Fall cutting management affects yield and persistence of alfalfa in Atlantic Canada

1999 ◽  
Vol 79 (1) ◽  
pp. 57-63 ◽  
Author(s):  
G. Bélanger ◽  
T. Kunelius ◽  
D. McKenzie ◽  
Y. Papadopoulos ◽  
B. Thomas ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
The United States ◽  
Atlantic Canada ◽  
Growing Degree Days ◽  
Plant Mortality ◽  
Degree Days ◽  
The Third ◽  
Medicago Sativa L ◽  
Cutting Management ◽  
Final Harvest

The existing recommendation to avoid harvesting alfalfa during a critical fall rest period, based on calendar dates, is under review in Canada and adjacent areas of the United States. The effect on yield and persistence of four fall cutting management treatments (based on cumulative growing degree-days between harvests) was investigated for two cultivars of alfalfa (Medicago sativa L. 'Apica' and 'Oneida VR') at five sites in Atlantic Canada. The average seasonal DM yield for the five sites in the first production year was 1.6 to 2.3 t ha−1 greater with an additional harvest as compared with the two-harvest system (Truro, Nappan, Fredericton, and Charlottetown) and the one-harvest system in St. John's. Seasonal DM yield benefits were reduced over time; by the third production year, there was no increase in seasonal DM yield with an additional harvest. The seasonal DM yield increased with increasing the interval between the final harvest and the previous one. Taking an additional harvest resulted in higher winter plant mortality between the first and second production years in Truro and Nappan, and the third and fourth production years in St. John's. At the other two sites (Charlottetown and Fredericton), and for the first three production years in St. John's, winter plant mortality was unchanged with an additional harvest but regrowth potential in the following year was reduced. At the two sites that experienced a severe winter (Nappan and Truro), the cultivar Oneida VR was more adversely affected by the additional harvest than Apica. Our results indicate that in Atlantic Canada, taking an additional harvest increases the risk of winterkill. If an additional harvest is to be taken, increasing the interval between the final harvest and the previous one to at least 500 growing degree-days will decrease the risk of winterkill and might have a positive effect on next year's regrowth. Key words: Medicago sativa L., alfalfa, yield, persistence, harvest management, cultivar

scholarly journals Effect of cumulative growing degree day on accumulation of alfalfa (Medicago sativa L.) root reserve saccharides

2008 ◽  
Vol 56 (2) ◽  
pp. 81-86
Author(s):  
Josef Hakl ◽  
Jaromír Šantrůček ◽  
Pavel Fuksa ◽  
Josef Kalista
Keyword(s):  
Medicago Sativa ◽  
Starch Content ◽  
Life Sciences ◽  
Vegetation Period ◽  
Water Soluble ◽  
Research Station ◽  
Growing Degree Days ◽  
Degree Days ◽  
Degree Day ◽  
Medicago Sativa L

The aim of this study was to investigate the relation between growing degree day method and accumulation of root reserve saccharides before over wintering by alfalfa (Medicago sativa L.) in the condition of Czech Republic. In 2002–2004, the field experiment was conducted at the Research station of the Czech University of Life Sciences in central Bohemia. The interval between summer and last autumn harvest was 40–50 days or 60–70 days, respectively. These intervals were expressed as cumulative growing degree-days (GDD) for each year. The plants were sampled in each autumn with four replicates for each variant; the average depth of sampling was 150 mm. The weight of roots, amount of starch, and water soluble saccharides (WSC) per m2 was determined. The total accumulation of root reserve saccharides was determined mainly by conditions during all vegetation period. The length of the interval or cumulative GDD influenced only variation of this basic amount. The GDD was corresponded better with starch content whilst WSC was more related to length of the interval. In central Bohemia condition, the GDD 600–700 °C was preliminary determined for maximal accumulation of root reserve saccharides. The GDD above this level did not significantly increase the root reserve accumulation. For exact verify of this model, other experiments in more sites are needed.

