Springtime dispersal patterns of Monilinia laxa conidia in apricot, peach, prune, and almond trees

1974 ◽  
Vol 52 (1) ◽  
pp. 167-176 ◽  
Author(s):  
J. B. Corbin ◽  
J. M. Ogawa
Keyword(s):  
Disease Development ◽  
Monilinia Laxa ◽  
Dispersal Patterns ◽  
Peach Fruit ◽  
Wind Speeds ◽  
Almond Trees ◽  
Host Structure ◽  
And Control ◽  
Rainy Days ◽  
Fruit Mummies

Numbers of airborne Monilinia laxa conidia were related to the maturity of the sporodochia, the nature of the host structure bearing them, and the presence or absence of rain or fog. Hirst spore traps collected more airborne conidia during rains and on rainy days than on dry days among prunaceous hosts during the spring of 1966 and 1967. Numbers of conidia were greatest (6440 m−3 h−1) in the first 3–4 h of rain, while in dry periods, numbers were greatest (1200 m−3 h−1) when ambient humidity was lowest and temperature and wind speeds were highest. Fruit mummies, twig cankers, limb cankers, pedicels, and peduncles all bore sporodochia. Rains washed off successive crops of conidia, and with 52 800 conidia cm−2 were collected directly below a sporulating peach fruit mummy. The significance of these dispersal periods in disease development and control is discussed.

scholarly journals Optimization of a Small Wind Power Plant for Annual Wind Speed Distribution

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1587
Author(s):  
Krzysztof Wrobel ◽  
Krzysztof Tomczewski ◽  
Artur Sliwinski ◽  
Andrzej Tomczewski
Keyword(s):  
Wind Speed ◽  
Power Plant ◽  
Wind Power ◽  
Power Plants ◽  
Control Method ◽  
Wind Power Plant ◽  
Switched Reluctance ◽  
Wind Speeds ◽  
Wind Speed Distribution ◽  
And Control

This article presents a method to adjust the elements of a small wind power plant to the wind speed characterized by the highest annual level of energy. Tests were carried out on the basis of annual wind distributions at three locations. The standard range of wind speeds was reduced to that resulting from the annual wind speed distributions in these locations. The construction of the generators and the method of their excitation were adapted to the characteristics of the turbines. The results obtained for the designed power plants were compared with those obtained for a power plant with a commercial turbine adapted to a wind speed of 10 mps. The generator structure and control method were optimized using a genetic algorithm in the MATLAB program (Mathworks, Natick, MA, USA); magnetostatic calculations were carried out using the FEMM program; the simulations were conducted using a proprietary simulation program. The simulation results were verified by measurement for a switched reluctance machine of the same voltage, power, and design. Finally, the yields of the designed generators in various locations were determined.

scholarly journals Investigation of the Superposition Effect of Oil Vapor Leakage and Diffusion from External Floating-Roof Tanks Using CFD Numerical Simulations and Wind-Tunnel Experiments

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 299
Author(s):  
Jie Fang ◽  
Weiqiu Huang ◽  
Fengyu Huang ◽  
Lipei Fu ◽  
Gao Zhang
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Simulation Method ◽  
Vapor Concentration ◽  
Monitoring And Control ◽  
Wind Tunnel Experiments ◽  
Ambient Wind ◽  
Wind Speeds ◽  
High Concentrations ◽  
And Control

Based on computational fluid dynamics (CFD) and Realizable k-ε turbulence model, we established a numerical simulation method for wind and vapor-concentration fields of various external floating-roof tanks (EFRTs) (single, two, and four) and verified its feasibility using wind-tunnel experiments. Subsequently, we analysed superposition effects of wind speed and concentration fields for different types of EFRTs. The results show that high concentrations of vapor are found near the rim gap of the floating deck and above the floating deck surface. At different ambient wind speeds, interference between tanks is different. When the ambient wind speed is greater than 2 m/s, vapor concentration in leeward area of the rear tank is greater than that between two tanks, which makes it easy to reach explosion limit. It is suggested that more monitoring should be conducted near the bottom area of the rear tank and upper area on the left of the floating deck. Superposition in a downwind direction from the EFRTs becomes more obvious with an increase in the number of EFRTs; vapor superposition occurs behind two leeward tanks after leakage from four large EFRTs. Considering safety, environmental protection, and personnel health, appropriate measures should be taken at these positions for timely monitoring, and control.

scholarly journals Study of air movement and temperature distribution in a greenhouse used as a dryer

2020 ◽  
Vol 307 ◽  
pp. 01051
Author(s):  
Soumaïla TIGAMPO ◽  
Vincent SAMBOU ◽  
Younouss DIEYE ◽  
Pape Moussa TOURE ◽  
Séckou BODIAN
Keyword(s):  
Load Capacity ◽  
Three Dimensional ◽  
Climatic Conditions ◽  
Load Model ◽  
Wind Speeds ◽  
Greenhouse Climate ◽  
Air Temperatures ◽  
Computer Fluid Dynamics ◽  
Materials Used ◽  
And Control

