Uncut Grass Research Articles

Effects of uncut grass refuges on the plant community of extensively managed hay meadows

Invertebrates inhabiting grasslands benefit from uncut grass refuges, yet effects on the plant community have not been properly quantified. We experimentally investigated the effects on the vegetation of two different types of refuges. While both consisted in not mowing 10–20% of a meadow area, they differed in their rotation frequency: (1) in within-year rotational refuges (WYRR), the location of the refuge within a meadow was changed at each mowing operation, usually twice a year; (2) in between-years rotational refuges (BYRR), the refuge changed location only between years. A third mowing regime without any refuge was included as control (C) for comparison. The study was conducted in thirty extensively managed meadows across the Swiss lowlands. The vegetation was sampled at two 1-m2 plots within each of the four strata defined by a stratified random design that accounted for the spatial location of the uncut refuge over the years. There were no overall significant negative effects of WYRR on plant species richness and composition at the meadow scale, although a small negative effect was detected locally (i.e. at the refuge scale) where a WYRR had been implemented more than once in the preceding three years. Leaving BYRR negatively impacted plant species richness (-11%), even reducing the number of indicator plant species by 22% (from 4.5 to 3.5 per 2 m2), regardless of when and where refuges were left uncut. A beta-diversity analysis revealed no difference at community level between the two refuge types and control meadows. Previous studies had evidenced positive effects of uncut refuges on herbivore and pollinator communities, while this study shows that the plant community is not affected as long as the location of the refuge is changed at each mowing operation. We thus recommend this measure for promoting biodiversity in extensively managed grasslands.

Asistiendo a la reintroducción de vizcachas (Lagostomus maximus): ¿Cómo aumentar el área de pastoreo seguro?

The reintroduction of fossorial mammals could be limited by the availability of satellite burrows that provide refuge from predators while foraging away from their permanent burrows, and by availability of short grasses. In order to generate information to assist in the reintroduction of vizcachas (Lagostomus maximus), we asked: 1) what type of satellite burrow do they accept based on burrow complexity, entrance size and distance from permanent burrows?, and 2) how did the provision of burrows and mowing affect their foraging range? We carried out the study in the Sierras of Cordoba, Argentina, with 13 vizcachas transferred to two adaptation pens equipped with permanent burrows. We mowed part of the vegetation around the pens and we dug 14 satellite burrows of two types: simple with only a tunnel, and complex with a tunnel and underground chamber. Burrows were situated between 1 and 16 m from the pens. For six months we evaluated satellite burrow occupancy. We also counted feces, estimated bare soil, and height of the vegetation in 15-m-long transects originating in the entrances of highly used burrows, which were distributed in two sectors. Occupancy was 2 and 67% for simple and complex satellite burrows, respectively, and was negatively related to burrow entrance size. There was no relationship between burrow occupancy and distance to adaptation pens. Transect sampling showed that 91% of the pellets were within 4 m of the pens or satellite burrows, and that they preferred cut to uncut grass. We conclude that building complex satellite burrows and mowing vegetation will increase secure foraging range for translocated vizcachas.

Larval and phenological traits predict insect community response to mowing regime manipulations.

