Seasonal Photosynthesis and Partitioning of Nonstructural Carbohydrates in Leafy Spurge (Euphorbia esula)

Weed Science ◽  
2007 ◽  
Vol 55 (4) ◽  
pp. 346-351 ◽  
Author(s):  
Russ W. Gesch ◽  
Debra Palmquist ◽  
James V. Anderson
Keyword(s):  
Late Summer ◽  
Leafy Spurge ◽  
Adventitious Bud ◽  
Adventitious Buds ◽  
Continuous Increase ◽  
Carbohydrate Partitioning ◽  
Growing Seasons ◽  
Autumn Leaf ◽  
Carbohydrate Status ◽  
New Strategies

Previous evidence indicates that changes in well-defined phases of dormancy in underground adventitious buds of leafy spurge in late summer and autumn are regulated by complex sensing and signaling pathways involving aboveground sugar signals. However, little information exists concerning seasonal photosynthesis and carbohydrate partitioning of leafy spurge, although such information would help to elucidate the involvement of sugar in controlling bud dormancy. An outdoor study was conducted over two growing seasons to determine and model seasonal patterns of photosynthesis and aboveground carbohydrate partitioning and their relationship to underground adventitious bud carbohydrate status. Photosynthesis and total nonstructural carbohydrate (TNC) content of aboveground tissues was greatest during vegetative growth. Photosynthesis gradually declined over the growing season, whereas TNC decreased sharply during flowering, followed by a gradual decline between midsummer and autumn. Leaf starch increased dramatically to midsummer before declining sharply throughout late summer and early autumn, whereas sucrose content responded inversely, indicating a mobilization of starch reserves and export of sugars to overwintering belowground sink tissues. Because newly formed underground adventitious buds showed a continuous increase in TNC from midsummer through autumn, export of sugars from aboveground tissues likely contributed to the increase in TNC. These results may facilitate new strategies for biological control of leafy spurge.

scholarly journals Effects of Environmental Temperature onCapnodis tenebrionisAdult Phenology

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Carmelo Peter Bonsignore
Keyword(s):  
Late Summer ◽  
Early Summer ◽  
Adult Density ◽  
Degree Days ◽  
Continuous Increase ◽  
Climate Conditions ◽  
Average Annual Temperature ◽  
Activity Temperature ◽  
The Difference ◽  
New Generation

The phenology ofCapnodis tenebrionisadults was presented with reference to two different climate conditions. In a temperate moderate-warm climate, adult density showed two separate peaks during the year: one in early summer of the overwintering generation and one with beetles emerging in the late summer. In a warmer semiarid climate, the overwintering adults and the new generation overlapped during summer with a continuous increase of adult density. The difference in the average annual temperature between areas during the study period was almost3∘C, and, in the warmer area, the new generation ofC. tenebrionisemerged at least one month earlier. To make a prediction of adult presence, a model utilizing degree-days was developed from data collected over a five-year period. Models obtained from equations (Logistic 4-parameter,y(x)=yo+a/(1+(x/xo)b)) of each year were developed to describe the relationship between degree-day accumulation (with a minimal threshold activity temperature of14.21∘Ccalculated in the laboratory) and the cumulative percentage of adult presence. According to the overall model, the 50% of overwintering beetles occurred at 726 degree-days (Biofix: 1st March) and the emerging beetles occurred at 801 degree-days (Biofix: 1st July). The results show that a change in temperature is an important aspect that highlights the adaptability of this species.

Planting Date Affects Survival and Height Growth of Hybrid Poplar

1986 ◽  
Vol 62 (3) ◽  
pp. 164-169 ◽  
Author(s):  
Edward A. Hansen
Keyword(s):  
Hybrid Poplar ◽  
Late Summer ◽  
Growing Season ◽  
Climatic Conditions ◽  
Planting Date ◽  
Planting Dates ◽  
Soil Frost ◽  
Growing Seasons ◽  
Poplar Cuttings ◽  
Energy Plantations

In this study I investigated the effects of planting date for soaked versus unsoaked cuttings of two hybrid poplar clones under irrigated versus unirrigated and weedy versus weed-free conditions. Cuttings were planted each year for 4 years. Survival at the end of the first growing season was generally greater than 90% for all planting dates. At the end of the second growing season survival for trees planted before July 16 was again generally more than 90%. However, cuttings planted from July 30 through August 27 showed a major decline in survival and survival of fall planted cuttings ranged from 6 to 90%. Mortality of late summer- or fall-planted cuttings occurred prior to the beginning of the second growing season and was attributed to frost heaving. The tallest trees were not those planted at the earliest possible dates (April in Rhinelander). Instead, the tallest trees at the end of the first and second growing seasons were those planted in early- and mid-May. This optimum planting period was the same regardless of clone, soaking, irrigation, or weed treatment. Actual optimum planting date would change with location and local climatic conditions. Some climatic indices may prove more universal in predicting when to plant. Although tentative, it appears that for best growth, unrooted hybrid poplar cuttings should be planted in soil warmer than 10 °C. Trees do not grow as well if planted immediately after soil frost leaves the ground. Key words: Energy plantations, plantation establishment, woody biomass, intensive culture, Populus.

