scholarly journals Optimization of nutritional and environmental conditions for biomass production and sporulation of entomogenous fungus Lecanicillium lecanii CA-1-G using two-stage cultivation system

2018 ◽  
Vol 9 (2) ◽  
pp. 14-20
Author(s):  
Gao Li
Keyword(s):  
Biomass Production ◽  
Environmental Conditions ◽  
Two Stage ◽  
Cultivation System ◽  
Entomogenous Fungus ◽  
Lecanicillium Lecanii

Temperature effect on biomass production and root/shoot biomass ratios in two arctic sedges under controlled environmental conditions

1984 ◽  
Vol 62 (10) ◽  
pp. 2150-2153 ◽  
Author(s):  
Jochen Kummerow ◽  
Barbara A. Ellis
Keyword(s):  
Biomass Production ◽  
Environmental Conditions ◽  
Large Fraction ◽  
The Arctic ◽  
Shoot Biomass ◽  
Eriophorum Vaginatum ◽  
Temperature Optimum ◽  
Active Growth ◽  
Leaf Production ◽  
Higher Temperature

The effect of differential root and shoot temperatures on biomass production of the arctic sedges Eriophorum vaginatum and Carex bigelowii was analyzed under controlled environmental conditions. Both species showed active growth at 2 °C root and shoot temperatures although warmer conditions substantially enhanced biomass production. In E. vaginatum, under the optimal 12 °C root and 12 °C shoot temperature regime, about six times more biomass was produced than under the 2 °C conditions. The corresponding temperatures for C. bigelowii were 12 °C root and 22 °C air, although the data did not preclude a higher temperature optimum for this species. The results support the hypothesis that in arctic sedges the root/shoot biomass ratios are small with low root temperatures, i.e., a relatively large fraction of the photosynthate is allocated to leaf production under cold conditions.

scholarly journals Tors in Central European Mountains – are they indicators of past environments?

2019 ◽  
Vol 16 (1) ◽  
pp. 67-87
Author(s):  
Aleksandra Michniewicz
Keyword(s):  
Central Europe ◽  
Environmental Conditions ◽  
Ice Sheet ◽  
Two Stage ◽  
Central European ◽  
Model Driven ◽  
One Stage ◽  
Different Types ◽  
Geological Factors ◽  
European Mountains

Abstract Tors represent one of the most characteristic landforms in the uplands and mountains of Central Europe, including the Sudetes, Czech-Moravian Highlands, Šumava/Bayerischer Wald, Fichtelgebirge or Harz. These features occur in a range of lithologies, although granites and gneisses are particularly prone to tor formation. Various models of tor formation and development have been presented, and for each model the tors were thought to have evolved under specific environmental conditions. The two most common theories emphasised their progressive emergence from pre-Quaternary weathering mantles in a two-stage scenario, and their development across slopes under periglacial conditions in a one-stage scenario. More recently, tors have been analysed in relation to ice sheet extent, the selectivity of glacial erosion, and the preservation of landforms under ice. In this paper we describe tor distribution across Central Europe along with hypotheses relating to their formation and development, arguing that specific evolutionary histories are not supported by unequivocal evidence and that the scenarios presented were invariably model-driven. Several examples from the Sudetes are presented to demonstrate that tor morphology is strongly controlled by lithology and structure. The juxtaposition of tors of different types is not necessarily evidence that they differ in their mode of origin or age. Pathways of tor remodelling and degradation under subaerial conditions are identified and it is argued that processes of tor formation and development are ongoing. Thus, tors are not reliable indicators of past environments, because they are considerably influenced by both geological factors, such as lithology and structure, and geomorphological factors such as hillslope setting..

scholarly journals Weed interference periods in sesame crop

2019 ◽  
Vol 43 ◽  
Author(s):  
Hamurábi Anizio Lins ◽  
Matheus de Freitas Souza ◽  
José Ricardo Tavares de Albuquerque ◽  
Manoel Galdino dos Santos ◽  
Aurélio Paes Barros Júnior ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Weed Control ◽  
Environmental Conditions ◽  
Critical Period ◽  
Sesamum Indicum ◽  
Initial Growth ◽  
Cultivation System ◽  
High Productivity ◽  
Weed Interference

ABSTRACT The sesame crop (Sesamum indicum L.) is sensitive to competition with weeds because of its low competitiveness that is directly linked to its slow initial growth. The control of weeds in the crop is an essential practice to ensure the high productivity of this oilseed. Therefore, to define the critical period of interference prevention is important to ensure efficiency and low control costs. Factors such as cultivar, environmental conditions, and cultivation system may alter the critical weed interference prevention period (CPWC). Therefore, the objective of this work was to determine the critical weed interference prevention period in two sesame cultivars. The critical weed interference prevention period for sesame cultivars, BRS Seda and CNPA G2, was defined in two years (2016 and 2017). Log-logistic regression of four parameters was used to determine the critical weed interference prevention period. The cultivar CNPA G2 was more competitive compared to the cultivar BRS Seda. The CPWC for BRS Seda was on average 67 and 52 days, whereas for CNPA G2 was 52 and 34 days, considering respectively, a loss of 5 and 10%. Weed control for BRS Seda and CNPA G2 should begin respectively between 12 and 15, and 17 and 20 days, considering a loss of 5 and 10%.

