Last week the question was: What is this insect on this rapeseed flower?
This is a mayfly. Mayflies are extremely old insects whose origins date back to approximately 300 million years ago. Juvenile mayflies are aquatic but leave the water when they become adults. They have just a day or two to mate before they run out of energy and die. Here is a good site with more info on mayflies.
Here is this week’s question: What happened to these strawberry blossoms?
The vast majority of growers wisely waited patiently a few weeks ago when temperatures were warm. Now that the forecast looks to be staying warm, folks are getting ready to plant. A few acres have already been planted and we should expect to see a lot of tractors rolling over the next week.
The soil was at a good temperature yesterday afternoon, though keep in mind the soil can fluctuate 10 or more degrees throughout the day. Looking at the average soil temp for the day is more accurate. For corn to germinate and come out of the ground quickly we want the average soil temp to be at least 55 at the 2 inch depth.
At 60 degrees at 2″ corn should germinate and come up quickly.
Here’s a look at some seeds in the furrow.
For pest management information throughout the season, take a look at the corn section or the SC Pest Management Handbook:
Last week we saw 3 consecutive nights in the 20’s with the lowest reaching 22 in some areas. Now that a week as passed, we can see the signs of damage on some of our jointing wheat.
Wheat a week after 3 subfreezing nights.
You wouldn’t know it just from looking at the field from the truck, but when we split the stems and look inside at the developing heads, the damage is apparent. What we should see in a healthy head is a nice white color and a turgid structure. Typically we can distinguish each individual floret. See below.
Healthy grain head. White in color and turgid structure.
The grain head below was damaged by the cold. You can see that it has lost its turgidity and looks kind of like the tip of a thin wet paint brush. It’s hard to see in the photo, but the color has turned to a pale tan. Color isn’t always the best indicator because differences can be so subtle that they are hard to see.
Damaged grain head. Loss of turgidity.
Here is a look at a good and bad head side by side for comparison.
These heads that are damaged won’t continue to develop, though the plants may remain green. If you are seeing a significant amount of damage in your fields, it may be wise to consult your crop insurance agent before adding any more inputs (i.e. fungicides at flag leaf). Here is a good publication describing exactly what happens to the plant when injured by cold weather. If you would like help identifying damage in your fields, please contact your local Extension Agent.
Last week the question was: What is this flowering weed?
This is oldfield toadflax. This is a pretty common winter weed. We see it blooming first thing in the spring all over the place, especially in lawns. We see it in fields some, though it’s not a serious weed to our winter crops. It’s fairly showy in fallow fields along with red sorrel. Here is a good page with a little more info.
Here is this week’s question: What is this insect on this rapeseed flower?
According to Weather Underground it got down to 28 this morning (3/15) and its forecast to reach 23 tommorow morning (3/16) and 27 Thursday night (3/17). The cold last night was enough to ruin most of the peach crop in SC. Wheat growers are nervous about what will become of their crop. Below is a table from Kansas State showing the temperatures at which wheat can sustain freeze damage.
We have a whole lot of wheat in the jointing stage right now, so if we reach 23 it could be bad news. The little wheat head pictured below is on it’s way up the stem and is highly vulnerable to a hard freeze. If damaged, it will be evident within a few days by a slightly greener or brown tint and loss of turgidity.
The photo below shows a wheat head from the 2016 season that was damaged by a frost in the boot stage. If we get damage in the jointing stage, the damaged tillers may not even make it to boot.
Head damaged by frost in the boot stage.
Unfortunately, there isn’t much we can do to protect our wheat fields. We’re at the mercy of mother nature.
Here is a great publication from Kansas State showing photos of freeze damage at each stage of wheat development with detailed descriptions of what happens when the plants are damaged. If you would like help assessing freeze damage over the next week or so, please contact your local Clemson Extension Agent.
Last week the question was: What are these flowers in this little pecan grove?
These are daffodils. They are some of the first flowers to emerge in the spring and they came extra early this year. Daffodils are flowering bulbs that will come back year after year. They are a favorite in flower gardens along with other flowering bulbs like tulips, hyacinths, and crocus. For more info, here is a great publication from Clemson about flowering bulbs.
Here is this week’s question: What is this flowering weed?
Our very oldest wheat fields are starting to joint. All of our winter crops seem to be about 3 weeks ahead of where we were last year. There’s a good bit more wheat planted this year than last year and its been looking pretty good all winter, despite growing way faster than we would like.
Split stem showing the grain head heading to the top.
Here’s another one that isn’t quite as far along.
It’s been cool in the mornings and there has frequently been dew on the ground, perfect conditions for powdery mildew. There’s plenty of it out there. Remember, powdery mildew isn’t normally a concern until the flag leaf emerges.
Once our flag leaf emerges, we want to use the following threshold: 20% of the leaf area is infected on the leaf just below the flag leaf and cool, wet weather is predicted to continue. If the weather gets hot, it’s likely we won’t have to worry about it at all.
Last year was an awful year for diseases. We saw leaf rust especially bad and some growers ended up terminating their crop because of it. Stripe rust was found in several areas as well, mostly in NC. Use this as a reminder that we need to be diligent in our disease control this year. The best time to apply fungicides is just after flag leaf emergence. Take a look at pages 15-16 of the Clemson Wheat Cheat Sheet for more info and labeled chemicals.
Its been a warm winter and the rapeseed is really starting to bolt. We are probably 3 weeks earlier than we were last year. That could be concerning if we get a hard freeze in the next few weeks.
A rapeseed field at about 30% bloom.
Some growers didn’t get a great stand, mostly due to the hurricane, and have had to think hard about whether to carry their crop to harvest or let it go. For those who are carrying it to harvest, now is the time for disease control. Most fungicide labels recommend timing applications at 20-30% bloom and possibly another later on. As warm as it’s been, Sclerotinia hasn’t been an issue at all, though we have seen it show up after bloom before. It can get started on the flower petals that drop to the ground and then infect the stems. An early bloom application helps with Alternaria also.
Insect pressure has been low, but if you do see the need to treat for seedpod weevils (The threshold is 2 or more weevils per plant during 50-75% bloom). Just remember that pollinators love those bright yellow flowers too. The best way to avoid pollinators while applying insecticides is to spray first thing in the morning or late in the evening.
For more information on rapeseed and canola production, take a look at this Canola Production page or contact your local Clemson Extension agent.
Posted in Canola/Rapeseed
Tagged alternaria, beneficial insects, bloom, bolting, bright yellow flowers, cabbage seedpod weevil, canola, clemson extension, fungicides, insecticides, pollinators, rapeseed, sclerotinia
Anyone planning to use the new dicamba or 2,4-D products this year should consider attending this meeting. Representatives from the manufacturers will be sharing valuable guidelines and precautions that applicators should be aware of before using.
Posted in Pesticides, Uncategorized, Upcoming Meetings
Tagged 24d, clemson extension, Clemson Pee Dee REC, cotton, dicamba, herbicide drift, herbicides, soybeans, stewardship