Rotation plans can help growers prevent insecticides and acaricides from losing their effectiveness.
Insecticides and acaricides are still used to alleviate the problem of insects and mite pests in greenhouse production systems. However, continued dependence on insecticides and/or acaricides can lead to resistance in insect and/or mite pest populations. Therefore, greenhouse producers need to understand the mode of action of designated insecticides and acaricides in order to develop a rotation plan aimed at reducing/delaying resistance to pesticides. The mode of action is how insecticides or acaricides affect the metabolism and/or physiological processes of insects or mites. The mode of action of all insecticides and acaricides can be found in the Insecticide Resistance Action Committee (IRAC) document titled “IRAC Action Mode Classification Scheme” on irac-online.org.
This article discusses the IRAC model of Action Groups 9 and 29, which are commonly referred to as “selective feeding blockers.” The three selective feeding blocker pesticides that can be used in greenhouse production systems are: pymetrozine (effort: Syngenta Crop Protection; Greensboro, NC), flunipropamide (aria: FMC Corp.) , Philadelphia, Pennsylvania), and pyrifluquinazon (Rycar: SePRO Corp.; Carmel, Indiana). Although all three insecticides were initially placed in the 9th group (9A-pymetrozine and pyrifluquinazon; and 9C-flonicamid), flunipropamide has been moved to the 29th due to different binding to specific receptor sites. group. In general, both groups act on chondroitin (stretch receptors) and sensory organs in insects, which are responsible for hearing, motor coordination, and gravity perception.
Pyrmeazine and pyrflurazine (IRAC group 9) are considered to be TRPV channel modulators in cartilage organs. These active ingredients disrupt the gate control of Nan-lav TRPV (Transient Receptor Potential Vanilla) by binding to the channel complexes in the receptor organs that stretch the tendons, which are essential for sensing and movement. In addition, the eating and other behaviors of the target pests may be disturbed. Flunicarmide (IRAC group 29) is considered to be an organ regulator of chondroitin with unknown target sites. The active ingredient inhibits the function of the perichondrium relaxation receptor organ that maintains sensation (for example, balance). Flonicamid (group 29) differs from pymetrozine and pyrifluquinazon (group 9) in that fluonicamid does not bind to the Nan-lav TRPV channel complex.
Generally, selective feeding blockers (or inhibitors) are a group of insecticides with a wide range of effects or physical modes of action, which can prevent insects from feeding by interfering with the neuromodulation of oral plant fluid intake. These insecticides can alter behavior by inhibiting or disrupting the passage of probes into the vascular fluid (phloem sieve) of the plant, which prevents the insects from getting nutrients. This leads to hunger.
Selective feeding blockers are active against certain phloem carnivores that are problematic in greenhouse production systems. These include aphids and whiteflies. Selective feeding blockers are active in the juvenile and adult stages, and they quickly inhibit feeding. For example, although aphids can live for two to four days, they will stop eating within a few hours. In addition, selective feeding of blockers may inhibit the spread of viruses carried by aphids. These insecticides are not active against flies (Diptera), beetles (Coleoptera) or caterpillars (Lepidoptera). Selective feeding blockers have both systemic activity and cross-layer activity (penetrating leaf tissue and forming a reservoir of active ingredients in the leaf), and can provide residual activity for up to three weeks. Selective feeding blocker insecticides have less direct and indirect toxicity to bees and natural enemies.
The mode of action of selective feeding blockers is not easy to cause insect resistance in a short time. However, long-term use of this mode of action may eventually reduce the effectiveness of selective feeding blocker insecticides. For example, there may be issues related to the cross-resistance of insecticides of group 9 and neonicotinoid (IRAC 4A group) resistant insects (based on the resistance of insecticides conferring the same chemical class and/or similar mode of action). The single drug resistance mechanism of drug resistance) because enzymes such as cytochrome P-450 monooxygenase can metabolize these pesticides. Therefore, greenhouse producers need to carry out proper management and apply insecticides with different modes of action between selective feeding blockers in the rotation program to avoid any problems related to drug resistance.
