scholarly journals Effects of Nocturnal Soil Temperatures and Meloidogyne incognita Densities on Cotton Seedling Growth and the Interaction with Thielaviopsis basicola

Plant Disease ◽  
2006 ◽  
Vol 90 (4) ◽  
pp. 519-522 ◽  
Author(s):  
W. S. Monfort ◽  
T. L. Kirkpatrick ◽  
C. S. Rothrock
Keyword(s):  
Plant Height ◽  
Meloidogyne Incognita ◽  
Growth And Development ◽  
Growing Season ◽  
Thielaviopsis Basicola ◽  
Plant Growth And Development ◽  
Population Densities ◽  
Pathogen Population ◽  
Growing Seasons ◽  
Soil Temperatures

Controlled studies were conducted to evaluate the effects of soil temperatures typical of field conditions during the first 6 weeks of the growing season in Arkansas and different population densities of Meloidogyne incognita on damage to cotton (Gossypium hirsutum) seedlings associated with the interaction between M. incognita and Thielaviopsis basicola. Treatments consisted of varying nocturnal temperatures that approximated the temperatures that occurred during the 2001, 2002, and 2003 growing seasons in southeastern Arkansas. Nocturnal temperatures in the study were as follows: high, the first week at 15°C, followed by 3 weeks at 17°C, 1 week at 21°C, and 1 week at 17°C (approximating the 2002 season); medium, 3 weeks at 15°C and 3 weeks at 19°C (approximating the 2003 season); and low, 1 week at 15°C, 1 week at 13°C, 2 weeks at 17°C, 1 week at 15°C, and 1 week at 17°C (approximating the 2001 season). Pathogen population densities were either 0 or 100 chlamydospores of T. basicola per gram of soil and 0, 2,000, 4,000, or 8,000 eggs of M. incognita per 500 cm3of soil. Plant height and fresh top weight increased with an increase in nocturnal temperature across treatments. There were significant reductions in plant growth and development with T. basicola, but not with M. incognita, at these nocturnal temperatures, but decreased plant height and weight were seen where both pathogens were present in comparison with either pathogen alone. Trends of increased disease associated with T. basicola were observed with increasing inoculum rates of M. incognita, indicating that the interaction between T. basicola and M. incognita occurs even at soil temperatures below the minimum temperature reported as necessary for damage from M. incognita.

scholarly journals Seasonal dynamics of methane emissions from a subarctic fen in the Hudson Bay Lowlands

2013 ◽  
Vol 10 (7) ◽  
pp. 4465-4479 ◽  
Author(s):  
K. L. Hanis ◽  
M. Tenuta ◽  
B. D. Amiro ◽  
T. N. Papakyriakou
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Growing Season ◽  
Near Surface ◽  
Growing Seasons ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Surface Soil Temperature ◽  
Filling Method ◽  
Highly Correlated

Abstract. Ecosystem-scale methane (CH4) flux (FCH4) over a subarctic fen at Churchill, Manitoba, Canada was measured to understand the magnitude of emissions during spring and fall shoulder seasons, and the growing season in relation to physical and biological conditions. FCH4 was measured using eddy covariance with a closed-path analyser in four years (2008–2011). Cumulative measured annual FCH4 (shoulder plus growing seasons) ranged from 3.0 to 9.6 g CH4 m−2 yr−1 among the four study years, with a mean of 6.5 to 7.1 g CH4 m−2 yr−1 depending upon gap-filling method. Soil temperatures to depths of 50 cm and air temperature were highly correlated with FCH4, with near-surface soil temperature at 5 cm most correlated across spring, fall, and the shoulder and growing seasons. The response of FCH4 to soil temperature at the 5 cm depth and air temperature was more than double in spring to that of fall. Emission episodes were generally not observed during spring thaw. Growing season emissions also depended upon soil and air temperatures but the water table also exerted influence, with FCH4 highest when water was 2–13 cm below and lowest when it was at or above the mean peat surface.

Growth and Development of Organic Arsenical-Susceptible and -Resistant Common Cocklebur (Xanthium strumarium) Biotypes Under Noncompetitive Conditions

1994 ◽  
Vol 8 (1) ◽  
pp. 154-158 ◽  
Author(s):  
William E. Haigler ◽  
Billy J. Gossett ◽  
James R. Harris ◽  
Joe E. Toler
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Plant Height ◽  
Growth And Development ◽  
Reproductive Potential ◽  
Dry Weight ◽  
Growing Season ◽  
Xanthium Strumarium ◽  
Relative Growth ◽  
Growth Development

The growth, development, and reproductive potential of several populations of organic arsenical-susceptible (S) and -resistant (R) common cocklebur biotypes were compared under noncompetitive field conditions. Plant height, leaf area, aboveground dry weights, and relative growth rate (RGR) were measured periodically during the growing season. Days to flowering, bur dry weight, and number of burs per plant were also recorded. Arsenical S- and R-biotypes were similar in all measured parameters of growth, development, and reproductive potential. Populations within each biotype varied occasionally in plant height, leaf area, aboveground dry weights, and reproductive potential.

