Upstart Farmers Roundtables are held every two weeks. After the event, they are available to members of the Upstart Farmers Community.
About the Upstart Farmers Roundtables
Upstart Farmers Roundtables are an informal, biweekly event. Using Google Hangouts video calling, a small group of Upstart Farmers comes together to share their experiences and learn from each other. Each week is guided by a discussion topic, with growers welcome to ask their own questions.
Roundtables are exclusively for Upstart Farmers, and recordings are only released to the Upstart Farmers Community.
Roundtable: Bring Your Plant Problems!
This week, farmers brought photos of their plant problems to share and discuss with the group.
Plant Problem #1: The Seedling Tray
Submitted by Carey Martin
What’s the problem? Carey has very hard city water, with a pH ranging between 8.3 and 9.1. Entire seedling trays are weakened and deficient. He has since flushed the trays with fresh water but is unsure that they will come back. The seedlings were planted in a seedling mix.
Our Thoughts: Seedling mixes are often more dense than traditional potting mixes, so if plugs are too large or trays are over watered, you can get poor oxygen exchange, leading to moss, algae, and/or compaction. Using a potting mix and decreasing the amount of water should help. Other farms have used coco coir, peat, Flexi-Plugs, or similar plugs with success.
Arugula also does poorly in plug trays, which could be contributing to poor germination and appearance. It is very sensitive to heat and prefers cool environments.
These seedlings are worth saving. Once they are planted in the towers and placed in a good nutrient solution, they should rebound.
Problem #2: Aphids!
Submitted by Tracy Holz
Whats the problem? Tracy Holz has aphids. They flourish during transition seasons. Tracy has tried lady bugs and sprays, but the problem persists.
Our Recommendations: Spray regularly! We use pyrethrins generously in series with Azadirachtin-based pesticides (Azamax) and Botaniguard. You must be diligent about your spraying schedule – and that’s the hardest part!
For background control, aphidous wasps are the preferred biological control. Some have had good luck with ladybugs or lacewings; some haven’t.
We have written about aphids before here, here,
Plant Problem #3: White Fungus on Chives
Submitted by Phil Cuddeback
What’s the problem? Phil has an unknown disease affecting his chives. The white spots are obvious.
Our Recommendations: Chives and members of the onion family are generally hardy, but there are a couple of fungal and viral diseases who that will target the family. It’s very difficult to diagnose from just this photo, but after further review, it does appear to be something fungal.
Plant Problem #4: Rot and Mold
Submitted by Phil Cuddeback
What’s the problem? When this picture was taken, the Freight Farm was very humid. Seedlings were coated in a white fuzz or mold, and recent transplants developed brown spots on the underside and rotting around the base of the stem. A fibrous material also grew around the rot. The problem was thought to be Botrytis.
Our Thoughts: This doesn’t look much like botrytis, but it could be. Plants in hydroponic, humid environments can be susceptible to a number of diseases. Pythium is also very common and will cause a brown rot. Rhizoctonia is another possibility.
With fungal pathogens, one of the best controls is to reduce humidity and increase air circulation.
Plant Problem #5: Brown Roots
Submitted by Phil Cuddeback
What’s the problem? A Freight Farmer saw brown discoloration of seedling roots. Their guess was water with low levels of dissolved oxygen. Introducing miccorhizae bacteria into the system may have helped.
Our Thoughts: This may not even be a disease problem. If seedlings are sitting in standing water with low dissolved oxygen, this can happen. If you’re adding bacterial supplements or nutrition in a system with low dissolved oxygen, it can actually decrease the dissolved oxygen problem and cause root die back.
Certain supplements, like fulvic or humic acid, can also discolor the roots, which is harmless.
Plant Problem #6: Leaf Blight or Spot
Submitted by Carey Martin
What’s the problem? This light brown, stippled leaf spot or blight appeared and worsened overnight, before Carey had time to even get to the store and purchase a spray. He removed and destroyed the plants.
Our Thoughts: This almost looks like a mixture of two or more problems. It has some of the qualities of a bacterial blight along with some qualities of a magnesium deficiency.
Plant Problem #7: Deficiency
Submitted by Carey Martin
What’s the problem? This basil has interveinal chlorosis and necrotic spots.
Our Thoughts: This is clearly a nutrient deficiency. Our guess is a potassium or magnesium deficiency. To verify, you need to look at more of the new growth.
In fertilizer mixes, the deficiency is more often magnesium than potassium. Haydn recommends dumping or replacing the hydroponic solution more frequently.
What’s our biggest tip?
Above all else, make friends with your extension agent. Extension agents, who may work at a county office, or even your nearest university’s plant sciences department are happy to help examine and diagnose plant problems. These folks are experts.
Sending or showing them actual plant samples is far more effective than photos.