Time for Greenhouse Clean Up
The greenhouse can be a point source of various pests that pop up during transplant production or later in the field. Bacteria, fungal spores and viruses from previous crops can persist on bench surfaces, pots, trays, and equipment. Plant residues and weeds that hang over in the greenhouse harbor diseases, insects, and mites.
- Pull weeds and remove from the greenhouse.
- Sweep and vacuum debris from greenhouse surfaces and containers before sanitizing. Organic matter will decrease the sanitizing power of products such as sodium hypochlorite (bleach).
- Sanitize benches, floors, and tools. If you reuse any plant containers (not recommended) they should be disinfected.
- Several types of disinfectants can be used in the greenhouse for plant pathogen and algae control: quaternary ammonium compounds such as Green-Shield®, Physan 20®, and KleenGrow™ ; hydrogen peroxide & peroxyacetic acid products such as ZeroTol ® 2.0, Oxidate®2.0, and Sanidate®12.0; and sodium hypochlorite/chlorine bleach.
- Organic growers should always check with their certifying organization before using any NEW material in their growing practices. For list of products see: Organic Material Review Institutes (OMRI), www.omri.org
For more detailed information on greenhouse clean up and disinfectants see:
http://ag.umass.edu/greenhouse-floriculture/fact-sheets/cleaning-disinfecting-greenhouse
Water pH and Alkalinity Considerations in Greenhouse and High Tunnel Production.
Teresa Rusinek, Vegetable Production Specialist, CCE Eastern NY Commercial Horticulture pH and Alkalinity, what’s the difference?
Simply put, pH is a measure of how acidic or basic a solution is. Positively charged molecules such as H+ make solutions acidic which lowers pH while negatively charged OH– molecules will make a solution more basic and raise pH. The pH scale runs from 1-14 with the value 1 being most acidic, 7 is neutral, and 14 most basic. This scale is logarithmic, meaning a change in one pH unit corresponds to a ten-fold increase or decrease in acidity or basicity. For example, pH 5 is ten times more acidic than pH 6. Sometimes people will refer to basic solutions (high pH) as alkaline and this is where folks can get confused with the term ALAKINITY.
Alkalinity is the ability of water to neutralize acids due to dissolved alkalis (bicarbonates) in it. Alkalinity is often reported in part per million (PPM) of calcium carbonate (CaCO3). The primary source of alkalinity in ground water aquifers, rivers, ponds and lakes are limestone deposits that have reacted with water over time. High water levels can dilute alkalinity levels just as low water levels can concentrate them. It is recommended to sample water sources at least once a year or whenever water levels change dramatically.
Irrigation, pesticide application, and sanitation
When water alkalinity is high, it’s likely that the pH is above optimum as well. Alkalinity regulates the buffering capacity of the water so the higher the alkalinity, the more acid is required to change the pH. Growers often use injectors to add an acid to irrigation water to reduce alkalinity. Conventional growers can use sulfuric acid while organic growers may use an OMRI approved citric acid product. The acid combines with the bicarbonates to form carbon dioxide and water. Ideally, water alkalinity should be around 100 PPM CaCO3.
In a greenhouse or high tunnel setting, high water alkalinity can have profound effects on soil or media pH and overall plant health. Think of alkalinity as “liquid limestone”, with each irrigation, the pH of the soil/media increases a bit. Over time, the soil /media pH increases significantly and ties up nutrients like iron and manganese. This effect happens faster in containers.
Photo Credit: Teresa Rusinek
[Alt text: The yellowing of new growth in tomato transplants is due to iron deficiency induced by the high pH of 7.4 of the media it is growing in.]
Note that water pH and alkalinity can also impact the stability and effectiveness of some commonly used organic and synthetic pesticides, and sanitizing agents. Water pH can be adjusted by using commercially available acidifying/buffering agents before adding the pesticide or sanitizer. The pesticide label usually states optimal pH ranges. If you are unsure, contact a technical representative of the product manufacturer. Applicators can test their water pH prior to a spray application using a pH litmus strip or a pH meter.
Water alkalinity and pH adjustments are easy to make and can significantly improve crop health as well as the performance of pesticides and sanitizers. If you need help or have questions on the process, contact your local CCE Extension specialist.
