INFLUENCE OF FALL APPLIED 2,4-D AMINE AND MCPA ON COLD HARDINESS AND OTHER AGRONOMIC CHARACTERS OF WINTER WHEAT AND RYE

1986 ◽  
Vol 66 (4) ◽  
pp. 837-843
Author(s):  
D. B. FOWLER ◽  
M. L. GRAHAM ◽  
R. ASHFORD

The effects of 2,4-D and MCPA amine treatments on cold tolerance and other agronomic characters of winter wheat (Triticum aestivum L.) and rye (Secale cereale L.) were studied in controlled environment and field trails. For both species, the level of cold tolerance achieved in controlled environments was reduced following exposure to 2,4-D and MCPA at rates up to 2.24 kg ha−1. In contrast, similar rates of fall applied 2,4-D and MCPA did not affect the cold tolerance of wheat and rye growing in the field. Treatment of plants from different seeding dates indicated that the observed field herbicide tolerance was not influenced by large differences in plant growth stage. Yield and other agronomic characters were also unaffected by fall 2,4-D and MCPA treatment. In contrast, broadleaf weed control was obtained with rates as low as 0.28 kg ha−1 for both herbicides, emphasizing the large safety margin between rates required for effective winter annual weed control and crop tolerance levels. From a practical standpoint, the influence of other management practices, such as delayed seeding, were of much greater importance in winter cereal production than the effects of commerical rates of 2,4-D or MCPA applied in the fall for broadleaf weed control.Key words: Wheat (winter), rye, 2,4-D amine, MCPA amine, cold tolerance

1976 ◽  
Vol 56 (1) ◽  
pp. 45-50 ◽  
Author(s):  
D. B. FOWLER ◽  
L. V. GUSTA ◽  
K. E. BOWREN ◽  
W. L. CROWLE ◽  
E. D. MALLOUGH ◽  
...  

Winter cereal trials consisting of 10 cultivars representing cold hardiness potentials ranging up to the hardiness of Frontier winter rye were seeded at test sites throughout Saskatchewan for 2 yr. At most sites in the Brown soil zone only winter rye survived without extensive winter damage. At sites in the Black and Gray soil zones, winter survival was sufficient to provide agronomic data for several winter wheat cultivars. Considerable yield compensation took place in stands exhibiting partial winterkill, and as a result hardier cultivars did not always demonstrate a yield advantage.


1977 ◽  
Vol 57 (1) ◽  
pp. 213-219 ◽  
Author(s):  
L. V. GUSTA ◽  
D. B. FOWLER

Several parameters affecting cold tolerance of winter cereals in artificial freeze tests were examined. Supercooling followed by freezing resulted in death occurring at a higher temperature than when freezing was initiated just below 0 C. The cold tolerance of fully acclimated crowns of winter wheat and a winter rye were reduced an average of 5 C after two thawing and freezing cycles. The duration of freezing in artificial freeze tests has a significant effect on the LD50 of winter cereals. Rapid thawing (2–4 C/min) resulted in death occurring at a higher temperature than slow thawing (0.5–2 C/h).


1989 ◽  
Vol 69 (2) ◽  
pp. 355-366 ◽  
Author(s):  
A. L. BRULE-BABEL ◽  
D. B. FOWLER

Field survival is the most commonly employed method of evaluating the winter hardiness of cereals. However, the inherent difficulties with field trials have stimulated a continued interest in the use of controlled environments and prediction tests for the evaluation of cold hardiness. In the present studies, cold hardiness expression of wheat (Triticum aestivum L.) cultivars acclimated in controlled environments was found to be similar to that reported for field conditions in Saskatchewan, Canada. LT50 and tissue water content measurements on wheat and rye (Secale cereale L.) cultivars acclimated in controlled environments were highly correlated with cultivar field survival ability. Investigation of the relationship between field survival and tissue water content during cold acclimation in controlled environments indicated that, to be effective as a screening method for cold hardiness, measurements of tissue water content should be made on fully acclimated plants for which the acclimation conditions have been rigorously controlled. Level of acclimation was not as critical for cold hardiness screening when LT50 measurements were utilized; however, maximum resolution also required fully acclimated plants. Although a strong relationship (r = −0.80 to −0.89) was found to exist with field survival potential, an inability to detect small, but important, differences without excessive replication would generally restrict the use of LT50 and tissue water content to situations where large homogeneous plant populations were available and only coarse screens for cold hardiness were required.Key words: Cold acclimation, winter wheat, winter rye, cold hardiness, water content, replication