For the restoration of biodiversity in agricultural grasslands, it is essential to understand how management acts as an ecological filter on the resident species. Mowing constitutes such a filter: only species that possess functional traits enabling them to withstand its consequences can persist in the community. We investigated how the timing of mowing modulates this filtering effect for insects. We predicted that two traits drive species responses. Species with larval development within the meadow vegetation will suffer more from mowing than species whose larvae develop in or on the ground, or outside the meadows, while species with a later phenology should benefit from later mowing. We conducted a five-year experiment, replicated at 12 sites across the Swiss lowlands, applying three different mowing regimes to low-intensity hay meadows: (1) first cut of the year not earlier than 15 June (control regime); (2) the first cut delayed until 15 July; and (3) leaving an uncut grass refuge on 10-20% of the meadow area (after earliest first cut on 15 June). Before the first cut in years 4 or 5, we sampled larvae of Lepidoptera and sawflies, and adults of moths, parasitoid wasps, wild bees, hoverflies, ground beetles, and rove beetles. Overall, before the first cut of the year, abundances of species with vegetation-dwelling larvae were higher in meadows with delayed mowing or an uncut grass refuge, with some taxon-specific variation. In contrast, species whose larval development is independent of the meadow vegetation showed no differences in abundance between mowing regimes. Species richness did not differ among regimes. For species with vegetation-dwelling larvae, a fourth-corner analysis showed an association between early phenology and the control regime. No associations were found for the other functional groups. Our results show that slight modifications of mowing regimes, easily implementable in agri-environmental policy schemes, can boost invertebrate abundance, potentially benefitting insectivorous vertebrates.

Build it and they will come: grasshoppers check-in to a grassland bee hotel

A five-floor bee hotel was constructed using wooden pallets in an area of urban grassland in Ipswich, United Kingdom. Within one month of construction, two grasshopper species were observed using the hotel, with nymphs in shaded, uncut grass at the base, while adults were observed on all five floors and the roof. On the fourth floor, a stridulating field grasshopper, Chorthippusbrunneus, was sighted on two separate occasions. Further research is required to determine whether bee hotels may be an effective ‘shade’ refuge for grasshoppers in open grassland, while also providing an effective platform for stridulation.

No detrimental effects of delayed mowing or uncut grass refuges on plant and bryophyte community structure and phytomass production in low-intensity hay meadows

To maintain European semi-natural grasslands, agri-environment schemes (AES) have been established in many countries but their biodiversity benefits have remained limited. We tested the effects of three new mowing regimes designed to benefit biodiversity in extensively managed meadows across the Swiss lowlands. Our experimental treatments mimicked easily implementable farming practices. We previously showed that invertebrates benefit from delayed mowing and leaving an uncut grass refuge. Here we focus on the effects on plant and bryophyte communities.We compared the standard AES practice (earliest mowing on June 15, no fertilizer input, but no restriction on number of cuts) to three alternative mowing regimes: (i) earliest mowing delayed by one month, (ii) maximum of two cuts per year with at least eight weeks in between, and (iii) leaving an uncut refuge on 10–20% of the meadow area in 12 study areas in the Swiss lowlands. We also tested for the interactive effects of ambient temperature, precipitation, elevation, meadow size, local forest cover, time since AES registration, and phytomass production.After five years of application, we found no difference in the effects of mowing regimes on vascular plant or bryophyte species richness, community composition, phytomass, flowering phenology or average plant height (the latter two indices were derived from the literature). However, cutting frequency and hay nutritional quality (C:N and Ca:P ratios) were lower under delayed mowing. Vascular plant and bryophyte species richness as well as forage quality were negatively related to phytomass, while the latter was positively related to mean summer temperature and negatively to time since AES registration.We conclude that supporting invertebrate biodiversity with alternative mowing regimes has no detrimental effects on the vascular plants and mosses, while the reduced forage quality calls for additional financial compensation of the farmers adopting these agri-environment schemes.

Do Corncrakes Crex crex benefit from unmown refuge strips?

SummaryCorncrakes Crex crex mainly breed in grassland, where they are threatened by mowing. Conservation requires delayed mowing or modified mowing methods. In large fields, it has been suggested that leaving strips of uncut grass may reduce mortality, especially of unfledged chicks. We attended mowing operations (2012–2015) in the Lower Oder Valley National Park in north-eastern Germany, where 10-m refuge strips were introduced. We documented the escape behaviour of adults and chicks and their use of refuge strips by observations and radio-telemetry. Flightless chicks crossed significantly shorter distances of mown area (< 20 m) than adults. When mowing from the outside inwards, chicks were not able to successfully escape to the field edge at > 31 m, adults at > 60 m distance to the edge and returned to the unmown block. Twenty-three percent of adults, 30% of families and 49% of independent chicks survived in 10 m-wide strips until such strips were either mown or left as refuges. Whereas adults departed the strips the next day, independent chicks stayed for up to 22 days after mowing in 15–30 m wide refuges. We recommend refuge strips for breeding sites where more effective measures cannot be applied. Farmers face less additional effort and lower financial losses compared with delayed mowing. A width of 10 m should be considered as the absolute minimum, because most birds left the cover already > 10 m for the first time and only wider refuges served as temporary habitat for young.