Water relations of Pinus radiata under plantation conditions

1964 ◽  
Vol 12 (2) ◽  
pp. 111 ◽  
Author(s):  
RD Johnston
Keyword(s):  
Soil Moisture ◽  
Late Summer ◽  
Soil Surface ◽  
Experimental Period ◽  
Mean Value ◽  
Soil Conditions ◽  
Dry Period ◽  
Autumn Leaf ◽  
Leaf Water Deficit ◽  
Old Trees

Two groups of four 9-year-old trees of P. radiata were isolated "droughted" by lining trenches, and covering the soil surface, with plastic film. Two similar groups served as controls. Soils in the control plots dried out to above pF 4.2 during a 6 weeks' drought in late summer, and again in a shorter dry period in autumn. Leaf water deficit (L.W.D.) was correlated with soil moisture tension (S.M.T.) while there was available soil moisture, and rose during the drought to a maximum of 22.8. Autumn rain which wet the upper part of the soil profile reduced the L.W.D. to a mean value of 12. In the droughted plots, S.M.T. rose to above pF 4.2 in the first six weeks and remained high for the rest of the experimental period. During normal weather with occasional light falls of rain, L.W.D. was maintained at about 17-significantly higher than the corresponding values for the control plots. With the onset of dry weather, L.W.D. in the droughted plots rose further, but not significantly higher than in the controls. L.W.D. decreased when rain occurred, although less than in the control plots. P. radiata is able to maintain moderate turgidity in its needles, even under very dry soil conditions, as long as there is frequent precipitation sufficient to wet the foliage.

Surface burning in a mature stand of Pinus resinosa and Pinus strobus in Michigan: effects on understory vegetation

2001 ◽  
Vol 10 (1) ◽  
pp. 91 ◽  
Author(s):  
David D. Neumann ◽  
Donald I. Dickmann
Keyword(s):  
Late Summer ◽  
Pinus Resinosa ◽  
Red Pine ◽  
Phytolacca Americana ◽  
Vegetative Cover ◽  
White Pine ◽  
Periodic Surface ◽  
Surface Fires ◽  
Growing Seasons ◽  
Surface Burning

Beginning in 1991, periodic surface fires (frontal fire intensities <200 kW m–1) were introduced into a mixed red pine (Pinus resinosa Ait.) and white pine (P. strobus L.) plantation (dbh 16–60 cm). Replicated plots of 0.4–0.5 ha were either burned three times at biennial intervals (early May of 1991, 1993, and 1995), burned once (early May 1991), or not burned. Measurements were conducted during the 1994 and 1995 growing seasons. The pine overstory was largely unaffected by the fires. The understory on unburned plots contained 16 111 large seedlings (>1 m, ≤ 1.9 cm dbh) and 3944 saplings (2.0–5.9 cm dbh) per ha, consisting of 23 woody angiosperm taxa. Plots burned once contained 60% of the large seedlings, 7% of the saplings, and 6 fewer taxa than unburned plots. No large seedlings and few saplings were found in plots burned biennially. Cover of low (<1 m) woody and herbaceous vegetation in plots burned once or three times was twice that of unburned plots, even in the growing season immediately following the May 1995 re-burn. Recovery of low vegetative cover in the re-burned plots was rapid, exceeding that in once-burned or unburned plots by late summer following the burn. Species richness of low vegetation was 20–25% higher in burned than unburned plots, except in the year immediately following reburning. Taxa dominating this site following burning were Sassafras albidum (Nutt.) Nees, Rubus spp., Phytolacca americana L., and Dryopteris spinulosa (O.F. MÜll.) Watt. Restoration of low-intensity surface fires to ecosystems dominated by mature red pine or white pine is feasible, but major changes in understory structure and composition will occur.