Occurrence of the Entomogenous Fungus Beauveria bassiana in Pecan Orchard Soils in Georgia

1991 ◽  
Vol 26 (3) ◽  
pp. 360-366 ◽  
Author(s):  
Ronald D. Harrison ◽  
Wayne A. Gardner
Keyword(s):  
Pest Management ◽  
Beauveria Bassiana ◽  
Environmental Conditions ◽  
Soil Type ◽  
Management Practices ◽  
Soil Samples ◽  
Entomogenous Fungus ◽  
Fungal Propagules ◽  
Fungus Beauveria Bassiana ◽  
Orchard Soils

Soils from 19 pecan orchards in ten Georgia counties were sampled for Beauveria bassiana (Balsamo) Vuillemin propagules utilizing a selective oatmeal-dodine agar. The 543 soil samples were collected at times corresponding to adult pecan weevil, Curculio caryae (Horn), emergence from the soil and larval penetration into the soil. Fungal propagules were detected in the soils of each of the 19 orchards on both sampling dates. Therefore, soils in pecan orchards in Georgia appear to contain B. bassiana propagules during periods of adult and larval activity of pecan weevils regardless of location, soil type, or pest management practices. Environmental conditions in these orchard soils are apparently conducive for B. bassiana stability and persistence and may enhance efforts to augment the natural inoculum.

scholarly journals GROWTH OF A LETTUCE CROP IN NASA's BIOMASS PRODUCTION CHAMBER

HortScience ◽  
1991 ◽  
Vol 26 (6) ◽  
pp. 778F-778 ◽  
Author(s):  
R.M. Wheeler ◽  
C.L. Mackowiak ◽  
J.C. Sager ◽  
B. Vieux ◽  
W.M. Knott
Keyword(s):  
Relative Humidity ◽  
Biomass Production ◽  
Lactuca Sativa ◽  
Environmental Conditions ◽  
Life Support ◽  
Support Systems ◽  
Dark Period ◽  
Respiration Rates ◽  
Nutrient Film Technique ◽  
Metal Halide Lamps

Lettuce (Lactuca sativa cv. Waldmann's Green) plants were grown in a large, tightly sealed chamber for NASA's Controlled Ecological Life Support Systems (CELSS) program. Plants were started by direct seeding and grown in 64 0.25-m2 trays (six plants per tray) using nutrient film technique. Environmental conditions included: 23°C, 75% relative humidity, 1000 ubar (ppm) CO2, a 16/8 photoperiod, and 300 umol m-2 s-1 PPF from metal halide lamps. Although the chamber was typically opened once each day for cultural activities, atmospheric ethylene levels (measured with GC/PID) increased from near 15 ppb at 23 days after planting (DAP) to 47 ppb at 28 DAP. At harvest (28 DAP), heads averaged 129 g FW or 6.8 g DW per plant, and roots averaged 0.6 g DW per plant. Some tipburn injury was apparent on most of the plants at harvest. By 28 DAP, stand photosynthesis rates for the entire chamber (approx. 20 m2) reached 17.4 umol CO2 m-2 s-1, while dark-period respiration rates reached 5.5 umol CO2 m-2 s-1. Results suggest that good yields can be obtained from lettuce grown in a tightly sealed environment.

Pilot-scale two-stage process: a combination of acidogenic hydrogenesis and methanogenesis

2005 ◽  
Vol 52 (1-2) ◽  
pp. 131-138 ◽  
Author(s):  
S.-K. Han ◽  
S.-H. Kim ◽  
H.-W. Kim ◽  
H.-S. Shin
Keyword(s):  
Food Waste ◽  
Environmental Conditions ◽  
Loading Rate ◽  
Pilot Scale ◽  
Uasb Reactor ◽  
Maximum Efficiency ◽  
Two Stage ◽  
Loading Rates ◽  
High Loading Rate ◽  
Stage Process

This study was performed to optimize both acidogenic hydrogenesis and methanogenesis, and then to develop a pilot-scale two-stage process producing not only CH4 but also H2. Firstly, acidogenic hydrogenesis of food waste was examined in pilot-scale leaching-bed reactors using dilution rate (D) as a tool to improve the environmental conditions. The maximum efficiency of 71.4% was obtained by adjusting D from 4.5 to 2.5 d−1 depending on the state of degradation. Secondly, the wastewater from acidogenic hydrogenesis was converted to CH4 in a pilot-scale UASB reactor. The COD removal efficiency exceeded 95% up to the loading rates of 13.1 g COD/L/d, which corresponded to HRT of 0.25 d (6 h). Lastly, a pilot-scale two-stage process was devised based on a combination of acidogenic hydrogenesis and methanogenesis. Over 120 days, the pilot-scale process resulted in large VS reduction of 70.9% at the high loading rate of 12.5 kg VS/m3/d in a short SRT of 8 days.

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