Simple modifications of mowing regime promote butterflies in extensively managed meadows: Evidence from field-scale experiments

Restoring biodiversity-rich grasslands within cultivated matrices represents a real conservation challenge. One set of options consists in adopting less disruptive mowing regimes, as mowing impacts on invertebrates can be considerable. We experimentally tested the effect on butterfly populations of a spatio-temporal modification of mowing regimes within extensively managed meadows. The control regime (C) followed the standard Swiss agri-environment schemes (AES) regulation: no cutting before 15 June and no fertilisation. The second regime consisted of delaying (D) the first possible cut by one month (to 15 July). The third regime consisted in maintaining a 10–20% uncut grass refuge (R) during mowing operations. This experiment was replicated at 12 study sites across the Swiss lowlands, and applied yearly since 2010. Butterflies were sampled in 2013. Butterflies generally benefitted from D- and R-regimes. Before the onset of mowing operations, both D- and R-regimes yielded higher butterfly densities (+70%) compared to the C-regime, demonstrating positive cumulative effects (i.e. carry-over effects from one year to the next), not only for the whole butterfly community, but also for resident, multivoltine, mono- and oligophagous species. After 15 June, densities were about six times higher in D- than in C- and R-meadows until D-meadows were cut mid-July. Species richness of specialist butterflies was significantly higher in R-meadows (+60%) compared to C-meadows. This study is the first that demonstrates positive and cumulative effects of delaying the first cut or leaving a refuge on butterfly populations. It would be easy to implement these measures within European and Swiss AES regulations.

Uncut grass refuges mitigate the impact of mechanical meadow harvesting on orthopterans

Semi-natural grasslands require regular harvesting (cutting) or grazing to avoid vegetation succession, and this is well known to promote plant diversity. However, recent studies have shown that meadow harvesting has a severe direct negative impact on orthopterans and other grassland invertebrates. In view of this, leaving areas of uncut grass as refuges has often been recommended as a mitigation measure. Yet to date no studies have tested this hypothesis. We experimentally investigated the direct influence of leaving a 10% uncut grass refuge in the centre of 50m diameter meadow plots on orthopteran population. During harvest, orthopteran densities dramatically declined within mown areas and doubled within refuges, showing that during the mowing stage some individuals actively moved to uncut areas, safe from the impact of post-mowing stages. After baling, final orthopteran population sizes were on average 53% higher in plots with an uncut refuge, compared to plots without. To maximise the benefit of refuges, we recommend mowing towards the refuge, as this is likely to drive field invertebrates into the refuge.

