EFFECTS OF BRACHYPTEROLUS PULICARIUS (L.) (COLEOPTERA: NITIDULIDAE) ON FLOWERING AND SEED PRODUCTION OF COMMON TOADFLAX

1992 ◽  
Vol 124 (4) ◽  
pp. 631-636 ◽  
Author(s):  
A.S. McClay
Keyword(s):  
Seed Production ◽  
Seed Weight ◽  
Shoot Biomass ◽  
Percentage Germination ◽  
Linaria Vulgaris ◽  
Potted Plants ◽  
Delayed Onset ◽  
Adult Feeding ◽  
Viable Seeds ◽  
Total Seed

AbstractImpact of the flower- and shoot-tip-feeding beetle, Brachypterolus pulicarius (L.), on growth, flowering, and seed production of common toadflax, Linaria vulgaris (L.) Mill., was investigated using potted plants. Brachypterolus pulicarius had no effect on root or shoot biomass of attacked plants. Adult feeding by B. pulicarius delayed onset of flowering by 27 days relative to controls. Flowering of attacked plants was suppressed from mid-June until mid-July, but by mid-August flowering was similar to that of control plants. Total seed weight, individual seed weight, and percentage germination were all reduced significantly on attacked plants, resulting in a 74% reduction in number of viable seeds produced. Brachypterolus pulicarius is univoltine in Alberta, overwintering mainly as pupae.

scholarly journals Heliotropism and water availability effects on flowering dynamics and seed production in Macroptilium lathyroides

2006 ◽  
Vol 28 (2) ◽  
pp. 45-52 ◽  
Author(s):  
Armando Martins dos Santos ◽  
Luis Mauro Gonçalves Rosa ◽  
Lucia Brandão Franke ◽  
Carlos Nabinger
Keyword(s):  
Seed Production ◽  
Water Availability ◽  
Yield Components ◽  
Seed Weight ◽  
Field Capacity ◽  
Leaf Movements ◽  
Independent Effects ◽  
Total Seed ◽  
Macroptilium Lathyroides ◽  
Response To Water

The experiment was carried out in pots in a glasshouse, with one plant per pot and nine repetitions per treatment. The treatments consisted of free or restricted leaves, submited to 90-100% or 60-70% soil field capacity (FC). Only independent effects of water availability or leaf movement were observed on yield components. Plants under well-watered conditions and with freely orienting leaves were taller, and had a larger number of ramifications. The greater development favored the setting of a higher number of inflorescences per plant in these treatments. This behavior resulted in a high number of flowers, green and mature legumes per plant, thus resulting in high seed production which was the most evident response to water availability. Although individual seed weight was higher in the water stress treatment, total seed production was higher for well-watered plants, with no statistically significant effect of leaf movements.

Seed production in woodland and isolated trees of Eucalyptus melliodora (yellow box, Myrtaceae) in the South Western Slopes of New South Wales

2000 ◽  
Vol 48 (6) ◽  
pp. 681 ◽  
Author(s):  
G. E. Burrows
Keyword(s):  
Seed Production ◽  
Seed Weight ◽  
Physical Parameters ◽  
Mixed Mating ◽  
Isolated Trees ◽  
South Wales ◽  
Large Numbers ◽  
The Mean ◽  
Viable Seeds ◽  
Number Of Seeds

Seed production in woodland and isolated Eucalyptus melliodora Cunn. ex Schauer trees was investigated. Measurement of physical parameters such as mean capsule weight, mean seed weight and mean ratio of the weight of the capsule contents to the weight of the empty capsule showed no significant differences between woodland and isolated trees. In contrast, reproductive output as measured by mean number of seeds per capsule, mean number of seeds per 10 g of capsule contents and mean seed weight as a percentage of the weight of the capsule contents, was significantly lower (45–48% less) in isolated trees than in woodland trees. Mean percentage seed germination was also significantly lower (14% less) in the isolated trees and the mean number of viable seeds per 10 g of capsule contents was only 38% of the woodland trees. These results indicate that E. melliodora, like many eucalypts, has a mixed mating breeding system with preferential outcrossing but is also capable of self pollination leading to a reduction in seed yield and viability. The woodland and isolated trees produced a mean of 4.6 and 2.1 seeds per capsule, respectively. It would be relatively easy to collect large numbers of seeds from isolated trees of E. melliodora and subsequently propagate potentially genetically inferior plants.