THE CRITICAL FALL HARVEST PERIOD FOR ALFALFA IN INTERIOR BRITISH COLUMBIA

1986 ◽  
Vol 66 (3) ◽  
pp. 565-578 ◽  
Author(s):  
DARRYL G. STOUT
Keyword(s):  
British Columbia ◽  
Medicago Sativa ◽  
Total Yield ◽  
The Third ◽  
Prime Concern ◽  
Medicago Sativa L ◽  
Cutting Management

Alfalfa (Medicago sativa L.) was grown under irrigation and harvested three times each year at Kamloops, British Columbia. The third cut was taken at five or six different times between 15 Aug. and 1 Nov. to identify the critical fall harvest period. Harvesting the third cut on 15 Aug. or 20 Aug. caused the most decrease in the yield of the first cut in the next year; thus the critical fall harvest period is from about 15 Aug. to 15 Sept. On average the total annual yield varied by only about 10% for the different times of third cut. When the third cutting was made on 15 Sept. or later, the average total yield varied by only about 6%. The winters of 3 of the 6 yr of the experiment were colder than normal. Thus, when yield is of prime concern, it is recommended that the timing of the third cut in interior B.C. be taken between 15 Sept. and 16 Oct.Key words: Alfalfa, cutting management, winter injury, yield, fall harvest period, Medicago sativa

CRITICAL AUTUMN HARVEST PERIOD FOR ALFALFA IN THE ATLANTIC REGION BASED ON GROWING DEGREE-DAYS

1985 ◽  
Vol 65 (3) ◽  
pp. 573-580 ◽  
Author(s):  
A. BOOTSMA ◽  
MICHIO SUZUKI
Keyword(s):  
Medicago Sativa ◽  
Rest Period ◽  
Field Tests ◽  
Temporal Variations ◽  
Growing Degree Days ◽  
Degree Days ◽  
Atlantic Region ◽  
Medicago Sativa L ◽  
Starting Date ◽  
Food Reserves

Air temperature normals (1951–1980 period) were analyzed for over 200 locations in the Atlantic region to estimate spatial and temporal variations in the critical autumn period during which alfalfa (Medicago sativa L.) should not be harvested to allow plants to reach adequate winter hardiness by accumulating sufficient food reserves in the roots. Data are presented which show that the starting date of the critical harvest period could be estimated from the average date when 450 growing degree-days above 5 °C remain in autumn (F450). F450 compared well with starting dates determined experimentally in 3 yr of field tests at three locations in Ontario. F450 varied from before 10 Aug. in northwestern New Brunswick and parts of Newfoundland to after 4 Sept. in southwestern Nova Scotia. Annual differences in climate cause F450 to vary with a standard deviation of about 5–6 days at a given location. A zonation map describing spatial variation in the rest period was prepared as a general guide for cutting management.Key words: Alfalfa, Medicago sativa L., cutting management, winter survival, climate zonation

FORAGE CROP MATURITY ZONATION IN THE ATLANTIC REGION USING GROWING DEGREE-DAYS

1984 ◽  
Vol 64 (2) ◽  
pp. 329-338 ◽  
Author(s):  
A. BOOTSMA
Keyword(s):  
Medicago Sativa ◽  
Trifolium Pratense ◽  
Phleum Pratense ◽  
Growing Degree Days ◽  
Degree Days ◽  
Atlantic Region ◽  
Maturity Stages ◽  
Trifolium Pratense L ◽  
Medicago Sativa L ◽  
Phleum Pratense L

Accumulated growing degree-days above 5 °C (GDD) were used to estimate the average time of occurrence of maturity stages before first harvest in post seeding years for alfalfa (Medicago sativa L.), double cut red clover (Trifolium pratense L.) and timothy (Phleum pratense L.) in the Atlantic region of Canada. Maturity stages recommended for first cut were reached after an average accumulation of approximately 350, 400 and 450 GDD, depending upon the cultivar. Estimates of maturity dates based on the average air temperature (T) for May and June were highly correlated with annually observed dates of selected maturity stages [Formula: see text]. T was also used to estimate regional variation in maturity dates based on normals for the 1951–1980 period from 231 climate stations. Eight maturity zones (M1 to M8) were designated for the region. Estimated average dates when forage cultivars reach maturity stages recommended for first cut ranged from on or before 15 June–25 June in the Annapolis and Saint John River valleys to after mid-July in parts of Newfoundland.Key words: Medicago sativa L., Phleum pratense L., Trifolium pratense L., cutting date, temperature, zonation

EFFECTS OF EARLY SUMMER AND FALL CUTTING MANAGEMENT ON DRY MATTER YIELDS, DIGESTIBILITY, CRUDE PROTEIN, AND SURVIVAL OF SARANAC AND NARRAGANSETT ALFALFAS