Sun drying is the oldest way to preserve but also to valorize and store surplus agricultural production. Nowadays, several types of dryers have been developed, but the solar greenhouse dryer is an ideal solution in our tropical countries because of its implicit and higher load capacity. The greenhouse climate depends on several factors, namely the outdoor climatic conditions (air temperature, wind speed, radiation, etc.) but also on the type of materials used to cover the greenhouse. The study was carried out on a parabolic greenhouse covered by a polyethylene film with a concrete base (absorber) which in turn is placed on the ground and will be tested under the climatic conditions of Dakar, Senegal. It is in this context of sustainable development that this work is carried out. The goal is to determine the distribution of temperatures and wind speeds in the greenhouse. The simulation was carried out using the three-dimensional computer fluid dynamics software (CFD). The turbulence method (k-ε) was used and to solve the radiation transfer equation (RTE) we introduce the discrete ordered method DO. We also add the “Solar Load Model” which gives the position of the sun and its radiations in relation to the layout of the greenhouse according to the date and time of the simulation. The simulation is carried out in a closed greenhouse and the results found can be used to improve the design and control of the greenhouse climate. Air temperatures and velocities simulation give an average of 325.95 K and 0.114 m/s respectively.

scholarly journals RESIDUAL EFFECTS OF PESTICIDES IN PEACH ORCHARDS ON THE MAIZE WEEVIL Sitophilus zeamais (COLEOPTERA: CURCULIONIDAE)

2016 ◽  
Vol 38 (3) ◽  
Author(s):  
SANDRO DANIEL NÖRNBERG ◽  
ANDERSON DIONEI GRÜTZMACHER ◽  
DORI EDSON NAVA ◽  
RICARDO ALEXANDRE VALGAS ◽  
ÂNGELO LUIS OZELAME
Keyword(s):  
Residual Effect ◽  
Variable Number ◽  
Residual Effects ◽  
Maize Weevil ◽  
Peach Fruit ◽  
Laboratory Conditions ◽  
Spraying Plants ◽  
Peach Trees ◽  
And Control ◽  
Treatment Application

ABSTRACT The aim of this study was to evaluate the residual effect of pesticides sprayed on peach orchards on S. zeamais. The study consisted of two experiments, according to the method of pesticide application. For Experiment I, pesticides were directly sprayed on peach trees and in Experiment II, the application of pesticides was performed under laboratory conditions. In both Experiments, the effect of pesticides was assessed in laboratory through the release of ten weevils per peach fruit. The effect of treatments was assessed by variable number of surviving insects. The results for pesticides [a.i. (ml or g.100L)] have shown that application of treatments in the field (Experiment I), malathion (200) presented persistence at 1DAT (Days after treatments spraying) and control higher than 80%, and thiametoxan (30) up to 3 DAT , while for phosmet (200) and fenthion (100), the control percentage was over 70% at 1 DAT . Under laboratory conditions, the application of the same insecticides showed control of 100% at 120 HAT (Hours after treatment application). In this context, the use of insecticides by spraying plants must be considered an alternative method for the control of S. zeamais in peach, being necessary to the development and adoption of new control tools for its management.

MODELING, SIMULATION AND CONTROL OF IRRIGATION ON YOUNG ALMOND TREES

2014 ◽  
pp. 479-486
Author(s):  
J. Arriaga ◽  
I.F. García-Tejero ◽  
J.L. Muriel-Fernández ◽  
V.H. Durán-Zuazo ◽  
F.R. Rubio
Keyword(s):  
Modeling Simulation ◽  
Almond Trees ◽  
Simulation And Control ◽  
And Control

Empirical Evidence of Long-Distance Dispersal in Miscanthus sinensis and Miscanthus × giganteus

2011 ◽  
Vol 4 (1) ◽  
pp. 142-150 ◽  
Author(s):  
Lauren D. Quinn ◽  
David P. Matlaga ◽  
J. Ryan Stewart ◽  
Adam S. Davis
Keyword(s):  
Miscanthus Sinensis ◽  
High Wind ◽  
Dispersal Patterns ◽  
Long Distance ◽  
Bioenergy Grasses ◽  
Wind Speeds ◽  
Miscanthus Giganteus ◽  
Prevailing Wind Direction ◽  
Wind Events ◽  
Dispersal Distances

AbstractMany perennial bioenergy grasses have the potential to escape cultivation and invade natural areas. We quantify dispersal, a key component in invasion, for two bioenergy candidates:Miscanthus sinensis and M. × giganteus. For each species, approximately 1 × 106 caryopses dispersed anemochorously from a point source into traps placed in annuli near the source (0.5 to 5 m; 1.6 to 16.4 ft) and in arcs (10 to 400 m) in the prevailing wind direction. For both species, most caryopses (95% for M. sinensis and 77% for M. × giganteus) were captured within 50 m of the source, but a small percentage (0.2 to 3%) were captured at 300 m and 400 m. Using a maximum-likelihood approach, we evaluated the degree of support in our empirical dispersal data for competing functions to describe seed-dispersal kernels. Fat-tailed functions (lognormal, Weibull, and gamma (Γ)) fit dispersal patterns best for both species overall, but because M. sinensis dispersal distances were significantly affected by wind speed, curves were also fit separately for dispersal distances in low, moderate, and high wind events. Wind speeds shifted the M. sinensis dispersal curve from a thin-tailed exponential function at low speeds to fat-tailed lognormal functions at moderate and high wind speeds. M. sinensis caryopses traveled farther in higher wind speeds (low, 30 m; moderate, 150 m; high, 400 m). Our results demonstrate the ability of Miscanthus caryopses to travel long distances and raise important implications for potential escape and invasion of fertile Miscanthus varieties from bioenergy cultivation.

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