Common Milkweed Seed Maturation

Weed Science ◽  
1973 ◽  
Vol 21 (6) ◽  
pp. 568-569 ◽  
Author(s):  
L. L. Evetts ◽  
O. C. Burnside
Keyword(s):  
Seed Production ◽  
Seed Weight ◽  
Close Association ◽  
Seed Maturation ◽  
Time Interval ◽  
Viable Seed ◽  
Asclepias Syriaca ◽  
Hypocotyl Length ◽  
Viable Seeds ◽  
Germinated Seeds

A 2-year experiment was conducted to determine the time interval between flowering and viable seed production in common milkweed (Asclepias syriacaL.). A high percentage of seeds harvested 6 weeks after flowering germinated. Seeds harvested 6 and 7 weeks after flowering resulted in seedlings with significantly shorter radicles and hypocotyls than seeds harvested 8 weeks after flowering. There was a close association between seed weight and radicle and hypocotyl length. Common milkweed produced viable seeds 5 to 6 weeks after flowering.

Effect of seeding rate on seed production of perennial ryegrass after establishment with a grain companion crop in the Peace River region of north-western Canada

2001 ◽  
Vol 81 (2) ◽  
pp. 265-271 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Perennial Ryegrass ◽  
Seed Weight ◽  
Seeding Rate ◽  
Grass Seed ◽  
Peace River ◽  
River Region ◽  
Companion Crop ◽  
Viable Seeds

A field study in the Peace River region of north-western Canada evaluated the effect of seeding rate on the seed yield and quality of perennial ryegrass (Lolium perenne L.) in the year after establishment with a grain companion crop. Each of two sites was sown with 70 kg ha–1 barley (Hordeum vulgare L.) and under-sown, in 30-cm rows, with three cultivars (All*Star, Barclay and Repell) of diploid perennial ryegrass at seeding rates of 150, 300, 600, 1200, 2400 and 4800 viable seeds m–2. During the establishment year of the perennial ryegrass, the grain yield of the barley companion crop was comparable to commercial yields for the region. Time of seed maturity, seed yield and thousand-seed weight of perennial ryegrass were not significantly (P ≤ 0.05) affected by the seeding rate, but were by cultivar. There was a significant (P ≤ 0.01) seeding rate × cultivar interaction for fertile tiller density and specific seed weight. Seed dockage differed significantly (P ≤ 0.001) among cultivars (16.7–27.9%) and increased with seeding rate (19.8–24.2%), and the germination capacity of the harvested seed was unaffected by seeding rate or cultivar. Grass seed yield was positively associated with fertile tiller density for each cultivar (r = 0.454***, n = 72 for All*Star; r = 0.364***, n = 72 for Repell; and r = 0.719***, n = 72 for Barclay). Compared with the other cultivars, Barclay matured 13 –15d later, had the lowest density of fertile tillers (1330 m–2), the highest seed dockage (27.9%) and the lowest seed yield (345 kg ha–1). All*Star had the highest seed yield (774 kg ha–1), the lowest seed dockage (16.7%), and the highest thousand-seed weight (1.55g). Repell was intermediate in seed yield (633 kg ha–1) but similar to All*Star, rather than Barclay, in other characteristics. The later maturity, creeping habit and prostrate stature of Barclay may have reduced its ability to produce fertile tillers and seed as efficiently as the other two cultivars at this northern latitude. In the Peace River region, there is potential for under-seeding a spring grain crop with perennial ryegrass for the production of successive harvests of grain and grass seed, provided the cultivar of perennial ryegrass is adequately adapted for seed production. The seeding rate for the perennial ryegrass is not particularly critical and 150–300 viable seeds m–2 should be adequate for diploid perennial ryegrass grown in rows with a grain companion crop. Key words: Perennial ryegrass, Lolium perenne L., grass seed production, grass seed quality, seeding rate, grain companion crop

Timing and Measurement of Weed Seed Shed in Corn (Zea mays)

1996 ◽  
Vol 10 (3) ◽  
pp. 535-543 ◽  
Author(s):  
Frank Forcella ◽  
Dean H. Peterson ◽  
James C. Barbour
Keyword(s):  
Seed Production ◽  
Dry Weight ◽  
Weed Seed ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Seed Processing ◽  
Wild Mustard ◽  
Green Foxtail ◽  
Viable Seeds ◽  
Total Seed