Filíocht Nua: New Poetry

Filíocht Nua: New Poetry Pat Boran The Island for Bob Quinn Remote, solitary, its back to its neighbours, facing the broad Atlantic and the dream of a bright New World, that unkempt heap of sand set down in our back yard by a builder in the early 1970s became, the afternoon he failed to show, our own small island: bays and mountains, the major rivers, greys instead of forty shades of green. Immune to damp and cold, down on our knees like the migrant workers of a generation before, we laboured beyond nightfall until a door in the darkness opened and saw us lifted clear of our obsession. But who could sleep that night leaving our small-but-perfect local wonder with no one to defend it, alone there under a cloud-marbled sky? Moonlight flooding the house, I crept back down to check, and found, to my astonishment, a fleet of snails, like so many Norse or Spanish or Phoenician sails, their glistening trails criss-crossing the hostile dark. [End Page 68] Stones Two mounds of stones erected by the roadside overlook the bay, so that as you pass on this light-swept peninsular road you’d be hard-pressed to say if they be years or millennia old, or entirely new made— the first like a symbol of birth, then, just up the way, a burial mound, and between them scarcely anything, a lay- by vantage point you glimpse, as you do most things, too late, travelling at light speed the distance between megalith and ghost estate. [End Page 69] Winter Burial i.m. Liam Brady Twin jet trails crossing the sky; here’s us frozen in the lake of time and up there God goes blithely skating by. Snowman No matter that we prayed to God himself (Father, Son and Holy Ghost), as well as half a dozen saints we knew by name and some odd talent or disfigurement— the ability to raise the dead, to put out fires with their breath, to balance all night up a pole— the thaw still came. The head was first to go, the belly lost a pound or two, an eye came loose, the carrot nose slipped an inch then disappeared entirely overnight: perhaps a rat or early bird had dragged it off. Before we knew it our snowman became snow-thing, stooped and hunched, a drunk in a dirty linen suit, a gate-crasher who’d lost his way, forced to spend the night outside alone. Who could love him any more? Even the crozier that had made him seem so wise last week—our own St Patrick— lay now like a question mark at his feet. [End Page 70] Nebula After winter drew up its raft of bone and wrack and shadow along the shoreline; after the moon’s pale eye peered deeper into the garden’s breeze-block soul; after the smoke-stacks filled with grief and the stray cats gathered on the one flat roof for miles to keen their loss—chairs face-down on the table, dishes stacked on newsprint shelves, brushes in hand as the dawn came up between us we raised a nebula of dust motes, stopping to admire it, as the gods are wont to do, before setting out for home. [End Page 71] Apple “If you want to make an apple pie from scratch, you must first create the universe.” —Carl Sagan Now, at last, with the volume down and the stage-curtain of the night drawn shut, it’s time to zoom in on this one still somehow strangely bright fallen apple, since morning sat here on my table, a glistening keepsake, temptation’s fruit, for all the world a numinous thing: the stalk’s delicate, perfect serif rising from the wormhole navel; the skin’s luminous photograph in three dimensions of the whole, scarcely plausible history of time, of the universe to this moment—impossible to understand but simply expressed, the infinite eclipsed by the tangible, by the close-at-hand. [End Page 72] The Garden Back in the back garden’s light-dappled arbour where the bees were like satellites orbiting planets of fruit, the uncut grass...

Foraging habitat selection by breeding Common Kestrels Falco tinnunculus on lowland farmland in England

Capsule Breeding Common Kestrels prefer to forage over recently cut grass than all other habitat types on farmland. Aims To identify foraging habitat and prey of Common Kestrels during the breeding season. Methods We observed seven pairs of Common Kestrels during the breeding season over three years, using fixed vantage point observations. We recorded foraging attempts, and habitat and prey data for where the birds chose to forage. Compositional Analysis was used to establish use of each habitat category relative to that habitat’s availability within the Kestrels’ observed foraging ranges. Results We found that Kestrels select habitats non-randomly, with cut grass (le;5cm, all cut less than two weeks previously) being the most used relative to availability. Prey taken varied with grass height: the ratio of mammals to invertebrates was greater on cut grass (4.36 mammals: 1 invertebrate) than on longer, uncut grass swards (1.73 mammals: 1 invertebrate). Conclusion Our results highlight the importance of areas of long and short grass in close juxtaposition, to provide conditions suitable for prey and access to them, respectively. The creation and maintenance of such small-scale habitat heterogeneity will be the key to maximizing the benefits of English agri-environment schemes for Common Kestrels.

