SOUTH DAKOTA
SOUTH DAKOTA STATE UNIVERSITYPlant Science and Biology/Microbiology Departments and USDA-ARS Northern Grain Insect Research Laboratory (NGIRL), Brookings, SD 57007 USA.
http://triticum.sdstate.edu
Personnel changes.
Scott Haley resigned his position as winter wheat breeder
for South Dakota State University, effective 31 December, 1998.
He is now winter wheat breeder at Colorado State University. During
his tenure at SDSU, Dr. Haley developed an aggressive cultivar
development program for HRWW and recently HWWW. Cultivars released
under his leadership include Nekota, Crimson, and Tandem. The
region is fortunate that he will remain in winter wheat breeding.
Jackie Rudd, spring wheat breeder at SDSU, has been assigned as
interim project leader until a replacement for Dr. Haley has been
found. A search is currently being conducted.
Winter wheat breeding and genetics.
S.D. Haley, S.A. Kalsbeck, R.S. Little, F. Hakizimana,
and Z. Zhang.
Crop Report. Winter wheat production in South Dakota in
1998 was estimated at 61.1 million bushels from 1.42 million harvested
acres acre, for an average of 43.0 bu/acre. The 1998 growing season
in South Dakota could be characterized roughly as follows: timely
planting with adequate moisture for good stand establishment;
mild temperatures during the fall extending into the winter; much
below average winterkill resulting from an extremely mild winter;
a very warm spring, resulting in accelerated plant development
and heading 1014 days earlier than normal; dry soil moisture conditions
in late spring; obvious root rot symptoms later during the season
(in some areas); adequate soil moisture and moderate temperatures
during grain filling; significant tan spot, Septoria tritici,
and leaf rust pressure in many areas during the grain filling
period.
Cultivar development. The SDSU Winter Wheat Breeding Program
conducted testing at eight locations throughout South Dakota (Brookings,
Watertown, Highmore, Selby, Wall, Winner, and under two different
rotation systems at the Dakota Lakes research Farm near Pierre).
Unlike the severe winters of 1996 and 1997, each of the breeding
trials came through the winter in excellent condition. Although
winter injury was unimportant in 1998, several diseases (e.g.,
tan spot, root rot, and leaf rust) were prevalent and responsible
for significant reductions in both yield and quality. No-till
production systems have profoundly altered the range of varieties
available for producers in South Dakota. During the past few years,
certain winter wheat varieties developed in the southern Great
Plains (e.g., Jagger and 2137) have gained attention in South
Dakota. The primary reasons for this are their superior resistance
to leaf spotting diseases (tan spot and Septoria), perceptions
of improved response to higher fertilizer rates, and the observation
that proper crop residue management and no-till planting reduces
winter-hardiness requirements. There is some concern with the
increasing acreage (from Oklahoma to South Dakota) of stem rust
susceptible varieties such as Jagger and 2137. Without question,
development of hard red and hard white winter wheats adapted for
the varied production systems in South Dakota is a significant
challenge. Although we will continue to pursue maintenance and
improvement of winter-hardiness, such an objective may ultimately
be inconsistent with the increasing focus on crop residue management
and no-till planting. To address these varied challenges, each
year 800- 1000 new cross combinations are made and 600-800 new
experimental lines are developed by the Winter Wheat Breeding
Program.
Seed increases. Two lines are currently being increased
with the intent to release in the autumn of 1999. SD92107
(pedigree: Brule//Bennett/Chisholm/3/Arapahoe) is an awned, red-glumed,
medium-late, standard-height hard red winter wheat with excellent
winter hardiness and a very broad disease resistance package.
SD92107 would potentially be targeted toward conventional summer-fallow
production systems (with minimal or no crop residue at planting)
across South Dakota where the potential for winter injury is of
greatest concern. Grain yield has been excellent in situations
where winter injury has been an important factor in variety rankings.
SD92107 is 2 days later to heading and 5 cm taller in height than
Arapahoe. It is moderately resistant to stem rust, leaf rust,
tan spot, and wheat streak mosaic virus. Composite milling and
bread-baking data indicate that SD92107 has average to below average
milling characteristics and above average baking characteristics.
SD93267 (pedigree: Shield/Roughrider//SD76598-7/Agassiz)
is an awned, white-glumed, medium-early, standard- height hard
red winter wheat with excellent fall establishment characteristics
and winterhardiness. SD93267 would potentially be targeted toward
conventional summer fallow production systems (with minimal or
no crop residue atplanting) in western South Dakota where optimum
fall stand establishment is a primary concern. SD93267 is moderately
resistant to stem rust, tan spot, and wheat streak mosaic virus,
and is moderately susceptible to leaf rust. It has a very long
coleoptile and good straw strength for its height. Composite milling
and bread-baking data indicates that SD93267 has above average
milling characteristics and average to above average baking characteristics.
