Papers by Benoit Jeannequin
Computers and Electronics in Agriculture, 2006
SERRISTE is a decision making system that generates daily climate set points for greenhouse grown... more SERRISTE is a decision making system that generates daily climate set points for greenhouse grown tomatoes. The system is based on the mathematical formalisation of expert practices and scientific knowledge, as a constraint satisfaction problem. The structure of SERRISTE is presented, as well as the knowledge used to describe the relationship between the crop behaviour and the greenhouse climate, and the relationship between set points and the resulting greenhouse climate. The performances of the system have been tested in three different locations in France by applying a blind reference management and SERRISTE management to two identical greenhouse compartments at each location. The main results are that SERRISTE maintains higher day to night temperature differences and lower vapour pressure deficit than the reference management, and leads to energy savings in the range of 5-20%. The SERRISTE crop yields at least the same harvest as the reference one. Moreover, the crop behaviour in summer is enhanced by the use of SERRISTE, because the plants are more vegetative and more able to endure high temperatures.
Annals of Botany, 2001
The eects of withdrawing nitrogen (N) from the nutrient solution of adult tomato plants growing i... more The eects of withdrawing nitrogen (N) from the nutrient solution of adult tomato plants growing in rockwool in a greenhouse were investigated over a 6 week period during fruit production. The treatment reduced total plant growth after a lag period of about 2 weeks. The commercial fruit yield after 6 weeks of N deprivation was 7 . 7 kg m À2 compared to 9 . 3 kg m À2 in control plants. During the experiment, growth of the ÀN plants was fuelled by N reserves contained in both the substrate (rockwool) and in plant organs. The nitrogen budget calculated for ÀN plants showed that only a small amount of organic-N was readily available for internal cycling from organs such as stems. It served mainly to feed growing fruits which were the main sinks in the plant. The study also established that stores of nitrate-N were fully depleted but it took 45 d for the ÀN plants to metabolize completely their nitrate reserves. This indicates that internal nitrate is not a readily-accessible store of labile N. An estimation of the critical N concentration ( %N c ) in the aerial dry matter was made from the data. Thus, for a crop yielding about 9 . 9 tons DM ha À1 , %N c was close to 2 . 5 %. This result is discussed in light of existing models that describe the ontogenic decline in %N c in dry biomass of C 3 plants. The study indicates that the current regime of N fertilization practised in soilless cultures not only leads to ineective nitrogen use but also to large losses of N to the environment; N concentrations should be decreased in feeding recipes. The use of N-free nutrient solutions prior to the termination of plant culture may also be a means of limiting the loss of eutrophying elements, such as nitrate, to the environment. # 2001 Annals of Botany Company
Acta Horticulturae, 1998
ABSTRACT A simulation approach (called CONSERTO) has been developed for analyzing different techn... more ABSTRACT A simulation approach (called CONSERTO) has been developed for analyzing different technical management strategies used in greenhouse tomato production during a cultivation cycle. It focuses on the modeling of the quasi permanent interaction between the dynamics of the biophysical system (crop and physical environment) and the grower's decision making process that, indirectly, generates various actions affecting the biophysical system. The most original aspects of the approach pertain to the modeling of the technical management strategy that a grower applies over the cultivation cycle, the integration of a decision making system with a biophysical system and the fully objectoriented implementation of both the discrete-event simulation environment and the domain knowledge components (biophysical and decision systems).
II Modelling Plant Growth, Environmental Control and Farm Management in Protected Cultivation, 1998
Mathematical and Control Applications in Agriculture and Horticulture, 1991
Plant Pathology, 2014
ABSTRACT Botrytis cinerea causes grey mould, a disease common on many economically important crop... more ABSTRACT Botrytis cinerea causes grey mould, a disease common on many economically important crops. Although much attention is paid to the airborne inoculum of this fungus, as it sporulates abundantly in favourable conditions, knowledge on the abundance and genetic characteristics of soilborne inoculum could help improve control strategies. In this study, the soilborne inoculum of B. cinerea was quantified in two greenhouses at different times surrounding the cultivation of four successive lettuce crops. Between 0 and 1177 CFU of B. cinerea per gram of soil were recorded. There was no significant correlation between abundance of soilborne inoculum and subsequent disease incidence on lettuce (P=0.11). Sixty-five strains collected from diseased plants and sixty-six strains collected from the soil were investigated for their genetic diversity. The soil strains showed lower genetic diversity than the lettuce strains when considering the unbiased gene diversity within the nine microsatellite loci, the mean number of alleles per locus and the haplotypic diversity. The genetic differentiation between lettuce and soil strains decreased over three successive lettuce crops. In the same time, the genetic structure of the two groups of strains tended to become similar. These results are consistent with the hypothesis of a flow of inoculum between the lettuce crop and the soil, and vice-versa. Our study shows that grey mould management should pay more attention to the inoculum of B. cinerea present in the soil.This article is protected by copyright. All rights reserved.
