scholarly journals Productivity and Profitability of Poplars on Fertile and Marginal Sandy Soils under Different Density and Fertilization Treatments

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 869
Author(s):  
Solomon B. Ghezehei ◽  
Alexander L. Ewald ◽  
Dennis W. Hazel ◽  
Ronald S. Zalesny ◽  
Elizabeth Guthrie Nichols
Keyword(s):  
Leaf Rust ◽  
Weed Control ◽  
Populus Deltoides ◽  
Cost Effective ◽  
Area Index ◽  
Foliar Nitrogen ◽  
Fertile Soil ◽  
Marginal Soils ◽  
Chrysomela Scripta ◽  
Beetle Damage

We evaluated the productivity and profitability of four highly productive poplars including Populus deltoides × P. deltoides (DD ‘140’ and ‘356’), P. deltoides × P. maximowiczii (DM ‘230’), and P. trichocarpa × P. deltoides (TD ‘185’) under two densities (2500 and 5000 trees ha−1), and three fertilization treatments (0, 113, 225 kg nitrogen ha−1) at three sandy coastal sites varying in soil quality. Green stem biomass (GSB) was estimated from the sixth-year stem diameter. Leaf-rust (Melampsora castagne) and beetle damage (by Chrysomela scripta Fabricius), the leaf area index (LAI) and foliar nitrogen, were measured in year two. At all sites, DD and DM had higher survival (>93%) than TD (62–83%). DD produced greater GSB (92.5–219.1 Mg ha−1) than DM (54–60.2 Mg ha−1) and TD (16.5–48.9 Mg ha−1), and this was greater under the higher density (85.9–148.6 Mg ha−1 vs. 55.9–124.9 Mg ha−1). Fertilization significantly increased GSB on fertile soil but not marginal soils; a higher rate did not significantly enhance GSB. Leaf rust was higher for fertile soil (82%) than marginal soils (20–22%), and TD ‘185’ (51% vs. others 34%). C. scripta damage was higher for the higher density (+42%) than lower density, and TD ‘185’ (50% vs. others >38%). LAI was higher on fertile soil (1.85 m2 m−2) than marginal soils (1.35–1.64 m2 m−2), and under the lower density (1.67 m2 m−2 vs. 1.56 m2 m−2). The high GSB producer DD ‘356’ had the lowest LAI (1.39 m2 m−2 vs. 1.80 m2 m−2). Foliar nitrogen varied among genomic groups (DD ‘140’ 1.95%; TD ‘185’ 1.80%). Our plots were unprofitable at a 27 USD Mg−1 delivered price; the biggest profitability barriers were the high costs of higher density establishment and weed control. The best-case treatment combinations of DD (‘140’, ‘356’) would be cost-effective if the price increased by 50% (USD 37.54 Mg−1) or rotations were 12 years (fertile-soil) and longer (marginal soils). The requirement for cost-effectiveness of poplars includes stringent and site-specific weed control which are more important than fertilizer applications.

The effect of ozone on cottonwood – leaf rust interactions: independence of abiotic stress, genotype, and leaf ontogeny

1987 ◽  
Vol 65 (5) ◽  
pp. 949-953 ◽  
Author(s):  
James S. Coleman ◽  
Clive G. Jones ◽  
William H. Smith
Keyword(s):  
Leaf Rust ◽  
Populus Deltoides ◽  
Leaf Age ◽  
Leaf Length ◽  
Ozone Treatment ◽  
Shoot Biomass ◽  
Leaf Ontogeny ◽  
Leaf Production ◽  
Leaf Injury ◽  
Eastern Cottonwood

The interaction of an acute ozone dose, plant genotype, and leaf ontogeny on the development of cottonwood leaf rust on eastern cottonwood (Populus deltoides Bartr.) was investigated. A rust-resistant (ST 66) and a rust-susceptible (ST 109) clone were exposed to charcoal-filtered air or were fumigated with 393 μg m−3 (0.20 ppm) ozone for 5 h. Forty hours after fumigation, leaf material of different developmental ages was inoculated with urediospores of Melampsora medusae Thum., and uredia production was measured after 10 days. Ozone fumigation of cottonwoods significantly reduced uredia production by M. medusae on both clones and all leaf ages without causing visible leaf injury or measurable changes in cottonwood height growth, leaf production, leaf length, or root/shoot biomass. Uredia production was strongly affected by ozone treatment, cottonwood genotype, and leaf age, but interactions among these three factors did not occur.

