scholarly journals Weather Uncertainty and Efficacy of Fumigation in Tomato Production

2019 ◽  
Vol 12 (1) ◽  
pp. 199
Author(s):  
Feng Wu ◽  
Berdikul Qushim ◽  
Zhengfei Guan ◽  
Nathan S. Boyd ◽  
Gary E. Vallad ◽  
...  

This study quantifies the effect of weather factors on fumigation efficacy in terms of weed control, tomato yield, and the overall economic performance of fumigants. High soil temperature was found to reduce the efficacy of all fumigants against nutsedge, while rainfall only reduced the efficacy of a limited number of fumigants. The fumigants’ economic performance over a range of weather conditions was further simulated to identify the fumigant that is most effective under diverse weather conditions. The results show that although 1,3-D:Pic:Kpam outperforms methyl bromide over the experiment period, methyl bromide is still the best treatment when accounting for the impact of weather variability. The study illustrates the sensitivity of fumigant efficacy to weather conditions and the importance of achieving consistent and sustainable efficacy. The regression model and the expected utility model, along with the simulation techniques, form a useful tool that can be applied across regions or crops.

2014 ◽  
Vol 41 (1) ◽  
pp. 48-55 ◽  
Author(s):  
A. Shahin ◽  
S.M. AbouRizk ◽  
Y. Mohamed ◽  
S. Fernando

In cold regions, weather introduces a great deal of uncertainty to weather-sensitive construction activities, resulting in project schedules that deviate from plans. To maximize construction process productivity, decisions regarding process execution planning and sequence of work need to be made, based on reliable plans and schedules. Faced with winter weather uncertainty in cold regions, this task becomes quite challenging. This paper follows the framework that was proposed in the literature for simulating weather-sensitive construction projects executed under cold weather conditions. In the literature, the authors applied the framework steps to enable simulating and planning pipeline construction activities under severe cold weather. The proposed framework sets out a work breakdown structure of activities to account for and quantify weather impact on the project schedule. The steps outlined in the framework are followed to enable simulating and planning tunnelling construction activities executed under severe cold weather conditions. Relevant simulation findings, which clarify the impact of cold weather events on construction projects and can assist in project planning and decision support, are reported.


2014 ◽  
Vol 28 (2) ◽  
pp. 377-384 ◽  
Author(s):  
Pratap Devkota ◽  
Jason K. Norsworthy

Isothiocyanates (ITCs) were evaluated as an alternative to methyl bromide (MeBr) for control of Palmer amaranth, large crabgrass, and yellow nutsedge; reduction of tuber density; and increase in marketable tomato yield in low density polyethylene (LDPE)-mulched tomato production. Allyl ITC was applied at 450, 600, and 750 kg ai ha−1; metham sodium (methyl ITC generator) was applied at 180, 270, and 360 kg ai ha−1; and MeBr plus chloropicrin (mixture of MeBr and chloropicrin at 67 : 33%, respectively) was applied at 390 kg ai ha−1. A nontreated weedy check was included for comparison. There was no injury to tomato plants following allyl ITC, metham sodium, or MeBr application. Allyl ITC at 750 kg ha−1or metham sodium at 360 kg ha−1controlled Palmer amaranth ≥ 79%, large crabgrass ≥ 76%, and yellow nutsedge ≥ 80% and was comparable to the weed control with MeBr. Highest rates of allyl ITC and metham sodium reduced yellow nutsedge tuber density (≤ 76 tubers m−2) comparable to the MeBr application. Total marketable tomato yield was ≥ 31.6 t ha−1in plots treated with allyl ITC at 750 kg ha−1or metham sodium at 360 kg ha−1. Marketable tomato yield from the highest rate of allyl ITC or metham sodium were similar to the yield (38.2 t ha−1) with MeBr treatment. Therefore, allyl ITC at 750 kg ha−1and metham sodium at 360 kg ha−1are effective alternatives to MeBr for Palmer amaranth, large crabgrass, and yellow nutsedge control in LDPE-mulched tomato.


