Smiley,
R.W., L.-M. Patterson, and K.E.L. Rhinhart. 1996. Fungicide
seed treatment effects on emergence of deeply planted
winter wheat.
Journal of Production Agriculture 9:564-570.
ABSTRACT
Winter
wheat seed is often planted deeply (>3 in.) into stubble-mulch
fallow in the semi-arid Pacific Northwest. Stand establishment
is affected by factors that influence the rate of seed germination
and coleoptile growth. Systemically translocated triazole and
imidazole fungicide seed treatments were compared for effects
on seedling emergence under conditions of deep seed placement
and variable seed-zone moisture in stubble-mulch fallow systems.
Fungicides included RTU Vitavax Thiram (carboxin + thiram),
Dividend (difenoconazole), Raxil Thiram (tebuconazole + thiram),
NuZone and Flo-Pro IMZ (imazalil), and Apron (metalaxyl). Gaucho
(imidacloprid), a seed-treatment insecticide, was applied in
some experiments. Seven field and three greenhouse experiments
were performed from 1993 to 1995. Emergence in the field tended
to be superior for seed treated with Dividend, alone or mixed
with Apron, in plantings made from 1- to 5-in. deep into soil
with 5 to 17% seed-zone water content and at 71 to 80oF. RTU
Vitavax Thiram had variable effects on seedling emergence. NuZone
and Raxil Thiram, alone or mixed with Gaucho, generally delayed
emergence when treated seed was planted at depths more than
2-in. In the greenhouse, treated seed was planted at the 1-in.
depth into moist (7, 10 or 15% w/w), warm (75oF) silt loam overlain
by 4-in. of dry silt loam, simulating a planting at 5-in. depth
into stubble-mulch fallow during September. Emergence of Dividend-treated
seed at each soil moisture content was usually more rapid than
for other treatments, including seed planted without fungicide
treatment. This research demonstrated that emergence of winter
wheat planted deeply into stubble-mulch fallow is often improved
when seed is treated with Dividend compared with RTU Vitavax
Thiram and, among the systemically translocated triazole fungicides,
Dividend is a better choice than Raxil when planting depths
exceed 2 in.
Smiley, R.W., and L.-M. Patterson.
1995. Winter Wheat Yield and Profitability from Dividend
and Vitavax Seed Treatment. Journal of Production Agriculture
8:350-354.
ABSTRACT
Fungicide
seed treatment is required to protect winter wheat (Triticum
aestivum L.) from infection by smut fungi in the Pacific
Northwest. Vitavax (carboxin) dominated this market for 25 yr
before Dividend (difenoconazole) was registered as a smut-control
treatment in 1994. Relative effects of these fungicides on productivity
and profitability of winter wheat are not known; therefore,
the objectives of this study were to collect data relative to
those factors under commercial conditions. Twenty four experiments
that included these fungicides were performed over 5 yr at 12
locations, using seven cultivars. Up to 44 comparisons of cultivar
x location x year were possible for some fungicide treatments
and application rates. Grain yields were equivalent for Vitavax-treated
and untreated seed. Dividend increased yield 5% (2.7 bu/acre)
over the Vitavax treatment, for an $8.25 increase in net profit
per acre. Profitability of Dividend was increased by reducing
the application rate from the standard rate of 0.5 fl oz/cwt
to 0.25 fl oz/cwt. Profitability of Dividend was higher in regions
where wheat production is less than 40 bu/acre compared to areas
of higher productivity. Five winter wheat cultivars differed
in yield response to Dividend. Neither fungicide affected test
weight or kernel weight. This research demonstrated that, by
using Dividend, producers can maintain profitability while reducing
fungicide application rates by a factor of ten.
Smiley,
R., J. Gourlie, R. Whittaker, S. Easley, K. Rhinhart, E. Jacobsen,
A. Burnett, J. Jackson, D. Kellogg, and T. Zeckman. 2004. Seed
treatments for chickpea (garbanzo bean). Oregon Agricultural
Experiment Station Special Report 1054:120-127.
ABSTRACT
Seed
treatment fungicides were evaluated for their effect on productivity
of a kabuli chickpea (‘Sinaloa B') at Moro and Pendleton,
Oregon, during 2002 and 2003. Seed treatments improved emergence
and grain yield by reducing Pythium damping-off at the time
of seedling emergence. Fungicide seed treatments did not reduce
the incidence or severity of root diseases on mature plants.
Treatments also failed to improve the market grade, compared
to grain produced from untreated seed. This research confirmed
the need to treat kabuli chickpea with fungicide seed
treatments to maintain optimum productivity. The importance
of fungicide mixtures capable of protecting against seed transmission
of the Ascochyta blight pathogen was also discussed. A fungicide-by-disease
matrix was provided as a guide for preparing mixtures of seed
dressings.
Montfort,
F., B.L. Klepper, and R.W. Smiley. 1996. Effects of two triazole
seed-treatments, triticonazole and triadimenol, on growth and
development of wheat. Pesticide Science 46:315-322.
ABSTRACT
The
triazole fungicides, triadimenol and triticonazole, applied
as seed-treatments at various rates on spring wheat, affected
plant growth, shoot development, and root axis production. The
main growth regulatory effects were reductions in lengths of
the coleoptile, the first foliar leaf and the subcrown internode.
A marked effect on tiller appearance occurred with high rates
of triadimenol. Modification of root system development included
a reduction in the number of seminal roots, increased outgrowth
of roots associated with the coleoptilar-node, and a reduction
of roots at the first foliar node (correlated with reduced production
of tiller 1). Seed-treatment effects on both shoot and root
development illustrated the close relationship between these
plant structures. Both fungicides induced both beneficial and
deleterious effects on wheat growth and development, but the
magnitude of deleterious effects were less with triticonazole
than with triadimenol.