In west central Minnesota the extent and duration of weed seed shed was measured for two years in corn that received cultivation but no herbicides. Percentage of seed production represented by viable (filled) seeds was about 79% for green foxtail, 68% for wild mustard, 49% for Pennsylvania smartweed, 48% for common lambsquarters, and 35% for redroot pigweed. Percentage viable seeds varied from 11% in 1993 to 59% in 1994 for redroot pigweed, but was more stable for other species. Seed shed commenced in late August in a cool year (1993) and early August in a warm year (1994). Average growing degree days (base 10 C) from corn planting until 25% seed shed was 983 for common lambsquarters, 984 for wild mustard, 1004 for Pennsylvania smartweed, and 1034 for both green foxtail and redroot pigweed. Brief weather events, such as wind storms, dispersed large percentages of total seed production within a single day. More than one-fifth of all viable seeds of green foxtail, redroot pigweed, and common lambsquarters were retained by the seedheads and dispersed by combines at harvest. In contrast, seeds of early-maturing species, such as wild mustard, were completely dispersed before corn harvest in the warmer year, but one-third of seeds were retained by seedheads at harvest in the cooler year. Measurement of seed shed was compared using five seed trap designs. The preferred design consisted of a 10-cm-diam plastic cup, whose bottom was replaced by a brass screen, and the entire unit attached to a small wooden stake for support. This design provided, on average, the highest estimates of seed production, least among-replication variability, highest correlation with weed population density and aboveground dry-weight, lowest assembly cost, and greatest ease for sample access and seed processing.

Nutrient availability, dimorphic seed production, and reproductive allocation in the annual grass Amphicarpum purshii

1989 ◽  
Vol 67 (8) ◽  
pp. 2514-2521 ◽  
Author(s):  
G. P. Cheplick
Keyword(s):  
Seed Production ◽  
Biomass Allocation ◽  
Seed Weight ◽  
Growth Period ◽  
Nutrient Addition ◽  
Shoot Biomass ◽  
Growing Period ◽  
Dimorphic Seed ◽  
Disturbed Habitats ◽  
Reproductive Characters

The effect of nutrient addition on dimorphic seed reproduction and biomass allocation was investigated in amphicarpic peanut grass (Amphicarpum purshii Kunth). This annual, which grows in disturbed habitats on the Coastal Plain of eastern North America, produces self-fertilizing cleistogamous spikelets under ground and potentially outcrossing chasmogamous spikelets above ground. For each of three sibling families raised in the greenhouse from aerial seeds, 11 plants were fertilized twice during the growth period while 11 plants received no fertilizer. Total spikelet output and seed weight increased in response to fertilizer addition for both aerial and subterranean reproductive components, but changes were greater for aerial reproduction. Biomass allocation to subterranean spikelets and seeds was unaffected by nutrient addition. As measured by coefficients of variation, phenotypic variation for six aerial reproductive characters was about twice as great as that for six subterranean reproductive characters. Subterranean and aerial seed output were significantly related to shoot biomass for fertilized plants, but only mean aerial seed weight showed a significant relation to biomass when nutrients were not provided. These results support the hypothesis that early subterranean seed production provides reproductive insurance in peanut grass, whereas later aerial reproduction on newly formed tillers allows plants to increase reproductive output at the end of the growing period according to the availability of resources.

Impact of post-anthesis glyphosate on woolly cupgrass seed production, seed weight and seed viability

2015 ◽  
Vol 95 (6) ◽  
pp. 1193-1197 ◽  
Author(s):  
Robert E. Nurse ◽  
Stephen J. Darbyshire ◽  
Marie-Josée Simard
Keyword(s):  
Seed Production ◽  
Seed Weight ◽  
Soil Seed Bank ◽  
Seed Viability ◽  
Leaf Sheath ◽  
Embryo Viability ◽  
Weed Growth ◽  
Woolly Cupgrass ◽  
Eriochloa Villosa ◽  
Viable Seeds

Nurse, R. E., Darbyshire, S. J. and Simard, M.-J. 2015. Impact of post-anthesis glyphosate on woolly cupgrass seed production, seed weight and seed viability. Can. J. Plant Sci. 95: 1193–1197. Herbicides are generally applied at early stages of crop and weed growth to protect crop yield. Few studies have evaluated the effect of late (post-anthesis) applications of glyphosate as a management option to limit the seed production of weed escapes, such as woolly cupgrass (Eriochloa villosa). We propagated woolly cupgrass under greenhouse conditions and then applied three glyphosate treatments post-anthesis including: (1) an untreated control; (2) 900 g a.e. ha−1; and (3) 1800 g a.e. ha−1. Terminal inflorescences were collected 21 d after glyphosate application, and seed production, seed weight and embryo viability were assessed. Post-anthesis glyphosate applications did not influence seed production, but reduced seed weight and viability by 50 and 96%, respectively. Therefore, glyphosate applied just before the woolly cupgrass inflorescence begins to emerge from the leaf sheath (as late as the R1 stage in soybeans) is an effective strategy to manage woolly cupgrass reproduction and stop viable seeds from entering the soil seed bank or other dispersal pathways.

VARIATION AMONG BRITISH COLUMBIA AND NORTHERN ALBERTA POPULATIONS OF RASPBERRIES, RUBUS IDAEUS SUBSPP. STRIGOSUS MICHX.

1972 ◽  
Vol 52 (6) ◽  
pp. 1067-1072 ◽  
Author(s):  
M. C. J. VAN ADRICHEM
Keyword(s):  
British Columbia ◽  
Seed Weight ◽  
Fruit Weight ◽  
Winter Hardiness ◽  
Rubus Idaeus ◽  
Specific Character ◽  
Positive Correlation ◽  
Total Seed ◽  
Northern Alberta ◽  
Number Of Seeds

Several population samples of Rubus idaeus subspp. strigosus Michx. (raspberries) were collected in British Columbia and northern Alberta and a number of characters were studied and compared with the cultivar Trent. Significant differences between populations were found for cane length, number of buds per cane, percentage of buds growing, number of inflorescences and flowers per bud, fruit and seed weight. There was a positive correlation between the total seed weight and the number of seeds, and between the total seed and fruit weight. No distinct types could be established based on location or elevation. None of the populations showed significantly better winter hardiness than the cultivar Trent, and although some had a specific character that was superior, none was found to have overall superiority.

Effect of burr burial on seed production of Trifolium subterraneaum subsp. brachycalycinum and other annual legumes

1986 ◽  
Vol 26 (1) ◽  
pp. 59 ◽  
Author(s):  
MDA Bolland ◽  
WJ Collins
Keyword(s):  
Seed Production ◽  
Sandy Soil ◽  
Seed Weight ◽  
Trifolium Subterraneum ◽  
Annual Legumes ◽  
Seed Yields

On sandy soil near Esperance, W.A., prevention of burr burial compared with covering developing burrs with sand drastically reduced the seed production of three subspp. of Trifolium subterraneum (brachycalycinum, subterraneum and yanninicum) and of T. israeliticum by reducing burr production and seed weight. However, T. globosum produced similar amounts of seed from unburied and buried burrs. On sandy soil at Shenton Park, Perth, W.A., prevention of burr burial also reduced seed production of T. subterraneum subspp. brachycalycinum and subterraneum, this being due to fewer burrs, fewer seeds per burr and lighter seed. For subsp. brachycalycinum, seed yields were two to five times greater from burrs which developed within loose gravel than from those developed over sand (in which fewer burrs were able to bury) as a result of increased production of burrs, more seeds per burr and heavier seed. However, for subsp. subterraneum seed yields were similar from burrs whether developed over gravel or sand.

scholarly journals Nitrogen Fertilizer Management Practices to Enhance Seed Production by `Anaheim Chili' Peppers

1990 ◽  
Vol 115 (2) ◽  
pp. 245-251 ◽  
Author(s):  
J.O. Payero ◽  
M.S. Bhangoo ◽  
J.J. Steiner
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Management Practices ◽  
Irrigation System ◽  
Seed Mass ◽  
Fruit Production ◽  
Trickle Irrigation ◽  
Total N ◽  
Leaf Petiole ◽  
Total Seed

The effects of six applied N treatments differing by rates and frequencies of application on the yield and quality of pepper (Capsicum annuum var. annuum L. `Anaheim Chili') grown for seed was studied. The timing of N applications was based on crop phenology, leaf petiole nitrate-nitrogen concentrations (NO3-N) minimum thresholds, and scheduled calendar applications of fixed amounts of N. Solubilized NH4NO3 was applied through a trickle-irrigation system to ensure uniform and timely applications of N. Rate of mature (green and red) fruit production was unaffected by any treatment except weekly applications of 28 kg·ha-1 of N, which stopped production of mature fruit before all other treatments. Early season floral bud and flower production increased with increasing amounts of N. The two highest total N treatments produced more floral buds and flowers late in the season than the other treatments. Total fruit production was maximized at 240 kg N/ha. Differences in total fruit production due to frequency of N application resulted at the highest total N level. Red fruit production tended to be maximized with total seasonal applied N levels of 240 kg·ha-1 and below, although weekly applications of N reduced production. Total seed yield was a function of red fruit production. Pure-1ive seed (PLS) production was a function of total seed production. Nitrogen use efficiency (NUE) for red fruit production also decreased with N rates >240 kg·ha-1, but PLS yield and NUE decreased in a near-linear fashion as the amount of total seasonal applied N increased, regardless of application frequency. Season average NO3-N (AVE NO3-N) values >4500 mg·kg-1 had total seed and PLS yields less than those treatments <4000 mg·kg-1. Six-day germination percentage was reduced with weekly N applications of 14 kg·ha-1. Seed mass was reduced with weekly N applications of 28 kg·ha-1. Final germination percent, seedling root length and weight, and field emergence were unaffected by any of the N treatments. These findings indicate that different N management strategies are needed to maximize seed yield compared to fruit yield and, therefore, there may be an advantage to growing `Anaheim Chili' pepper specifically for seed.

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