Scab resistance. Breeding efforts for improved head scab
resistance in winter wheat are currently focused to address: i)
characterization of scab resistance or tolerance among commercially
grown cultivars and elite and preliminary lines from the breeding
program and ii) identification of winter wheat germplasm sources
that show a high level of resistance to scab. To meet these objectives,
we have been conducting both greenhouse and field evaluation of
materials for scab resistance. During the winter 199798, 150 entries
were evaluated for scab resistance under artificial inoculation
in the greenhouse. Of these entries, 23 genotypes were released
cultivars, 35 genotypes were advanced experimental lines from
our program, 33 genotypes were from the Winter Wheat Cooperative
Scab Screening Nursery, and 59 genotypes were from the Northern
and Southern Regional Performance nurseries. Overall, scab infection
in the greenhouse was exceptionally severe and data were deemed
unreliable. The field evaluation in Brookings in 1998 included
a standard-plot planting of the Winter Wheat Cooperative Scab
Screening Nursery and a replicated, spring-transplanted hill-plot
evaluation (under artificial inoculation and mist-irrigation)
of the same set of materials grown in the greenhouse. Although
the field plots escaped scab infection, a high level of infection
was observed in the spring-transplanted hill-plots and several
promising genotypes were retained for further evaluation. In addition
to these activities, two international nurseries (7th FAWWON and
21st IWSWSN, 285 entries) and the Regional Germplasm Observation
Nursery (RGON, 450 entries) were grown at the Watertown location
where a moderately high level of natural scab infection was observed.
From these three nurseries, several genotypes combining good winterhardiness,
good scab resistance, and acceptable grain filling characteristics
were identified. These genotypes have been included in the winter
crossing block and will be re-evaluated for scab resistance during
the 1998-99 field season.
Spring wheat breeding.
J.C. Rudd, B.G. Farber, Y. Jin, R. Rudd, and R. Devkota.
Production. The 1998 production of HRSW in South Dakota
was 59.2 million bushels from 1.9 million acres. The average yield
was 32.0 bu/acre, which is slightly more than the 5-year average.
Durum production in the state was 624,000 bushels from 24,000
acres, with an average grain yield of 26 bu/acre.
New Release. SD3219 was released March 1999 as Ember.
Ember is an early, standard height HRSW from the cross 'Guard
/ Sharp // Grandin'. It has been in South Dakota yield trials
since 1995 and regional trials in 1996 and 1997. It can best be
described as a transitional cultivar. It has better scab tolerance
than currently grown cultivars (similar to Ingot) but is not highly
resistant. Based on South Dakota yield trials, Ember yields three
bu/acre more than Ingot and similar to Russ and Oxen. Ember is
early in maturity (same as `Butte 86') and the average plant height
is 3 cm shorter than Butte 86. It is moderately resistant to the
prevalent races of stem and leaf rust. The scab tolerance of Ember
is similar to Ingot, but is less than BacUp. Ember has an excellent
test weight on a clean basis but is sometimes hard threshing.
The Wheat Quality Council data indicates that the bread-making
properties of Ember are acceptable. Wheat and flour protein content
averages 1 % lower than Grandin. Mixing time and mixing tolerance
are similar to Grandin.
Increase with intent to release. SD3407 and SD3414
are being increased with the intent to release in 2000. They are
both early heading and standard height. These HRSW lines came
from a composite of crosses involving Sumai 3, Fan 1, 2375, Butte
86, SD3080, and SD3116. The scab reacton indicates that Sumai
3 is a parent, but it is not certain. The type 2 scab resistance
of both lines is better than BacUp but less than Sumai 3. Grain
yield and kernel retention under scab are better than BacUp and
Sumai 3.
Fusarium Head Scab screening. This project began after
the 1993 scab epidemic in the spring wheat region. Mist-irrigated
greenhouse and field screening nurseries were established and
disease evaluation methods were developed. Breeding materials
are evaluated for scab resistance using three generations per
year: two generations in the greenhouse and one generation in
the field. The autumn greenhouse season is September to December
and thespring greenhouse season is January to April. We have the
capacity to screen 4,000 individual hills during each greenhouse
season. We now have 2 acres in the field under mist-irrigation
and have the capacity to expand to 6 acres at our current site.
Both the field and greenhouse nurseries are inoculated with infected
grain (corn and wheat) and conidial suspensions, and mist-irrigation
is used to provide a favorable environment for infection.
Interactions of tan spot and scab resistance. Casual observations
indicate that spring wheat lines tolerant to scab are more susceptible
to tan spot and that lines with tan spot resistance are more susceptible
to scab. As part of his Ph.D. thesis, Ravindra Devkota is studying
the genetic relationships of tan spot and scab resistance. Preliminary
results indicate that scab tolerance and tan spot resistance are
inherited independently and that improvement can be made for both
traits simultaneously. This study is particularly important for
reduced tillage systems since the residue left on the surface
is a host for the pathogens of both diseases.
Wheat Entomology.
Louis S. Hesler and Walter E. Riedell, Northern Grain
Insects Research Laboratory, USDA-ARS, Brookings, SD 57006.