Bt-Cry3Aa transgene expression reduces insect damage and improves growth in field-grown hybrid poplar

2014 ◽  
Vol 44 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Amy L. Klocko ◽  
Richard Meilan ◽  
Rosalind R. James ◽  
Venkatesh Viswanath ◽  
Cathleen Ma ◽  
...  
Keyword(s):  
Large Scale ◽  
Populus Deltoides ◽  
Integrated Management ◽  
Populus Trichocarpa ◽  
Hybrid Poplar ◽  
Volume Growth ◽  
Field Trials ◽  
Leaf Beetle ◽  
Insect Damage ◽  
Beetle Damage

The stability and value of transgenic pest resistance for promoting tree growth are poorly understood. These data are essential for determining if such trees could be beneficial to commercial growers in the face of substantial regulatory and marketing costs. We investigated growth and insect resistance in hybrid poplar expressing the cry3Aa transgene in two field trials. An initial screening of 502 trees comprising 51 transgenic gene insertion events in four clonal backgrounds (Populus trichocarpa × Populus deltoides, clones 24-305, 50-197, and 198-434; and P. deltoides × Populus nigra, clone OP-367) resulted in transgenic trees with greatly reduced insect damage. A large-scale study of 402 trees from nine insertion events in clone OP-367, conducted over two growing seasons, demonstrated reduced tree damage and significantly increased volume growth (mean 14%). Quantification of Cry3Aa protein indicated high levels of expression, which continued after 14 years of annual or biannual coppice in a clone bank. With integrated management, the cry3Aa gene appears to be a highly effective tool for protecting against leaf beetle damage and improving yields from poplar plantations.

scholarly journals Bulked Segregant Analysis Identifies Molecular Markers Linked to Melampsora medusae Resistance in Populus deltoides

2000 ◽  
Vol 90 (9) ◽  
pp. 1039-1042 ◽  
Author(s):  
G. M. Tabor ◽  
T. L. Kubisiak ◽  
N. B. Klopfenstein ◽  
R. B. Hall ◽  
H. S. McNabb McNabb
Keyword(s):  
Molecular Markers ◽  
Leaf Rust ◽  
Populus Deltoides ◽  
Bulked Segregant Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Genetic Distances ◽  
Resistance Locus ◽  
The North ◽  
Melampsora Medusae ◽  
Central United States

In the north central United States, leaf rust caused by Melampsora medusae is a major disease problem on Populus deltoides. In this study we identified molecular markers linked to a M. medusae resistance locus (Lrd1) that was segregating 1:1 within an intraspecific P. deltoides family (C9425DD). Previous field results were confirmed in the controlled environment of a growth chamber through an excised whole-leaf inoculation method. Using bulked segregant analysis we identified two random amplified polymorphic DNA (RAPD) markers (OPG10340 and OPZ191800) that are linked to Lrd1. Based on segregation in a total of 116 progeny, the genetic distances between OPG10340 and OPZ191800 and the resistance locus were estimated as 2.6 and 7.4 Haldane centimorgans (cM), respectively. Multipoint linkage analyses strongly suggest the most likely order for these loci is Lrd1, OPG10340, and OPZ191800. These markers may prove to be instrumental in the eventual cloning of Lrd1, as well as for marker-assisted selection of leaf-rust resistant genotypes.

scholarly journals Measuring socioeconomic position in New Zealand

2012 ◽  
Vol 4 (4) ◽  
pp. 271 ◽  
Author(s):  
Clare Salmond ◽  
Peter Crampton
Keyword(s):  
New Zealand ◽  
Socioeconomic Position ◽  
Health Research ◽  
Household Income ◽  
Explanatory Power ◽  
Cost Effective ◽  
Socioeconomic Deprivation ◽  
Living Standards ◽  
Area Index ◽  
Individual Level