Raymond is a professor and extension expert in Horticultural Entomology/Plant Protection in the Entomology Department of Kansas State University. His research and promotion plans involve plant protection in greenhouses, nurseries, landscapes, greenhouses, vegetables and fruits. rcloyd@ksu.edu or 785-532-4750
As growers become more and more busy in the spring, and the margin of error becomes smaller and smaller, it is especially important for growers to ensure that every part of their farming work is accurate. This is especially true for breeders who use rootless cuttings for reproduction.
According to Dr. Ryan Dickson, a promotion expert at the University of New Hampshire, a common problem with spring greenhouse operations is excessive cutting. He said that this means giving too much to the plants and rooting them prematurely.
“When you over-atomize in the early stages of production, it is possible to leach fertilizer nutrients from the lining,” Dickson said. “There is also the risk of water accumulation in the substrate, which reduces the oxygen content of the cutting base and delays rooting.”
He said: “When you receive the rootless cuttings, the plant is actually on the verge of death. This is your job. You need to restore it to health and produce a high-quality lining that has the greatest potential for the next grower. Mat.” “In the early stages of spread, it strikes a good balance between too much and too little fog. As the plants grow, you will continue to make adjustments, so a serious and serious grower is required.”
Dixon said that the downside of applying too little fog is that the risk of mowing drying out is higher, because even a little withering can delay rooting. The problem of omissions and deficiencies may not be so forgiving. Growers often overuse mist as insurance.
According to Dixon, if the plant discharges excessively and high leaching occurs, the pH in the growth medium will also increase during reproduction.
The nutrients in the medium help stabilize the pH. If these nutrients are filtered out due to excessive irrigation or watering, the pH may rise above the optimal level. “He said. “This brings up two problems. The first is that the nutrients absorbed by the plant during rooting are very low. The second reason is that as the pH value increases, the solubility of certain micronutrients (such as iron and manganese) will decrease and cannot be absorbed. If you find that your nutrients are insufficient and the plants are yellowing, the pH in the medium is high and the nutrients are low, then the simple first step is to add fertilizer and increase the nutrient content in the medium. This will provide nutrients to green the leaves, and also help to lower the pH and increase the utilization of iron and manganese. ”
In order to fine-tune the atomization process, Dickson recommends spending time in the greenhouse to observe the plants and atomization. He said that ideally, growers should atomize the plants after they are dry but before they wilt. If the grower is fogging up while the leaves are still wet, or the plant is wilting, there is a problem.
He said: “You can wean the plant.” “And once the plant has roots, it shouldn’t foggy at all.”
Dickson recommends monitoring the pH and nutrient content during planting to determine if nutrients have been filtered out and to determine if fertilization is required. Dickson also recommends regular checking of pH and EC content. He also said that any new crops or crops that may be more susceptible to nutritional problems should be checked regularly. Dixon said that the two plants that may be more dangerous are petunia and large flower cho.
He said: “These are strong crops that are sensitive to both low nutrients and high pH.” “Crops with longer rooting times, such as bones and crusty plants, are also checked. They usually require more time under fog. Therefore, there is a greater potential to extract nutrients from the medium before rooting.”
I taught one of my greenhouse crop production courses in the fall. In that course, we focused on flowering potted plants, cut flowers and foliage plants. As part of the laboratory, we planted many potted plants, including poinsettia. In the laboratory, we practiced using “total crop management”-a holistic approach based on integrating data and data collection with key assessments for containerized crop production (Figure 1). First, we must regularly monitor greenhouse environmental factors, such as daylight integral, daily average temperature, and day-night temperature difference. When the plant is growing or there is a graphical tracking curve, the height of the plant; the characteristics of the substrate and irrigation water, such as pH and electrical conductivity (EC); and the pest population. When using data about the greenhouse environment, plant growth, substrate, water, and pests, decision-making is much easier. You don’t have to guess what’s going on in the greenhouse or container; instead, you know and make more informed decisions.
