Preliminary Report - 1996 Wheat TriaIs
INTRODUCTION:
The following is the preliminary variety trial information for
single (1996) and multiple year (1994-1996) comparisons in
Minnesota. Average yield data for newer varieties which were only
grown for one or two years have been adjusted mathematical to
allow valid comparisons. Two-year and especially one-year data
are less reliable and should be interpreted with caution.
Similarly, averages across multiple environments, whether they
are different years and/or locations, provide a better estimate
of mean performance. The least significant difference or LSD is a
statistical method to determine whether the observed yield
differences between two varieties is due to true, genetic
differences between the varieties or to interactions with other
variables such as the presence of disease and difference in soil
fertility. If the yield difference between two varieties equals
or exceeds the LSD value, the higher yielding was indeed superior
in yield. If the difference was less, the yield difference may
have been due to environmental interactions rather than genetic
differences, and we are unable to distinguish the better of the
two. The 5% unit indicates that with 95% confidence, the observed
difference is indeed a true difference in performance. Lowering
this confidence level will allow more varieties to be different
from each other, but increases the changes that false conclusions
are drawn.
SUMMARY:
The 1996 season was just like 1995, different from the norm.
Delayed planting, repeated flooding, orange wheat blossom midge,
scab, and drought all impacted the wheat crop. Similar to 1995,
scab was not present in production statewide, but rather limited
to the northern tier counties. Yields in the southern part of the
state were record breaking. The average yields of the southern
locations (St. Paul, Waseca and Lamberton) was 62 bushels per
acre this year. This compares to an average of 57 bushels per
acre in 1995 and a three-year average of 52 bushels per acre. No
data was collected at the West Central Experiment Station in
Morris this year. The northern locations (Crookston, Stephen, and
Roseau) averaged 49 bushels per acre in 1996 compared to 43
bushels per acre last year and a three-year average of 39 bushels
per acre.
Table 4 presents the average grain yield for the combined
locations in the north, south, and the whole state for both 1996
and the three-year averages. The varieties are ranked by
maturity, not yield. In this year's yield trials, Nordic, Verde,
and Marshall were among the highest yielding varieties across the
southern locations. All varieties yielding more than 59.9 bushels
per acre are within the first LSD 5% unit of 9.8 bushels per
acre. Statistically meaning that we are unable to conclude that
any variety within this group has a higher yield potential.
The three-year average (1994- 1996) data shows Oxen, Hamer, Lars
and Russ as top yielders. Again, any variety yielding more than
56.6 bushels per acre is within the first LSD unit of 5.1 bushels
per acre, indicating that statistically we are unable to
distinguish the varieties for their yield potential from one
another. Verde, Hamer, Lars and Oxen were the top producing
varieties across the northern locations this year. Although 13
varieties yielded more than 50.7 bushels per acre and are all
within the first LSD unit of 8 bushels per acre. Over the three-
year average (1994-1996), Lars and Norlander are on top.
Similarly to the single year data, 10 varieties yielding more
than 45.3 bushels per acre are all within the first LSD unit of
4.5 bushels per acre.
Certainly, grain yield is very important in varietal choices.
However, net return per acre in dollars is not simply a function
of bushels but also of what management inputs (chemical,
fertilizer, machinery) were needed to realize that yield.
Response to disease, grain quality, and other agronomic
characteristics like lodging susceptibility may impact your
decision as a function of your ability to manage these risks or
limiting factors which could affect your net return per acre.
Varietal characteristics are presented in Table 5. All values are
three-year averages (1994-1996) except for scab values which are
based on 1995 and 1996 data. The foliar disease rating is based
on data from North Dakota State University trials. The foliar
disease rating is based on a complex of leaf diseases, including
Septoria, tan spot, and bacterial diseases. The rating does not
differentiate among these diseases. Therefore, the rating should
be used with care and only with consideration for varietal
selection in areas where these diseases historically have been a
problem or if the previous crop was either wheat or barley.
The varietal response to scab is presented as a severity rating
similar to the rating for leaf and stem rust. The resistance to
spread in the head is presented in the severity rating and is one
of the resistance mechanisms. In addition, a second rating is
provided to characterize the ability of a variety to maintain
sound, plump kernels despite disease symptoms. The ability to
maintain sound, plump kernels is a second component to
resistance.
Variety selection for 1997 should again be a balance between
yield potential, disease responses and quality parameters.
Pioneer 2375 still dominates the average because of its tolerance
to scab but has susceptibility to Septoria and tan spot. In
addition, problems with shattering, lodging and poor competition
with weeds increase as the variety is grown further north,
especially north of US Highway 2.
This year one new private and two new public varieties were
released. The University of Minnesota released BacUp, while
South Dakota State University released Oxen. Western Plant
Breeders released Sharpshooter. Unfortunately, this variety was
not included in the state yield trial. AgriPro's Gunner was
included in the yield trial but release was delayed to 1997. Two
varieties from the Agriculture Canada's program were also
included in the results. AC Cora was tested for the second year
and AC Domain was tested for the first time.
A short description of each of the new entries, including
Sharpshooter, is provided below. Except for Gunner, which will be
increased for certified seed in 1997, dealers should have enough
seed for at least 50,000 acres of each of these new varieties.
NEW VARIETIES:
1. BacUp is an awned, very early maturing hard red spring wheat
from the University of Minnesota with a low to intermediate yield
potential. BacUp segregates for plant height and is susceptible
to lodging and leaf disease, similar to Sharp but better than
2375. BacUp is both resistant to leaf and stem rust. Insufficient
data from NDSU was available to provide a reliable foliar disease
rating. BacUp is resistant to scab both for spread through the
head or expressed in the severity rating as well as it's ability
to maintain sound, plump kernels as expressed in the tolerance.
BacUp has very high test weight, and very high grain protein
percentage, as much as 2.0 percentage points higher than Grandin.
The milling and baking quality are excellent, similar to Grandin.
BacUp is specialty use wheat. Do not plant BacUp on more than 15
to 20% of your acreage. Use the high quality of BacUp to improve
quality of other wheat through blending.
2. Oxen is an awned, medium early hard red spring wheat from
South Dakota State University with a high yield potential and a
wide area of adaptation. Oxen is a semi-dwarf wheat with short
to intermediate plant height and intermediate to low resistance
to lodging, similar to Kulm but better than Sharp. Oxen is
moderately resistant to both leaf rust and stem rust. Oxen is
moderately resistant to scab, similar to Butte 86, but less than
2375. Oxen has a medium test weight, similar to Russ and Verde,
and a medium grain protein percentage, similar to 2375 or Hamer.
The milling and baking quality are equal to Russ and 2375.
3. Sharpshooter is a new release from Western Plant Breeders
derived from a cross of Sharp with a Chinese spring wheat, used
as a source of resistance to scab. According to its breeder,
Sharpshooter is very similar to Sharp in most agronomic, quality,
and disease response characteristics. Sharpshooter differs from
Sharp in its response to scab. Under heavy disease pressure,
Sharpshooter can out yield Sharp while maintaining better seed
quality.
4. Gunner is a late maturing variety from Agri-Pro with an
intermediate to high yield potential. Gunner is a tall stature
wheat with good resistance to lodging, similar to Marshall.
Gunner is moderately susceptible to leaf rust, but resistant to
stem rust. Based on limited data, Gunner has good foliar disease
resistance, similar to Lars. Gunner is moderately resistant to
moderately susceptible to scab, similar to 2375, and maintains
test weight and sound kernels as good or close to 2375. Gunner
has high grain protein percentage and medium high to high test
weight, similar to Grandin. Milling and baking quality are
medium to high, similar to Kulm.