1977 ◽  
Vol 57 (4) ◽  
pp. 1049-1054 ◽  
Author(s):  
D. B. FOWLER ◽  
L. V. GUSTA

Changes in cold hardiness (LT50), fresh weight, dry weight and moisture content were measured on crowns of winter wheat (Triticum aestivum L.) and rye (Secale cereale L.) taken from the field at weekly intervals in the spring of 1973 and 1974 at Saskatoon, Sask. In all trials, Frontier rye came out of the winter with superior cold hardiness and maintained a higher level of hardiness during most of the dehardening period. For cultivars of both species, rapid dehardening did not occur until the ground temperature at crown depth remained above 5 C for several days. Changes in crown moisture content tended to increase during dehardening. Over this same period crown dry weight increased for winter rye but did not show a consistent pattern of change for winter wheat. Two test sites were utilized in 1974. One site was protected by trees and the other was exposed. General patterns of dehardening were similar for these two sites, but cultivar winter field survival potentials were reflected only by LT50 ratings for the exposed test site. The influence of fall seeding date on spring dehardening was also investigated. Late-seeded wheat plots did not survive the winter in all trials. However, where there was winter survival, no differences in rate of dehardening due to seeding date were observed.


1960 ◽  
Vol 38 (3) ◽  
pp. 353-363 ◽  
Author(s):  
J. E. Andrews

Young winter rye seedlings, grown and hardened at 1° or 1.5 °C in the dark, developed a high level of cold hardiness at two stages prior to emergence of the first leaf. The first maximum occurred when coleoptiles were less than about 1 mm in length and was followed by a decrease in hardiness. A second and higher maximum occurred when coleoptiles were about 15–30 mm in length (5 weeks at 1.5 °C; 7 weeks at 1 °C) and it was followed by a rapid decrease in hardiness beginning at about the time the leaf broke through the coleoptile. Genetic differences corresponding with those obtained in the field were established by hardening seedlings for 7 weeks at 1 °C and exposure to −15 °C for 16 hours or by hardening for 5 weeks at 1.5 °C and exposure to −14 °C for 16 hours. The use of a lower (−4 °C) hardening temperature resulted in a large increase in cold hardiness at the younger stages of development but little or no increase where seedlings had already reached a maximum of hardiness from exposure to 1.5 °C for 5 weeks. Satisfactory genetic differences were not determined by exposure to −14 °C for 16 hours after hardening at −4 °C. In general the response to hardening of young winter rye seedlings was similar to that found with winter wheat.


1968 ◽  
Vol 40 (2) ◽  
pp. 88-95
Author(s):  
H. H. Blomqvist ◽  
E. A. Jamalainen

The present work describes a method for the testing of the resistance of winter cereal varieties to Fusarium nivale, Typhula ishikariensis and T. incarnata. The shooting of the plants was carried out in greenhouses and after a period of 3 weeks of coldhardening the plants were infected, covered with cellulose wadding and placed in a temperature of 2°C. Once the varieties with the highest susceptibility were severely infected by the fungi the test was suspended and the plants were given some 2 weeks to recover prior to being analysed. The tested varieties were well known from field trials during a number of years. The results agree in the main with those obtained in the field. The Finnish winter wheat and winter rye varieties showed a greater degree of resistance to the above fungi than the Swedish ones. The injury inflicted by F. nivale on winter rye was more severe than that on the winter wheat varieties. T. ishikariensis and T. incarnata were considerably more pathogenic to wheat than F. nivale, and the tested varieties showed varying degrees of resistance to these fungi. The results likewise point to a correlation existing in the resistance to the three low temperature parasitic fungi.