At the beginning of the semester, students were provided with goals for their final height, greenhouse conditions, water quality, and the scope of the pouring substrate test. For poinsettia, the ideal target pH is 5.8 to 6.2, and the EC is 2.5 to 4.5 mS/cm. Poinsettia is considered to be a “normal” crop (not too low, not too high) relative to the pH requirements, but from the higher EC value, it can be seen that it is considered a “heavy feeder”.
Two weeks after planting the poinsettia, we conducted the first pourable substrate test. This is the mystery. A student came back from the greenhouse and seemed a little confused. Poinsettia has a pH between 4.8 and 4.9. Initially, I suggested that the handheld pH and EC meter might not be calibrated correctly. So they went out, recalibrated the meter, and got similar results. Other students are filtering back to the laboratory, and their pH is also very low. I thought the calibration solution might not be good, so we opened a new bottle of solution and recalibrated. Again, we got similar results. As a result, we tried different hand-held meters, and then tried calibration solutions of different brands. The pH of the substrate is absolutely low.
What is the reason for the low pH? Next, we studied diluted fertilizer, clean water, fertilizer stock solution and syringes. The pH and EC of the diluted fertilizer solution we used seemed to be normal, and the results showed that there was no problem. Working backwards from the hose end, we tested clean municipal water. Again, these values ​​seem to be in range. We do not acidify our water because the municipal water we use has an alkalinity of about 60 ppm-”plug and play” water. Next, let’s take a look at our fertilizer stock solution and fertilizer injector. We use a mixture of 21-5-20 to lower the pH and 15-5-15 to raise the pH to make a fertilizer solution that can replenish water to manage the pH of the substrate. We mixed a brand new inventory solution, and it is certain that the injectors are indeed calibrated and injected correctly.
So, what is it that causes the pH to drop? I can’t think of anything in our facility that would cause problems. Our problem must be caused by other reasons! I decided on one thing we haven’t measured: alkalinity. Therefore, I took out the alkalinity test kit and tested the clear municipal water. Look, the alkalinity is not the usual 60s. On the contrary, it is about 75% lower than usual among teenagers. Our greenhouse manager called the city to ask about low alkalinity. The city has recently changed its approach, and it is certain that they have reduced the alkalinity concentration below the previous standard.
We finally know that the culprit is: low alkalinity in irrigation water. 21-5-20 may cause excessive acid reaction with new low-alkalinity municipal water. We took some steps to normalize the pH of the substrate. First of all, in order to quickly increase the pH of the substrate, we carried out a flowable limestone application. For long-term pH management, we also changed the fertilizer to 100% of 15-5-15 to take advantage of the effect of pH increase, and completely omitted the acidic 21-5-20.
Why talk about poinsettia when it enters full production in the spring? The moral of this story has nothing to do with poinsettia. Instead, it emphasizes the value of regular monitoring and testing. The words of Lord Kelvin, a mathematical physicist and engineer, are summed up as a value summary in routine monitoring: “To measure is to know.” After sowing, without any through testing, the problem is likely to remain undiagnosed for a long time. When we found that the substrate pH was low, the shoots still looked good and there were no visual symptoms. However, if we do not perform any watering, then the first sign of a problem may be symptoms of micronutrient poisoning on the leaves. If the symptoms of the problem are visible, then some damage has been caused. This story also demonstrates the value of systematic problem-solving methods (Figure 2). When we first solved the problem, the city that changed our water treatment process was not in our minds. However, after thoroughly investigating the internal factors that we can control, we believe that this must be an external factor that we cannot control, and expanded the scope of our investigation.
