Roberto G. Lopez provided important tips on the deployment, maintenance and cleaning of HPS lamps for supplemental lighting of ornamental crops and vegetable crops.
Greenhouse growers, especially those in northern latitudes, often use supplemental (also known as photosynthesis or assimilation) lighting to produce uniform, consistent, and high-quality crops throughout the year.
Light-emitting diode (LED) lamps are now about 40% more energy efficient than double-ended high pressure sodium (HPS) lamps [bulbs (or lamps), reflectors (or lamps) and ballasts], but each photosynthetic LED lamp The initial cost of photons is about 3 to 10 times that of HPS lamps.
Recent surveys indicate that only 2% to 5% of growers have installed LED lamps as supplementary lighting. Therefore, most greenhouses that use supplemental lighting still rely on HPS fixtures (Figure 1).
In this article, I will focus on the use and maintenance of HPS fixtures.
Traditionally, high-intensity discharge (HID) lamps, including HPS and metal halide (MH), are used for supplemental lighting because they convert electrical energy into photosynthetically active radiation (PAR) with an efficiency of 25% to 30%.
Tycoon HPS lamps have electromagnetic ballasts, and the bulb is single-ended (the lamp is connected to a single socket). About 13 years ago, electronic ballasts came out. These lamps are generally smaller, colder, quieter, and lighter, and most importantly, their energy efficiency is 10% to 15% higher than their magnetic ballast parts. In addition, compared with magnetic ballasts, the rate of reduction in efficiency is slower.
About nine years ago, with the introduction of 1,000-watt double-ended (connected to the sockets at both ends) lamps, the efficacy of HPS lamps increased significantly (>65%).
According to a research report by Bruce Bugbee of Utah State University, the slow start and stable output of electronic ballasts may help extend the life of double-ended HPS lamps. The photosynthetic photon flux (PPF) emitted by these lamps is approximately 1,840 µmol·s–1, and the efficacy is between 1.7 and 1.8 J·s–1.
According to the manufacturer, the life expectancy of a double-ended HPS bulb is 10,000 to 15,000 hours, with an initial light output of 90%. Therefore, if your fixture runs 2,000 hours per year, you will need to replace the bulb within 5 to 7.5 years.
In 2008, the Light Research Center (LRC) of the Rensselaer Polytechnic Institute (RPI) reported that most LED garden luminaires cannot replace HPS luminaires on a one-to-one basis while still maintaining the original PPF. Therefore, to provide the same PPF as an HPS lamp, about three times as many LED lamps are needed.
It is important to remember that the efficacy of LED lamps is increasing every year, and now some lamp manufacturers do offer 650 watt LED lamps and are a one-to-one alternative to HPS lamps.
LRC also found that compared with HPS, the shade of some LED luminaires has increased due to the size and number of luminaires required to provide the same PPFD installation as HPS in the greenhouse. Among all the lamps tested by RPI-LRC, the shading of the LEDs reduced the sunlight in the greenhouse by 13% to 55%, while the HPS lamps reduced by 5%.
Installing, maintaining, and operating HPS lights is a major investment in greenhouse operations. However, most of the upfront costs associated with fixtures can be calculated and weighed against the potential benefits (i.e. increased production of vegetables or shorter crop turnaround time for seedlings).
Even if you have made a substantial capital investment in these lamps, depending on your location, when the benefits provided by supplemental lighting are small and they should be turned off, it usually takes four to six months (April to September) ( Depending on your location) This is also a good time for maintenance and replacement).
From October to March, the total amount of light received per day, known as Daylight Integral (DLI), may be the limiting factor for greenhouse crop production in northern latitudes. Therefore, the greatest benefit of supplemental lighting occurs at night or cloudy days in the north and south from November to February from this time period.
Keep in mind that supplemental lighting requires much higher light intensity than photoperiod lighting, which requires 2 to 3 µmol·m–2·s–1 (10 to 20 foot candles) and usually at night between 10 o'clock and 4 hours Rest in the afternoon to 2 am For example, most young plant growers provide supplementary light intensity of 70 to 90 µmol·m–2·s–1 at plant height. A higher strength of 120 to 200 µmol·m-2·s-1 is recommended for vegetables (Figure 1).