1990 ◽  
Vol 70 (3) ◽  
pp. 667-675 ◽  
Author(s):  
YVES CLOUTIER ◽  
ANDRÉ COMEAU ◽  
MICHÈLE BERNIER-CARDOU ◽  
DENIS A. ANGERS

A field study was conducted to determine the effect of soil moisture on the survival of three winter cereal species. Treatments were applied by watering and weighing the soil to the desired water content. Plants were overwintered in a plastic greenhouse in 1988 and in 1989, in which the air was not heated, but the soil was slightly heated on cold days to avoid very low temperatures. Soil temperature did not fall below −16 °C. Soil temperature rate of change was dependent on moisture content. Puma winter rye and Otrastajuskaja 38 winter wheat were the hardiest, followed by Wintri winter triticale and Norstar winter wheat. Harus winter wheat was less hardy, and Champlein winter wheat was totally winter killed. The highest survival rate was obtained at moderate to high soil moisture content. The soil contained 44% water at field capacity and 19% at the wilting point. The drier the soil in the range 13–23%, the greater the mortality indicating a negative effect of long-term drought on plant survival. By contrast, the wettest treatments: 58% and partial ice encasement, did not reduce survival. However, total ice encasement killed 50–75% of the plants depending on the cultivar. There was an interaction between cultivar and moisture treatment. The data suggest that a moisture level intermediate between the wilting point and field capacity should be sought in studies of cold hardiness.Key words: Moisture, winterkill, ice encasement, wheat, rye, triticale


1988 ◽  
Vol 68 (2) ◽  
pp. 449-456 ◽  
Author(s):  
P. NADEAU ◽  
R. PAQUIN

Cold tolerance (LT50) and level of polyamines were measured in crowns of winter wheat (Triticum aestivum L.), winter rye (Secale cereale L.), timothy (Phleum pratense L.) and alfalfa (Medicago sativa L.) grown in two Quebec locations widely different in climates. Putrescine increased in winter cereals and timothy during cold hardening and showed a major peak at the end of winter at both locations (Saint-Hyacinthe and La Pocatière). There was a significant correlation between putrescine levels and cold tolerance during fall. However, in alfalfa, putrescine increased only at the end of winter and, like other species, decreased rapidly as plants underwent spring deacclimation. Levels of spermine and cadaverine remained low and showed little variation during winter. Spermidine levels were higher than spermine but remained stable during fall and winter. No significant correlation was observed between spermine, spermidine and cadaverine levels and cold hardiness.Key words: Polyamines, winter cereals, forage species, cold hardening


1988 ◽  
Vol 66 (3) ◽  
pp. 409-413 ◽  
Author(s):  
C. J. Andrews

Exposure of cold-hardened seedlings of a range of winter cereals (11 winter wheats, 1 winter barley, and 1 winter rye) to a light intensity of 100 μE∙m−2∙s−1 during ice encasement at −1 °C markedly increased survival in comparison with that in dark ice encasement. Cold hardiness of 'Dover' winter barley and 'Fredrick' and 'Norstar' winter wheats was significantly greater after a short period of light ice encasement than dark ice encasement. Less ethanol and more CO2 accumulated in plant crowns in light than dark ice, and lactic acid accumulated in the early days of ice encasement but was little influenced by light. There was greater utilization of total nonstructural carbohydrate in the crown in dark, than in light, and greater utilization of total nonstructural carbohydrate in ice than in air at −1 °C. Considerably less oxygen was consumed by plants in light than in dark ice, while leaves in aqueous solutions at −1 °C evolved significant levels of O2 in light but consumed O2 in the dark. It is proposed that the changes in metabolic components in light are associated with low-temperature photosynthesis, which provides cellular oxygen and greater levels of energy in support of cell maintenance in plants during ice encasement.


EDIS ◽  
2020 ◽  
Vol 2020 (3) ◽  
Author(s):  
Jason Ferrell ◽  
Gregory MacDonald ◽  
Pratap Devkota

Successful weed control in small grains involves using good management practices in all phases of production. In Florida, winter weeds compete with small grains for moisture, nutrients, and light, with the greatest amount of competition occurring during the first six to eight weeks after planting. Weeds also cause harvest problems the following spring when the small grain is mature. This 4-page publication discusses crop competition, knowing your weeds, and chemical control. Written by J. A. Ferrell, G. E. MacDonald, and P. Devkota, and published by the UF/IFAS Agronomy Department, revised May 2020.


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