting. The premise of the experiment was to determine where best to deploy light for tomato yields. "In other words, to find where a photon has its greatest light use efficiency for tomato production," says Leo.
Proper design and setup
Being a light study, a lot of thought was given to a proper design and setup by Dr. Leo Marcelis' lab at Wageningen University & Research. For a toplight, the light intensity is measured across a horizontal plane. Intra-canopy light level calibration is not so simple since it occupies a volume. To make sure that the intra-canopy light level was equally calibrated to the other toplight treatments, Dr. Marclis' team had to measure light levels along the z-plane on each side of the tomato row.
Current lights were used for all treatments of the trial. There was an HPS treatment as a control, while the other treatments utilized LED toplight or a combination of LED toplight and intra-canopy lighting, all created using Current lighting products. For all treatments, supplemental light accounted for about 60% of the total light (PAR) radiation. A light level of 300 µmols m-2 s-1 was utilized across all treatments.
Being a light study, a lot of thought was given to a proper design and setup by Dr. Leo Marcelis' lab at Wageningen University & Research. For a toplight, the light intensity is measured across a horizontal plane. Intra-canopy light level calibration is not so simple since it occupies a volume. To make sure that the intra-canopy light level was equally calibrated to the other toplight treatments, Dr. Marclis' team had to measure light levels along the z-plane on each side of the tomato row.
Current lights were used for all treatments of the trial. There was an HPS treatment as a control, while the other treatments utilized LED toplight or a combination of LED toplight and intra-canopy lighting, all created using Current lighting products. For all treatments, supplemental light accounted for about 60% of the total light (PAR) radiation. A light level of 300 µmols m-2 s-1 was utilized across all treatments.
Double-digit yield improvement
So what are the results? The results of this study show that intra-canopy LED lighting, even when light input is the same, can increase yields by 14%.
Tomorrow on the GreenTech, the researchers will dive further into their findings. Yet, they can already reveal their study found that by delivering 34% of the daily light integral (DLI) to mature leaves deep within the canopy, and 66% from top lighting (TL), two of the most common tomato cultivars produced an average of 14% more fruit than those with 100% top lighting. There was also no impact on quality or taste, with the harvested fruit receiving similar Brix scores for sugar content and also recording similar levels of acidity to the fruit grown under 100% TL.
"LED intra-canopy lighting, when deployed and used properly, is another tool and strategy for the grower to improve tomato yields even further in their operation," the researchers conclude. "This novel use of LED lighting changes the arithmetic of production by increasing yields."
So what are the results? The results of this study show that intra-canopy LED lighting, even when light input is the same, can increase yields by 14%.
Tomorrow on the GreenTech, the researchers will dive further into their findings. Yet, they can already reveal their study found that by delivering 34% of the daily light integral (DLI) to mature leaves deep within the canopy, and 66% from top lighting (TL), two of the most common tomato cultivars produced an average of 14% more fruit than those with 100% top lighting. There was also no impact on quality or taste, with the harvested fruit receiving similar Brix scores for sugar content and also recording similar levels of acidity to the fruit grown under 100% TL.
"LED intra-canopy lighting, when deployed and used properly, is another tool and strategy for the grower to improve tomato yields even further in their operation," the researchers conclude. "This novel use of LED lighting changes the arithmetic of production by increasing yields."
"There has been some indication, historically, in the literature about the advantages and applications of intra-canopy lighting, so we knew that results from this trial would probably reflect this. Simply put, I would have been content with single-digit yield improvements (up to 7 or 8% yield improvement). Dr. Leo Marcelis and his team at Wageningen University & Research found an average yield improvement of 14% and were similarly excited by the results", says Hans Spalholz, Horticulture Scientist at Current.
The research will be presented tomorrow, June 14th, 2022, from 16:00-16:30 at the Vision Theatre on the GreenTech in Amsterdam.
