scholarly journals Factors Influencing the Formation of Tobacco-Specific Nitrosamines in French Air-Cured Tobaccos in Trials and at the Farm Level

Author(s):  
C deRoton ◽  
A Wiernik ◽  
I Wahlberg ◽  
B Vidal

AbstractSeveral trials the results of which are compiled in this paper, were carried out at the Tobacco Institute of Bergerac (ITB) and in the area nearby from 1996 to 2003. The objective was to study the formation of tobacco-specific nitrosamines (TSNA) in dark air-cured and burley tobaccos during curing and post-curing treatment under the conditions of cultivation, curing and storage commonly applied by the growers in the south-western part of France. For experimental purposes special treatments were performed in certain trials.The results showed that the main genetic trait involved in the formation of TSNA is the propensity of a variety to convert nicotine to nornicotine (NN). In addition, the ability of a variety to lose water rapidly limits the formation of nitrite and hence also the formation of TSNA. Furthermore, agricultural practices that led to an increase of alkaloid concentrations in the tobacco leaves also led to an increase of TSNA concentration. Priming, a mode of harvest which speeds up the cure, as compared to stalk-cutting, as well as low temperatures during curing, limit the formation of TSNA, but do not yield tobaccos of the best quality. Ventilation in the barn plays a major role, and the leaves cured in well ventilated curing structures, such as plastic sheds, generally contained smaller amounts of TSNA than leaves cured in a conventional curing barn. The results also indicated that the TSNA concentrations may increase after the end of cure, if the cured tobaccos were kept hanging in the barn under humid conditions. The concentration of TSNA may also continue to increase, whereas nitrite concentrations tend to decrease, when the leaves are kept in bales.It can be concluded that the French climatic conditions with moderate temperatures and low relative humidity at the time of curing, are favourable for the production of air-cured tobaccos with a good quality and low TSNA concentrations (1.5-3.5 µg/g), provided that the variety has low NN content, the nitrogen fertilization is moderate, the curing is performed in a well ventilated environment, the tobacco is taken down and stripped as soon as it is cured, and the bales are stored as briefly as possible before the leaves are threshed and stabilized.

1994 ◽  
Vol 74 (3) ◽  
pp. 607-610 ◽  
Author(s):  
Peter M. A. Toivonen ◽  
B. J. Zebarth ◽  
P. A. Bowen

Broccoli quality in British Columbia can vary with season and with the farm site on which it is grown. One major management difference between farms is nitrogen fertilization rate. This work was conducted to determine the effect of nitrogen fertilization (0, 125, 250, 375, 500 and 625 kg N ha−1) and growing season (three plantings in 2 consecutive years) on vitamin C content, head size and storability of broccoli (Brassica oleracea var. Italica, 'Emperor'). The climatic conditions during crop growth and development had a greater overall effect on vitamin C content, head diameter and head weight than nitrogen fertilization. Weight and vitamin C losses during storage in the first year were not affected by nitrogen fertilization rates. Moderate nitrogen application rates of 125 and 250 kg N ha−1 in all three plantings produced a head size considered optimal for marketing. Key words: Postharvest, vegetable quality, climatic conditions


1988 ◽  
Vol 27 (4II) ◽  
pp. 595-604 ◽  
Author(s):  
Eshya Mujahid Mukhtar ◽  
Hanid Mukhtar

Agricultural production depends upon certain crucial inputs e.g., water, fertilizer etc. In the less developed regions of South Asia in general, and the indo-Pakistan sub-continent in particular, the use of these inputs depends not only upon the financial affordability but also upon the institutional accessibility of farmers to these inputs. Besides high economic costs, bureaucratic controls and corruption regarding the distribution of inputs have created problems of limited accessibility, especially to the small farmers. In the absence of any credit, information and/or input distribution networks, the use of these inputs, and related productivity gains, become confined to that class of farmers which not only has better access to these inputs but is capable of using them in the best possible way e.g. use of water and fertilizer in the appropriate amount and at the appropriate time. This paper attempts to study how input use and input productivity vary across farm sizes, with some reference to the infrastructural and institutional factors, whose development play an important role in improving the distribution and productivity of inputs. For such an analysis, a comparison of the two Punjabs i.e. Pakistani and Indian Punjabs, presents an ideal framework, Separated by a national boundary since 1947, the two Punjabs enjoy a common history and culture, similar agricultural practices and agro-climatic conditions, Government policies in the two Punjabs, however, have not only differed between the two provinces at the same time, but also over time in the same province. It may be noted that due to certain policy measures, land distribution, tenancy conditions, promotion of agricultural co-operatives and provision of infrastructural features, such as roads and electricity, are relatively more improved in Indian than Pakistani Punjab.


Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 60
Author(s):  
Vincenzo Michele Sellitto ◽  
Severino Zara ◽  
Fabio Fracchetti ◽  
Vittorio Capozzi ◽  
Tiziana Nardi

From a ‘farm to fork’ perspective, there are several phases in the production chain of fruits and vegetables in which undesired microbial contaminations can attack foodstuff. In managing these diseases, harvest is a crucial point for shifting the intervention criteria. While in preharvest, pest management consists of tailored agricultural practices, in postharvest, the contaminations are treated using specific (bio)technological approaches (physical, chemical, biological). Some issues connect the ‘pre’ and ‘post’, aligning some problems and possible solution. The colonisation of undesired microorganisms in preharvest can affect the postharvest quality, influencing crop production, yield and storage. Postharvest practices can ‘amplify’ the contamination, favouring microbial spread and provoking injures of the product, which can sustain microbial growth. In this context, microbial biocontrol is a biological strategy receiving increasing interest as sustainable innovation. Microbial-based biotools can find application both to control plant diseases and to reduce contaminations on the product, and therefore, can be considered biocontrol solutions in preharvest or in postharvest. Numerous microbial antagonists (fungi, yeasts and bacteria) can be used in the field and during storage, as reported by laboratory and industrial-scale studies. This review aims to examine the main microbial-based tools potentially representing sustainable bioprotective biotechnologies, focusing on the biotools that overtake the boundaries between pre- and postharvest applications protecting quality against microbial decay.


Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 214
Author(s):  
Agathe Roucou ◽  
Christophe Bergez ◽  
Benoît Méléard ◽  
Béatrice Orlando

The levels of fumonisins (FUMO)—mycotoxins produced by Fusarium verticillioides—in maize for food and feed are subject to European Union regulations. Compliance with the regulations requires the targeting of, among others, the agroclimatic factors influencing fungal contamination and FUMO production. Arvalis-Institut du végétal has created a national, multiyear database for maize, based on field survey data collected since 2003. This database contains information about agricultural practices, climatic conditions and FUMO concentrations at harvest for 738 maize fields distributed throughout French maize-growing regions. A linear mixed model approach highlights the presence of borers and the use of a late variety, high temperatures in July and October, and a water deficit during the maize cycle as creating conditions favoring maize contamination with Fusarium verticillioides. It is thus possible to target a combination of risk factors, consisting of this climatic sequence associated with agricultural practices of interest. The effects of the various possible agroclimatic combinations can be compared, grouped and classified as promoting very low to high FUMO concentrations, possibly exceeding the regulatory threshold. These findings should facilitate the creation of a national, informative and easy-to-use prevention tool for producers and agricultural cooperatives to manage the sanitary quality of their harvest.


2002 ◽  
Vol 6 (3) ◽  
pp. 497-506 ◽  
Author(s):  
L. Ruiz ◽  
S. Abiven ◽  
P. Durand ◽  
C. Martin ◽  
F. Vertès ◽  
...  

Abstract. The hydrological and biogeochemical monitoring of catchments has become a common approach for studying the effect of the evolution of agricultural practices on water resources. In numerous studies, the catchment is used as a "mega-lysimeter" to calculate annual input-output budgets. However, the literature reflects two opposite interpretations of the trends of nitrate concentration in streamwater. For some authors, essentially in applied studies, the mean residence time of leached nitrate in shallow groundwater systems is much less than one year and river loads reflect annual land use while for others, nitrate is essentially transport limited, independent of soil nitrate supply in the short term and annual variations reflect changes in climatic conditions. This study tests the effect of agricultural land-use changes on inter-annual nitrate trends on stream water of six small adjacent catchments from 0.10 to 0.57 km2 in area, on granite bedrock, at Kerbernez, in Western Brittany (France). Nitrate concentrations and loads in streamwater have been monitored for nine years (1992 to 2000) at the outlet of the catchments. An extensive survey of agricultural practices from 1993 to 1999 allowed assessment of the nitrogen available for leaching through nitrogen budgets. For such small catchments, year-to-year variations of nitrate leaching can be very important, even when considering the 'memory effect' of soil, while nitrate concentrations in streamwater appear relatively steady. No correlation was found between the calculated mean nitrate concentration of drainage water and the mean annual concentration in streams, which can even exhibit opposite trends in inter-annual variations. The climatic conditions do not affect the mean concentration in streamwater significantly. These results suggest that groundwater plays an important role in the control of streamwater nitrate concentration. Keywords: nitrate, diffuse pollution, agricultural catchment, nitrogen budget, leaching, Kerbernez catchments