Early Season Peas in the High Tunnel
Natasha Field, Program Aide, CCE Eastern NY Commercial Horticulture Program
Growing peas in a high tunnel in the spring is an effective way to bring them to market three to four weeks earlier than field grown peas. In the Capital District of NY, peas generally are planted in mid-April and begin bearing late June in the field. But planting them in a high tunnel in March allows for the plants to grow and reach harvest starting around the last week of May and first week of June.
Benefits
- Harvest three to four weeks earlier
- Seed corn maggot avoidance – peas germinate before first flight of seed corn maggot emerges
- Decreased risk of disease – reduced leaf wetness lessens disease pressure compared to field grown peas
Cultural Recommendations
In our trials, peas were placed in single rows, two feet apart. We recommend trellising, both because of the narrow spacing and because the plants may be double the height in the tunnel that they are outside. Peas can be trellised with either vertical floral netting or a Florida weave with twine and t-posts. Both short (24-36 inch tall) and tall (48-60 inch tall) varieties can be grown in this system provided sufficient trellising is in place.
Photo credit: Natasha Field
[Alt Text: Two images of a pea rows in high tunnels. The one on the left is grown on a plastic mesh support system and the one on the right is grown on a horizontal string support system.]
Managing the temperatures in the high tunnel should be a priority. After the temperatures get above 80F and the humidity is high, disease issues can begin to appear.
Harvesting twice a week is recommended for best quality, especially once the weather begins to get hot. Excessive heat can cause off-flavor issues in the peas. Some varieties may produce pods until mid-July but it might not be economically worthwhile to keep high tunnel peas beyond the end of June, depending on your markets and outdoor pea production.
For high tunnels that have been in production for many years, following an early pea crop with a late summer cover crop after may be an option for improving soil health and helping to reduce disease pressure in other cash crops, like tomato or cucumber.
Additional resources:
2020 Pea Variety Trial | Natasha Field and Crystal Stewart-Courtens. CCE ENYCHP | 2020
2021 Pea Variety Trial | Natasha Field and Crystal Stewart-Courtens. CCE ENYCHP | 2021
2024 Winter Greenhouse Growers School
When: Thursday, January 18, 2024 Where: Cornell Cooperative Extension of Albany County 24 Martin Road, Voorheesville, NY 12186
For the full agenda click here
Topics include:
Saving your crops when the weather doesn’t cooperate*
Tough to tackle: phytophthora, fusarium & bacteria in the greenhouse*
Updates from NYS Ag & Markets*
Fertilizer management to reduce use of pesticides and PGRs
Pesticide Compatibility**
Internet Marketing
Worker Protection Standard and DEC Updates**
NYSDEC pesticide applicator credits provided for categories: *10, 1a, 3a, 24, 25** CORE
Pre-registration required. Walk-ins will NOT be allowed. Register by January 16th, 2023 at: https://caahp.ccext.net/civicrm/event/info?reset=1&id=183.
If you need assistance with registration, call 518-765-3518 or email cce-caahp@cornell.edu.
For program questions, contact: Jingjing Yin, jy578@cornell.edu or 518-429-8608.
If you need assistance with registration, call 518-765-3518 or email cce-caahp@cornell.edu.
For program questions, contact: Jingjing Yin, jy578@cornell.edu or 518-429-8608.
Please Click Here to Take CCE Tomato Survey
Field equipment sanitation survey (weed seeds and other pests/pathogens)
A group of university (including Cornell) crop pest management and food safety researchers across the U.S. is currently gathering grower and ag industry information on field equipment sanitation practices with the goal of designing research to address needs of the agricultural industry and consumers.
Agricultural field equipment includes: planters and transplanters, tillage implements, tractors, harvesters, cultivation equipment, trucks, trailers, sprayers, mowers, or any other piece of equipment that is shared across fields.
Specifically, our team is interested in understanding if stakeholders are concerned about the movement of weed seeds, nematodes, insect, plant disease inoculum, and even some human health pathogens on equipment used for field operations. Additionally, we want to know what cleaning or sanitation practices you may have in place to mitigate the spread of pests.
To develop baseline information and guide future research and extension efforts, we are asking for growers and industry participation in a VERY BRIEF and ANONYMOUS survey (less than 5 minutes) so that we can get some sense of the concerns, practices, and barriers related to equipment sanitation in various crop sectors around the U.S.
Your participation would be greatly appreciated whether you think about this kind of thing regularly, or not at all.
The survey can be accessed online using this link: https://forms.gle/DUxQQWXVh8LiANWa9 The survey can also be accessed by scanning this QR code:
