Evaluation of herbicides for hair fescue (Festuca filiformis) management and potential seedbank reduction in lowbush blueberry

2019 ◽  
Vol 33 (6) ◽  
pp. 840-846
Author(s):  
Scott N. White
Keyword(s):  
Seed Production ◽  
Perennial Grass ◽  
Lowbush Blueberry ◽  
Alternative Bearing

AbstractHair fescue is a widespread, seed-limited perennial grass in lowbush blueberry fields. Growers rely on pronamide, an expensive and difficult herbicide to use, for hair fescue management. Recent herbicide registrations provide opportunity to reduce pronamide use, though effects of these herbicides on hair fescue suppression and seedbank reduction are not well understood. The objectives of this research were to determine (1) the effects of herbicides currently registered in lowbush blueberry on suppression of hair fescue tufts and (2) whether suppression of hair fescue with these herbicides reduces hair fescue seedbanks. Pronamide gave the most consistent reductions in flowering tuft density, though applications after both autumn pruning and autumn of the nonbearing year were required to reduce the hair fescue seedbank by >60% across sites. Nonbearing-year hexazinone applications did not control hair fescue or reduce the seedbank. Nonbearing-year terbacil applications reduced flowering tuft density, but hair fescue recovered in the bearing year, and the seedbank was not reduced. Glufosinate applications following autumn pruning or in the spring of the nonbearing year did not suppress hair fescue or reduce the seedbank. Spring nonbearing-year foramsulfuron applications, alone or after autumn or spring glufosinate applications, reduced hair fescue flowering tuft density, but hair fescue recovered in the bearing year, and the seedbank was not reduced. In contrast, autumn and spring glufosinate applications followed by spring nonbearing-year foramsulfuron applications, when combined with autumn nonbearing-year pronamide applications, reduced flowering tuft density in both the nonbearing and bearing years and reduced the hair fescue seedbank by 58% to 83% across sites. Results indicate that hair fescue seedbanks can be reduced in lowbush blueberry fields and that a reduction in pronamide use will require alternative bearing-year treatments to prevent tuft recovery and seed production.

scholarly journals Fall-bearing Year Herbicides and Spring-nonbearing Year Foramsulfuron Applications for Hair Fescue Management in Lowbush Blueberry

2020 ◽  
Vol 30 (6) ◽  
pp. 670-676
Author(s):  
Scott Neil White ◽  
Linshan Zhang
Keyword(s):  
Seed Production ◽  
Seedling Recruitment ◽  
Block Design ◽  
Perennial Grass ◽  
Interactive Effects ◽  
Production Cycle ◽  
Seedling Density ◽  
Vaccinium Angustifolium ◽  
Lowbush Blueberry ◽  
Randomized Complete Block Design

Hair fescue (Festuca filiformis) is a tuft-forming perennial grass that reduces yields in lowbush blueberry (Vaccinium angustifolium) fields. Nonbearing year foramsulfuron applications suppress hair fescue, but there is interest in increasing suppression through foramsulfuron use in conjunction with fall-applied herbicides. The objective of this research was to determine the main and interactive effects of fall-bearing year herbicide applications and spring-nonbearing year foramsulfuron applications on hair fescue. The experiment was a 5 × 2 factorial arrangement of fall-bearing year herbicide (none, terbacil, pronamide, glufosinate, dichlobenil) and spring-nonbearing year foramsulfuron application (0, 35 g·ha−1) arranged in a randomized complete block design at lowbush blueberry fields in Portapique and Stewiacke, Nova Scotia, Canada. Spring-nonbearing year foramsulfuron applications did not reduce total tuft density or consistently reduce flowering tuft density, flowering tuft inflorescence number, or flowering tuft seed production. Fall-bearing year pronamide applications reduced hair fescue density for the 2-year production cycle, although additional bearing year density reductions occurred when pronamide was followed by spring-nonbearing year foramsulfuron applications at Stewiacke. Fall-bearing year dichlobenil applications reduced total and flowering tuft density at each site, although reductions in flowering tuft inflorescence number and seed production were most consistent when followed by spring-nonbearing year foramsulfuron applications at Stewiacke. Suppression extended into the bearing year at each site, and dichlobenil should be examined further for hair fescue control. Fall-bearing year glufosinate applications reduced hair fescue total tuft density at each site and flowering tuft density and flowering tuft seed production at Stewiacke. Fall-bearing year glufosinate applications followed by spring-nonbearing year foramsulfuron applications also reduced nonbearing year flowering tuft inflorescence number and bearing year hair fescue seedling density at Stewiacke, indicating that this treatment may reduce hair fescue seedling recruitment at some sites. Fall-bearing year terbacil applications did not suppress hair fescue and are not recommended for hair fescue management in lowbush blueberry.

