Oklahoma wheat estimating program, 6/2012

              USDA-NASS
OKLAHOMA
FIELD OFFICE
OKLAHOMA WHEAT ESTIMATING PROGRAM
2012 CROP YEAR JUNE 2012
The USDA’s National Agricultural Statistics Service program for wheat in-cludes
a number of estimates that are made on a schedule spanning the en-tire
crop year. The inclusion of any state in the national program is depend-ent
on that state’s portion of the national wheat crop. Oklahoma compiles
estimates for acreage, yield, total production, prices, and planted variety for
winter wheat. Crop progress and conditions are also tracked throughout the
year and grain stock estimates are compiled quarterly for wheat.
The survey data used to estimate wheat come from a series of probability
and non-probability surveys conducted throughout the year. A general de-scription
of a probability survey is one for which every farming operation has
a known probability of being selected and when selected, represents a
known number of similar operations throughout the state. Probability sur-veys
produce not only indications for a particular category, but an estimated
sampling error associated with each of those indications. Survey information is gathered volun-tarily
from wheat growers across the state of Oklahoma, except for the price data, which is col-lected
from grain elevators. All individual data collected through any of these surveys are held in
the strictest confidence and are used only in combination with other reports to generate state and
county level estimates.
The crop year for wheat estimates begins in December when producers report the acres they
planted in the fall. In May, the first harvested acreage forecast is set. Planted and harvested
acreage is then reviewed using survey data collected in June, with the end-of-year estimates be-ing
published in late September.
Yield per acre estimates are based on both data reported by producers, as well as data collected
from field observations. Monthly probability yield surveys, conducted from May through August,
collect information from producers about their expected yields. Another monthly probability sur-vey,
Wheat Objective Yield, collects field observations for winter wheat. Small plots are laid out
in about 180 randomly selected fields across the state. Counts are made and clippings are taken
for analysis up through harvest. Gross yield per acre and post harvest loss are combined to de-termine
an indication of net yield per acre.
Winter wheat crop progress and conditions are collected and published on a weekly basis
throughout most of the year along with selected weather data.
Stocks on hand are estimated four times a year for all wheat. Prices
received by farmers are estimated monthly and are then used to de-rive
a market-year average price. County level estimates for acre-age,
yield, and production are prepared in the Fall after the Annual
Small Grains Summary. Data for the county estimates come from a
combination of all the above-mentioned survey data, as well as a
very large end-of-the-year acreage and production survey conducted
in August after harvest.