Christopher is an assistant professor of horticulture in the Department of Horticulture at Iowa State University. ccurrey@iastate.edu
Interpersonal relationships deteriorate, and sometimes they gradually disappear. Sometimes the breakup is dramatic, sometimes it is subtle and noticeable. Usually, this is the best. Regardless of how or why someone left you, or you left them, this is how you handle the situation, which creates a lasting view and memory of you and your company. Nothing makes managers feel more uncomfortable than asking employees to resign or be fired. Usually, the ball becomes confusing when it is necessary to convey the details of leaving to other team members.
Leaving is not a bad thing. It is usually best when an employee chooses to leave or is left by management. Outgoing employees may be looking for better opportunities that they cannot reach with you, or you may improve working conditions and profitability by eliminating people who are not suitable for your company. However, resignation seems to make everyone feel uneasy and expose sensitive insecurity, especially for managers.
A common behavior-the behavior of most of our managers is guilty at some point in our career-defaults to negative comments about leaving or leaving. When you have word of mouth about leaving or former employees, what information would you send to your current employees about you and the company? When someone leaves you, it’s easy to focus on their character faults, and vice versa. But in a work environment, it’s important to remember that there are many people who are still in touch with you and hope you see how you perform at that moment, especially if the departing employees work hard to build their company success of. Your behavior will be their prediction of what they will do if they choose to resign. More importantly, let them know whether you really value the efforts of current employees.
Your job is to inspire confidence in your employees at these moments; don’t make them nervous. You may be unemployed or fired at some point in your career. You may have personally experienced the feeling of being devalued by management during or after you left. In terms of connectivity, the green industry is uneasy if you will. Such derogation is likely to be passed back to you or the deceased employee through industry gossip. This kind of gossip leaves a bad taste in everyone’s mouth, and it is never a good thing for a positive corporate public relations culture.
What should you do in this situation? First of all, remember that personal feelings about the deceased do not play a role in your communication strategy. Pay attention to the facts. The agreement you discuss to leave should vary depending on how a person leaves. Also, please do it quickly. Waiting for the announcement of an employee’s resignation usually leads to gossip to complete the work for you. Control the conversation.
If employees voluntarily resign for their own reasons, please let them announce it in group meetings or employee meetings. Ask them to send emails or memos with other employees who cannot attend the meeting. This is their decision, not yours, and they have the right to leave at any time. For everyone who works for you, it is best to redefine this subconsciously. Moreover, it obliges employees to directly explain why they left and answer questions so that you do not confide in their mouths or make false statements when leaving. After their announcement, your job is to thank them for their services and contributions to the team and the company. I wish them all the best and keep a positive attitude with them before they move on.
When they announce, you should also clarify a plan to the rest of the employees, explaining how you intend to replace the employee or how to handle their responsibilities, until you do so. After they leave, do not go out of the way of pointing out their own shortcomings, reducing their work contributions or tolerating other employees’ negative comments on them. It will only make you look trivial, and it will also plant subconscious seeds of doubt in the minds of other employees.
If someone has to be fired due to poor performance or policy violation, then you should be the person who issued the notice to the employee. In this case, please send a written memo or email to the employee to minimize drama. In terms of timing, you should immediately notify any employees who will be directly affected by the resignation. Other staff can be notified on the next working day. When you let someone leave, pay attention to the language in which the notice was posted. It simply states that employees no longer work in the company and wish them the best.
It’s best not to go into details when you let someone go, although a certain degree of transparency can alleviate fear. In the announcement, you should encourage other employees to directly raise questions and concerns about resignation to you. At this time, you can determine the detailed information related to the individual. If an employee is allowed to violate a specific policy, it is best to review it directly with managers and supervisors to make them understand the importance of policy education, implementation, and documentation.
Change is hard, and even harder for some people. In most cases, change is good. Embrace employee changes in the company with a professional and positive attitude, and you will be on the right track to build a culture of trust.
Leslie (CPH) owns Halleck Horticultural, LLC, through which she provides horticultural consulting, business and marketing strategies, product development and branding and content creation for green industry companies. lesliehalleck.com
Regina Coronado, the chief grower of Bell Nursery, defeated a difficult situation and became the leader of the American gardening market.
