DAMAGE POTENTIAL OF THE SWEETCLOVER WEEVIL, SITONA CYLINDRICOLLIS (COLEOPTERA: CURCULIONIDAE), IN THE CANADIAN PRAIRIES

1978 ◽  
Vol 110 (8) ◽  
pp. 883-889 ◽  
Author(s):  
C. H. Craig
Keyword(s):  
Cultural Practices ◽  
Forage Yield ◽  
Sweet Clover ◽  
Damage Potential ◽  
Field Cage ◽  
Canadian Prairies ◽  
Melilotus Officinalis ◽  
Second Year ◽  
Growing Conditions ◽  
Type Of Injury

AbstractAdults of the sweetclover weevil, Sitona cylindricollis Fähr., injure seedling, vegetative, and yearling sweet clover, Melilotus officinalis (L.) Lam. In field cage tests an infestation of 1 weevil: 7 seedlings at the cotyledon stage destroyed less than 5%, and an infestation of 1 weevil: 1 seedling destroyed 100% of the seedlings. Significant reduction of seedlings was caused by infestations of I weevil: 3 or 5 seedlings depending upon growing conditions. An infestation of 4.5 to 9 weevils per emergent second-year plant caused a significant reduction, and an infestation of 18 weevils per plant caused almost total destruction of second-year forage yield. In the Canadian mid-west, weevil populations seldom exceed these minimum threshold values, therefore the weevil should not be considered a deterrent to either stand establishment or to stand retention in the second year. Defoliation of vegetative clover by weevils at the beginning of and mid-way through the critical period, which extends from 15 August to 20 September, caused a 50% loss of second-year forage yield. Because of cultural practices associated with sweet clover production in western Canada this may be the most severe type of injury wrought by the weevil.

scholarly journals Irrigation Timing as a Practice of Effective Weed Management in Established Alfalfa (Medicago sativa L.) Crop

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 550
Author(s):  
Panagiotis Kanatas ◽  
Ioannis Gazoulis ◽  
Ilias Travlos
Keyword(s):  
Medicago Sativa ◽  
Weed Management ◽  
Cultural Practices ◽  
Block Design ◽  
Chenopodium Album ◽  
Stand Density ◽  
Climatic Conditions ◽  
Amaranthus Retroflexus ◽  
Forage Yield ◽  
Medicago Sativa L

Irrigation is an agronomic practice of major importance in alfalfa (Medicago sativa L), especially in the semiarid environments of Southern Europe. Field experimentation was conducted in Western Greece (2016–2018) to evaluate the effects of irrigation timing on weed presence, alfalfa yield performance, and forage quality. In a randomized complete block design (four replications), two cultivars (“Ypati 84” and “Hyliki”) were the main plots, while three irrigation timings were the subplots (split-plot). The irrigation timings were IT-1, IT-2, and IT-3, denoting irrigation 1 week before harvest, 1 week after harvest, and 2 weeks after harvest, respectively. IT-1 reduced Solanum nigrum L. density by 54% and 79% as compared to IT-3 and IT-2, respectively. Chenopodium album L. density was the highest under IT-2. IT-3 resulted in 41% lower Amaranthus retroflexus L. density in comparison to IT-2, while the lowest values were observed under IT-1. Stand density and stems·plant−1 varied between years (p ≤ 0.05). Mass·stem−1 and alfalfa forage yield were affected by the irrigation timings (p ≤ 0.001). Total weed density and forage yield were negatively correlated in both the second (R2 = 87.013%) and the fourth (R2 = 82.691%) harvests. IT-1 and IT-3 increased forage yield, leaf per stem ratio, and crude protein as compared to IT-2. Further research is required to utilize the use of cultural practices for weed management in perennial forages under different soil and climatic conditions.