HortScience ◽  
2011 ◽  
Vol 46 (5) ◽  
pp. 715-720 ◽  
Author(s):  
Ted S. Kornecki ◽  
Francisco J. Arriaga

A 4-year experiment with different tillage practices for tomatoes was conducted in Cullman, AL, to determine the impact of plastic mulch (control), rye and crimson clover cover crops, and different subsoiler shanks (no shank, slim 13 mm thick and wide 20 mm thick) on tomato yield. Overall, during 2007 and 2008 growing seasons, total tomato yields (between 58,905 and 60,115 kg·ha−1) and marketable tomato yields (between 48,331 and 49,873 kg·ha−1) were significantly higher than in 2005 and 2006 (between 49,656 and 50,151 kg·ha−1 and from 40,581 to 41,194 kg·ha−1) for total and marketable tomato yields, respectively. During the 2006 and 2008 growing seasons, plastic cover provided higher yield (60,921 and 73,718 kg·ha−1) compared with rye and crimson clover overall shank treatments. In 2007, higher yield was produced following rye without shank (70,577 kg·ha−1) compared with plastic mulch and crimson clover treatments. Across years, tomato yield after crimson clover was lower compared with rye and plastic. Percent of marketable fruit yield to total yield exceeded 80% in all treatments, including the plastic control. Cover crops and shank treatments did not affect percentage of marketable tomato yield compared with total tomato yield. Cover crops, especially rye, can provide an alternative in tomato production for those producers not wanting to use plastic mulches.


2016 ◽  
Vol 23 (2) ◽  
pp. 469-474 ◽  
Author(s):  
Chiang-Ming Chen ◽  
Yu-Chen Lin ◽  
Eldon Y. Li ◽  
Chia-Chang Liu

Despite the existence of several weather studies in the tourism literature, there remain some gaps in knowledge. Uncertainty about weather conditions persists despite the impressive improvements in modern forecasting techniques. This study is a first attempt to investigate how weather uncertainty affects tourism demand. The findings indicate that the impact of weather on tourism demand is likely to grow with the increasingly “uncertain” nature of weather with regard, for example, to temperature and rain.


2019 ◽  
Vol 70 (11) ◽  
pp. 958
Author(s):  
Larn S. McMurray ◽  
Christopher Preston ◽  
Albert Vandenberg ◽  
Dili Mao ◽  
Jeffrey G. Paull

Multiple field experiments and a controlled-environment temperature study were conducted to investigate soil and weather conditions responsible for herbicide phytotoxicity in lentil (Lens culinaris Medik.) from post-emergent application of metribuzin. A linear relationship was observed between plant injury (% necrosis) and metribuzin rate in all 12 environments, but in only 11 environments for anthesis dry weight and nine environments for both plant density and grain yield. Grain-yield reduction from label metribuzin rates of 135 g a.i. ha–1 for sand and 285 g a.i. ha–1 for clay ranged from 0% to 32% and 0% to 67%, respectively, across all environments. Principal component analysis of soil and weather factors around the time of herbicide application suggested that metribuzin-induced plant damage in lentil was due to a combination of multiple soil and weather factors. However, heavy rainfall within 10 days of herbicide application, particularly on light-textured soils or where soil moisture was low, was most strongly linked to plant damage. Experiments targeting the impact of reductions in temperature post-metribuzin application showed no effect, and of light intensities pre- and post-metribuzin application showed low effects on plant-damage measures. Because rainfall in the 10 days after application is a major determinant of metribuzin damage in winter-grown lentil in southern Australia, a higher level of selective tolerance to metribuzin than that present in commercial cultivars is needed for its safe post-emergent use. Early and late measures of plant damage will be required to assess accurately plant tolerance to post-emergent metribuzin application in lentil.


2012 ◽  
Vol 26 (3) ◽  
pp. 449-454 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
Edward E. Gbur

Methyl bromide has been widely used for weed control in polyethylene-mulched tomato production. With the phaseout of methyl bromide in the United States, an effective alternative is needed. Field experiments were conducted in 2007 and 2009 to determine if allyl isothiocyanate (ITC) would provide substantive weed control in tomato along with crop tolerance under low-density polyethylene (LDPE) and virtually impermeable film (VIF) mulch. Treatment factors included two mulch types (LDPE and VIF) and six rates of allyl ITC (0, 15, 75, 150, 750, 1,500 kg ha−1). A standard treatment of methyl bromide : chloropicrin (67 : 33%) at 390 kg ha−1under LDPE mulch was also established. Allyl ITC was broadcast applied and incorporated in soil before forming raised beds and laying plastic mulch. Tomatoes were transplanted 3 wk after applying allyl ITC or methyl bromide treatments. Tomato injury was ≤ 8% in all treatments at 2 wk after transplanting (WATP). Allyl ITC at 913 (± 191) kg ha−1was required to control yellow nutsedge, Palmer amaranth, and large crabgrass equivalent to methyl bromide at 6 WATP and maintain marketable tomato yield equivalent to methyl bromide treatment. VIF mulch was not effective in increasing weed control or improving the marketable yield of tomato over LDPE mulch. This research demonstrates that allyl ITC under an LDPE mulch can have a practical application for weed control in polyethylene-mulched tomato in the absence of methyl bromide.


