Wichita Falls, Texas
August 3, 2007
Somewhere between putting grain in
the bin after harvest and putting seed in the drill for
planting, Texas wheat producers should pay attention to seed
quality, said a Texas
Cooperative Extension agent.
"During the past two years wheat
farmers have dealt with record-setting drought, heavy foliar
disease pressure and a breakdown of leaf rust resistance," said
Miles Dabovich, Extension agent for agriculture and natural
resources in Wichita County. "This year we added record-setting
rainfall to that equation."
The wet spring and summer have
raised concerns about wheat sprouting before harvest, he said.
"Wheat that has initiated
germination will be lower quality seed whether it is simply
swollen or already has a root exposed," Dabovich said. "This
type of seed will have lower germination and less seedling
vigor."
"Pre-harvest Sprouting in Wheat,"
a publication by Extension small grain specialist Gaylon Morgan,
notes that starch in the wheat kernel is converted to sugars
when the kernel absorbs moisture and begins to germinate. This
publication is online at
http://tcebookstore.org/. Click on the link to
"Agriculture," then "Crops," then "Small Grains."
"These sugars don't keep or store
as well as starch," Dabovich said. "Germination percentage and
the energy available for seedling vigor both suffer while the
seed is in storage.
"Seed tested right after harvest
may have germination as high as 90 percent, while seed tested
after three months of storage may have germination below 50
percent."
So is this type of wheat suitable
as seed? "It depends on your situation," Dabovich said.
"It's a good idea to
gauge seed quality by conducting a germination test prior to
planting. Don't rely on a post-harvest germination test.
"If a pre-planting test indicates
75 percent germination, about 25 percent of what you put in the
drill isn't going to germinate. Trying to compensate for poor
quality seed by increasing seeding rate isn't feasible when you
are planting wheat for forage or for forage and grain. And it is
very risky when you are planting wheat for grain, even when soil
temperature and moisture are good."
If the pre-planting test indicates
high levels of Smut or other serious disease, the seed isn't
worth using. If low levels are detected, the seed may be
suitable if a fungicide seed treatment is used, he said.
If germination, potential seedling vigor or disease raise doubts
about seed quality, the best bet is to buy and plant proven
seed.
"Target planting for the optimum
time, soil conditions and planting depth," Dabovich said.
"Quality seed has good germination and seedling vigor, two of
the main ingredients of forage and grain yields. "With the
harvest conditions we had this year, keeping seed quality in
mind could help some producers avoid a crop wreck later this
fall." |
