A Database for Triticeae and Avena
VIRGINIA POLYTECHNIC INSTITUTE AND STATE UNIVERSITY
Department of Crop and Soil Environmental Sciences 1, Blacksburg,
VA 240610404, USA.
J.J. Paling, C.A. Griffey, W.E. Thomason, J. Chen, J.A. Wilson,
D. Nabati, T.H. Pridgen, M.M. Alley, and E.G. Rucker.
J.J. Paling, C.A. Griffey, W.E. Thomason, and M.M. Alley.
Growing conditions. Although weather conditions in 2004 were
more favorable for wheat planting, growth, and harvest than in
2003, grain yields and test weights were impacted by hot temperatures
during the grain-fill period. Autumn temperatures were warm through
October and into mid November during the planting season. Temperatures
eventually declined and were colder than average and precipitation
was slightly below normal for much of the state during the winter.
Average daily temperatures through March 2004 were 5 degrees below
normal for the entire state. Many small grain fields lacked optimal
growth and tillering was poor in the early spring. Late planting,
inadequate topsoil moisture, and especially the cold temperatures
were contributing factors leading to delayed heading. Warmer,
dry weather arrived in late April. The month of May was dry and
warmer than normal for much of the eastern part of the state.
Temperatures exceeded 85 F (29 C) on 19 days in May at the experiment
station near Warsaw, VA. Similar hot and dry conditions were experienced
throughout much of eastern Virginia during May, 2004. Despite
later than normal heading, wheat ripened considerably earlier
due to the high temperatures. Wheat harvest began ahead of schedule,
but was delayed by rain and cloudy weather later in June.
Insects. Populations of the cereal leaf beetle and aphids
attracted the attention of wheat producers in 2004. High numbers
of aphids were found in wheat fields over most of the eastern
wheat production area in late April. Scouting was advised to determine
whether aphid populations had reached threshold control levels.
Control measures were recommended when populations reached threshold
and there was little activity of natural enemies in the field.
Cereal leaf beetle populations reached economic threshold level
later than usual in 2004 and persisted longer than anticipated.
Highest populations and damage were reported in late-planted wheat
fields having a low amount of foliage and in cover-crop fields.
Scouting was recommended through mid May in untreated fields on
the eastern shore.
Disease incidence and severity. Powdery mildew incidence
and severity were lower than usual for the second consecutive
year in the Eastern Shore and Coastal Plain regions because of
excessive precipitation in 2003 and early and persistent hot May
temperatures in 2004. Leaf rust incidence and severity were minimal
in most of the wheat production area, but were moderate to severe
on susceptible cultivars grown in research trials near Blacksburg.
Barley yellow dwarf virus was low to moderate at Warsaw and Blacksburg.
The incidence of FHB was much lower in 2004 than in 2003, when
epidemics were widespread and severe.
Production. The Virginia Agricultural Statistics Service
reported in January 2005 that Virginia wheat producers harvested
180,000 acres (72,900 ha) of winter wheat for grain in 2004, representing
a 12 % increase over 2003. More than 85 % of the 210,000 acres
(85,000 ha) of winter wheat planted was harvested for grain in
2004. Grain yields averaged 55 bu/acre (3,695 kg/ha) in 2004 and
were 9 bu/acre (605 kg/ha) higher than the very low 46 bu/acre
(3,090 kg/ha) average yield in 2003. Total 2004 wheat production
for the Commonwealth was 9.9 x 106 bushels (269,380 metric tons).
State cultivar tests. A total of 80 entries were evaluated
at seven locations across the Commonwealth in 2004. Included in
this total were 37 released cultivars and 43 experimental lines
(33 developed at Virginia Tech). Three white-seeded lines, one
recently released by Virginia Tech, were among the 80 entries
in the 2004 tests. Average grain yields ranged from 62 to 78 bu/acre
(4,166-5,241 kg/ha) with an overall location and test average
of 67 bu/acre (4,502 kg/ha). Wheat cultivars with yields significantly
above the test average were USG 3209, SS MPV 57, 99176, USG 3706,
SS 8308, USG 3592, and V9412. Seven experimental lines, six from
Virginia Tech, also yielded significantly higher than the average.