SPONTANEOUS SELF-FERTILIZATION IN RELATION TO SEED PRODUCTION IN SWEET CLOVER (MELILOTUS)

1931 ◽  
Vol 5 (6) ◽  
pp. 660-664 ◽  
Author(s):  
L. E. Kirk ◽  
T. M. Stevenson
Keyword(s):  
Seed Production ◽  
Pollen Grains ◽  
Sweet Clover ◽  
Flower Structure ◽  
Melilotus Officinalis ◽  
Stigmatic Surface ◽  
Melilotus Alba ◽  
Self Fertilization ◽  
Determining Factor ◽  
Selection Of

The chief determining factor in spontaneous self-fertilization in white sweet clover (Melilotus alba) appears to be the distribution of pollen within the unopened flowers. This in turn depends on (1) length of stamens, (2) length of style, (3) amount of pollen, and (4) size of cavity within the upper part of the keel. When the flower structure and quantity of pollen is such as to insure the deposition of pollen grains on the stigma before the blossom is likely to be disturbed by insects, the plant will be normally self-fertilized. In the yellow flowered species of sweet clover (Melilotus officinalis) spontaneous self-fertilization is effectively prevented, except in certain varieties, by a characteristic of the stigma which makes it unreceptive. Scarification of the stigmatic surface appears to be necessary before fertilization can take place. Variation occurs also, as in M. alba, in the length of stamens and style, size of keel cavity, and the amount of pollen.There is a high correlation in M. alba between the percentage of flowers which are naturally self-pollinated and the percentage of flowers which produce pods when the plants are caged to exclude insects. Selection of plants which are normally self-fertilized can be made by examining the early flowers, thus obviating the necessity of bagging or caging plants which do not possess this character.A strain of M. alba which is normally self-fertilized was found to produce almost twice as much seed as another strain which is normally cross-pollinated under comparable conditions in the field.

scholarly journals Effect of Cultural Practices on Neopamera bilobata in Relation to Fruit Injury and Marketable Yields in Organic Strawberries

Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 843
Author(s):  
Hannah R. Talton ◽  
Elena M. Rhodes ◽  
Carlene A. Chase ◽  
Marilyn E. Swisher ◽  
Justin M. Renkema ◽  
...  
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Cultural Practices ◽  
Life Stage ◽  
Management Program ◽  
Limited Information ◽  
Significant Difference ◽  
The Difference ◽  
Management Recommendations ◽  
Type Of Injury

The strawberry seed bug, Neopamera bilobata (Say), is an emerging pest of organic and conventional strawberries in Florida. There is limited information on this Rhyparochromidae species. Thus, the type of injury caused is not clearly documented and management recommendations are lacking. In this study, we evaluated the effect of strawberry cultivars, cover crops, and the presence of runners on N. bilobata populations and yield. We also investigated the effect of select cultivars and the presence of runners on N. bilobata injury levels. In addition, we used fruit bagging experiments to investigate the effects of N. bilobata population and life stage (nymph vs. adult) on strawberry fruits. There was no effect of cover crop or cultivar on N. bilobata populations. In the 2017–2018 season, strawberry plots with runners contained higher N. bilobata populations compared with plots without runners, and adult infestation was significantly higher than nymphal infestation. In the 2018–2019 season, the trend was reversed with higher numbers of N. bilobata collected in plots with runners removed. In the 2019–2020 season, there was no significant difference in N. bilobata populations in plots with and without runners. In both 2018–2019 and 2019–2020, nymphal infestation was higher than adult infestation. Less injury was recorded in “Florida Brilliance” compared with the other cultivars tested. In the 2019–2020 season, less injury was recorded from plots without runners while the difference was not significant in 2017–2018 or 2018–2019. Releasing five and ten adult N. bilobata on ripe (red) fruit produced a similar level of injury while no injury to unripe (green) fruit was observed. Both adults and nymphs cause injury to ripe fruit. These findings can help contribute to the development of an integrated pest management program for strawberry N. bilobata.

BIOSYNTHESIS OF THE COUMARINS. TRACER STUDIES ON COUMARIN FORMATION IN HIEROCHLOË ODORATA AND MELILOTUS OFFICINALIS

1960 ◽  
Vol 38 (2) ◽  
pp. 143-156 ◽  
Author(s):  
Stewart A. Brown ◽  
G. H. N. Towers ◽  
D. Wright
Keyword(s):  
Cinnamic Acid ◽  
Shikimic Acid ◽  
Perennial Grass ◽  
Coumaric Acid ◽  
Sweet Clover ◽  
Tracer Studies ◽  
Melilotus Officinalis ◽  
Specific Activities ◽  
Acid Pathway ◽  
Hierochloe Odorata