Seasonal changes in forage nutritive value of common weeds encountered in Missouri pastures

2019 ◽  
Vol 34 (2) ◽  
pp. 164-171
Author(s):  
Gatlin Bunton ◽  
Zach Trower ◽  
Craig Roberts ◽  
Kevin W. Bradley
Keyword(s):  
Tall Fescue ◽  
Crude Protein ◽  
Nutritive Value ◽  
Late Summer ◽  
Growing Season ◽  
Quality Parameter ◽  
Neutral Detergent Fiber ◽  
Weed Species ◽  
Growing Seasons

AbstractDuring the 2015, 2016, and 2017 growing seasons, weed and weed-free mixed tall fescue and legume forage samples were harvested from 29 pastures throughout Missouri for investigation of the nutritive value of 20 common pasture weed species throughout the season. At certain times during the growing season, many broadleaf weed species had greater nutritive values for a given quality parameter as compared with the available weed-free, mixed tall fescue and legume forage harvested from the same location. There were no significant differences in crude protein concentration between the weed-free forage and many weeds throughout the growing season. However, crude protein content of common burdock, common cocklebur, common ragweed, dandelion, horsenettle, and lanceleaf ragweed was greater than that of the corresponding forage sample at multiple collection periods. The digestible neutral detergent fiber (dNDF) content of all broadleaf weeds except lanceleaf ragweed was significantly lower than that of the weed-free forage at all collection periods. Conversely, large crabgrass had significantly greater digestible neutral detergent fiber levels than did the mixed tall fescue forage at all sampling dates. Dandelion and spiny amaranth had greater in vitro true digestibility (IVTD) content than did the forage for the entire growing season. Three perennial weeds—horsenettle, vervains, and late boneset—did not differ in IVTD levels as compared with the mixed tall fescue and legume forage at any collection date. For most summer annual weeds, the trend was toward greater digestibility earlier in the season, with a gradual decline and often lower IVTD by the late summer or early fall. The results of this study will enable producers to make more informed management decisions about the potential benefit or detriment a weed may provide to the overall nutritive value of the pasture system.

scholarly journals Influence of a Municipal Solid Waste Landfill on the Surrounding Environment: Landfill Vegetation as a Potential Risk of Allergenic Pollen

2019 ◽  
Vol 16 (24) ◽  
pp. 5064 ◽  
Author(s):  
Magdalena Daria Vaverková ◽  
Dana Adamcová ◽  
Jan Winkler ◽  
Eugeniusz Koda ◽  
Jana Červenková ◽  
...  
Keyword(s):  
Plant Species ◽  
Low Cost ◽  
Late Summer ◽  
Cost Effective ◽  
Early Spring ◽  
Early Summer ◽  
Allergenic Pollen ◽  
Grass Species ◽  
Vegetation Monitoring ◽  
Growing Seasons

When the landfill use comes to end, important subsequent steps include aftercare, safety assurance, and ecological regeneration. Landfill revegetation is cost-effective and eco-friendly approach in the management of landfill areas, which serves the purpose of stabilization and provides a pleasant landscape. There are various vegetation types that can be planted, yet grass species are often used for low-cost reasons. Plants can be important sources of air pollution, particularly by grass pollen. The main goal of our study was to identify plant species that produce allergenic pollen. Long-term vegetation monitoring took place on three sites in the growing seasons of years 2008–2018. Studied objects were landfills located in the Czech Republic. The vegetation was assessed using a floristic survey of identified plant species. Plant species that produced allergens were recorded. During the monitoring, 298 plant species were determined. Plant species with allergenic pollen have a considerable share in the landfill vegetation. Thus, landfills are potential sources of various kinds of allergenic pollen. Moreover, our results indicated that there are three periods of pollen production: early spring, late spring, and early summer; late summer; and autumn. The second period is typical for the production of highly allergenic pollen by grasses. Most detected plant species with allergenic pollen are common for all monitored sites, which demonstrates that the vegetation of landfills is a significant source of allergenic pollen.

Controlling vitrification in Larixdecidua via culture media manipulation

1989 ◽  
Vol 19 (10) ◽  
pp. 1334-1337 ◽  
Author(s):  
J. McLaughlin ◽  
D. F. Karnosky
Keyword(s):  
Mortality Rate ◽  
Total Nitrogen ◽  
Normal Development ◽  
Culture Media ◽  
Adventitious Bud ◽  
Adventitious Buds ◽  
Reversion Frequency ◽  
The Media ◽  
Media Manipulation ◽  
Bacto Agar

Vitrification rates obtained from our inverted embryo system were significantly decreased by lowering the cytokinin concentrations in Brown and Lawrence medium containing 10 mM L-glutamine from 10 to 1 mg/L, or by replacing 10 mM L-glutamine with equimolar concentrations of Ca(NO3)2 or by adding 1 g/L Gelrite to the normal 10 g/L Difco–Bacto agar in the culture media. In all treatments, decreased vitrification was accompanied with decreased adventitious bud production. With reduced N6-benzylaminopurine, vitrification decreased from 77 to 29%, but bud production decreased from 61 to 17 buds per explant and mortality increased from 3 to 33%. Incorporation of Ca(NO3)2 into the media decreased vitrification from 87 to 21%, but the number of adventitious buds per embryo decreased from 75 to 42. Vitreous shoots were reverted to normal development with an 81% reversion frequency and a 6% mortality rate by culturing these shoots on Gresshof and Doy medium with one-half total nitrogen. Elongation of previously vitreous shoots was best when these shoots were cultured on Gresshof and Doy medium + 0.5 mg/L N6-benzylaminopurine for 2 weeks, followed by subculture on Gresshof of and Doy medium + 10 g/L charcoal.