Savanna tree-grass competition is modified by substrate type and herbivory

Question: Woody plant and grass interactions in savannas have frequently been studied from the perspective of the response of one growth form on the other but seldom evaluated as two-way interactions. What causes woody plant encroachment in semi-arid savannas and what are the competitive responses of tree seedlings and grasses on rocky and sandy substrates? Methods: In this greenhouse study, we investigated the influence of substrate and grazing on responses to interspecific competition by tree seedlings and grasses. We measured competitive/facilitative responses on biomass and nutrient status of tree seedlings and grasses grown together. Results: Interspecific competition suppressed growth of trees and grasses. Tree seedlings and uncut grass accumulated double the biomass when grown without competition relative to when they competed. Competitive responses varied on different substrates. Grass biomass on rocky substrate showed no response to tree competition, but appeared to be facilitated by trees on sandy substrate. Grass clipping resulted in higher tree seedling biomass on rocky substrate, but not on sandy substrate. There was a positive response of grass nutrient status to competition from tree seedlings. Conclusion: Selective grass herbivory in the absence of browsing or suppression of shade-intolerant grasses by trees are commonly cited reasons behind bush encroachment in savannas. We show that grazing may confer a competitive advantage to tree seedlings and promote bush encroachment more readily on rocky substrates. This may be due to the imposed sharing of the soil depth niche on rocky substrates, whereas possible niche separation on sandy substrates minimizes the advantage conferred by reduced competition.

Hay harvesting causes high orthopteran mortality

Knowledge on the direct impact of the meadow harvesting process on field invertebrates has long been limited to studies that investigated impacts due to mowing. This study demonstrates that raking coupled with baling impacts orthopteran populations to a similar degree as mowing followed by tedding. At the end of the harvesting process, orthopteran surviving rate was 32% (SD=14) when meadows were mown with rotary mowers without conditioner and lower, 18% (SD=8), when mown with rotary mowers with conditioner. Conversely, given the strong impact of tedding, raking and baling, no evident advantages were found for the use of tractor bar mowers over rotary mowers without conditioner. Reduction in orthopteran densities observed after harvesting was slightly higher than the estimated mortality caused by the machineries, presumably because orthopteran reduction includes a small emigration and natural mortality. If conservation is the primary objective of the meadow, no conditioner should be used, uncut grass refuges should be left when mowing, and the number of time the meadow is harvested per year should be the minimum required to maintain the habitat.

My Summer of ‘68

You can always get warm, but it's hard to stay cool. My mother's words, muttered every summer since I can remember, rang like a mantra in my head as I stood in the uncut grass of a football field (the 20-yard line, to be precise), knees locked and eyes forward, arms akimbo, to balance a 28-inch-long metal stick at a 45-degree angle, just so. Perspira tion trickled down my temples and collected under my jaw, but I held still. Since reaching my teens, I'd come to dread the wasteland of summer vacation: heat and more heat, the sodden press of humidity that forced my painfully coifed pageboy to retract its hooks, sun that turned my caramel complexion to burnt umber if I forgot to wear a hat. It was the 19th of August, 1968, four days until the Soap Box Derby Parade and nine days before my 16th birthday, and I still hadn't figured out how to keep my minimalist emergency 'do (French twist with bangs pinned to the side) from shrinking to that fine corona of frizz usually found in the National Geographic photographs of ostrich heads. Why, oh why was I standing here at attention like a tin soldier, ankle-deep in crabgrass in the middle of a sweltering Midwestern summer, sweating out all the good sense Mom had pressed into the curls on my head? Four months earlier, in April, a week or so after Martin Luther King Jr.'s murder, I was packing up my cello one afternoon after orchestra practice when Rhonda bounded up, flute propped on her shoulder like a baseball bat, and clapped me on the back. Rhonda was always doing things like that; copper-skinned and confident (even in glasses!) to the point of being uncomfortably gung-ho, she was what my grandmother would call, wrinkling her nose, sturdy. I started to straighten up, but she couldn't wait. Rita, she whispered, I've got a terrific idea. Let's try out for the majorette squad! Funny thing is, even though I gulped and felt my heart pound into my throat, I thought it was a great idea, too. In the Byzantine hierarchy of high school, majorettes and cheerleaders were the Cream. Cheerleaders enjoyed a noisy devotion from the masses, but majorettes were the serene wizards, the silvery circumferences of their batons humming before them like horizontal pirouettes. If I said yes, if I tried out and actually made the squad, maybe I could finally be?I closed my eyes to savor the possibility?popular. Just thinking the word sent a shiver of longing through me. What was it like? Ever since junior high, I'd been called brainier. I thought I was used to it, but sometimes, on pale green spring mornings or glimpsing the tentative expression on my face reflected in a store window, I'd wonder. Although I'd never been exactly reviled, had never borne the brunt of schoolyard taunts or classroom pranks, I'd also never been pursued by a boy,