1972 ◽  
Vol 52 (6) ◽  
pp. 941-948 ◽  
Author(s):  
L. B. MacLEOD ◽  
H. T. KUNELIUS ◽  
F. W. CALDER
Keyword(s):  
Medicago Sativa ◽  
Crude Protein ◽  
Dry Matter ◽  
Early Summer ◽  
Good Survival ◽  
Considerable Decrease ◽  
Dry Matter Digestibility ◽  
Medicago Sativa L ◽  
Cutting Management

The effects of early summer and fall cutting managements on two alfalfa (Medicago sativa L.) cultivars were studied over a 3-year period. Removal of the first crop of Saranac and Narrangansett alfalfas at prebud stage, followed by two cuts at the early bloom stage before early September, and a late fall harvest on October 25, produced seasonal dry matter (DM) yields of 7.5–8.6 metric T/ha in the 1st year. Stand deterioration, however, was severe and by the 3rd year, practically all alfalfa had disappeared. Average percent crude protein (CP) in cut 1 was 17.7–21.9 and percent in vitro dry matter digestibility (IVD) 67.4–73.8. Removal of the first cut at bud stage with two subsequent harvests at the early bloom stage also allowed a total of three harvests before early September and resulted in seasonal DM yields of 8.6–8.8 in the 1st year. Although the survival of alfalfa was increased over the managements where cut 1 was at prebud stage, a considerable decrease of alfalfa was still observed in the 3rd year. Under this management, average CP in cut 1 was 15.8–16.3 and IVD 64.1–68.4. Harvesting the first crop at early to midbloom stage and the second crop at early bloom in early to mid-August, followed by third harvest in late October, resulted in good survival with seasonal DM yields of 6.1–10.6. Lower CP and IVD were recorded in cut 1 than in the more intensive managements. Under all managements, average CP in cuts 2 and 3 was 14.9–17.3 and 13.3–19.4, respectively. IVD was 54.5–60.7 in cut 2 and 56.0–64.4 in cut 3.

Growth and Development of Bigroot Morningglory (Ipomoea pandurata)

1991 ◽  
Vol 5 (4) ◽  
pp. 805-810 ◽  
Author(s):  
Michael J. Horak ◽  
Loyd M. Wax
Keyword(s):  
Root Growth ◽  
Growth And Development ◽  
Dry Weight ◽  
First Year ◽  
Growing Degree Days ◽  
Degree Days ◽  
Root:Shoot Ratio ◽  
Shoot Dry Weight ◽  
Second Year ◽  
Final Harvest

Growth and development of bigroot morningglory was observed and quantified. Emergence occurred 75 ± 5 growing degree days (GDD) after seeding. Flower and seed production began 630 ± 20 GDD after emergence and continued until the first frost killed the shoots. Seedlings needed approximately 460 GDD of growth to become perennial. In the second year of growth, plants emerged in early May and flowered within 425 ± 50 GDD. Shoot dry weight accumulation in first-year plants was 3.5 g for the first 600 GDD after which a fifteenfold increase in dry weight occurred. Root growth followed the same pattern, however the large increase in dry weight occurred approximately 300 GDD later than that of the shoots. The root:shoot ratio was 0.2 to 0.3 for the first 900 GDD and increased to greater than 1.0 by the final harvest.

scholarly journals Modeling the Environmental Suitability for Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus (Diptera: Culicidae) in the Contiguous United States

2017 ◽  
Vol 54 (6) ◽  
pp. 1605-1614 ◽  
Author(s):  
Tammi L Johnson ◽  
Ubydul Haque ◽  
Andrew J Monaghan ◽  
Lars Eisen ◽  
Micah B Hahn ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Sensitivity Threshold ◽  
Growing Degree Days ◽  
Degree Days ◽  
Maximum Entropy Modeling ◽  
Environmental Suitability ◽  
Suitability Maps ◽  
Number Percentage ◽  
County Scale