INTRODUCTION: Measures of socioeconomic position (SEP) are widely used in health research. AIM: To provide future researchers with empirically based guidance about the relative utility of five measures of SEP in predicting health outcomes. METHODS: Data from 12 488 adults were obtained from the 2006 New Zealand Health Survey. Seven health-related outcome measures with expected variations by SEP are modelled using five measures of SEP: a census-based small-area index of relative socioeconomic deprivation, NZDep2006; a questionnaire-based individual-level index of socioeconomic deprivation, NZiDep; an index of living standards, ELSI; education, measured by highest qualification; and equivalised household income. RESULTS: After including the individual measure of deprivation, the area-based measure of deprivation adds useful explanatory power, and, separately, the broader spectrum provided by the living standards index adds only a small amount of extra explanatory power. The education and household income variables add little extra explanatory power. DISCUSSION: Both NZiDep and ELSI are useful health-outcome predictors. NZiDep is the cheapest data to obtain and less prone to missing data. The area index, NZDep, is a useful addition to the arsenal of individual SEP indicators, and is a reasonable alternative to them where the use of individual measures is impracticable. Education and household income, using commonly used measurement tools, may be of limited use in research if more proximal indicators of SEP are available. NZDep and NZiDep are cost-effective measures of SEP in health research. Other or additional measures may be useful if costs allow and/or for topic-related hypothesis testing. KEYWORDS: Deprivation; inequalities; living standards; New Zealand; socioeconomic position

Interaction of Prodiamine and Flumioxazin for Nursery Weed Control

2010 ◽  
Vol 24 (4) ◽  
pp. 504-509 ◽  
Author(s):  
Glenn Wehtje ◽  
Charles H. Gilliam ◽  
Stephen C. Marble
Keyword(s):  
United States ◽  
Weed Control ◽  
Southeastern United States ◽  
Cost Effective ◽  
Fresh Weight ◽  
Weed Species ◽  
Rate Range ◽  
Nursery Production ◽  
Control Research ◽  
Large Crabgrass

Both prodiamine and flumioxazin are used in the nursery production and landscape maintenance industries in the southeastern United States for preemergence weed control. Research was conducted to determine whether a tank mixture of these two herbicides would be more effective than either component applied alone. Prodiamine alone, flumioxazin alone, and a 72 : 28 (by weight) prodiamine–flumioxazin mixture were each applied at a series of rates to containers filled with a pine bark–sand substrate that is typical for nursery production in the southeastern United States. Our intent was to have a rate range that hopefully extended from ineffective to lethal for each treatment series. Subsequent to treatment, containers were overseeded with either large crabgrass, spotted spurge, or eclipta. Percent control was determined by comparing treated weed foliage fresh weight to that of the appropriate nontreated control at 6 and 12 wk after application. ANOVA followed by nonlinear regression was used to evaluate the interaction of prodiamine and flumioxazin when combined and to determine the rate of each treatment series required for 95% control (if applicable) for each of the three weed species. Results varied with weed species. The mixture was synergistic and more cost effective than either of the components applied alone in controlling spotted spurge. With respect to large crabgrass control, the mixture was additive and slightly more cost effective than the components. Eclipta could only be controlled with flumioxazin, and this control was antagonized by the addition of prodiamine.