During the peak season of ornamental plant seedling production (January and February), the DLI in the greenhouse can be between 2 to 8 mol·m-2·d-1 in the north and 6 to 14 mol·m-2·d-1 in the south .
Research by Michigan State University has shown that when DLI is maintained between 10 and 12 mol·m, you can not only produce high-quality seedlings through supplementary lighting, but more importantly, depending on the species, the cropping time can be reduced at most 50% –2·d–1 is used for ornamental plants, and 12 to 15 mol·m–2·d–1 is used for vegetables.
In order to reach the target DLI of 12 to 15 mol·m–2·d–1, how many hours should the HPS light be turned on? The time the bulbs are on is as important as the amount of supplementary instantaneous light they provide. Table 1 shows some examples of how to implement supplementary DLI in the range of 3 to 19 mol·m-2·d-1.
What is the life expectancy of HPS bulbs? As mentioned earlier, under normal operating conditions, it is recommended to replace the bulb after 10,000 hours of use of mogul base lamps and 10,000 to 15,000 hours of double-ended lamps. The number of times the bulb is turned on or off will also affect the life of the bulb.
In order to get the highest output from your HPS ballast, reflector and bulb, routine maintenance and replacement are essential. Some HPS luminaire manufacturers recommend cleaning the reflector (luminaire), while others recommend a complete replacement. Everyone recommends replacing the bulb after the bulb reaches its maximum lifetime (Figure 2a and 2b).
However, let us be honest with ourselves: most growers will not do this. I was pleasantly surprised to see that an operation in New York was cleaning all their HPS reflectors and bulbs (Figure 4). I often see the reflector covered with dust, water stains or fingerprints (Figure 3), or the lamp has burned out or dimmed. It is estimated that just because the reflector is dirty, the light output will be reduced by 8% to 15%. Therefore, I asked several HPS manufacturers for their recommendations for reflector maintenance.
PL Light Systems stated that if the HPS is installed in a clean environment, or if the reflector is used for 1 to 3 years, it can be cleaned with a solution of vinegar and water in a ratio of 1:100. They also recommend cleaning your bulb and reflector annually for best performance. (Please note that not all manufacturers recommend cleaning reflectors. Therefore, you should contact the manufacturers of HPS fixtures for their specific recommendations. Most manufacturers can test your reflectors and tell you if they need to be replaced.)
The author is an associate professor and controlled environment/flower promotion expert in the Department of Horticulture at Michigan State University.
With innovative technology and active financing from Kentucky, vertical agriculture has developed to new heights.
In Morehead, a small city just a few hours from Louisville, Kentucky, one of the largest and most ambitious vertical farm companies in the United States is reaping the fruits of its planting four years ago. Morehead has only about 7,000 residents, but it has hundreds of thousands of tomatoes that thrive on the very unique vertical farm in AppHarvest's first planting facility.
This 60-acre factory opened in October and is currently growing steak tomatoes and will soon harvest tomatoes on the vines.
The company's goal is to provide Americans with fresher, healthier, and more delicious food while maintaining high standards of environmental management, employee care, and sustainable development. In January, AppHarvest’s first batch of steak tomatoes went on shelves in Kroger, Publix, Wal-Mart, Food City and Meijer stores, and was co-branded with Sunset Grown.
"I have known that consumers are ready for a long time. If you can provide consumers with better products... Consumers will determine the future better," said David Lee, board member and president.
The flagship AppHarvest plant is expected to produce approximately 45 million pounds of tomatoes annually from approximately 720,000 steak and vine tomato plants. "We expect that every American will have access to fresh, healthy, and affordable fruits and vegetables," said founder and CEO Jonathan Webb.
Weber said that because of the abundant rainfall and the ability to reach 70% of the United States within a day's drive, the Morehead location is a perfect fit for the company's first plant. “Therefore, building these facilities in an area where we can collect all rainwater, package it into fruits and vegetables and send it to consumers is critical to the company’s long-term resilience.”
The location of Kentucky is also important because the company focuses on "building operations and large indoor farms in economically disadvantaged areas of Appalachia," said Chief Communications Officer Travis Parman.