Effects of fall bearing year glufosinate applications, spring non-bearing year glufosinate applications, and spring non-bearing year foramsulfuron applications on hair fescue in lowbush blueberry

2020 ◽  
pp. 1-33
Author(s):  
Scott N. White ◽  
Linshan Zhang
Keyword(s):  
Seed Production ◽  
Seed Bank ◽  
Block Design ◽  
Perennial Grass ◽  
Interactive Effects ◽  
Seedling Density ◽  
Bank Management ◽  
Lowbush Blueberry ◽  
Randomized Complete Block Design ◽  
Herbicide Treatments

Hair fescue is a common perennial grass that reduces yields in lowbush blueberry fields. This grass is suppressed with non-bearing year foramsulfuron applications, though suppression may be improved through use of sequential glufosinate and foramsulfuron applications. The objective of this research was to determine the main and interactive effects of fall bearing year glufosinate applications, spring non-bearing year glufosinate applications, and spring non-bearing year foramsulfuron applications on hair fescue. The experiment was a 2 by 2 by 2 factorial arrangement of fall bearing year glufosinate application (0, 750 g ai ha-1), spring non-bearing year glufosinate application (0, 750 g ai ha-1), and spring non-bearing year foramsulfuron application (0, 35 g ai ha-1) arranged in a randomized complete block design at lowbush blueberry fields located in Parrsboro and Portapique, NS, Canada. Fall bearing year glufosinate applications, spring non-bearing year glufosinate applications, and spring non-bearing year foramsulfuron applications alone provided inconsistent hair fescue suppression. Fall bearing year glufosinate applications followed by spring non-bearing year foramsulfuron applications, however, reduced non-bearing year total tuft density, flowering tuft density, and flowering tuft inflorescence number at each site and reduced seed production at Portapique. Sequential fall bearing year and spring non-bearing year glufosinate applications or sequential spring non-bearing year glufosinate and foramsulfuron applications reduced flowering tuft density and flowering tuft inflorescence number at each site but did not consistently reduce total tuft density. Sequential herbicide treatments reduced bearing year seedling density and may therefore contribute to hair fescue seed bank management in lowbush blueberry.

Growth, seed production and effect of defoliation in an early flowering perennial grass, Alloteropsis semialata (Poaceae), on Cape York Peninsula, Australia

2001 ◽  
Vol 49 (6) ◽  
pp. 735 ◽  
Author(s):  
Gabriel M. Crowley ◽  
Stephen T. Garnett
Keyword(s):  
Plant Growth ◽  
Seed Production ◽  
Perennial Grass ◽  
Soil Surface ◽  
Plant Size ◽  
Perennial Grasses ◽  
Wet Season ◽  
Cape York ◽  
Seed Dynamics

Alloteropsis semialata (R.Br.) A.Hitchc. is one of the first perennial grasses in monsoonal Australia to produce seed at the start of the wet season. Patterns of growth and seed production and seed dynamics of Alloteropsis semialata were examined in this study, along with the effects of partial defoliation. Growth of Alloteropsis semialata tussocks started with the first pre-wet-season rains, and was then interrupted during a period with little rain. Growth ceased before the end of the wet season, indicating that factors other than moisture availability were limiting. Seeds of Alloteropsis semialata were germinable on production, but did not remain viable or persist on the soil surface through the dry season. Most seeds and young seedlings were harvested and no seedlings were recruited. Inflorescence production increased with plant size. Moderate defoliation in the early wet season had no impact on plant growth, but reduced inflorescence and seed production for at least 2 years. Absence of a seed bank and early wet-season flowering mean that Alloteropsis semialata is likely to be sensitive to long-term over-grazing.

The role of seedbanks in invasions by Hyparrhenia hirta (L.) Stapf in Australia

2019 ◽  
Vol 41 (5) ◽  
pp. 383 ◽  
Author(s):  
Vinod K. Chejara ◽  
Paul Kristiansen ◽  
R. D. B. (Wal) Whalley ◽  
Brian M. Sindel ◽  
Christopher Nadolny
Keyword(s):  
South African ◽  
Seed Production ◽  
Seed Dormancy ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Perennial Grass ◽  
Seed Banks ◽  
Invasive Weed ◽  
South Wales ◽  
Poor Seed