BYDV and bird cherry-oat aphid damage. Grain yield loss
caused by BCO and BYDV (barley yellow dwarf virus) may result
from direct damage to the winter wheat crop as well as from reduced
crop tolerance to environmental stress. A greenhouse study measured
the effects of BCO, BYDV, or BCO+BYDV on plant height, date of
anthesis, yield, and yield components of four winter wheat varieties
(Roughrider, Norstar, TAM107, and Vona). Grain yield was reduced
21 % by the BCO treatment, 46 % by the BYDV treatment, and 58
% by the BCO+BYDV treatment. There were no significant variety
X treatment interactions for any of the dependent variables. Thus,
the varieties tested had little difference in their response to
aphid and disease treatments in the absence of additional environmental
stress.
Host plant resistance. Research continued on evaluating and
understanding host-plant resistance mechanisms in wheat genotypes
against the BCO. In one set of experiments with 7 genotypes from
South Dakota (USA), Hungary, and Iran, genotype MV4 had significantly
fewer BCO than most other genotypes at 7, 11 and 14 days after
infestation with apterous adults. BCO nymphs developed more slowly
on MV4 than other genotypes, but genotype did not significantly
affect the number of progeny that BCO produced. BCO had a lower
intrinsic rate of increase on MV4 than on Arapahoe, MV8, or Ommid.
BCO produced more alate morphs on genotype MV4 and less alates
on genotype Vista. Antixenosis to BCO was not detected in these
experiments.
In a second set of experiments with MV4 and cereal-aphid resistant
lines, MV4 again performed well, showing antibiosis and antixenosis
to BCO. STARS 9303W, a Russian wheat aphid-resistant line, and
TAM 110, a greenbug-resistant line also showed antibiosis to BCO.
Development also continued on the evaluation of methods for quickly
but reliably evaluating resistance to BCO in wheat accessions.
Work is currently underway in developing a novel hydroponic method
to culture wheat and measure the effects of BCO infestation.
Remote sensing of cereal aphid crop damage. A greenhouse
study was performed to characterize leaf reflectance spectra of
wheat damaged by Russian wheat aphids and greenbugs and to determine
those leaf reflectance wavelengths that were most responsive to
crop stress imposed by these aphid pests. Leaf reflectance in
the 625 to 635 nm and the 680 to 695 nm ranges, as well as the
normalized total pigment to chlorophyll a ratio index, were significantly
correlated with total chlorophyll concentrations in both greenbug
and Russian wheat aphid damaged plants.
Effects of crop management practices. Infestation levels
of two insect pests of wheat were assessed in intercropped spring
wheat-alfalfa grown under high, moderate, or low crop management
intensity (CMI). CMI differed in the amounts of N-P-K fertilizer
and herbicide applied and the intensity of tillage operations.
Infestations of wheat stem maggot (Meromyza americana,
WSM) were assessed from 1990 to 1997. Percentage of white grain
heads caused by WSM varied among years but not by CMI level. More
white grains heads occurred in 1991 (2.0%)and 1997 (2.5%) than
in other years (each 1.3% or less). Cereal aphids infested up
to 95 percent of wheat tillers on various sampling dates from
1990 through 1996. In 1990, aphid infestation varied by sampling
date, CMI, and their interaction. Due to the interaction, the
mean percentages of aphid infestation by CMI treatment fluctuated
among the five sampling dates in 1990. In 1992 and 1996, aphid
infestation varied only by sampling date, with infestation greater
on later sampling dates. Neither CMI nor sampling date affected
levels of cereal aphids in 1991, 1993, 1994, and 1995. The CMI
in spring wheat-alfalfa intercrops had little or no influence
on infestation levels of WSM and cereal aphids.
Soil fertility and production research.
Howard J. Woodard, Anthony Bly, and Dwayne Winther.
Foliar N effects on protein and grain yield for winter and spring
wheat in South Dakota. Half of the treatment plots of 15 varieties
of HRWW and 15 varieties of HRSW were sprayed with a commercial
hood protected sprayer with 30 lbs/acre of total N as a 1:1 UAN
: water solution during the Feekes's 10.53 growth stage (post
anthesis stage). The other half were not sprayed any solution
N. Treatment plots received a fertilizer before planting if it
was required to meet the recommendation of 50 bu/a yield for winter
wheat and 40 bu/acre of spring wheat. Weed control was excellent,
and diseases were suppressed with Folicur if required. There were
increases in grain protein with some of the varieties. Winter
wheat crude protein increased in a range of 0.61.3 % with the
30 lb/acre treatment. Spring wheat crude protein increased in
a range of 0.51.3 % above the control treatment protein level.
Crude protein content responses were low because dry conditions
persisted in the spring and lowered yield potential, thus maintaining
higher grain protein contents in all treatments. Generally there
was a slight but non- significant decrease of grain yield due
to the foliar N treatment, but the yield of a few varieties increased
slightly. In another experiment, the same concentration and rate
of N as UAN applied above was applied at either the boot stage
(Feeke's stage 10.0) to determine if timing affected grain protein
and yield for a few winter and spring wheat varieties. The grain
yield from the post anthesis N application was greater than that
from the N applied at the boot stage.