Eastern Kentucky used to be a coal producing area, but AppHarvest hopes to transform it into a region known for feeding the United States with healthy agricultural products. "The men and women who power the country in coal mines are working with us in this facility," Weber said.
AppHarvest’s crops are grown with naturally grown seeds that are optimized for flavor and nutrition, Weber says, which distinguishes them from most tomatoes in grocery stores. "Most agricultural products are cultivated for transportation, so you can't get the nutrient density of our tomatoes."
Chief Sustainability Officer Jackie Roberts stated that harvesting agricultural products at the highest maturity and delivering them quickly means reducing overall wear and tear on the crop, and pointed out that 30% to 40% of the crops we grow The crop never made it to the grocery store shelf because of supply chain issues.
Roberts predicts that only 50 to 70 years of high-quality topsoil remains for human agriculture. "We need new ways to grow the most resource-efficient food," she said. "Another aspect of improving resource efficiency is the challenge of food waste. When you grow and transport a long way, the system will lose a lot. In Appalachia, close to 70% of the U.S. population within a day’s drive means Less travel time."
The price of tomatoes produced at the plant will be comparable to that of traditionally grown tomatoes, and board member Martha Stewart said this is part of the reason why the crop is so exciting. "I think we all want to be better for us, our families, and our friends. We want sustainable, chemical-free food. We want food that tastes good and that we can afford. Now organic Food is too expensive."
"People can vote with their dollars, then vote in the grocery store, and then decide what [they] want to put on the table," Weber added.
"Our world still has a long way to go in terms of rebuilding our food system," Weber said. "The new crown pneumonia epidemic emphasizes that in many aspects, but the good side is... the private sector can solve many problems facing our world. We can have high-quality and delicious products that every consumer can buy, but we Technology must be used to quickly rebuild American agriculture and the global food system."
AppHarvest's plants grow in soilless matrix rock wool, which is composed of fine-grained calcium carbonate. This provides space for the roots to grow and effectively absorb water and nutrients. Then they grow to about 45 feet tall, and the staff wraps them as they grow. Every day, the products are harvested and shipped to the shelves of the grocery store.
Weber said that the company's planting practices use 90% less water than traditional field-grown crops and increase yields per acre by 30%. Non-GMO and chemical-free crops are also grown using 100% recycled rainwater.
In order to achieve chemical pesticide-free crops, AppHarvest uses integrated pest management and biological pest control. "I like to call it Integrated Pest Management 2.0. We really focus on using different types of artificial intelligence, worker skills and training them to detect pests and diseases early," Roberts said.
She hopes that AppHarvest will not only effectively use resources, but also reduce the runoff of fertilizers and pesticides into local waterways. "It's really hard to prevent," she said.
AppHarvest is proud of its high-tech, environmentally friendly planting practices. Some of the technologies at the Morehead facility include machine learning, artificial intelligence, robotics, and more data-driven agriculture. From industrial software to sensors, lighting and humidity control, the business is leveraging technological development.
"There are many different technologies that are converging, and they will continue to develop in the next ten years," Weber said.
It all starts with water, Roberts said, noting that agriculture consumes 70% to 80% of our groundwater and surface water. "So we need better solutions. How can we grow more food with less water?"
AppHarvest uses a closed-loop system to collect rainwater on the roof and store it in 70 Olympic swimming pool-sized reservoirs. The water is then filtered through sand and UV treatment before entering the greenhouse for irrigation.
Continuously monitor the nutrients essential to plant growth in the water, and add nanobubbles to increase the oxygen in the water. This enables plants to better absorb nutrients in the water. Roberts said: "This makes the plant stronger and more resistant to diseases, and it is also a place where we can accumulate nutrients."
Unlike most greenhouse operations, AppHarvest has undergone a series of aggressive fundraising and financing to raise funds for its Morehead location and other planned facilities. It all started in 2019, when the company raised $520,000 through its investment platform Harvest Returns.
On February 1, the company completed the business merger with Novus Capital Corp., a listed special-purpose acquisition company, and began trading on NASDAQ under the stock codes APPH and APPHW. The company's stock opened at $35.69, and by the afternoon, the stock had soared 44%. As a result, Nasdaq temporarily suspended trading due to fluctuations. Trading resumed quickly and closed at 35.85 US dollars that day. As of February 15, the stock was trading at $33.26.