Yields of the highest producing cultivars and experimental lines
ranged from 71 to 78 bu/acre (4,770-5241 kg/ha). Average test
weights of wheat lines (based on seven locations across the state)
ranged from 54.9 lb/bu (706 kg/m^3^) to 59.3 lb/bu (763 kg/m^3^)
with a test average of 57.1 lb/bu (735 kg/m^3^). Out of the 26
entries with test weights significantly higher than the test average,
13 were released cultivars and 13 were experimental lines. Only
two cultivars (SS 8308 and V9412) and three experimental lines
(two from Virginia) had both grain yields and test weights significantly
higher than the test average.
Virginia no-till test. All 80 wheat entries in the Virginia
State wheat test were also planted no-till into corn stubble at
the Eastern Virginia AREC near Warsaw, VA, in October 2003. Yields
were 10-15 % lower than early season estimates based on late spring
tiller and spike numbers. The combination of late heading and
subsequent hot weather resulted in a shorter grain-fill period
and earlier maturity and led to low yields and test weights, also
observed in conventional-till tests at Warsaw. Grain yields averaged
59 bu/acre (3,964 kg/ha) with an average test weight of 57 lb/bu
(733 kg/m^3^). The top-yielding cultivars produced more than 65
bu/acre (4,367 kg/ha) in 2004. Released cultivars yielding higher
than the test average were SS MPV 57, SS 560, GA931233E17, 99176,
Pioneer 26R15, Featherstone 520, USG 3209, and SS8302.
Virginia wheat yield contests. There were 11 entries
in the 2004 Virginia wheat yield contests. Seven of the entries
were grown no-till, three were conventional till, and one entry
was with minimum tillage. All of the contestants planted certified
seed treated with a fungicide. No-till yields of the 2004 entries
averaged slightly higher (2 bu/acre, 134 kg/ha) in 2004 than in
2003. The highest yield under no-till was obtained by George Floyd
III of Northampton County. George produced 100 bu/acre (6,719
kg/ha) of Coker 9835 wheat after soybean. Richard Sanford of Westmoreland
County entered two fields. Richard produced 86 bu/acre (5,778
kg/ha) of Tribute in one field and 85 bu/acre (5,711 kg/ha) of
SS 520 in another field. Frank Hula of Charles City produced 83
bu/acre (5,577 kg/ha) of Renwood 3260. Juan Whittington of Amelia
and Joseph Reamy of Richmond harvested 90 and 81 bu/acre, (6,047
and 5,442 kg/ha), respectively, of Sisson wheat. William Crossman
of Westmoreland grew 71 bu/acre (4,770 kg/ha) of Pioneer 26R24.
The most dramatic improvement in yield in 2004 versus 2003 was
for entries grown using conventional-till systems. Average yield
of entries in 2004 was 30 bu/acre (2,016 kg/ha) or 40 percent
higher than in 2003. Theo Haberland of Orange County had the highest
yield under conventional-tillage. His field of SS 520 yielded
103 bu/acre (6,921 kg/ha) grown after a previous crop of soybean.
In Northumberland County, Clifton Brann produced 93 bu/acre (6,249
kg/ha) and the team of Craig and Dan Brann produced 96 bu/acre
(6,450 kg/ha) of Tribute wheat after corn. Ronnie Russell of Middlesex
produced 82 bu/acre (5,510 kg/ha) of SS 550, which was the only
minimum tillage entry in 2004. Congratulations to all contestants
in the Virginia Wheat yield contest for producing excellent wheat
yields in 2004.
M.M. Alley, Soil Fertility and Crop Management.
Research on wheat management. A survey of the micronutrient
content of Virginia wheat is being conducted to determine both
the tissue and grain levels associated with major soils used for
wheat production. Eight replicated field trials in the 2003-04
growing season found only three responses to micronutrient applications.
Two sites produced higher yields with foliar applications of manganese
while one site showed a positive response to foliar copper application.
All responsive sites were on Coastal Plain soils (sandy texture)
with pH values above 6.6. The nonresponsive sites had low levels
of dilute acid extractable copper, manganese, and zinc (one field),
but pH levels were less than 6.5. These results confirm that micronutrient
deficiencies are associated with high soil pH levels and that
dilute acid extractable levels of micronutrients are not well
associated with crop response. The field trials and the survey
of grain micronutrient contents will be repeated in the 2005 growing
W.E. Thomason, Small Grain Extension Specialist.