scholarly journals Effects of Season of Burning on the Microenvironment of Fescue Prairie in Central Saskatchewan

2003 ◽  
Vol 117 (2) ◽  
pp. 257 ◽  
Author(s):  
O. W. Archibold ◽  
E. A. Ripley ◽  
L. Delanoy
Keyword(s):  
Plant Cover ◽  
Growing Season ◽  
Control Plot ◽  
Area Index ◽  
Growing Seasons ◽  
Soil Temperatures ◽  
Second Year ◽  
Long Term Impact ◽  
Season Of Burning

The microenvironmental effects of spring, summer and autumn burns were investigated for a small area of fescue prairie in Saskatchewan over two growing seasons. Maximum fire temperature in all burns exceeded 300°C at a height of 5-10 cm in the canopy. At a depth of 1 cm in the soil, temperature increased to 40°C during the summer burn, but was unaffected by burns at other seasons. Spring-burned grasses recovered to the same height as the unburned control plot by the end of the first summer. Grass height was similar in all plots by the end of the second growing season, but aboveground biomass in all burned plots was about half that of the control. Graminoid leaf area index at the end of the second growing season ranged from 0.65 in the control plot to 0.27 in the autumn burn. Surface albedos dropped to about 0.03 immediately after burning and took about 3 months to return to the pre-burn values near 0.20. By mid-June of the second year, albedos were similar in all plots. Soil temperatures at 50 cm depth in the burned plots were higher than in the control during the first summer and lower during the winter. The greatest winter snowpack (73 mm water equivalent) accumulated in the control, compared to 48, 35 and 25 mm in the spring, summer and autumn burned plots, respectively. In the first growing season the greatest demand for water occurred in the spring plot followed by the summer, control and autumn plots. In the second season water demand did not differ significantly among plots, reflecting the similarities in plant cover. The microenvironmental effects of a single burning episode in fescue prairie disappear rather quickly, so that there is little long-term impact on the vegetation.

scholarly journals Вплив агроекологічних факторів на ріст пшениці твердої ярої залежно від мінеральних добрив та біопрепаратів

2013 ◽  
pp. 15-18
Author(s):  
Г. П. Жемела ◽  
Д. М. Шевніков
Keyword(s):  
Plant Height ◽  
Spring Wheat ◽  
Growth And Development ◽  
Growing Season ◽  
Growth Processes ◽  
Biological Products ◽  
Fertilizer Plant ◽  
Negative Effect ◽  
Complex Influence ◽  
Wheat Seeds

Застосування мінеральних добрив та інокуляції насіння пшениці твердої ярої біопрепаратами позитивно вплинуло на ріст і розвиток рослин. Дія мінеральних добрив на висоту рослин виявилася більш суттєвою, ніж дія біопрепаратів, але їхній комплексний вплив був більш ефективним щодо збільшення ростових процесів у рослин пшениці твердої ярої; у цьому разі не проявилася негативна дія несприятливих факторів веґетаційного періоду. Без застосування добрив висота рослин була 63,6 см, із застосуванням поліміксобактерину збільшувалася до 67,2, діазофіту – до 68,6 сантиметрів. The use of fertilizers and inoculation of wheat seeds solid spring biological products positively affected to the growth and development of plants. Effects of fertilizer on plant height was significantly more than biologics, but their complex influence was more effective in increasing the growth processes in solid spring wheat plants, in this case, apparent negative effect unfavorable growing season. Without the use of fertilizer plant height was 63.6 cm. Usingpolimiksobakterynuincreased to 67.2cm, diazofitu - to 68.6 cm.

scholarly journals Safflower grown in different sowing dates and plant densities

2012 ◽  
Vol 42 (12) ◽  
pp. 2145-2152 ◽  
Author(s):  
Rogério Antonio Bellé ◽  
Edileusa Kersting da Rocha ◽  
Fernanda Alice Antonello Londero Backes ◽  
Mauricio Neuhaus ◽  
Natalia Teixeira Schwab
Keyword(s):  
Plant Height ◽  
Growing Season ◽  
Dry Mass ◽  
Plant Population ◽  
Main Stem ◽  
Growing Seasons ◽  
Sowing Dates ◽  
Plant Densities ◽  
Quadratic Response ◽  
Total Plant

