Effects of Temperature on Damage to Velvetleaf (Abutilon theophrasti) by the Scentless Plant Bug Niesthrea louisianica

Weed Science ◽  
1987 ◽  
Vol 35 (3) ◽  
pp. 324-327 ◽  
Author(s):  
David T. Patterson ◽  
Robert D. Coffin ◽  
Neal R. Spencer
Keyword(s):  
Seed Production ◽  
Natural Populations ◽  
Growing Season ◽  
Abutilon Theophrasti ◽  
Controlled Environment ◽  
Temperature Regimes ◽  
Effects Of Temperature ◽  
Delayed Flowering ◽  
Two Temperature ◽  
Increase Population Density

In controlled-environment chambers, the scentless plant bug Niesthrea louisianica Sailer damaged reproductive structures of velvetleaf (Abutilon theophrasti Medik. # ABUTH) and reduced viable seed production by 98 to 99%, in comparison with insect-free control plants. The insect completed its life cycle on velvetleaf in two temperature regimes simulating warm growing-season conditions in Mississippi (29/23 C day/night) and Minnesota (24/18 C). Feeding by N. louisianica delayed flowering, capsule development, and capsule and seed maturation in biotypes of velvetleaf from Mississippi and Minnesota, in both temperature regimes. Numbers and weights of capsules and seed were lower in the infested plants. Augmentation of natural populations of N. louisianica to increase population density early in the growing season might be effective in reducing velvetleaf seed production.

Inter- and intra-varietal variation in aerobic methane emissions from environmentally stressed pea plants

Botany ◽  
2018 ◽  
Vol 96 (12) ◽  
pp. 837-850 ◽  
Author(s):  
Awatif M. Abdulmajeed ◽  
Mohammad I. Abo Gamar ◽  
Mirwais M. Qaderi
Keyword(s):  
Stress Factors ◽  
Interactive Effects ◽  
Controlled Environment ◽  
Uvb Radiation ◽  
Pisum Sativum L ◽  
Temperature Regimes ◽  
Varietal Variation ◽  
Growth Chambers ◽  
Effects Of Temperature ◽  
Two Temperature

Environmental stress factors can influence methane (CH4) emissions from plants. There are a few studies on the interactive effects of stress factors on plant aerobic CH4, but none on the comparative evaluation of CH4 emissions between and among plant varieties. We examined the effects of temperature, UVB radiation, and watering regime on CH4 emissions from 10 pea (Pisum sativum L.) varieties first and then selected two varieties with the highest (237J Sundance; var. 1) and lowest (422 Ho Lan Dow; var. 2) emissions for further studies. Plants were grown in controlled-environment growth chambers under two temperature regimes (22 °C / 18 °C and 28 °C / 24 °C, 16 h light / 8 h dark), two UVB levels (0 and 5 kJ·m−2·d−1), and two watering regimes (well-watered and water-stressed) for 14 days, after one week of growth under 22 °C / 18 °C. Higher temperatures and water stress increased CH4 emissions, and increased emission was associated with stress. Pea varieties varied in growth and CH4 emissions; var. 1 was more stressed and had higher emission than var. 2. In the stressed variety, the water-stressed plants grown under higher temperatures at UVB5 had the highest CH4 emission, whereas the well-watered plants grown under lower temperatures at UVB5 had the lowest emission. We conclude that climatic stress conditions increase CH4 emissions, which vary with plant varieties.

RESPONSE OF PEAS TO ENVIRONMENT: II. EFFECTS OF TEMPERATURE IN CONTROLLED-ENVIRONMENT CABINETS

1966 ◽  
Vol 46 (2) ◽  
pp. 195-203 ◽  
Author(s):  
B. Stanfield ◽  
D. P. Ormrod ◽  
H. F. Fletcher
Keyword(s):  
Plant Development ◽  
Dry Matter ◽  
Accumulation Rate ◽  
Stem Elongation ◽  
Controlled Environment ◽  
Dry Matter Accumulation ◽  
Average Temperature ◽  
Pisum Sativum L ◽  
Temperature Regimes ◽  
Effects Of Temperature

Effects of day/night temperature regimes from 7/4 to 32/24 °C on growth and development of Pisum sativum L. var. Dark Skin Perfection were studied in controlled-environment cabinets. Light intensity was about 1500 foot-candles and the photoperiod was 16 hours. Rate of plant development, in terms of nodes produced per day, increased steadily as the average temperature increased. Rate of stem elongation, however, was most rapid at 21/13 °C; and plant height was greatest at 16/10 °C. On a dry matter accumulation rate basis, vine growth decreased above and below a temperature optimum which shifted from 21/16 to 16/10 °C in the course of plant development. The combination of high day and high night temperatures caused an increase in the number of nodes to the first flower. Tillering was most prolific at the lower temperatures and was absent at 32 °C day temperatures. Pea yield decreased as temperature increased above 16/10 °C, due mainly to a reduction in the number of pods per plant.

