| Material Information
||The 1966 wheat varietal situation in Florida
||North Florida Station mimeo report
||3 leaves : ; 28 cm.
||Sechler, Dale Truman, 1926-
Chapman, Willis Harleston, 1916-
North Florida Experiment Station
West Florida Experiment Station
||North Florida Experiment Station
||Place of Publication:
||Wheat -- Varieties -- Florida ( lcsh )
Wheat -- Yields -- Florida ( lcsh )
||government publication (state, provincial, terriorial, dependent) ( marcgt )
non-fiction ( marcgt )
||Statement of Responsibility:
||by Dale Sechler, W.H. Chapman, Ralph Smith.
||At head of title: West Florida Experiment Station.
||NFES mimeo rpt. ;
| Record Information
||University of Florida
||All rights reserved by the source institution and holding location.
||oclc - 85773892
WEST FLORIDA EXPERIMENT STATION
NORTH FLORIDA EXPERIMENT STATION
North Florida Station Mimeo Report NFS 67-1-
THE 1966 WHEAT VARIETAL SITUATION IN FLORIDA
by Dale Sechler, W. H. Chapman, Ralph Smith1
Although wheat has been grown commercially in Florida only a few years, diseases have
necessitated a number of varietal changes. Leaf rust, mildew. Septoria, and the Helmintho-
sporium leaf spots have all been major disease problems, New and more virulent forms of
disease organisms occur and build up rapidly to destructive proportions. This has happened
several times in Florida, especially with leaf rust, and the new races (kinds or strains of
rust in the same manner as 'varieties" of grain) make a variety change necessary.
Mildew also can destroy a wheat crop although damage is usually checked by warm, sunny
weather before all foliage is destroyed. Loss of leaf area as well as new tillers results
in low yields. Mildew infection is favored by cool, cloudy weather.
Leaf spots caused by Septoria and the Helminthosporiums can cause a total crop loss
although damage is usually less severe. Symptoms can be found in almost any field with the
severity of damage dependent upon rainfall and temperature. These diseases are carried over
on plant residues or are brought in on the seed.
During the 1965-66 growing season all of the above diseases were present and did
considerable damage in specific areas. A new race of leaf rust was first noticed in 1965
and built up to epidemic proportions in several fields of Hadden wheat in 1966. At Jay,
where rust was severe, Hadden yielded only 22 bu./acre as compared to 43 bu./acre in 1965.
However, yields as high as 54 bu./acre was reported for Hadden in fields which were not
rusted. Leaf rust has been observed in Wakeland for several years but in 1966 rust was not
as virulent on this variety as it was on Hadden. Yields the past two years have beep
comparable. Ga. 1123 rusted severely at Jay in 1965 when it only yielded 16 bu./acre. In
1966, this variety was damaged less than the previously resistant Hadden variety and yielded
30 bu./acre. At the present time no commercial variety of wheat is available that is
resistant to all races of leaf rust known to be present in Florida.
Mildew was severe in some areas during 1966 but damage was checked by warm dry weather
late in the season. Changes in the mildew disease organism was evident in that it is
becoming more virulent on the formerly resistant Wakeland. Ga, 1123 has always been highly
susceptible as has Coastal. At the present time only Hadden is resistant to the mildew
problem as it exists in Florida.
As mentioned previously Septoria and Helminthosporium caused considerable leaf spotting
in some areas. The varieties grown in Florida have not shown consistent differences in
reaction to these disease organisms, however. No variety having good resistance to these
diseases is available. Damage from Septoria and the Helminthosporiums will be less where
Associate Agronomist and Agronomist and Head, North Florida Station, Associate Agronomist,
We.s Florida Station.
good rotation and sanitation practices are followed. Plowing under stubble and volunteer
wheat plants are good control measures. Seed-borne fungi can be killed by seed treatment
with the organic mercury compounds.
Wakeland.--This is an early maturing variety with moderately short straw and semi-
winter growth habit. Minor infections of leaf rust have occurred for three years but have
not reached destructive proportions. It is becoming more susceptible to mildew each year.
Grain quality and yield are good. Differences between Wakeland, Hadden and the other
varieties in susceptibility to Septoria are not consistent, since ultimate damage is a result
of rainfall and temperature conditions when plants are in a given stage of development.
Hadden.--This variety is similar in height to Wakeland but slightly earlier. It was
the most rust resistant variety in Florida until 1966 when a new virulent race did extensive
damage in some areas. No mildew has been found on this variety in the Southern United States.