Hyparrhenia hirta (L.) Stapf (also known as Coolatai grass, South African bluestem or thatching grass) has become a serious invasive weed in Australia. Within its native range, it is generally regarded as a useful grass particularly for thatching, and seed production is low with a low soil seed bank of from 2 to 200seedsm–2. Several hundred accessions of H. hirta were deliberately introduced into Australia up until the 1980s and nearly all were discarded because of poor seed production. However, at least one introduction in the 1890s in northern New South Wales (NSW), Australia, has possibly contributed to the present serious weed problem. Annual seed production from roadside stands in northern NSW ranged from 7000 to 92000seedsm–2 in 2015. The soil seed bank under dense H. hirta infestations in the same region in 2006 and 2007, was found to be ~30000seedsm–2 mostly confined to the top 2cm, with few dormant seeds and a large reduction of these numbers over the next 12 months when further seed input was prevented. Similar studies of other perennial grass weeds have found seed banks of similar sizes, but dormancy mechanisms ensure that their seed banks last for at least 10 years without further seed input. These results suggest that the present weedy populations of H. hirta have dramatically increased fecundity enabling a large seed bank to develop beneath dense stands. The development of seed dormancy and consequently a long-lived seed bank would make this weed even more difficult to control. Until seed dormancy develops, control of H. hirta in northern NSW can be effective provided further input into the seed bank can be prevented.

Silvertop in perennial grass seed production: Effects of type and timing of biotic stresses

2021 ◽  
Author(s):  
Julie Soroka ◽  
Bruce D. Gossen
Keyword(s):  
Seed Production ◽  
Poa Pratensis ◽  
Perennial Grass ◽  
Kentucky Bluegrass ◽  
Development Stage ◽  
Perennial Grasses ◽  
Grass Species ◽  
Biotic Stresses ◽  
Seed Harvest ◽  
Bromus Riparius

Seed production of perennial grasses is an important industry in Canada, but many fields exhibit high proportions of sterile heads with characteristic symptoms in a condition known as silvertop. In a 3-yr field study, biotic stress treatments were applied to caged plots of Kentucky bluegrass (<i>Poa pratensis</i>) and meadow bromegrass (<i>Bromus riparius</i>) to assess their effects on silvertop incidence. Treatments were: 1) control, 2) addition of grass-feeding insects, primarily grass plant bugs (Miridae), 3) inoculation with <i>Fusarium poae</i> spores, 4) both insects and spores, and in one year, 5) mechanical piercing of seed heads above the last node. Additionally, cores of the two grass species were potted and removed from the field in spring in each of 2 years. After 2-, 4-, and 6-wk intervals in a cold room at 4° C to stagger plant development stage, the five treatments were applied to caged plants of both grasses, which were maintained in a greenhouse until seed harvest. In both studies, the numbers of healthy seed heads, percentage of heads with silvertop, and seed weights were determined. In the field, stress treatments infrequently and inconsistently affected silvertop levels. Regression showed that the relationship between silvertop and seed yield, although significant, explained little of the variability in yield. Silvertop developed in all treatments in the greenhouse; treatments had no effect on silvertop levels, which were highest in plants treated at the R1 (boot) growth stage. This suggests that the boot stage of the two grass species is most vulnerable to silvertop occurrence.

Impacts of Fall Nitrogen Application on Seed Production in Leymus chinensis , a Rhizomatous Perennial Grass

2013 ◽  
Vol 105 (5) ◽  
pp. 1378-1384 ◽  
Author(s):  
Junfeng Wang ◽  
Xiaoyu Li ◽  
Song Gao ◽  
Zhuolin Li ◽  
Chunsheng Mu
Keyword(s):  
Seed Production ◽  
Perennial Grass ◽  
Leymus Chinensis ◽  
Nitrogen Application

Evaluation of terbacil-based herbicide treatments for hair fescue management in lowbush blueberry

2020 ◽  
pp. 1-29
Author(s):  
Scott N. White ◽  
Linshan Zhang
Keyword(s):  
Nova Scotia ◽  
Weed Management ◽  
Perennial Grass ◽  
Management Program ◽  
Industry Standard ◽  
Lowbush Blueberry ◽  
Herbicide Treatments ◽  
Grass Weed

Hair fescue is common tuft-forming perennial grass weed that reduces yields and hinders mechanical harvest in lowbush blueberry fields. PRE terbacil applications traditionally controlled hair fescue, but currently only provide suppression in most fields. Terbacil use has not, however, been evaluated in conjunction with other currently registered herbicides in lowbush blueberry. The objective of this research was to evaluate a range of terbacil-based herbicide treatments for hair fescue management in lowbush blueberry. The experiment was conducted at three lowbush blueberry fields in Nova Scotia, Canada. Spring non-bearing year terbacil applications (2000 g ai ha-1) exhibited variable efficacy on hair fescue with reduced total tuft density at one site and reduced flowering tuft density and flowering tuft inflorescence number at two sites. Suppression was limited to the year of application only. Terbacil followed by (fb) foramsulfuron (35 g ai ha-1) did not improve suppression. A terbacil tank mixture with glufosinate (750 ai ha-1), however, reduced flowering tuft density and flowering tuft inflorescence number at each site and reduced total tuft density at one site, suggesting improved suppression with terbacil+glufosinate relative to terbacil alone. Terbacil+glufosinate fb foramsulfuron gave additional reductions in total tuft density at two sites and reduced bearing year flowering tuft density at two sites, indicating that hair fescue suppression with this herbicide combination extends into the bearing year. Although less effective than the industry standard pronamide applications, terbacil+glufosinate or terbacil+glufosinate fb foramsulfuron could be used as part of a weed management program for hair fescue in lowbush blueberry.