The company announced in September 2020 that it will merge with Novus Capital to go public. It was initially sold at a price of $10 per share, with an estimated equity value of $1 billion.
As a result of the initial public offering, AppHarvest received approximately US$475 million in total proceeds, of which US$375 million came from common stock PIPE anchored by investors such as Fidelity, Inclusive Capital, and Novus Capital. The company said that this provides $435 million in unrestricted cash that will be used to fund operations, including building more farms, supporting growth and other general corporate purposes.
Weber hopes that the private sector will help take the lead in solving the world's food problems. The company is not only publicly traded, but also one of the few publicly certified B companies listed. As a certified B company, AppHarvest must legally consider the impact of their decisions on its employees, customers, suppliers, communities, and the environment.
"We believe that in the next ten years, every company—from Fortune 500 to startups—every company in the world needs to work towards the same goals we are talking about," Weber said. "If you are not, as a CEO, you should no longer look for quarterly revenue calls, nothing more."
As Weber said, this is part of creating value among all people, including wider stakeholders, the environment, communities, consumers-everyone the company affects. “As a company, it’s more difficult for us, but it’s the right approach. Finally, for investors, it’s a better return in the long run, because you have to make sure that your company is in the future It is feasible, relevant and resilient for decades."
Although the company is focused on its Morehead location, it also plans to grow aggressively, building a 60-acre facility outside of Richmond, Kentucky, and establishing a 15-acre leafy greens business in Berea, Kentucky.
The company hopes to have a total of 12 farms in central Appalachia by the end of 2025. "This means investing in important long-term investors. It means the complexity of the supply chain. It means ultimately looking at the world to solve global problems, but today we are focusing on the Appalachian region," Lee said.
Stewart believes that AppHarvest's tomatoes can surpass fresh produce and have a place in prepared foods such as sauces and soups. "We need to use this agricultural product to make our prepared foods and provide customers with this fresh agricultural product," she said.
Edible flowers are becoming more and more popular and can be successfully grown in hydroponic systems.
With the advent of spring, annual and perennial landscape plants are everywhere in the greenhouse for the upcoming summer. Although flowering bedding and garden plants are the most valuable part of the US greenhouse industry, there are also opportunities to produce these flowering plants-as a kind of edible plants!
Edible flowers are becoming more and more popular because they not only add a colorful appearance, but also a variety of flavors from sweet to sour to finished dishes. Although there is a lack of information on the hydroponic production of edible flowers, this month’s column will review some of the most important points to consider.
First of all, first choose the edible flower varieties you want to grow.
Some of the most popular edible flower varieties include familiar annual plants such as pansy (Viola × wittrockiana), viola (Violacornuta), snapdragon (Antirrhinum majus), nasturtium (Tropaeolum majus), wax (Begonia × semperflorens-cultorum) ) And tuber (Begonia) × tuberhybrida) begonia, African marigold and French marigold marigold, and Dianthus chinensis. There are also perennial plants with edible flowers, such as hibiscus (Hibiscus rosa-sinensis), peony (Paeonia lactiflora), rose (Rosa spp.), and clove (Syringa vulgaris).
When comparing the yield of edible flowering plants and flowers, one of the most significant differences you may encounter is pest control. Flowering plants grown for ornamental purposes can be treated with a variety of pesticides to control insects, mites, fungi and bacteria.
However, when planted for human consumption, most of the same pesticides used in ornamental production are not suitable for consumption and are not labeled for use on edible crops. Generally, the best way to ensure that your crops are safe (that is, they do not contain pesticide residues that exceed the allowable threshold) is to grow your own grafts instead of buying them. This will ensure that you are using plant materials that have never been treated with pesticides and are safe for human consumption.
In addition, almost all commercial plugs will be grown in plug trays filled with loose peat sprouting mixture. For hydroponic production, you need to plant seedlings in an inorganic substrate (rock wool or phenolic foam) or organic substrate (peat or coconut fiber) suitable for hydroponic production, and use an adhesive to fix the loose substrate together. This will help ensure your success.