2010 ◽  
Vol 16 (4) ◽  
Author(s):  
L. Lakatos ◽  
I. Gonda ◽  
M. Soltész ◽  
Z. Szabó ◽  
J. Nyéki

The objective of the present study is to explore the effect of cooling irrigation (aspersion) on the beginning of bloom and on the micro-climate of the plantation. The results show that the water sprayed in the orchard by micro-jet influenced decisively the temperature of the plantation. At higher temperatures (around 20 °C), the drop of temperature may attain 5–7 °C. A low relative humidity of the air may increase the relative effect, The frequent repetition (20 minute intervals) may keep the temperature low also in the buds. The beginning of bloom may delayed for more than ten days. The dynamics of blooming was characterised by a logistic curve in the treated as well as in the control plot. In the treated plot, the curve was steeper than in the control in spite of equal temperatures measured in the plots. Under our (Hungarian) climatic conditions, the method is successfully used to delay blooming dates. The main result is the diminution of the frost damage in the spring and the security of yield. The costs and water requirement should be calculated later.


Russian vine ◽  
2020 ◽  
Vol 14 ◽  
pp. 85-89
Author(s):  
N.A Tikhomirova ◽  
◽  
M.R. Beibulatov ◽  
N.A. Urdenko ◽  
R.A. Buival ◽  
...  

The economic efficiency of the cultivation of grapes as a branch of agriculture depends on the adaptation of grape varieties to the soil and climatic conditions of the place of growth. When developing new agricultural practices and technological solutions for the cultivation of grapes, it is necessary to assess the econom-ic efficiency of the proposed innovative ap-proaches. The cultivation of such grape varie-ties is becoming important and relevant, which, with high productivity and the use of differen-tiated care technology, require minimal costs when servicing the bushes and harvesting. In-creasing labor productivity in the viticulture industry is the most important condition for the intensive development of production. One of these conditions today is the formation of a bush according to the technology element, the shape of a bush AZOS-1, which allows to re-duce the cost of care and harvesting of grapes. The conducted research on the technology of cultivation of table grape varieties in connec-tion with the use of a new form of bush made it possible to economically substantiate the economic efficiency of growing grapes.


2006 ◽  
Vol 36 (2) ◽  
pp. 397-403
Author(s):  
Amauri Bogo ◽  
Ricardo Trezi Casa ◽  
Luis Sangoi ◽  
Paulo Tarcísio Domatos Borba

The relationship between pre-flowering climatic conditions and sugary disease incidence was quantified in grain and forage sorghum genotypes at two sowing periods (mid November and mid December). The trials were carried out over the 2001/02 and 2002/03 growing seasons, in Lages, Santa Catarina State. Four commercial male-fertile sorghum hybrids (BR 600-forrage, BR 700-grain, BR 701-forage/silage and BR 800-forage) and one male-sterile inbred line (BR 001-A) were evaluated. When each genotype reached the flowering stage, 50 panicles were marked and sprayed with a suspension of Claviceps africana (1,000 spores mL-1). Air temperature, humidity and rainfall were recorded through out the growing cycle. Low temperatures three to four weeks prior to flowering, increased susceptibility. At both sowing periods, average night temperatures lower than 15°C during the critical period of pre-flowering turned the fertile hybrids as susceptible as the male-sterile inbred to ergot infection. The tested hybrids differed in their ability to tolerate pre-flowering cold stress. Seed set in uninoculated heads under pollination bags was also reduced, suggesting that increased susceptibility to sugary disease was the result of low temperature induced sterility.


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