A note on the effect of temperature on the performance of early-weaned pigs

1979 ◽  
Vol 29 (3) ◽  
pp. 423-426 ◽  
Author(s):  
K. J. McCracken ◽  
B. J. Caldwell ◽  
N. Walker
Keyword(s):  
Conversion Ratio ◽  
Feed Conversion Ratio ◽  
Effect Of Temperature ◽  
Controlled Environment ◽  
Feed Conversion ◽  
Winter Conditions ◽  
Satisfactory Performance ◽  
Temperature Regimes ◽  
The Mean ◽  
Two Temperature

ABSTRACTTwo temperature regimes were compared in relation to the growth and feed conversion ratio of groups of cage-reared pigs between 10 and 38 days of age. The treatments were: 27°C at 10 days reducing by 1°C every 4 days to 20°C at 38 days; and 27°C at 10 days reducing by 1°C daily to 20°C at 17 days and then remaining constant. Twelve replicates using 244 pigs were completed, the group size varying between 9 and 12 pigs. The mean growth rates on the two temperature regimes were respectively 234 and 243 g/day, and in both cases feed conversion ratio (kg DM/kg gain) averaged 1·03. It is concluded that temperatures lower than those currently recommended for pigs weaned at 14 to 16 days into controlled-environment houses would support satisfactory performance with direct savings in heating costs under winter conditions.

Variation of Seed Dormancy and Germination Ecology of Cowcockle (Vaccaria hispanica)

Weed Science ◽  
2014 ◽  
Vol 62 (3) ◽  
pp. 483-492 ◽  
Author(s):  
Hema S. N. Duddu ◽  
Steven J. Shirtliffe
Keyword(s):  
Seed Dormancy ◽  
Great Plains ◽  
Northern Great Plains ◽  
Light Conditions ◽  
Primary Dormancy ◽  
Local Environments ◽  
Temperature Regimes ◽  
Effects Of Temperature ◽  
Two Temperature ◽  
Seed Dormancy And Germination

Cowcockle, an introduced summer annual weed of the Northern Great Plains, is being considered for domestication because of its high quality starch, cyclopeptides, and saponins. Loss of seed dormancy is one of the key desirable traits for domestication. To determine the potential for domestication of this species, an understanding of the seed dormancy and germination patterns is required. The objectives of this study were to evaluate seed dormancy in cowcockle ecotypes and determine how temperature and light affect seed dormancy. We evaluated 15 populations of cowcockle for primary dormancy by exposing them to five temperatures (5, 7.5, 10, 15, and 20 C) under two temperature regimes (constant and alternating) in both dark and light conditions. Freshly matured seeds of all the populations showed high levels of primary dormancy except ‘Mongolia’. Lower levels of dormancy at medium temperatures (10 and 15 C) and greater dormancy at low and high temperatures suggest conditional dormancy, a state at which seeds germinate over a narrower range of conditions compared to nondormant seeds. The effects of temperature regime, light, and their interaction was significant only at suboptimal (5 and 7.5 C) and supraoptimal (20 C) temperatures. Under these conditions, alternating temperatures were more effective in breaking the conditional dormancy, followed by light. The variation in optimum temperature, light, and their interactions among the cowcockle populations may be due to the plants evolving to adapt to their local environments. From a domestication perspective, the conditional dormancy in cowcockle can be observed as an evolutionary mechanism that prevents untimely germination following maturity and may not be a major obstacle for its domestication.

Effect of Shade on Velvetleaf (Abutilon theophrasti) Growth, Seed Production, and Dormancy

1995 ◽  
Vol 9 (3) ◽  
pp. 452-455 ◽  
Author(s):  
Iliya A. Bello ◽  
Micheal D. K. Owen ◽  
Harlene M. Hatterman-Valentp
Keyword(s):  
Plant Height ◽  
Seed Production ◽  
Seed Weight ◽  
Dry Weight ◽  
Growing Season ◽  
Abutilon Theophrasti ◽  
Leaf Number ◽  
Number Of Leaves ◽  
Number Of Seeds ◽  
Number Of Branches

Growth, seed production, and dormancy of velvetleaf in response to shading were evaluated in the field. Velvetleaf plant height, leaf number, number of branches, and plant dry weight decreased linearly with increasing shade. No differences were observed for plant height, number of leaves, or branches/plant when plants were shaded 30% or not shaded throughout the growing season. However, the 76% shade treatment reduced velvetleaf height (1984 only), leaf number, stem branches, and plant dry weight. These reductions were greater in 1984 than 1985 except for plant dry weight that decreased by 88% each year. The number of capsules and the number of seeds/plant decreased linearly with increasing shade levels, while the seed weight increased with increasing shade level. Shading also decreased seed dormancy. These results demonstrate that shade suppresses velvetleaf growth and seed production, and shortens the dormancy of seeds that are produced by these plants.

Velvetleaf (Abutilon theophrasti) Population Dynamics Following a Single Year's Seed Rain

1996 ◽  
Vol 10 (3) ◽  
pp. 581-586 ◽  
Author(s):  
Robert G. Hartzler
Keyword(s):  
Population Dynamics ◽  
Seed Production ◽  
Verticillium Wilt ◽  
Management Strategies ◽  
Growing Season ◽  
Seed Rain ◽  
Abutilon Theophrasti ◽  
Control Treatment ◽  
Average Increase

At a northern Iowa location, populations of 145, 203, 62, and 37 velvetleaf plants/m2emerged in the four years following seed production by 0.4 velvetleaf plants/m2growing in soybean. Annual velvetleaf densities in areas with no seed input averaged less than 6 plants/m2. At a central Iowa location, verticillium wilt reduced velvetleaf seed production, resulting in an average increase of 9 plants/m2in the two years following seed production compared to the control treatment. This type of information is necessary to develop economic optimum thresholds, but the variability between locations demonstrates the difficulty in predicting crop and weed responses to management strategies implemented early in the growing season.

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

scholarly journals Effects of temperature on the behaviour and metabolism of an intertidal foraminifera and consequences for benthic ecosystem functioning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Noémie Deldicq ◽  
Dewi Langlet ◽  
Camille Delaeter ◽  
Grégory Beaugrand ◽  
Laurent Seuront ◽  
...  
Keyword(s):  
High Temperature ◽  
Ecosystem Functioning ◽  
Photosynthetic Activity ◽  
Species Traits ◽  
Biogeochemical Cycles ◽  
Variable Environment ◽  
Sediment Reworking ◽  
Temperature Regimes ◽  
Slow Moving ◽  
Effects Of Temperature

AbstractHeatwaves have increased in intensity, duration and frequency over the last decades due to climate change. Intertidal species, living in a highly variable environment, are likely to be exposed to such heatwaves since they can be emerged for more than 6 h during a tidal cycle. Little is known, however, on how temperature affects species traits (e.g. locomotion and behaviour) of slow-moving organisms such as benthic foraminifera (single-celled protists), which abound in marine sediments. Here, we examine how temperature influences motion-behaviour and metabolic traits of the dominant temperate foraminifera Haynesina germanica by exposing individuals to usual (6, 12, 18, 24, 30 °C) and extreme (high; i.e. 32, 34, 36 °C) temperature regimes. Our results show that individuals reduced their activity by up to 80% under high temperature regimes whereas they remained active under the temperatures they usually experience in the field. When exposed to a hyper-thermic stress (i.e. 36 °C), all individuals remained burrowed and the photosynthetic activity of their sequestered chloroplasts significantly decreased. Recovery experiments subsequently revealed that individuals initially exposed to a high thermal regime partially recovered when the hyper-thermic stress ceased. H. germanica contribution to surface sediment reworking substantially diminished from 10 mm3 indiv−1 day−1 (usual temperature) to 0 mm3 indiv−1 day−1 when individuals were exposed to high temperature regimes (i.e. above 32 °C). Given their role in sediment reworking and organic matter remineralisation, our results suggest that heatwaves may have profound long-lasting effects on the functioning of intertidal muddy ecosystems and some key biogeochemical cycles.

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