Fine root decomposition under grass and pine seedlings in controlled environmental conditions

Soil carbon (C) stocks generally decrease following land use conversion from pasture to conifer (pine) plantation. In exploring whether factors relating to fine root decomposition might be involved in that effect, a 1-year pot experiment in a controlled temperature glasshouse was designed to test the role of three factors on fine root decomposition. The factors were: fine root type (roots of grass— Themeda triandra, and pine— Pinus radiata), soil source (top soil from a native grass pasture and top soil from an adjacent pine plantation), and species planted and its treatment (pine, uncut grass, defoliated grass, and soil-only control). The dry mass loss in 1 year, averaged across all factors, was 39% of the initial mass and the average decomposition rate constant ( k) was 0.51 year −1. Only the species planted had an effect on dry mass loss from decomposing roots, i.e. pine seedlings reduced the decomposition rate of fine roots. Carbon loss from decaying fine root was affected by the decomposing root type as well as the species planted in the soil. The C loss from pine root decomposition was slower than from grass root decomposition, and pine seedlings reduced the rate of C loss from decomposing root. All three factors affected N loss. Net N loss was found only from decaying grass roots, N being accumulated in decaying pine roots. Decaying pine fine root accumulated more N when in soil from the plantation (having lower N concentration) than when in soil from the native pasture (with higher N concentration). In conclusion, the findings have led us to a hypothesis for field testing that, in terms of carbon, pine roots decompose to soil humus slower than grass roots because of differences between ecosystems in both root litter quality and soil environment as determined by the plant species growing.

Impact of defoliation on the distribution of 15N-labelled synthetic sheep urine between shoots and roots of Agrostis capillarisand soil N pools

An experiment was carried out to test the hypothesis that defoliation of a semi-natural grassland species influenced the fate of the urea nitrogen (N) from sheep urine. The distribution of the 15N added as urea in a synthetic sheep urine (SSU) at 50 g N m−2, to Agrostis capillarisand fallow soil was followed over a period of 56 days in the plant and soil in a glasshouse microplot experiment. The grass was subject to three regimes; regular twice weekly defoliation, a single defoliation (both to 40 mm), and uncut. Regular cutting increased the total N concentration of shoots and reduced the biomass of roots, though 15N recovery in the shoots was not appreciably different from the uncut grass. A single defoliation immediately before SSU addition decreased 15N recovery. More 15N was recovered in the surface 50 mm of soil beneath the regularly cut than in the single and uncut treatments. The soil mineral N pool was the largest sink for SSU 15N. Microbial N increased threefold with the addition of SSU, but effects of the grass treatments on the proportion of SSU 15N in the microbial biomass could not be detected. It was concluded that regular defoliation of grass compared with no cutting could lead to greater losses of NO3− by leaching and denitrification.

