 Our field is looking a bit ragged. The leaves are starting to
senescence or die. Our field is at physiological
maturity (R9), which means
the seeds are as big and heavy as they are going to be and we're just
waiting for harvest. So, if it were to rain, it wouldn't really help
the plants. Now, before we can harvest this field the seeds will have to dry
down or lose moisture that's in them and the stalks will have to dry, too.
 The heat and drought have speeded up the plants' maturation process. The
leaves are yellowing and drying up. It's been 14 days since we've had
a rain and that rain was just a sprinkle. The hottest day so far in
August was on August 21st when it reached 106 F. That's hot!
 This is the front of an R9 plant. The dried floral parts have stuck
to the head the whole summer. The head is starting to dry down to a
harvestable moisture content. You know, if you stare at that head long
enough, you can almost make out eyes and it starts to look like a space
alien! What do you think? Sorry, I've been out in the sun too long.
 This is the back side of the previous head. It has a nice
buttery-yellow color and the bracts have turned brown. The rest of the
head will eventually turn brown.
 This is the cross section of the same head. Like most of the heads we've
observed lately, this one has the brownish areas indicating head moth larvae
activity. There's a little bit of Rhizopus head rot visible, but it
doesn't appear to be too bad.
 The small, shriveled seeds are from the center of the head, while the
larger seeds are from the outside edge.
This is what I've been worried
about for a couple weeks. This is an example of drought stress and it will
have a serious impact on yields.
 This is a seed that is physiologically mature. Notice its color is more
grayish than when we looked at a seed a
couple weeks ago. It still has
too much moisture inside it to be harvested and stored in a grain bin.
The seeds and sunflower heads have to be dry enough that seeds can be
separated from the heads in the harvesting process.
 At this point in the season we'll start to see things, such as this stem
that has lodged or broken over, that we
haven't seen throughout the growing
season. This damage is due to the stem weevil that we've talked about
before. As the plants mature and dry down we'll see more stalk
lodging. Farmers don't like to see lodged plants because these lodged
plants won't be able to be harvested.
 We've talked about sunflower heads being too large and this one is a good
example. This plant didn't have other
plants very close, so it
compensated for that extra space by developing a very large head. This head
was so heavy that it broke the stem -you can see the brown break-line about
ten inches below Dale's hand. This head will probably hang on and make
it to harvest, but the seeds will likely be shriveled.
 We thought this was an interesting plant. Notice, it doesn't have a head
and its leaves and leaf petioles (stems) are purple. I don't know why
the head is missing, but the reason the leaves are purple is because the
head is gone. In a healthy plant, sugars that are made in the leaves through
the process of photosynthesis are transported and deposited into the seeds,
but because this plant's head is gone, there's no place for the sugars to
go. So, the leaves are purple.
 Well, there's the same golf ball we saw when we were looking for emerged
seedlings in May. It was easy to see with the leaves starting to die.
|
Our field is looking a bit ragged. The leaves are starting to
senescence or die. Our field is at physiological
maturity (R9), which means
the seeds are as big and heavy as they are going to be and we're just
waiting for harvest. So, if it were to rain, it wouldn't really help
the plants. Now, before we can harvest this field the seeds will have to dry
down or lose moisture that's in them and the stalks will have to dry, too.