Competitive Abilities of Six Corn (Zea maysL.) Hybrids with Four Weed Control Practices

1994 ◽  
Vol 8 (1) ◽  
pp. 124-128 ◽  
Author(s):  
Garry Tyron Ford ◽  
Jane Mt. Pleasant
Keyword(s):  
Weed Control ◽  
Dry Matter ◽  
Field Experiments ◽  
Leaf Angle ◽  
Corn Plant ◽  
Corn Hybrids ◽  
Area Index ◽  
Maize Hybrids ◽  
Grain Yields ◽  
Plant Characteristics

Six corn hybrids were studied in field experiments in 1989 and 1990 to identify hybrids and corn plant characteristics that may be valuable in systems using reduced levels of weed control. Four weed control treatments (no-control, cultivation-only, band herbicide-plus-cultivation, and broadcast herbicide) represented main plots and maize hybrids were subplots. Medium-season hybrids with differences in height, early-season vigor, and leafiness were used. There were significant differences among hybrids in leaf angle, leaf width, leaf number, plant height, leaf area index (LAI), plant dry matter (DM) and grain and stover yields. Lower yielding hybrids had grain yields that ranged from 87 to 91% of the highest yielding hybrid. Aboveground corn characteristics were not correlated with weed numbers, weed cover, or weed biomass. A significant interaction between hybrid and weed control for grain yields was observed in 1989, suggesting that some hybrids are more competitive when weed pressure is high.

Effects of competition with weeds on the growth, development and yield of sorghum

1993 ◽  
Vol 120 (2) ◽  
pp. 187-196 ◽  
Author(s):  
A. P. Everaarts
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Canopy Structure ◽  
Ground Cover ◽  
Stem Length ◽  
Yield Reduction ◽  
Area Index ◽  
Weed Growth ◽  
Competition For Light ◽  
Number Of Leaves

SUMMARYIn two field experiments in Suriname, competition between weeds and sorghum (Sorghum bicolor(L.) Moench) was studied in the rainy seasons of 1982 and 1983. The crop was kept either weed-free or without weed control for each of six different periods of time from planting. Observations made at the end of each period allowed an analysis to be made of the growth and development of a crop with and without weed control.Due to the crop canopy structure and fertilizer placement near the row, weed growth was concentrated in the rows. Starting atc.20–30 days after planting, competition with weeds reduced ground-cover and leaf area index of the crop. Competition reduced growth rates, leading to lower yields. Plant population density was not affected, but competition reduced the number of leaves present. Stem length initially increased with competition in one season, but was retarded in another. Competition for nutrients was strong and was found as early as 15 days after planting. Nitrogen was the element most competed for initially. Competition for water occurred, but competition for light seemed unlikely. About 20 weed-free days after planting were necessary to avoid yield losses and around 30 weed-free days to attain negligible weed growth at harvest. Yield reduction was mainly due to a decrease in number of grains per panicle. Competition during floret establishment (c.30–40 days after planting) should be avoided.

scholarly journals Efficacy of Non-Chemical Weed Control during Plug Establishment of a Wildflower Meadow

2007 ◽  
Vol 25 (2) ◽  
pp. 83-88
Author(s):  
Jonathon I. Watkinson ◽  
Wallace G. Pill
Keyword(s):  
Weed Control ◽  
Panicum Virgatum ◽  
Wood Chip ◽  
Cost Effective ◽  
Dry Weight ◽  
Growing Season ◽  
Schizachyrium Scoparium ◽  
Shoot Biomass ◽  
Experimental Conditions ◽  
Weed Growth

Abstract The efficacy of non-chemical weed control during plug establishment of a wildflower meadow on glyphosate-killed turf grass was studied. Each field sub-block (not-tilled or twice-tilled to 15 cm (6 in) depth) on killed grass received the following sub-plot soil cover treatments: no cover, woven polypropylene weed fabric, double shredded hardwood/softwood mulch at 7.5 cm (3 in) depth, or fabric covered by mulch. Each 3 × 3 m (10 × 10 ft) subplot was planted in late spring with 100 plugs on 30 cm (1 ft) centers at the following frequency: Baptisia australis (10), Coreopsis lanceolata (20), Solidago speciosa (10), Panicum virgatum (20), and Schizachyrium scoparium (40). Tillage of the killed grass not only failed to benefit wildflower establishment, but increased weed shoot biomass during the second growing season. Greater wildflower shoot dry weights at 120 days after transplanting with mulch (with or without underlying fabric) than with fabric alone or no cover was associated with greater soil moisture, reduced soil temperature range, and reduced weed cover and shoot biomass. Weed fabric compared to no cover failed to affect wildflower shoot dry weights during either growing season but decreased weed growth during the second growing season. Fabric under mulch compared to mulch alone generally failed to affect wildflower growth and had no effect on weed growth during either growing season. During the second growing season, weed shoot dry weights remained low in mulched plots and remained high in non-mulched plots. Regardless of cover, wildflower shoots underwent considerable dry weight gain, while weed shoot dry weights generally remained constant or declined during the second growing season compared to the first. We conclude that, at least under our experimental conditions, applying a 7.5 cm (3 in) layer of wood chip mulch directly over glyphosate-killed turf was the most efficaceous and cost effective method of establishing a wildflower meadow using wildflower plugs. Neither placing weed fabric under the mulch nor twice-tilling the killed turf before mulch application benefitted wildflower shoot growth.