Abstract The mosquitoes Aedes (Stegomyia) aegypti (L.)(Diptera:Culicidae) and Ae. (Stegomyia) albopictus (Skuse) (Diptera:Culicidae) transmit dengue, chikungunya, and Zika viruses and represent a growing public health threat in parts of the United States where they are established. To complement existing mosquito presence records based on discontinuous, non-systematic surveillance efforts, we developed county-scale environmental suitability maps for both species using maximum entropy modeling to fit climatic variables to county presence records from 1960–2016 in the contiguous United States. The predictive models for Ae. aegypti and Ae. albopictus had an overall accuracy of 0.84 and 0.85, respectively. Cumulative growing degree days (GDDs) during the winter months, an indicator of overall warmth, was the most important predictive variable for both species and was positively associated with environmental suitability. The number (percentage) of counties classified as environmentally suitable, based on models with 90 or 99% sensitivity, ranged from 1,443 (46%) to 2,209 (71%) for Ae. aegypti and from 1,726 (55%) to 2,329 (75%) for Ae. albopictus. Increasing model sensitivity results in more counties classified as suitable, at least for summer survival, from which there are no mosquito records. We anticipate that Ae. aegypti and Ae. albopictus will be found more commonly in counties classified as suitable based on the lower 90% sensitivity threshold compared with the higher 99% threshold. Counties predicted suitable with 90% sensitivity should therefore be a top priority for expanded mosquito surveillance efforts while still keeping in mind that Ae. aegypti and Ae. albopictus may be introduced, via accidental transport of eggs or immatures, and potentially proliferate during the warmest part of the year anywhere within the geographic areas delineated by the 99% sensitivity model.

WINTERHARDINESS OF ALFALFA CULTIVARS IN SOUTHERN SASKATCHEWAN

1973 ◽  
Vol 53 (4) ◽  
pp. 773-777 ◽  
Author(s):  
D. H. HEINRICHS
Keyword(s):  
North America ◽  
Medicago Sativa ◽  
Great Plains ◽  
Climatic Conditions ◽  
Northern Great Plains ◽  
Dry Land ◽  
The Third ◽  
The Usa ◽  
Medicago Sativa L

Winter injury occurring at Swift Current, Saskatchewan, was recorded in 17 tests during the period 1962–72. Cultivars developed in the Northern Great Plains Region of the USA and in Canada were generally more winter-hardy than cultivars developed in other regions of North America or in Europe. Cultivars classified as Medicago media Pers. were more winter-hardy than those classified as Medicago sativa L. Very few USA cultivars were more winter-hardy than Vernal, but most Canadian cultivars were. In nonhardy cultivars winter injury never occurred during the first winter, but it often occurred in the second winter and frequently in the third winter. There was considerably more winter injury among alfalfa cultivars on irrigated land than on dry land. Based on results from these tests, 50 cultivars and strains have been classified for relative winterhardiness under climatic conditions in southern Saskatchewan, Canada.

Effect of cutting management, seeding rates and sowing method on seed yield of alfalfa (Medicago sativa L.)

2020 ◽  
Vol 52 (4) ◽  
Author(s):  
Jamshaid Ahmad ◽  
Asif Iqbal ◽  
Athar Mahmood ◽  
Muhmmad Aamir Iqbal ◽  
Haroon Zaman Khan ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Seed Yield ◽  
Medicago Sativa L ◽  
Cutting Management

Bloat in cattle fed alfalfa selected for a low initial rate of digestion

1994 ◽  
Vol 74 (3) ◽  
pp. 451-456 ◽  
Author(s):  
J. W. Hall ◽  
W. Majak ◽  
D. G. Stout ◽  
K.-J. Cheng ◽  
B. P. Goplen ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Protein Content ◽  
Key Words ◽  
Dry Matter ◽  
Initial Rate ◽  
Legume Species ◽  
The Third ◽  
Fourth Cycle ◽  
Medicago Sativa L

Investigations of legume species which do and do not cause bloat suggested that a bloat-safe alfalfa (Medicago sativa L.) might be produced by reducing its initial rate of digestion. This study compared a third cycle alfalfa synthetic selected for a low initial rate of digestion (LIRD) with a control cultivar (Beaver). The occurrence of bloat was not significantly lower when cattle were fed cycle 3 LIRD than when fed Beaver in three grazing trials or in two of three feedlot trials. The deviation of the results in the third trial could not be explained by differences in dry matter or protein content. When grown under irrigation, the 4 h dry matter disappearance (DMD) of cycle 3 LIRD was 89% to 96% of that for Beaver. This reduction was much less than has been hypothesized to prevent bloat. Without irrigation the 4 h DMD of both cultivars were reduced by 1–3% while cycle 3 LIRD continued to have a lower DMD than Beaver. LIRD may provide some protection against bloat on dry rangelands though the response may be variable in years when moisture is well supplied. Studies with a fourth cycle LIRD selection will investigate this further. Key words: Legumes, Medicago sativa L., nylon bag, digestion

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