Coumarin formation has been studied with C14in the perennial grass, Hierochloë odorata, and in yellow sweet clover, Melilotus officinalis. In general the latter species yielded inconsistent data. In Hierochloë, o-coumaric, cinnamic, and shikimic acids and L-phenylalanine were the best of 10 compounds tested as coumarin precursors, the first two at least being incorporated with little randomization of C14. Acetate was more poorly utilized. It was concluded that the aromatic ring of coumarin arises via the shikimic acid pathway in preference to acetate condensation. When the time of metabolism was varied, o-coumaryl glucoside and free o-coumaric acid rapidly acquired high specific activities from cinnamic acid-C14, but coumarin and melilotic acid became active much more slowly. A lag in the acquisition of C14by coumarin for the first 6 to 8 hours was followed by a rectilinear increase until at least 24 hours. Much the greatest accumulation of C14was found in o-coumaryl glucoside during this entire period. Furthermore, this compound when fed to Hierochloë is comparable to cinnamic acid as a coumarin precursor. These findings suggest a possible function for o-coumaryl glucoside or a derivative in coumarin biosynthesis.

Comparing fall and spring seeding of Kochia scoparia on saline soil

1993 ◽  
Vol 73 (4) ◽  
pp. 1055-1065 ◽  
Author(s):  
H. Steppuhn ◽  
D. G. Green ◽  
G. Winkleman ◽  
J. A. Kernan ◽  
E. Coxworth
Keyword(s):  
Saline Soil ◽  
Plant Competition ◽  
Early Spring ◽  
Late Spring ◽  
Shoot Biomass ◽  
Forage Production ◽  
Kochia Scoparia ◽  
Canadian Prairies ◽  
Plant Densities ◽  
Growing Conditions

Kochia scoparia naturally invades distributed soils in the Brown soil zone of the Canadian Prairies and offers potential as a forage crop in saline environments. A 3-yr study conducted on severely saline soil near Swift Current, Saskatchewan, compared kochia production resulting from fall (natural- and implement-seeded) and spring (early- and late-seeded) treatments. Late spring-seeded crops produced, on average, 5.4 t of dry, shoot biomass per ha per yr. Early spring and fall-seeded kochia (naturally or implement-placed) yielded between 5.4 and 10.9 t ha−1. Of the nine comparisons between forage yields from fall and spring seedings, six favored fall over spring, two were equal, and one produced more forage from early spring seedings than from the naturally-seeded fall treatment. The late spring treatment consistently produced the least forage. Fall seedings exhibited a greater potential for forage production because fall-seeded plants usually established early in the growing season and in sufficient number to fully exploit soil and water resources when conditions became favorable and effective rooting depths were not restricted by concentrated salt layers. When drier growing conditions prevailed, the lower plant densities associated with early spring seedings tended to minimize plant competition and foster greater forage production. Key words: Kochia forage, seeding dates, salinity, Kochia establishment, Kochia agronomy

Effects of grazing dates on forage and beef production of mixed prairie rangeland

1999 ◽  
Vol 79 (3) ◽  
pp. 335-341 ◽  
Author(s):  
M. P. Schellenberg ◽  
N.W. Holt ◽  
J. Waddington
Keyword(s):  
Carrying Capacity ◽  
Average Daily Gain ◽  
Bouteloua Gracilis ◽  
Early Spring ◽  
Forage Yield ◽  
Canadian Prairies ◽  
Crested Wheatgrass ◽  
Forage Digestibility ◽  
Short Period ◽  
Mixed Prairie