Hans Spalholz (GE Current, A Daintree Company), Leo Marcelis (Wageningen University & Research) Investigating the Impact of Intra-canopy Lighting on Tomato Yields. A Research by WUR & Current.
Publication date: Mon 13 Jun 2022
Author: Arlette Sijmonsma
© HortiDaily.com
The research will be presented tomorrow, June 14th, 2022, from 16:00-16:30 at the Vision Theatre on the GreenTech in Amsterdam.
Hans Spalholz (GE Current, A Daintree Company), Leo Marcelis (Wageningen University & Research) Investigating the Impact of Intra-canopy Lighting on Tomato Yields. A Research by WUR & Current.
Publication date: Mon 13 Jun 2022
Author: Arlette Sijmonsma
© HortiDaily.com
Catalogue 2021-2022: Here it Comes
We are pleased to share with you our 2021-2022 PRO-MIX Professional Product Catalogue. Be the first to virtually get your hands on it in the new Toolbox section of our website.
|
|
|
MYKE® ONLINE TRAINING
Refresh your MYKE® knowledge and train your new staff members on the benefits of of using MYKE®! Use the link below to access the 5 short videos. The trainings are easy, informative, and very helpful!
Photoperiod and flowering
Floraldaily - Publication date: Thu 14 Apr 2022
One of the most important environmental factors affecting flowering induction is Photoperiod. Photoperiod is defined as the time plants are exposed to light in a daily cycle.
Plants can be classified based on photoperiodic response in day-neutral, short-day and long-day plants. Day-neutral plants flower at the same time irrespective of the photoperiod. Short-day plants are plants that require a photoperiod shorter than a specific threshold (called ‘critical photoperiod’) to initiate flowers (qualitative short-day response) or plants that flower initiation is accelerated by shorter photoperiods (quantitative short-day response). Long-day plants are plants that require a photoperiod longer than a specific threshold to initiate flowers (qualitative long-day response) or plants that flower initiation is accelerated (quantitative long-day response) by longer photoperiods.
Plants with photoperiodic responses (short-day and long-day plants) are further classified into 2 groups based on the specific response to varied photoperiods: qualitative and quantitative response. Qualitative response in plants happens when a particular photoperiod is an absolute requirement for the occurrence of flowering initiation. In contrast, a quantitative response is when plant flower initiation takes place in both short and long days but one condition accelerates flowering initiation. The degree of quantitative responses is typically cultivar-specific and cultivars with weaker quantitative responses may be mistakenly considered as day-neutral plants.
But, how does photoperiod affect flowering?
Previous research has demonstrated that plants respond to the dark period in each day cycle. For example, Short-day plants will not flower during a short dark period, which is linked to a long day.
Based on the fact that plants respond to dark periods we can then learn that night interruption can break one long night into two short nights. In this case, short nights are related to long-day conditions meaning flowering induction of flowering inhibition (depending on the type of plant) can be controlled by night interruption. Why is this helpful? When trying to promote long-day conditions we usually turn on lights for longer periods. However, by doing night interruption, less electric light is needed. Therefore money can be saved.
Plants of course can have the benefit of longer days which can also promote photosynthesis, growth, and development. But if your intention is only to control the photoperiod, then night interruption can be a good option.
Other important piece of information when looking to induce a photoperiodic response is to learn that plants can have a response to photoperiod from very low light levels (Around 2 μmol m-2 s-1). This is why specific lamps are designed to induce a photoperiodic response. Flowering lamps are usually low intensity. These lamps provide good characteristics in light quantity and quality to induce a photoperiodic response. We also need to learn flowering lamps are not designed to promote strong effects in photosynthesis or growth. They are designed to trigger just a photoperiodic response.
Light quality in flowering induction
Short-day and long-day plants have different photoperiodic response mechanisms, involving components of photo-perception and biological timing. The roles of photoreceptors are essential in the signaling of the photoperiodic control mechanism.