The most suitable hydroponic systems for edible flowers are those used for the production of leafy green vegetables and culinary herbs-the most famous are the nutrient membrane technology (NFT) and deep flow technology (DFT) or raft system.
Although both NFT and DFT can be successfully used to grow flowering plants, compared with DFT, the NFT system is usually very suitable for circular harvesting of flowers, because the NFT channel is usually placed at waist height, and flowers can be harvested without bending over. DFT systems usually installed on the ground are in contrast. Avoid using systems that are conducive to growing fruit vines, such as plate/bag culture or Dutch barrels.
The greenhouse environment used for the production of hydroponic edible flowers-light, temperature and carbon dioxide-is an area where producers can draw from existing production literature to produce flower crops in containers with substrates.
Just because the flowers are grown by hydroponics, it will not fundamentally change the environmental production requirements. For example, cool-growing annual plants such as pansy, viola, and snapdragon should still be planted in cool air temperatures.
Unlike a greenhouse environment, the switch from a soilless substrate to a hydroponic system requires some trial and error in the development of a mineral nutrition plan.
Although you can find fertilizer requirements for most edible flower species, they will be used in soilless substrates rather than hydroponic systems. However, the recommended substrate culture conductivity (EC) and the classification of various crop varieties according to fertilizer requirements (ie light-eating, medium-eating, and heavy-eating plants) provide a good indicator of nutrients for growers who are just starting to grow in water need. Similarly, the recommended substrate pH can be used as a guide to determine the optimal pH of the nutrient solution. A good starting range is a nutrient solution with a pH of 5.5 to 6.0 and an EC of about 1.5 mS/cm, and further improvements can be made according to the crop response. My opinion on the new edible flower hydroponic grower? First jump 2 feet, then dive into the water.
Growing edible flowers by hydroponics provides any agricultural grower with the opportunity to add exciting new crops and expand their product portfolio, which is exactly what growers should achieve in the post-pandemic world. Moreover, although there are currently very few resources dedicated to the production of hydroponic edible flowers, you can use the existing knowledge system to grow the same species in a container with a substrate to give your crop a good start.
The author is an associate professor in the Department of Horticulture at Iowa State University. Contact him at ccurrey@iastate.edu
In the next 12 months, the pandemic and new consumer interest in health and wellness will make micro-vegetables the focus of attention.
I heard rumors that the chefs are a little tired of micro-vegetables and are calling back the growers' orders. But this is not what my chef friend in Dallas, Texas told me. Besides, I certainly don’t think that home gardeners’ interest in micro-vegetables has declined. For all of them, micro-vegetables are entering.
In fact, the proliferation of pandemic gardening has made mini-vegetables the top priority of family growers again. Every day I see another article about micro-vegetables, from a bunch of health websites to gardening blogs and social media channels.
In fact, I must admit that all recent exposure to microvegetable marketing has pushed me back into the growing game. It has been a few years since I kept growing micro-vegetables, but recent repeated exposures have allowed me to start again. There is no doubt that the awareness around growing micro-vegetables at home will undoubtedly affect the increase in demand for grocery stores and meals or takeaways.
Health and wellness will be at the forefront of consumer awareness in a larger way in 2021 and beyond. The pandemic has made healthy eating and immune system support a top priority for many of us right now. In addition, fighting the effects of excessive screen time and home computer work is at the top of everyone's to-do list.
Since our body and mind are under tremendous pressure, we must easily incorporate healthier fresh vegetables into our diet.
In fact, what I want to say is that when it comes to how we — or not — how to take care of ourselves when we put things in our mouths, most Americans have gotten a big wake-up call. We are all looking for simple and easy ways to improve our diet and nutrition. What is easier than adding a handful of miniature vegetables to our soup or sandwich?
The large amounts of nutrients accumulated in such a small package are a powerful tool for home consumers and growers. The nutrient content of micro-vegetables such as coriander, red cabbage and radish is 40 times that of mature vegetables. It is undeniable that micro-vegetables are of great help.
In addition to touting the benefits of mini-vegetables as color and flavor enhancements for diners, both growers and chefs should take advantage of the real, genuine health benefits that these small vegetables can add to each plate.