Conventional belief is that mixed prairie range is harmed by early spring use but not by moderate grazing after the grasses have flowered. Our hypothesis was that mixed prairie range may be grazed for a limited period in the growing season providing rest is allowed for the remainder of the year. This 6-yr test was established on a rolling site of range pasture, which contained, by area, 65% upland mixed prairie, 5% lowland bluegrass (Poa spp.) and 30% crested wheatgrass (Agropyron cristatum). The species mix is commonly found in southern Canadian prairies. The mixed prairie grasses were needle and thread (Stipa comata), northern wheatgrass (Elymus lanceolatus), western wheatgrass (Pascopyrum smithii) and blue grama (Bouteloua gracilis). Each pasture was 1.6 ha and was grazed with yearling beef cattle once a year beginning mid-May; the end of June; mid-August or late September. Forage yields in grazing-exclusion cages averaged 580, 2960, and 1370 kg ha−1 for the mixed prairie, lowland grasses, and crested wheatgrass, respectively. The date of grazing in the previous year did not affect current-year maximum forage yield. The main determinant of maximum forage yield was a combination of spring soil moisture plus April to June precipitation. Available forage for grazing, on average, doubled from mid-May until the end of June for the three forage types. There were year-by-grazing date interactions, which were related to distribution of precipitation. Mixed prairie was the preferred forage at the last two grazing dates. Forage digestibility, N and P content were highest during the May and June grazing period and declined thereafter. Average daily gain of the steers decreased from 0.9 kg d−1 in May and late June to 0.2 kg d−1 by late September. Annual carrying capacity (in standard animal units) was 40 d ha−1 in May and averaged 55 d ha−1 for the other dates, which were not different. Grazing mixed prairie did not have a negative effect on the yield of native grasses when used for only one short period per year. Delayed use from mid May to end of June increased available forage and carrying capacity. Key words: Mixed grass prairie, crested wheatgrass, grazing, weather effects

Influence of Deep Tillage and a Rye Cover Crop on Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) Emergence in Cotton

2012 ◽  
Vol 26 (4) ◽  
pp. 832-838 ◽  
Author(s):  
Justin D. DeVore ◽  
Jason K. Norsworthy ◽  
Kristofor R. Brye
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Cultural Practices ◽  
Palmer Amaranth ◽  
Deep Tillage ◽  
Amaranth Seed ◽  
Soil Seedbank ◽  
Second Year ◽  
The Impact ◽  
Moldboard Plow

Glyphosate-resistant Palmer amaranth has become a major problem for cotton producers throughout much of the southern United States. With cotton producers relying heavily on glyphosate-resistant cotton, an alternative solution to controlling resistant Palmer amaranth is needed. A field experiment was conducted during 2009 and 2010 at Marianna, AR, in which a rye cover crop and no cover crop were tested in combination with deep tillage with the use of a moldboard plow and no tillage to determine the impact on Palmer amaranth emergence in cotton. To establish a baseline population, 500,000 glyphosate-resistant Palmer amaranth seeds were placed in a 2-m2area in the middle of each plot and incorporated into the soil, and emergence was evaluated five times during the season. In 2009, both tillage and the cover crop reduced Palmer amaranth emergence in cotton, but the combination of the two reduced emergence 85%. In the second year, only the cover crop reduced Palmer amaranth emergence in cotton, a 68% reduction. Cover crops and deep tillage will not eliminate glyphosate-resistant Palmer amaranth; however, use of these tools will likely reduce the risks of failures associated with residual herbicides along with selection pressure placed on both PRE- and POST-applied herbicides. Additional efforts should focus on the integration of the best cultural practices identified in this research with use of residual herbicides and greater focus on limiting Palmer amaranth seed production and reducing the soil seedbank.

scholarly journals Short-Term Plant Community Responses to Warming and Defoliation in a Northern Temperate Grassland

ISRN Ecology ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Eliza S. Deutsch ◽  
Edward W. Bork ◽  
James F. Cahill ◽  
Scott X. Chang
Keyword(s):  
Plant Community ◽  
Community Dynamics ◽  
Plant Biomass ◽  
Temperate Grassland ◽  
Community Diversity ◽  
Native Plant ◽  
Short Term ◽  
Canadian Prairies ◽  
Growing Seasons ◽  
Second Year

Little is known about the short-term impacts of warming on native plant community dynamics in the northern Canadian prairies. This study examined the immediate effects of elevated temperature and defoliation on plant community diversity, composition, and biomass within a native rough fescue (Festuca hallii (Vasey) Piper) grassland over two growing seasons. We used open-top chambers to simulate climate change and defoliated vegetation in midsummer of the first year to simulate biomass loss associated with periodic ungulate grazing. Warming marginally increased plant species diversity and changed community composition shortly after treatment, but effects were not apparent the second year, and there were no apparent impacts on plant biomass. Nonetheless, warming may have impacted community diversity indirectly through reduced soil moisture content, a pattern that persisted into the second year. Overall, this northern temperate grassland demonstrated limited community-level changes to warming even in the presence of defoliation.

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