From coffee and soybeans to herbs and spices, from decorations to vegetables, to decorations, Regina Coronado has grown almost all of them. She moved from her home in Guatemala to Florida, Texas, Georgia, Washington and now North Carolina, and did it all over the country. Since 2015, she has been engaged in the cultivation of Bell Nursery here.
As Coronado entered the ranks of the US greenhouse industry, she had to overcome many challenges and look for opportunities where others only saw obstacles.
“First of all, I am an immigrant. If you are from another country, you must prove that you are skilled.” Coronado said that she obtained a visa, then a green card and became a US citizen in 2008. “The second thing is that this is a male-dominated industry, so you have to be a bit tough to survive.”
Through her perseverance, dedication and unwavering spirit of improvement, Coronado has overcome these difficulties and created a successful career in the greenhouse industry.
Combining her love of the outdoors with her love of science, Coronado earned a degree in agriculture in Guatemala. When she realized she was in a minority—even in her home country, she was working as a soil laboratory technician for coffee growers.
“When the boss left, I applied for his position, and when I went to the human resources department, they told me that I met all the requirements, but [they] did not allow me to be the head of the soil laboratory because [because] I am too young, I am a woman,” Coronado said.
A few months later, she found an opportunity in the United States. A person in Guatemala bought a small nursery in Florida, and he hired an agronomist to spend three months there to learn greenhouse business to help him rebuild a greenhouse in Guatemala. After Coronado arrived in the United States, three months became 26 years, and it is still increasing.
When working in that nursery, she often plugged in from Speedling. “I saw that greenhouse for the first time, and I thought,’Wow, I wish I could work here!’” Coronado said, who ended up working at Speedling for 7 years as a major vegetable grower in Texas , And then in Georgia.
There, she met Louis Stacy, the founder of Stacy Greenhouse. One day, when he visited Speedling, he left his business card in Coronado and told her if he needed to call her at work. She started working for him in South Carolina in 2002, where she learned all about perennials.
“For me, he is an excellent mentor,” Coronado said of Stacey. Stacey died in January, at the age of 81 a few days before the interview. “I just miss everything he taught me over the years, such as his commitment to excellence. He really put the word “quality” in my mind because in his mind, the only way we can compete is with Competing for high-quality plants.”
When Stacy retired, Coronado sought opportunities in western Washington state to work in gardening in the Northwest, and then she returned to the east to join Bell Nursery.
As the chief grower of Bell Nursery, Coronado is responsible for the production of perennials. It covers an area of ​​about 100 acres and is distributed in two facilities: one specializes in cultivating colorful flowers such as lilies, iris, dianthus and phlox, and the other specializes in planting. Cover plant and jade host.
She said: “I like everything I grew up.” “For me, growth is a passion, and I am lucky to be paid for my passion.”
Coronado supervises an irrigation team, chemical application team, and plant maintenance team at each location (about 40 miles apart). She works in turns at each factory for a few days, focusing on reconnaissance and quality control.
Coronado said: “I do a lot of things myself, do a lot of quality control on potting, pruning, weeding and row spacing, because Bell’s goal is to send high-quality plants to the store.” “I spend a lot of time testing water and soil. , And try to use new varieties and new chemicals. In other words, I never have time to be bored.”
“For people and myself, this is never-ending training,” Coronado said. “I always try to stay up-to-date, because for me, growing up is like being a doctor. If you fall behind, it’s not good for me or the company because we want to improve efficiency.”
Coronado is committed to improving himself and the people around him. This is a way for her to give back to the industry. As her career develops, the industry has been warmly welcomed and helped by her.
“I am very happy to have the opportunity to come to the United States,” said Coronado, who returns to Guatemala every year. “When I first came to the United States, my life was very difficult, but it has always been my blessing to be here. I believe that if there is a chance, I need to try it. Sometimes the opportunity will only come once, if I don’t seize the opportunity, it will Lost opportunity.”