Grain quality and yield are good. Hadden makes an early upright growth which could make it
preferable for early grazing. Hadden may tend to lodge at the base more than Wakeland.
Georgia 1123.--This variety is similar in height to the above varieties but later than
either Wakeland or Hadden. Leaf rust has been very severe on this variety although in 1966,
damage was less than on Hadden. Stem rust is seldom a problem in Florida but Ga. 1123 is
more susceptible to prevalent races than either Hadden or Wakeland. It is more susceptible
to mildew than Wakeland, and tends to be lower than Wakeland or Hadden in both test weight
and yield. The variety requires more cold weather for heading than Hadden or Wakeland and,
therefore, should not be seeded after mid-December. It is resistant to soil-borne mosaic and
Hessian fly although these have not, as yet, been problems in Florida. Georgia 1123 has a
winter growth habit and makes little vegetative growth until late in the season.
Coastal.--This is a moderately short variety that is later than the above varieties.
Little leaf rust has been found on this variety in recent years although five years ago it
was rusting out completely. These races would probably build back up on this variety if
widely grown. It is very susceptible to mildew. Growth is upright and early vegetative
growth is abundant. Grain quality and yield have been unpredictable due to disease
Bledsoe.--This is a tall but relatively stiff strawed variety of about the same
maturity as Wakeland. It is moderately resistant to mildew and soil-borne mosaic but very
susceptible to the newer races of leaf rust. Growth is semi-upright. Grain quality and
yield have been unpredictable due to disease susceptibility.
Blue Boy.--This is a new very short variety released from North Carolina but unadapted
to Florida. It is very susceptible to leaf rust and mildew under our conditions. Grain
yield and quality have been very low.
Chancellor.--The variety is a late winter type that is not suited to Florida conditions.
It is very susceptible to leaf rust and mildew resulting in very low yields.
In view of the disease situation in Florida at the present time, it would not seem
advisable to recommend any one variety over another. A grower should recognize the fact
that races of leaf rust are present which could destroy any of the possible varieties. The
nature of rust resistant varies from Hadden to Wakeland to Georgia 1123 but a rust race or
races might build up and destroy one of more of these varieties providing inoculum is present
when conditions for a buildup are favorable. Mildew is almost always present and only Hadden
is resistant to this disease. Hadden is also the earliest variety which should enable
earlier seeding of soybeans following wheat. In spite of these advantages, the Hadden
variety was damaged more severely by rust than Wakeland or Georgia 1123 in West Florida
during 1966. In view of these facts it might seem desirable to spread the risk by splitting
the wheat acreage primarily between Hadden and Wakeland. If seed of these are not available,
Georgia 1123 or Coastal would be the next choice. It is hoped that a selection resistant to
the prevalent rust problems can be found in the near future.
Jay, Florida (3 yr. avg. 1964-66)
.Quinc, Florida (4 yr. avg. 1963-66) J. Flo a
Mildew Leaf Rust Test Yield2 Stem Rust3 Test Avg.-3 locations
Date Height % % wt. Yield Yield bu % wt. Yield Yield
Headed in infection infection #/bu. bu/A 1965 1966 (4 avg.) infection /bu. bu./A bu./A
Wakeland 4/12 43 24 8 58.1 31.1 39.3 35.6 39.0 20 59.2 39.1 36.4
Hadden 6 43 0 TR 59.1 33.0 43.2 22.7 37.7 10 59.8 38.2 36.3
Ga. 1123 14 44 42 30 52.9 22.5 15.9 30.3 30.9 70 54.4 29.5 28.0
Coastal 18 45 55 4 56.6 22.4 31.8 ---- 38.3 5 58.3 31.1 30.6
Bledsoe 12 50 25 62 58.1 26.7 35.6 ---- 36.8 TR 59.5 37.9 33.8
Blue Boyl 15 35 22 85 47.5 15.6 20.4 22.0 21.2 52.0 28.1 21.6
Chancellor 16 44 80 68 55.0 15.3 6.9 22.7 26.5
Blue Boy averages
for 1965 and 1966 only at Ouincy, for 1965 and 1966 at Jay, for 1966 at Marianna.
Coastal yields for 1964 and 1965 and Bledsoe yields for 1963, 1964, and 1965 at Jay.
Stem rust observation for 1964 only.