scholarly journals Pathogenicity and Formulation of Typhula phacorrhiza, a Biocontrol Agent of Gray Snow Mold

Plant Disease ◽  
1998 ◽  
Vol 82 (9) ◽  
pp. 1003-1006 ◽  
Author(s):  
C. Wu ◽  
T. Hsiang
Keyword(s):  
Wheat Bran ◽  
Biocontrol Agent ◽  
Field Testing ◽  
Kaolin Clay ◽  
Snow Melt ◽  
Wheat Cultivars ◽  
Snow Mold ◽  
Significant Control ◽  
Typhula Ishikariensis ◽  
Winter Wheat Cultivars

In previous testing, we found that gray snow mold, caused by Typhula ishikariensis or T. incarnata, could be controlled by applying T. phacorrhiza onto turf grass prior to snowfall. To test for phytopathogenicity of this biocontrol agent, the five most disease-suppressive isolates were cultured on mixed grains and applied to 12 turfgrass cultivars and 2 winter wheat cultivars in December 1995 and 1996. After snow melt in April 1996 and 1997, significantly greater winter injury was visible on plots treated with the pathogens compared to T. phacorrhiza-treated plots or untreated plots. Except for one cultivar in 1996, there were no significant differences between T. phacorrhiza-treated plots and untreated plots. Pelletized alginate formulations of T. phacorrhiza containing kaolin clay with various nutritional amendments were tested for viability and efficacy. After 64 weeks of storage, viability remained >85% at -15°C and >70% at 4°C, but <30% at 10°C and 25°C. Significant control of gray snow mold by T. phacorrhiza using small numbers of pellets (20 g/m2) was equivalent to using larger amounts of mixed grain inoculum (200 g/m2) or wheat bran inoculum (100 g/m2) in 2 years of field testing.

Effect of plant age on water content in crowns of fall rye and winter wheat cultivars differing in snow mold resistance

2001 ◽  
Vol 81 (3) ◽  
pp. 541-550 ◽  
Author(s):  
D. A. Gaudet ◽  
A. Laroche ◽  
B. Puchalski
Keyword(s):  
Winter Wheat ◽  
Water Content ◽  
Developmental State ◽  
Early Spring ◽  
Plant Age ◽  
Wheat Cultivars ◽  
Snow Mold ◽  
Winter Wheat Cultivars ◽  
Controlled Environments ◽  
Mold Resistance

Resistance to snow molds in winter wheat increases with plant age, and older plants express higher levels of resistance than young plants. Experiments were conducted to study the effect of plant age on percent crown water content (%CWC) and dry weights in fall rye and winter wheat cultivars grown under controlled environments and in the field at Lethbridge, AB. Under controlled environments, the oldest (6 wk of pre-hardening growth at 20°C) treatments accumulated the greatest dry weights following exposure of plants to 1 to 6 wk hardening conditions at 2°C, compared with younger (1 to 4 wk pre-hardening growth) treatments. Exposure of plants to hardening temperatures had the greatest effect on %CWC values, which decreased, gradually, from 82–89% (4.95–8.67 g H2O g–1 DW) in unhardened treatments to 67–72% (2.05–2.65 g H2O g–1 DW) in plants receiving the 6 wk pre-hardening and 6 wk hardening growth. However, the oldest treatments (4 to 6 wk pre-hardening growth) always exhibited the lowest %CWC values among all hardening treatments. The %CWC in the oldest (6 wk) unhardened plants was also lower ([Formula: see text] = 80.8% or 4.24 g H2O g–1 DW) than in the youngest (1wk) unhardened plants ([Formula: see text] = 91.2% or 11.31 g H2O g–1 DW ), demonstrating that water loss occurs in older plants in the absence of low hardening temperatures. In a field study at Lethbridge during the autumn, winter, and early spring of 1997–1998 and 1998–1999, different seeding dates were employed to obtain plants differing in age and developmental state. The %CWC in early-seeded treatments was lower during the autumn, and remained lower in early spring, compared with later seeded cultivars. The %CWC in crowns was negatively associated with the snow mold resistance rating of a fall rye and five winter wheat cultivars under controlled environment conditions, and among a fall rye and 13 winter wheat cultivars in the field; the highest correlation values in the field were observed from mid-November to mid-March during 1997–1998 (r = –0.84), and 1998–1999 (r = – 0.76). These results indicate that the type of snow mold resistance that increases with plant age is related to the accumulation of crown dry matter and the ability of wheat and rye plants to lose crown water in response to both extended growth at warm temperatures and hardening at low, above freezing temperatures. Key words: Carbohydrates, fructans, low temperature basidiomycete, Coprinus psychromorbidus

Screening winter wheat for resistance to cottony snow mold under controlled conditions

1991 ◽  
Vol 71 (4) ◽  
pp. 957-965 ◽  
Author(s):  
D. A. Gaudet ◽  
G. C. Kozub
Keyword(s):  
Winter Wheat ◽  
Screening Test ◽  
Wheat Cultivars ◽  
Freezing Resistance ◽  
Snow Mold ◽  
Percent Survival ◽  
Controlled Conditions ◽  
Percentage Survival ◽  
Winter Wheat Cultivars ◽  
Mold Resistance

A screening test was developed to determine the level of resistance of winter wheat to cottony snow mold (Coprinus psychromorbidus) under controlled conditions. The best separation in disease reaction among cultivars occurred following prehardening growth for 1 wk at 20 °C, hardening at 2 °C for 3 wk, and inoculation and incubation with the cottony snow mold pathogen at −3 °C for 9 wk. Percent survival was determined following a 3-wk recovery in the greenhouse. Extending prehardening growth to 6 wk increased the overall level of survival, but reduced the ability of the screening test to differentiate among cultivars. In general, there was a decrease in the percent survival in the 3-wk prehardening growth treatment compared with the 1- and 6-wk treatments. Percent survival and the ability to differentiate among cultivars decreased with increasing length of incubation with the cottony snow mold pathogen at −3 °C. The snow mold resistance and LT50 temperatures of 24 winter wheat cultivars, Kodiak fall rye and winter triticale were determined. Winter wheat cultivars CI14106, PI186822, Sprague, M81-8661, Münstertaler, and PI172582 exhibited high percentage survival following inoculation with cottony snow mold, but all cultivars exhibited low levels of freezing resistance except Münstertaler, which exhibited an intermediate level of freezing resistance. Key words: Freezing resistance, winter wheat

scholarly journals Reaction of Winter Wheat Cultivars to Artificially Inoculated Seed-borne Pink Snow Mold

2002 ◽  
Vol 52 (3) ◽  
pp. 231-233 ◽  
Author(s):  
Norio Iriki ◽  
Takashi Nakajima ◽  
Akira Kawakami
Keyword(s):  
Winter Wheat ◽  
Wheat Cultivars ◽  
Snow Mold ◽  
Winter Wheat Cultivars
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