Use of field margins by foraging yellowhammers Emberiza citrinella

Some agri-environment schemes promote the creation and management of a variety of non-crop habitats on farmland in the UK, yet there has been relatively little monitoring to assess how species, particularly birds, use these habitats. The present study deals with a declining UK farmland bird species, yellowhammer Emberiza citrinella, and considers to what extent grass margins of arable fields are used as a foraging habitat when feeding nestlings. Studies were carried out in lowland mixed farmland in southern England. Grass margins and other non-crop field boundary habitats, such as hedgerows and ditches, were selected relative to cropped areas by yellowhammers. No significant difference was found between use of cut and uncut grass margins. Studies have shown that grass margins support high densities of invertebrates and their provision at the edge of arable fields would benefit yellowhammers during the breeding season both as habitat for prey and as nesting habitat. During the breeding season from May to August, management should create cut and uncut grass margins in close proximity to each other. This could be achieved by cutting only the outer edge of the grass margin, maintaining cover next to the hedgerow. Cut areas would provide easier access to food resources for birds and prevent weed encroachment to the crop, whilst adjacent uncut areas would maintain invertebrate sources and provide nesting cover for yellowhammers.

Surface characteristics and energy fluxes above different plant canopies

The micrometeorological profile measurements carried out at an agricultural site within the NOPEX area were used for an estimation of aerodynamic characteristics of investigated fields, surface resistances and fluxes in fields with rye, spring barley, winter wheat and uncut grass. Changes in the roughness length and zero plane displacement with wind speed were analysed. Empirical relationships between the friction velocity and wind speed at the top of the canopy were obtained for all investigated fields, except the field with sparse spring barley. It was shown that the zero plane displacement for relatively dense rye canopy is affected by changes in the wind speed. Such relationship was not statistically significant for remaining three canopies. Using the sensible heat flux calculated by modified Monin–Obukhov method and measured values of the net radiation and heat flux into the soil, the latent heat flux was determined as the last term of the energy balance equation. The surface resistances were calculated from the rearranged Penman–Monteith equation. Their values averaged over the period between 11:00a.m. and 4:00 p.m. ranged between 49sm−1 for relatively dense rye canopy to 344sm−1 in the case of the field with sparse spring barley. The statistical relationship between the evapotranspiration and surface resistances was found and quantitatively expressed.

The Effects of Competition on Growth and Form in Glechoma hederacea

Morphological responses to competition were analysed in Glechoma hederacea, a clonal herb with plagiotropic shoots. Ramets of clones were grown either in isolation or in competition with cut or uncut Lolium perenne swards. G. hederacea produced the same above ground biomass, but different morphologies when grown with short and tall grass. Despite considerable reductions in biomass and stolon branching when grown with competition rather than in isolation, the capacity for lateral extension of primary stolons was maintained. All other measured variables were reduced by competition, except for stolon internode length and petiole length and mass. These variables reached their greatest values in the uncut grass treatments. These responses could promote avoidance of competition by escape in both the horizontal and vertical planes; growth through vegetated sites would be rapid, and sites where competitors are absent would be occupied more densely. Reductions in PAR and in the R/FR ratio incident on the plant are both implicated in inducing these morphological changes. Differences in relative humidity, caused by the proximity of neighbours, also appeared to exert a considerable influence upon growth and morphology of G. hederacea. Connected parts of G. hederacea clones grown with and without competition developed different morphologies; each primary stolon behaved as an integrated physiological unit, developing a morphology appropriate for the conditions in which it was growing.

Armyworm Control, 1987

Abstract A satisfactory infestation of true armyworm was reported near Cloquet, Minn., by the St. Louis County extension agent. 18- × 35-ft plots were located in an uncut orchard grass field containing approximately 10 larvae/sq ft. Soil moisture was extremely short at the time the treatments were made. Plots were replicated 3 times and arranged in a randomized complete block. Insecticide was applied in the late afternoon at 75°F. Approximately 15 gal total material was applied/acre using a hand-held CO2 sprayer at 40 psi pressure. Live and dead larvae in lVa sq ft/plot were counted 24 h after treatment. Counting sites were selected by dropping a yardstick and counting larvae in the 3 inches on either side of the stick. A damage rating was taken 1 wk posttreatment both for this study and for educational use.