Plant photoreceptors are light-sensitive molecules confirmed by a protein and a light sensible pigment capable of regulating flowering by altering the expression of a key flowering regulator. The main photoreceptors involved in flowering regulation are the red/far-red light receptors, called phytochromes. Phytochromes are proteins responsible for photoperiod sensitivity in plants that utilize a linear tetrapyrrole, bilin chromophore to sense red/far-red light, existing in two inter-convertible forms.
One form of phytochrome is Pr, which is considered the inactive form of phytochrome and has a primary absorption peak at the wavelength of 660 nm (red) and a secondary absorption peak at a wavelength around 380 nm (UV-A). The other form of phytochrome is Pfr, which is considered the active form of phytochrome with an absorption peak at 730 nm far-red wavelengths and a smaller peak at 408 nm blue wavelengths.
Pfr accumulation can inhibit flowering in short-day plants and have the exact opposite effect (Flower induction) in long-day plants. During the dark period Pfr changes to Pr form. This is why long periods of darkness in short-day plants promote flowering. If we do a brief exposure with red light during a dark period, Pr will convert again to Pfr form. This is why night interruption works! In summary, night interruption can be used to avoid flowering in short-day plants or promote flowering in long-day plants.
Research applications
There are other factors affecting flowering response. Some good examples are temperature and Daily Light Integral (DLI). This is why flowering lamps can be really useful for research purposes.
When trying to test photoperiodic treatments and response in plants, it is recommended to extend the period of light artificially under the same temperature and maintain the same DLI within the treatments. In order to maintain the same DLI, the extended period of light should be really low light intensity. By applying treatments correctly we will be able to measure only the effect of photoperiod in flowering response.
Greenhouse application
We can use different lamps in greenhouse operations to promote or inhibit flowering. Regular lamps designed for greenhouse operation to promote higher DLI (e.g. L1000 by Current) can also be used to induce a photoperiodic response. By adding light using regular growing lamps we can increase DLI, which can be good for different crops and also be useful to create longer days when looking to promote flowering in long-day plants or inhibits flowering in short-day plants. If your objective is only to induce a photoperiodic response, then night interruption can be used.
In order to create a short day in a greenhouse, we usually use covers to eliminate natural light, when natural light is above the threshold for a short-day plant. Other options include moving plants or transplants from the greenhouse to a growth chamber in darkness for specific periods of time in order to induce flowering in short-day plants.
There is always an advantage in learning about photoperiod when working with long and short-day plants. Remember the more you know the better you can manage not only your growing system. But also your investment of capital for your projects… and of course! If you need any help in the process Hort Americas will be on board to help you make the best decisions for your projects.
Chris Higgins, CEO, Hort Americas
Plants can be classified based on photoperiodic response in day-neutral, short-day and long-day plants. Day-neutral plants flower at the same time irrespective of the photoperiod. Short-day plants are plants that require a photoperiod shorter than a specific threshold (called ‘critical photoperiod’) to initiate flowers (qualitative short-day response) or plants that flower initiation is accelerated by shorter photoperiods (quantitative short-day response). Long-day plants are plants that require a photoperiod longer than a specific threshold to initiate flowers (qualitative long-day response) or plants that flower initiation is accelerated (quantitative long-day response) by longer photoperiods.
Plants with photoperiodic responses (short-day and long-day plants) are further classified into 2 groups based on the specific response to varied photoperiods: qualitative and quantitative response. Qualitative response in plants happens when a particular photoperiod is an absolute requirement for the occurrence of flowering initiation. In contrast, a quantitative response is when plant flower initiation takes place in both short and long days but one condition accelerates flowering initiation. The degree of quantitative responses is typically cultivar-specific and cultivars with weaker quantitative responses may be mistakenly considered as day-neutral plants.
But, how does photoperiod affect flowering?
Previous research has demonstrated that plants respond to the dark period in each day cycle. For example, Short-day plants will not flower during a short dark period, which is linked to a long day.