2019 ◽  
Vol 22 (4) ◽  
pp. 589-600 ◽  
Author(s):  
Xiang Cao ◽  
Zhengfei Guan ◽  
Gary E. Vallad ◽  
Feng Wu

The Florida tomato industry is facing challenges of increased production costs and decreased yields resulting from the methyl bromide (MBr) phase-out under the Montreal Protocol for environmental concerns. MBr and several accepted alternative soil fumigant systems are analyzed in this study from an economic perspective. This article focuses on identifying optimal fumigant systems by analyzing the cost effectiveness and economic risk associated with MBr and several other commercially available soil fumigant systems using data collected from scientific field trials. The results obtained show that a 67:33 formulation of MBr: chloropicrin is the most cost-effective treatment, and no alternative fumigant systems investigated can substitute MBr cost-effectively in Florida tomato production. The analysis indicated that switching from MBr (67:33) to the new industry standard PicChlor 60 approximately resulted in a loss of $3,569 per acre in gross revenue and $1,656 per acre in profit using market prices in the 2013/14 season. Higher market prices would further increase the loss.


Author(s):  
Jakub Lickiewicz ◽  
Katarzyna Piotrowicz ◽  
Patricia Paulsen Hughes ◽  
Marta Makara-Studzińska

Background: The number of meteoropaths, or people negatively affected by weather conditions, is rising dramatically. Meteoropathy is developing rapidly due to ever poorer adaptations of people to changes in weather conditions. Strong weather stimuli may not only exacerbate symptoms in people with diseases of the cardiovascular and respiratory systems but may also induce aggressive behavior. Researchers have shown that patients suffering from mental illnesses are most vulnerable to changes in the weather and postulate a connection between the seasons and aggressive behavior. Methods: The goal of the study was to analyze the relationship between coercive measures and weather factors. The researchers identified what meteorological conditions prevailed on days with an increased number of incidents of aggressive behavior leading to the use of physical coercion towards patients in a psychiatric hospital in Poland. In order to determine the impact of weather conditions on the frequency at which physical coercion measures were used, the hospital’s “coercion sheets” from 1 January 2015 to 31 March 2017 were analyzed. The data were correlated with meteorological data. In order to determine the relationship between the occurrence of specific weather conditions and the number of coercive interventions (N), researchers utilized Spearman’s rank correlation analysis together with two-dimensional scatter diagrams (dependency models), multiple regression, stepwise regression, frequencies, and conditional probability (%). Results: Lower barometric pressure and foehn wind increased aggressive behavior in patients that led to coercive measures. For temperature (positive correlation) and humidity (negative correlation), there was a poor but statistically significant correlation. Conclusions: Monitoring weather conditions might be useful in predicting and preventing aggression by patients who are susceptible to weather changes


Author(s):  

The effect of climatic changes on surface and underground runoff cannot be explained without studying such changes on such processes of moisture transfer in soils as infiltration, evaporation, migration of moisture to the frost front. These processes are components of moisture exchange in soils and almost completely determine the mechanisms of runoff formation and its climatic interconformity. The paper discloses the main links of vertical moisture exchange in soils with environmental factors such as temperature, precipitation, wind speed and water vapor pressure. On the example of the Volga basin, changes in moisture flows in soils over the past decades are considered. Methods. To reveal the patterns of moisture exchange, a physically sound mathematical model of vertical heat-moisture transfer in soils and snow cover was used. Numerical experiments were carried out to assess the impact of all the main weather factors that cause long-term changes in vertical moisture flows in soils for the period 1952-2019. Results. Calculations showed that in the 1970s there were significant changes in soil moisture flows. There was a preferential increase in downstream flows and a decrease in upstream flows, which under certain weather conditions led to an increase in the level of groundwater. In recent decades, the growth of descending soil moisture flows in the river basin. Volga and, accordingly, groundwater levels have slowed down.


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