Seed availability, landscape suitability and the regeneration of perennial grasses in moderately degraded rangelands in semiarid Australia

2015 ◽  
Vol 37 (3) ◽  
pp. 249 ◽  
Author(s):  
Judith M. Bean ◽  
Gavin J. Melville ◽  
Ronald B. Hacker ◽  
Stephen P. Clipperton
Keyword(s):  
Seed Production ◽  
Perennial Grass ◽  
Weather Conditions ◽  
Perennial Grasses ◽  
Grass Species ◽  
Natural Landscape ◽  
Seed Availability ◽  
Landscape Processes ◽  
Production Areas ◽  
Seasonal Weather

Two experimental sites were selected in the semiarid rangelands of north-west New South Wales, Australia. The sites had contrasting soil types and vegetation communities, but were similar in the existence of topographically high areas occupied by populations of perennial grasses. Adjacent slopes had very low numbers of perennial grass plants, indicating a moderate level of degradation. Shrubs, including Eremophila sturtii R.Br. (turpentine), were present but had not thickened to cause severe degradation. The topographically high areas were fenced as seed production areas. Replicates of a control and two cultural treatments: (1) piles of fine branches of turpentine placed along the topographic contour and (2) pits dug by a revolving metal drum, were established on the adjacent slopes. Maximum regeneration of perennial grasses took place, during favourable seasonal weather conditions, under the piles of branches on the site characterised by long gentle slopes of relatively impervious hard-setting red earths. Seed availability was not a limiting factor and a significant amount of seed was apparently sourced from the seed production areas. The piles of branches were very effective in promoting germination and survival of the perennial grasses, Monachather paradoxus Steud. and Aristida jerichoensis (Domin) Henrad, and species with large seed-retaining inflorescences, but not Thyridolepis mitchelliana (Nees) S.T. Blake. The piles of branches increased capture of seed, developed an improved seedbed and established a more mesic micro-environment and were, therefore, effective in enhancing natural landscape processes. At the site characterised by a medium-textured lithosol, even during favourable seasonal weather conditions, numbers of new plants were much lower. Pits were obliterated during the first heavy rains and the piles of branches had a negative impact on the survival of the second cohort of T. mitchelliana. At both sites, levels of germination and survival needed for regeneration of perennial grasses only occurred where a treatment effective in enhancing natural landscape processes had been established prior to favourable seasonal conditions. Pits were not effective in doing this at either site, nor for any of the perennial grass species.

Seedling recruitment of the exotic grass Andropogon gayanus (Poaceae) in northern Australia

2005 ◽  
Vol 53 (3) ◽  
pp. 243 ◽  
Author(s):  
Trish A. Flores ◽  
Samantha A. Setterfield ◽  
Michael M. Douglas
Keyword(s):  
Seed Production ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Perennial Grass ◽  
Effective Control ◽  
Northern Australia ◽  
Wet Season ◽  
Soil Cultivation ◽  
Andropogon Gayanus

Andropogon gayanus Kunth. (Gamba grass), a tall perennial grass from Africa, is invading savanna ecosystems in northern Australia. This study investigated A. gayanus recruitment to determine the habitats at risk of invasion and to provide recommendations for its management. A. gayanus is able to establish and spread into new areas because of its high seed production (averaging 70 000 seeds m–2) and ability to establish across a range of habitats: from open woodlands on relatively dry lateritic soils to the more closed forests on black soil of the floodplain margins. Seedling emergence occurred in the absence of soil cultivation, although soil cultivation did increase emergence in the wetter habitats (Melaleuca uplands and floodplain margins). Seedling survival was high in the savanna (~90%) but low in the wetter habitats owing to wet-season inundation. A seed longevity trial based on burying seed in the field and retrieving between 1 and 12 months after burial showed that less than 1% of seeds survived in the seedbank after 12 months. Effective control programs are needed immediately because of the vast area and range of habitats in northern Australia that could potentially be invaded by A. gayanus. Management that can limit site disturbance and seed production, and can incorporate follow-up control for one to two years, should be an important part of an A. gayanus control strategy.

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