Based on the fact that plants respond to dark periods we can then learn that night interruption can break one long night into two short nights. In this case, short nights are related to long-day conditions meaning flowering induction of flowering inhibition (depending on the type of plant) can be controlled by night interruption. Why is this helpful? When trying to promote long-day conditions we usually turn on lights for longer periods. However, by doing night interruption, less electric light is needed. Therefore money can be saved.
Plants of course can have the benefit of longer days which can also promote photosynthesis, growth, and development. But if your intention is only to control the photoperiod, then night interruption can be a good option.
Other important piece of information when looking to induce a photoperiodic response is to learn that plants can have a response to photoperiod from very low light levels (Around 2 μmol m-2 s-1). This is why specific lamps are designed to induce a photoperiodic response. Flowering lamps are usually low intensity. These lamps provide good characteristics in light quantity and quality to induce a photoperiodic response. We also need to learn flowering lamps are not designed to promote strong effects in photosynthesis or growth. They are designed to trigger just a photoperiodic response.
Light quality in flowering induction
Short-day and long-day plants have different photoperiodic response mechanisms, involving components of photo-perception and biological timing. The roles of photoreceptors are essential in the signaling of the photoperiodic control mechanism.
Plant photoreceptors are light-sensitive molecules confirmed by a protein and a light sensible pigment capable of regulating flowering by altering the expression of a key flowering regulator. The main photoreceptors involved in flowering regulation are the red/far-red light receptors, called phytochromes. Phytochromes are proteins responsible for photoperiod sensitivity in plants that utilize a linear tetrapyrrole, bilin chromophore to sense red/far-red light, existing in two inter-convertible forms.
One form of phytochrome is Pr, which is considered the inactive form of phytochrome and has a primary absorption peak at the wavelength of 660 nm (red) and a secondary absorption peak at a wavelength around 380 nm (UV-A). The other form of phytochrome is Pfr, which is considered the active form of phytochrome with an absorption peak at 730 nm far-red wavelengths and a smaller peak at 408 nm blue wavelengths.
Pfr accumulation can inhibit flowering in short-day plants and have the exact opposite effect (Flower induction) in long-day plants. During the dark period Pfr changes to Pr form. This is why long periods of darkness in short-day plants promote flowering. If we do a brief exposure with red light during a dark period, Pr will convert again to Pfr form. This is why night interruption works! In summary, night interruption can be used to avoid flowering in short-day plants or promote flowering in long-day plants.
Research applications
There are other factors affecting flowering response. Some good examples are temperature and Daily Light Integral (DLI). This is why flowering lamps can be really useful for research purposes.
When trying to test photoperiodic treatments and response in plants, it is recommended to extend the period of light artificially under the same temperature and maintain the same DLI within the treatments. In order to maintain the same DLI, the extended period of light should be really low light intensity. By applying treatments correctly we will be able to measure only the effect of photoperiod in flowering response.
Greenhouse application
We can use different lamps in greenhouse operations to promote or inhibit flowering. Regular lamps designed for greenhouse operation to promote higher DLI (e.g. L1000 by Current) can also be used to induce a photoperiodic response. By adding light using regular growing lamps we can increase DLI, which can be good for different crops and also be useful to create longer days when looking to promote flowering in long-day plants or inhibits flowering in short-day plants. If your objective is only to induce a photoperiodic response, then night interruption can be used.
In order to create a short day in a greenhouse, we usually use covers to eliminate natural light, when natural light is above the threshold for a short-day plant. Other options include moving plants or transplants from the greenhouse to a growth chamber in darkness for specific periods of time in order to induce flowering in short-day plants.
There is always an advantage in learning about photoperiod when working with long and short-day plants. Remember the more you know the better you can manage not only your growing system. But also your investment of capital for your projects… and of course! If you need any help in the process Hort Americas will be on board to help you make the best decisions for your projects.
Chris Higgins, CEO, Hort Americas