scholarly journals Biomass and Total Nonstructural Carbohydrate Partitioning in Relation to Nursery Digging Date, and Subsequent Growth, Development and Fruiting Pattern of Strawberry Runner Plants Propagated in California High-latitude Nurseries

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 996B-996
Author(s):  
Daniel S. Kirschbaum ◽  
Kirk D. Larson ◽  
Steven A. Weinbaum ◽  
Theodore M. DeJong
Keyword(s):  
High Latitude ◽  
Soluble Sugars ◽  
Late Summer ◽  
Dry Mass ◽  
Fruit Production ◽  
Growing Seasons ◽  
Nonstructural Carbohydrate ◽  
Growth Development ◽  
One Year ◽  
Chilling Units

The pattern of total nonstructural carbohydrate [starch and soluble sugars (TNC)] accumulation in strawberry (Fragaria ×ananassa Duch.) nursery runner plants, cv. Camarosa, was determined for three growing seasons. A similar study was conducted on `Selva', but for only one year. Growth, development and fruit production patterns of plants transplanted to growth chambers (GC) or fruiting fields were also evaluated. The experiments were carried out on plants propagated in high latitude (41°50' N) nurseries in California (Siskiyou County). Plants were sampled beginning late summer through early autumn and analyzed for dry mass (DM) and TNC. Plants from different digging dates were established in GC or fruit evaluation plots in Irvine, Calif. (33°39'N). Initial TNC concentration in storage tissues at the time of nursery digging increased steadily from the second week of September to the third week of October. Crown and root TNC concentration and content were correlated positively with the accumulation of chilling units (CU = hours ≤7.2 °C) in the nursery. Root TNC concentration consistently increased from 6% to 10% DM in `Camarosa' (a short-day cultivar), and from ∼4% to 14% DM in `Selva' (a day-neutral cultivar) from mid-September to the first week of October. The root TNC content increased ∼2.5 times in `Camarosa' and ∼3.7 times in `Selva' during the same period. Transplant growth, development, and fruiting pattern were affected by digging date. Root TNC concentration and content were more sensitive to CU accumulation than crown TNC concentration and content. Therefore, root sampling appeared to be more appropriate than crown sampling for assessing the carbohydrate status and optimal digging dates of strawberry nursery runner plants early in the fall.

scholarly journals Colonization Patterns, Phenology and Seasonal Abundance of the Nearctic Leafhopper Erasmoneura vulnerata (Fitch), a New Pest in European Vineyards

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 731
Author(s):  
Carlo Duso ◽  
Giulia Zanettin ◽  
Pamela Gherardo ◽  
Giulia Pasqualotto ◽  
Damiano Raniero ◽  
...  
Keyword(s):  
Late Summer ◽  
Seasonal Abundance ◽  
Growing Seasons ◽  
Rural Buildings ◽  
North Eastern ◽  
Colonization Patterns ◽  
A Minor ◽  
The Impact ◽  
First Time ◽  
Leaf Symptoms

The Nearctic leafhopper Erasmoneura vulnerata (Fitch), detected in Europe for the first time (north-eastern Italy) in 2004, has remained a minor pest of grapevine for more than 10 years. The first outbreaks of E. vulnerata were reported in 2016 in commercial vineyards located in north-eastern Italy. High population densities and severe leaf symptoms (i.e., leaf discoloration and fall) were observed in late summer despite the application of insecticides. Investigations were carried out from 2017 to 2019 in 10 vineyards located in Veneto region (Vicenza and Verona provinces) to shed light on the seasonal abundance of E. vulnerata on different Vitis vinifera cultivars. Pest phenology was studied in six vineyards where the impact of insecticides was minimal. Erasmoneura vulnerata completed three generations in each of the growing seasons. Vineyard colonization by overwintered adults showed a clear edge effect, suggesting the influence of overwintering sites (e.g., rural buildings and hedgerows) in vineyard margins. The impact of natural enemies on pest populations appeared to be limited and mostly related to egg parasitoids. Organic vineyards were more heavily infested by E. vulnerata compared to conventional vineyards, likely due to the minimal efficacy of natural insecticides typically used in the former farms.

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