Research on bread wheat quality. Promising bread wheat
cultivars have been planted in several management trials in the
state. These cultivars are being grown with optimal nitrogen management
practices. Seeding rate studies have been established in both
yield trials and demonstrations. Seeding rates range from below
optimum to above optimum (260 to 650 seeds/m^2^ or 15 to 35 seeds/row
ft) and will be evaluated to determine appropriate seeding rates
to optimize yield of bread wheat . Initial plant stands from two
locations in the autumn 2004 are presented in Figure 1.
C. A. Griffey, J. Chen, J. A. Wilson, D. Nabati, T. Pridgen,
and J. Paling
Fusarium head blight is a destructive disease of wheat and
barley in the humid and semihumid production areas of the world
(Schroeder and Christensen 1963). Scab epidemics have occurred
in 26 U.S. states and five Canadian provinces and in the 1990s
contributed to yield losses exceeding 500 x 10^6^ bushels (Rudd
et al. 2001). Monetary losses due to FHB during the past decade
have been valued at $3 billion (Van Sanford et al. 2001). Fusarium
head blight epidemics in 1998 and 2003 devastated much of the
SRWW crop in the mid-Atlantic region. Virginia has been no exception,
with epidemic disease levels in 1998 causing losses estimated
at 92,595 metric tons, at a value of $14.4 million (Griffey et
al. 1999), reinforcing the need to accelerate development of FHB-resistant
cultivars adapted to this region. Specific objectives implemented
in the Virginia Tech Breeding Program are to: 1) identify and
select FHB-resistant SRWW lines derived from traditional breeding
populations; 2) identify and select FHB-resistant wheat lines
derived from crosses between nonadapted lines with FHB resistance
(type II in particular) and adapted lines possessing resistance
to other diseases of economic importance; and 3) accelerate development
of FHB-resistant lines using a combination of backcrossing, doubled
haploid, and MAS breeding methods.To develop high yielding, FHB
resistant SRW wheat lines, we have deployed a combination of topcross,
doubled haploid, backcross, and molecular-marker assisted breeding
methods (Tables 1 and 2). We first verified type-II resistance
levels in FHB resistance sources currently used in breeding programs.
Additionally, we characterized currently cultivated and adapted
SRW wheat genotypes for FHB resistance or susceptibility. We found
and confirmed high levels of type-II resistance in six wheat lines
from China, three from Canada, one from France, and two from Japan
(Chen et al. 2000). We also identified or confirmed the presence
of tolerance to kernel infection, yield loss, and DON production
in SRWW cultivars, such as Roane, McCormick, and Tribute (Wilson
et al. 2003). Initially, we developed a doubled haploid line,
VA01W-476, which expressed a high level of resistance in both
greenhouse and field trials. This line has been used as a parent
in many breeding programs in the eastern United States. We also
have made great progress in the development of FHB-resistant lines
using top-crossing and backcrossing methods. VA02W-713, a topcross
(Ning7840/Pioneer2691//Roane) derived elite FHB-resistant SRWW
line, ranked 1st in grain yield (77 bu/acre) among 54 entries
in Virginia's 2004 Advance Wheat Test over three locations and
will be evaluated in Virginia's Official Variety Trials in 2005.
Table 1. Breeding stocks developed and evaluated
for FHB resistance by the Virginia Tech breeding program during
the past 5 years.
Table 2. Efficiency of different breeding
methods in developing adapted FHB-resistant wheat lines. FHB index
< 1.5, incidence < 50 %, number of infected spikelets (severity)
Type-II FHB resistance has been successfully transferred from
diverse sources, such as Chinese wheat lines W14, Shaan85, Futai8944,
Futai8945, Futai8946, Ning9016, Ning7840, Yumai 7, Er-Mai 9, and
Wuhan 1, and the French line VR95B717, into adapted SRWW backgrounds
Roane, Ernie, Pioneer 2684, Renwood 3260, Madison, Jackson, and
a Sisson sib via backcrossing. Twenty-six SRWW lines possessing
both high yield potential and FHB resistance were selected among
268 lines evaluated in Virginia's 2004 Scab Observation tests.
These lines will be evaluated in 15 states as part of a collaborative
research initiative in 2005. In addition, a set of NILs incorporating
FHB resistance QTL from W14 and Futai 8944 into Roane and Ernie
backgrounds have been developed using molecular-marker-assisted
backcross breeding. Molecular markers in 3BS and 5AS QTL regions
are being used to assist in the selection and breeding process.
Haplotypes of the 3BS QTL and combinations of haplotypes of 3BS
and 5AS QTL are being used to characterize FHB resistance in advanced
wheat lines (Table 3).