The objectives of this study were to test the effects of different plant densities on stem characteristics in two growing seasons: Fall/Winter and Spring/Summer. The plant densities evaluated were 48, 64, 80, 96, 112 and 128plants m-2. The Fall/Winter growing season was from 04/04/2008 to 23/08/2008 and the Spring/Summer growing season was from 03/10/2008 to 23/12/2008. Total and partial plant height did not differ among plant densities in the Fall/Winter growing season. However, in the Spring/Summer growing season total plant height had a quadratic response to increase in plant population whereas the partial height did not vary. In the Fall/Winter cultivation, plants presented larger stems and branches diameter, branches length and total number of nodes main stem and branches diameters, number and length of branches, fresh and dry mass decreased as density increased in the two growing seasons. The capitulum's diameter decreased as density increased in the Fall/Winter growing season, but at the Spring/Summer growing season it decreased in the density from 48 to 96plants m-2 and increased in the density from 112 a 128plants m-2.

scholarly journals Modification of Plant Height via RNAi Suppression of MdGA20-ox Gene Expression in Apple

2016 ◽  
Vol 141 (3) ◽  
pp. 242-248 ◽  
Author(s):  
Kai Zhao ◽  
Feng Zhang ◽  
Yi Yang ◽  
Yue Ma ◽  
Yuexue Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Interference ◽  
Plant Height ◽  
Growth And Development ◽  
Plant Growth And Development ◽  
Transgenic Lines ◽  
Key Enzyme ◽  
Apple Cultivars ◽  
Lower Plant ◽  
Ga Content

GA20-oxidase (GA20-ox) is a key enzyme involved in the biosynthesis of gibberellic acid (GA). To investigate its role in plant growth and development, we suppressed MdGA20-ox gene expression in apple (Malus domestica cv. Hanfu) plants by RNA interference (RNAi). After 20 weeks of growth in the greenhouse, significant phenotype differences were observed between transgenic lines and the nontransgenic control. Suppression of MdGA20-ox gene expression resulted in lower plant height, shorter internode length, and higher number of nodes compared with the nontransgenic control. The expression of MdGA20-ox in transgenic plants was significantly suppressed, and the active GA content in transgenic lines was lower than that in the nontransgenic control. These results demonstrated that the MdGA20-ox gene plays an important role in vegetative growth, and therefore it is possible to develop dwarfed or compact scion apple cultivars by MdGA20-ox gene silencing.

scholarly journals Cowpea and beet intercropping agro-economic dynamics under spatial arrangement and cowpea population density

2020 ◽  
Vol 38 (2) ◽  
pp. 192-203 ◽  
Author(s):  
Aridênia P Chaves ◽  
Francisco Bezerra Neto ◽  
Jailma SS Lima ◽  
Josimar N Silva ◽  
Renato LC Nunes ◽  
...  
Keyword(s):  
Experimental Design ◽  
Population Density ◽  
Economic Efficiency ◽  
Maximum Yield ◽  
Growing Season ◽  
Spatial Arrangement ◽  
Productivity Index ◽  
Population Densities ◽  
System Productivity ◽  
Growing Seasons

ABSTRACT The objective of this work was to evaluate the effect of planting spatial arrangements between the cowpea and beet crops in intercropping and of cowpea population densities on the crop’s productivity and in the agro-economic efficiency of the association at two growing seasons. The experimental design was of randomised blocks with the treatments arranged in a 4 x 3 factorial scheme, in four replications. The first factor was constituted by three spatial arrangements between the component cultures (2:2, 3:3 and 4:4), formed by beet rows alternated with cowpea rows, while the second factor was constituted by the population densities of cowpea: 40, 60, 80 and 100% of the recommended population in single crop (RDSC). The production and its components were evaluated in the beet and cowpea. Apart from these characteristics, the following agro-economic indicators were also determined for each treatment: system productivity index (SPI), the land equivalent coefficient (LEC), and the monetary equivalent ratio (MER). The maximum production of commercial beet roots was obtained with 15.60 t ha-1 productivity at density of 61.82% of RDSC within the 4:4 arrangement, while the maximum yield of cowpea green grains of 2.23 t ha-1 was reached at density of 79.57% of RDSC within 2:2 spatial arrangement. The productivities of beet roots of extra A, extra AA and great types decreased with increasing cowpea population density, without any influence of the tested spatial arrangements. The maximum mean productivity of cowpea green pods of 1.74 t ha-1 was obtained at density of 87.47% of RDSC, reached within 2:2 spatial arrangement. The maximum economic efficiency of the cowpea-beet intercropping was obtained with MER of 1.11 at cowpea density of 100% of RDSC, irrespective of the spatial arrangement and growing season.

scholarly journals Vegetative Growth of Three Southern Highbush Blueberry Cultivars Obtained from Micropropagation and Softwood Cuttings in Two Florida Locations