In terms of trends, creating a "premium" family dining experience is now also important for consumers. Home chefs are looking for ways that they can not only improve the nutrition of the food they make, but also enhance the sensory experience of the dishes. This is where the extra enhancement of color and flavor provided by the micro-vegetables comes in handy.
When I registered with some of my preferred culinary experts, they assured me that the micro-vegetables were still on the menu. Fresh Origins Micro Fines Herbs Mix and Micro Intensity Mix are two of the most popular products, especially for the bright color value of each product.
I’ve been told that there has also been a shift in micro-vegetable cooking professionals from standard clam shells with mixed micro-vegetables to single-type micro-vegetables with a more monochromatic appearance.
In addition to mixed vegetables, red-veined sorrel, coriander and arugula miniature vegetables topped the list of popular varieties. There are also some more interesting miniature vegetables that are favored, including snowdrops, miniature nasturtiums, Mexican marigolds and pea tendrils. Check out the "Plating Art" website for some visual inspiration (here).
When I asked my local Dallas chef friend where they got their specialty micro-vegetables, the focus was on local sourcing. The fresher and more localized micro-vegetables, the better. Someone pointed me to Profound Foods, a Dallas-Fort Worth "food center" that provides an online market for locally grown and produced food. In addition to many other foods, they also have a seasonally rotating selection of micro-vegetables (here).
Profound Foods is committed to connecting local farmers with local chefs to meet the growing demand for sustainable food. They also allow household consumers to order their produce and other fresh food for home delivery. You must place a cooler at your door, and your fresh produce will be put in the cooler. Unfortunately, it looks like my zip code has not yet entered their home delivery area, but anyone can register as a pickup customer at the designated locations around Metroplex.
I think this is a good model, which combines all aspects of traditional wholesale agricultural product procurement by local chefs and restaurants, as well as a farmer’s market platform for family consumers. The center is a solution that connects chefs and consumers with local fresh produce, while addressing the pressure of face-to-face shopping caused by the pandemic. This is an excellent opportunity for local farmers to expand the influence of the community.
In the end, I want to say that the prospects for micro-vegetables in 2021 are very good. Make sure that when talking about the health benefits of micro-vegetables, you are taking advantage of the huge consumer awareness boom, and don’t forget to show consumers how they can use micro-vegetables to enhance and enhance their home eating experience.
Leslie (CPH) owns Halleck Horticulture, LLC, through which she provides horticulture consulting, business and marketing strategies, product development and branding, and content creation for green industry companies. lesliehalleck.com
Check out some of the major headlines in the industry.
AppHarvest has announced its initial public offering (IPO). The resulting company AppHarvest, Inc. will be listed on the Nasdaq Stock Exchange (effective February 1) with the stock codes "APPH" and "APPHW".
Jonathan Webb, founder and CEO of AppHarvest, said: "Today marks an important milestone for AppHarvest and American Agriculture, as we are driving the next chapter in our growth as a public company." "We are here. The funds raised in the transaction will further advance our mission to transform agriculture through the development of large-scale sustainable food production in the center of Central Appalachia. Currently, nearly half of all fresh grape crops sold in the United States are imported In order to build a more resilient food system, we must cultivate more efficiently and be close to where food is needed."
Red Sun Farms, a greenhouse grower with offices in the United States, Canada and Mexico, announced that it is adding 35 acres of planting space for the 2021 winter planting season.
This new addition follows the 63.8-acre Phase III expansion project in Kingsville, Ontario, which will be completed in 2020. Red Sun's Mexico branch also completed a 25-acre expansion last year.
With new growth, Red Sun has 476 acres of planting space in Mexico, 211 acres of planting space in Canada, and a "substantial" foothold in the United States.
Shenandoah Growers' brand "That's Tasty" will launch a live potted herbal medicine program in April.
"Quality and freshness are critical to this product line," said Chief Customer Officer Steven Wright. "So we invested resources to ensure that we harvest, pack and deliver the plants within 24 hours. That's the freshest you can get. s things."
Shenandoah Growers will ship what it claims is "the first ever pre-packaged shipping display stand designed specifically for live herbs." The company said this will allow the plants to be sold immediately upon arrival.