There are isolated reports of corn for grain and soybeans starting to be harvested in a few areas of Iowa. The latest USDA/NASS weekly crop conditions survey shows that as we are now moving into mid-September 2015, about 88% of the state's corn is in dent stage and 26% of the crop has reached maturity.
"Crops continue to mature in Iowa and generally are in good shape with 80% of corn and 75% of soybeans in good-to-excellent condition. This past week there was seed corn being harvested and silage being chopped in several parts of the state, and some early corn and soybean harvest for grain in some places," says Greg Thessen, head of the USDA/National Ag Statistics Service's Upper Midwest regional office in Des Moines.
Soybean growth and development is coming along, too
While corn is considered mature when it reaches the "black layer" stage in the kernel, how do you gauge soybean maturity? "In northeast Iowa, most soybean fields are currently at least halfway through the R6 stage, which is also called R6.5, which means the lower leaf canopy is yellowing," says Brian Lang, Iowa State University Extension field agronomist at Decorah. "The R7 stage begins when one pod on the main stem has reached its mature tan or brown color, and is basically safe from frost." Soybean stages are illustrated and defined at extension.agron.iastate.edu/soybean/production_growthstages.html.
How to tell soybean development for a full season variety
ISU's Brian Lang offers the following explanation on how to gauge soybean maturity:
* R6: Full seed (pods contain green seeds that fill the pod to capacity at one of the four uppermost nodes on the main stem), 20 days to R7. At R6.5 stage (about half way through R6 stage) mid-canopy leaves begin to yellow and drop.
* R7: Beginning maturity (one pod on the main stem has reached its mature tan or brown color), 10 days to R8 (safe from a significant yield reduction if a killing frost occurs at this point).
* R8: Full maturity (95% of the pods have reached their mature color).
The complete weekly Iowa Crops & Weather Report is available on the Iowa Department of Agriculture & Land Stewardship website IowaAgriculture.gov or on USDA's site nass.usda.gov/ia. The report summary follows here:
CROP REPORT: Widely varying amounts of precipitation were received at the beginning of the week, but drier conditions prevailed later in the week, allowing Iowa farmers 4.9 days suitable for fieldwork for the week ending September 13, 2015, according to USDA's National Ag Statistics Service. Activities for the week included seed corn harvest, chopping silage, cutting hay, and isolated reports of corn for grain and soybean harvest. There were continued reports of disease pressure on corn.
Topsoil moisture levels fell slightly to 0% very short, 6% short, 81% adequate and 13% surplus. Subsoil moisture levels rated 0% very short, 6% short, 81% adequate and 13% surplus.
Iowa corn crop reaches 88% in dent stage and 26% mature
Iowa's corn crop on Sept. 13 was 88% in the dent stage or beyond, with 26% mature. That's four days ahead of last year, but one week behind the five-year average. Corn condition rated 80% good to excellent. And 62% of Iowa's soybeans were starting to turn color or beyond, while 18% of soybeans were dropping leaves, three days ahead of 2014, but two days behind normal. Soybean condition rated 75% good to excellent.
Third cutting of alfalfa hay was 83% complete, 10 days ahead of last year, but a week behind the average. Pasture condition is rated 66% good to excellent. Livestock were reported as having very little stress.
IOWA PRELIMINARY WEATHER SUMMARY—For week ended September 13, 2015
By Harry Hillaker, State Climatologist, Iowa Department of Agriculture & Land Stewardship
The past reporting week began with very warm and humid weather and frequent rainfall. Rain fell nearly statewide from Sunday (Sept. 6) evening into Monday (Sept. 7) morning with very heavy rainfall over portions of central and south-central Iowa. This was followed by another statewide rain event from Monday (Sept. 7) night into Tuesday (Sept. 8) morning with the heaviest rains concentrated over southwest areas of the state. Wednesday (Sept. 9) and Thursday (Sept. 10) were not quite as warm.
Light rain fell over the northern one-third of Iowa and far western portions of the state from Wednesday afternoon into Thursday morning. Rain also fell nearly statewide on Thursday into Friday (Sept. 11) morning although amounts were mostly light excepting a few localized areas of around an inch of rain across the east.
Below normal temperatures and above normal rainfall
Dry and much cooler weather prevailed over the weekend. Rain totals for the week varied from 0.11 inches at Hampton and 0.14 inches at Castana (Monona Co.) to 6.35 inches at Bagley (Guthrie Co.), 5.53 inches at Lake Rathbun and 5.15 inches at Bedford. Statewide average was 1.38 inches; normal for the week is 0.82 inches.
Daytime highs climbed into the 80s in many areas from Monday through Thursday with Burlington, Donnellson, LeClaire and Muscatine reporting the highest temperatures with 89 degree readings on Monday (Sept. 7). Meanwhile, temperatures fell to 37 degrees at Sheldon on Saturday (Sept. 12) morning and 38 degrees at Elkader, Manchester and Stanley on Sunday (Sept. 13) morning. Very cool late week weather just barely cancelled out the very warm start to the week with temperatures for the week as a whole averaging 0.4 degrees below normal.