HortScience ◽  
2014 ◽  
Vol 49 (5) ◽  
pp. 556-561 ◽  
Author(s):  
Silvia R. Marino ◽  
Jeffrey G. Williamson ◽  
James W. Olmstead ◽  
Philip F. Harmon
Keyword(s):  
Tissue Culture ◽  
Plant Height ◽  
Growing Season ◽  
Vaccinium Corymbosum ◽  
Highbush Blueberry ◽  
Plant Canopy ◽  
Growing Seasons ◽  
Canopy Volume ◽  
Shoot Number ◽  
Southern Highbush

Field performance of southern highbush blueberry (Vaccinium corymbosum L. interspecific hybrids) cultivars Emerald, Jewel, and Primadonna derived from softwood cuttings (SW) and tissue culture (TC) was evaluated in Citra and Haines City, FL, in 2010–12. Both fields were planted in Apr. 2010 on sandy soil amended with pine bark. Plant height and width were recorded at both locations, from which plant canopy volume was calculated. Additionally, whole plants were harvested at planting and after the first growing season, after the first fruit harvest, and after the second growing season. Average plant height and width, number of major canes, and total shoot number were determined at each sampling date. Dry weights for roots, crowns, canes, shoots, and leaves were obtained. Although propagation method affected plant canopy volume during the first season, no effects were observed by the end of the second growing season. At planting and after the first and second growing seasons, TC plants of the three cultivars had more major canes. Total shoot number per plant was greater for TC ‘Jewel’ at all dates but ‘Emerald’ TC plants had more shoots only at planting and after the first growing and harvest seasons. Tissue culture resulted in increased plant dry weights of ‘Jewel’ and ‘Emerald’ after the first and second growing seasons. There were no significant differences in total number of shoots or plant dry weight between TC and SW-derived ‘Primadonna’ plants at any point during the study.

scholarly journals Improving Garlic Using Wheat Straw Mulch

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 611b-611
Author(s):  
Angela M. O'Callaghan
Keyword(s):  
United States ◽  
Wheat Straw ◽  
Growing Season ◽  
Northeastern United States ◽  
Straw Mulch ◽  
Growing Seasons ◽  
Cultural Conditions ◽  
Soil Temperatures ◽  
Wheat Straw Mulch ◽  
Research Facilities

Garlic (Allium sativum L.) has been cultivated in much of the world for millennia. Little scientific research, however, has focused on improving cultural conditions for production in the temperate regions of the northeastern United States, where garlic is gaining importance as a horticultural crop. To study the effectiveness of wheat straw (Triticum aestivum) mulch on garlic, experiments were conducted at the Cornell Univ. research facilities in East Ithaca, N.Y., during the 1993–94 (year 1) and 1994–95 (year 2) growing seasons and at the Homer C. Thompson Vegetable Research Farm, Freeville, N.Y., during the 1994–95 growing season. Two clones, one bolting and one nonbolting, were studied in year 1, and four varieties, three bolting and one non bolting, in year 2. All were fall-planted (mid-October), and mulch treatments were covered with wheat straw early in the following December. Control plots were not covered. The mulch either remained on the crop throughout the growing season or was removed early in the spring to expedite soil warming. This is the common practice among growers who use mulch only for winter protection. The presence of mulch during the winter increased the survival rate. Soil temperatures under the wheat straw were significantly lower during the summer than soil temperatures in unmulched plots, which could have contributed to the increase found in the yield and average bulb size of several of the cultivars. Maintaining the mulch through the entire growing season reduced weed pressure >30%. We found no significant increase in the amount of basal fungal infection. The results indicate that using straw mulch can improve garlic produced in the northeastern United States.

Seed dispersal and dormancy patterns in northern willows: ecological and evolutionary significance

1983 ◽  
Vol 61 (12) ◽  
pp. 3207-3216 ◽  
Author(s):  
Roseann Densmore ◽  
John Zasada
Keyword(s):  
Seed Dispersal ◽  
Boreal Forest ◽  
High Temperatures ◽  
Field Experiments ◽  
Growing Season ◽  
Evolutionary Significance ◽  
Cold Stratification ◽  
Cold Climates ◽  
Growing Seasons ◽  
Soil Temperatures

Seeds of the 24 common Salix species of the Alaskan boreal forest and tundra were set to germinate in laboratory and field experiments, and seed dispersal times were observed. During the growing season, 16 species disperse short-lived, nondormant seeds. At the end of the growing season, eight other species, all tundra willows, disperse conditionally dormant seeds. These fall-dispersed seeds are fully developed in the same length of time as summer-dispersed seeds, but they develop dormancy while being held on the plant until the leaves senesce. At the time of dispersal, some seeds are capable of germinating at high temperatures, but no seeds can germinate at the low soil temperatures occurring then. Cold stratification gradually widens the range of temperatures at which seeds can germinate, and seeds germinate at low soil temperatures in the spring shortly after snowmelt. Salix species dispersing dormant seeds during the fall appear to have evolved, as an adaptation to short growing seasons in cold climates, from taxa dispersing nondormant seeds during the summer.

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