scholarly journals Varieties and mulching influence on weed growth in wheat under Indo- Gangetic plain of India

2016 ◽  
Vol 8 (2) ◽  
pp. 515-520 ◽  
Author(s):  
Diwakar Mani ◽  
M.K. Singh ◽  
S.K. Prasad
Keyword(s):  
Weed Control ◽  
Growth And Yield ◽  
Index Number ◽  
Dry Matter Accumulation ◽  
Paddy Straw ◽  
Gangetic Plain ◽  
Area Index ◽  
Saw Dust ◽  
Maize Straw ◽  
Density And Biomass

Weeds are one of the primary factors responsible for reducing wheat yield. Despite, herbicides’ being one of the important components of weed management programme in India, but it was not adopted by resource poor farmers. Keeping these facts in view, a field experiment was carried out at Agricultural research farm, Institute of Agricultural sciences, Banaras Hindu University during the rabi (winter) season of the year 2012-13 to scrutinize the influence of ‘mulching’ and ‘varieties’ on weed control potential as well as growth and yield of wheat. The treatments comprised of five wheat varieties (C-306, K-8027, K-0307, DBW-39 and HD-2888) and four mulching treatments (No-mulch, paddy straw 6t/ha, maize straw 6t/ha, and saw dust 6t/ha). Surface application of paddy straw mulch 6t/ha considerably reduced the density and biomass of broad leafed weeds and grasses and showed higher weed control efficiency over other treatments like maize straw 6t/ha, saw dust 6t/ha and no-mulch. Varieties DBW-39 and K-0307 was highly effective in smothering of the weeds and produced higher dry matter accumulation, leaf area index, number of grain/earhead, biological yield and harvest index of wheat.

Chemical Weed Control in Southern Hardwood Nurseries

1984 ◽  
Vol 8 (1) ◽  
pp. 16-22
Author(s):  
David B. South
Keyword(s):  
Weed Control ◽  
Methyl Bromide ◽  
Lower Cost ◽  
Control Program ◽  
Cost Effective ◽  
Perennial Grasses ◽  
Effective Control ◽  
The Past ◽  
Weed Seeds

Abstract In the past, hardwood nurserymen often relied on fumigation with methyl bromide for weed control. Today, however, herbicides can provide cost-effective control of grasses and most annual broadleaf weeds in hardwood seedbeds. New herbicides like sethoxidim can be used to control annual and perennial grasses while germination of many broadleaf weeds can be inhibited by oryzalin, oxadiazon, or napropamide. Resistant weeds can be controlled by directed applications of glyphosate. Use of these herbicides reduces the need for fumigation, which often lowers the population of beneficial endomycorrhizal fungi. Fumigation may still be required when controlling high populations of nutsedge or when pathogens are a problem. Although use of chemicals can make control of weeds easier, the nurseryman should not rely entirely on fumigation or herbicides for weed control. If left alone to reproduce, populations of resistant weeds can quickly increase. The nurseryman should therefore adhere strictly to a comprehensive year-round weed control program that prevents introduction, reproduction, and spread of weeds. Even with these efforts, several years may be required to deplete the reservoir of weed seeds in the soil. The nurseryman who is successful will be able to produce more uniform, higher-quality seedlings at a lower cost.

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