The Computerized Greenhouse, 1993
Collaborative research was conducted in the south of France to assess constraints related to both... more Collaborative research was conducted in the south of France to assess constraints related to both climate heterogeneity and ventilation systems on the control potential of a Lecanicillium muscarium-based formulation against whiteXies in Mediterranean greenhouses. Four series of small-scale greenhouse trials were performed in 2001 and 2002. Two applications at 4-5 day intervals of Mycotal were conducted on young larvae of the greenhouse whiteXy, Trialeurodes vaporariorum, at the rate recommended by the manufacturer (ca. 10 10 viable spores per liter of water suspension). The climatic heterogeneity was taken into account by comparing the fungus-induced mortality of nymphs located on lateral row plants to that of nymphs on center row plants. In spite of signiWcant diVerences in air Xows (0.7-1.2 and 0.3 ms ¡1 , respectively) there was no eVect on fungus eYcacy (53-76% mortality). When comparing the inXuence of greenhouse equipment (sophisticated glasshouse vs. polyethylene-covered greenhouse), the fungus was not aVected (89-96% mortality) in spite of signiWcant diVerences in ventilation rates. The results conWrmed that entomopathogenic Hyphomycetes have a strong potential for microbial control of whiteXy larvae infesting tomato crops at moderate ambient humidity in Mediterranean greenhouses in spite of windy periods. These investigations conWrmed that microclimatic conditions prevailing in the targeted insect habitat (under-leaf surface boundary layer) are greatly disconnected from that of both outside and inside the greenhouse. In northern Mediterranean greenhouses, non-stressed tomato crops provide unexpected favorable conditions for mycoinsecticide use against a phyllophagous insect. 2004 Elsevier Inc. All rights reserved.
Scientometrics, 2014
ABSTRACT We performed an analysis of published literature related to fruit and vegetable and inde... more ABSTRACT We performed an analysis of published literature related to fruit and vegetable and indexed in the Web of Science®, covering the period 2000–2009. The EU27 and the USA are the two leading actors in terms of number of fruit and vegetable articles published. This paper compares their publication outputs using bibliometric methods. We assessed the fruit and vegetable species, topics (from Web of Science® categories), countries and institutions involved. The top species, topics and institutions are ranked according to their number of publications. Collaboration networks between countries were mapped to visualize the intensity of the relationships involved in international fruit and vegetable research and to obtain an overall picture of the fruit and vegetable research landscape. These results can be useful for policy makers.
Scientia Horticulturae, 2000
In greenhouse tomato crops, several manual operations are performed each week to keep the plants ... more In greenhouse tomato crops, several manual operations are performed each week to keep the plants in optimal growth conditions. But growers are trying to reduce labour costs by spacing out the manual operations. An experimental study was conducted on one particular operation, axillary bud deshooting. The aim is to determine the effect of the deshooting frequency on vegetative growth and fruit yield, in order to help growers to determine the optimal frequency. The trials were conducted in an experimental station in Ale Ânya (south France). Four deshooting frequencies were compared on two cultivars: every 7 (control), 10, 14 and 21 days. Deshooting frequency affected both vegetative growth and yield: when deshooting was performed seldom (every 21 days), the stem diameter and the vigour scored by experts were decreased; the number of fruits per m 2 was also reduced, leading to a signi®cantly lower yield. Moreover, the harvest started later than on the control. When the axillary buds were eliminated frequently (7 days), even those located near the apex, it reduced vegetative growth, but not yield. Therefore, from a biological point of view, the optimal deshooting frequency lies between 7 and 14 days, probably depending on climate, season and cultivar vigour. #
Fruits, 2009
Introduction. The fruit and vegetable sector group of the French National Institute for Agricultu... more Introduction. The fruit and vegetable sector group of the French National Institute for Agricultural Research (INRA) undertook a bibliometric analysis of INRA scientific academic literature on fruits and vegetables for the 2000-2006 period. This study made it possible to produce quantitative and qualitative indicators that will shed light on the institute's scientific position in relation to the fruit and vegetable sectors. Materials and methods. Different steps were taken to constitute and process a corpus of INRA researcher publication data. The citation corpus gathering bibliographic data was constituted using the Web of Science. The Sphinx data processing program allowed the constituted databases to be structured and manipulated. Results. After the data were cleaned, there was a total of 1463 articles published by INRA authors between 2000 and 2006; this constituted the "fruit and vegetable corpus" studied, which represented 8% of the total number of INRA publications during this period. The typology of fruits and vegetables studied at INRA, the INRA research centres involved, the main subjects addressed by INRA research divisions and the national and international partnerships of INRA authors were analysed. Conclusion. The analysis presented highlights the overall magnitude of research dedicated to fruits and vegetables at INRA. This research is undertaken in the principal research centres of horticulture and/or fruit regions, with a high level of involvement of Southeast centres of France. Partnerships with other French and foreign organisations are numerous.
Fruits, 2011
Introduction. The fruit and vegetable sector group of the French National Institute for Agricultu... more Introduction. The fruit and vegetable sector group of the French National Institute for Agricultural Research (INRA) carried out a bibliometric analysis of INRA publications on fruits and vegetables produced between 2002 and 2006. While a previous study focused on scientific publications indexed by the Web of Science, this study took into account the remaining INRA publications, i.e., gray literature, technical papers and scientific papers not indexed by the Web of Science. Materials and methods. Different steps were taken to constitute and process a corpus of INRA researchers' publication data. The citation corpus gathering bibliographic data was mainly constituted using the INRA institutional repository (ProdINRA). To ensure exhaustivity, a survey was carried out to collect INRA researchers' publications. Due to the different types of publications involved, we had to develop an original method to constitute a complete database which could allow bibliometric analysis. The Sphinx Plus 2 Survey program was used to analyze publications and Pajek software was used to visualize networks. Results. A total of 2,224 publications were authored by INRA between 2002 and 2006. We analyzed the typology of fruits and vegetables studied at INRA, the INRA research centers and research divisions involved, the main research topics, and the national and international partners of INRA authors. Graphic visualizations allowed an attractive presentation of relationships between authors within and outside INRA. Conclusion. This study led to the mapping of INRA fruit and vegetable research publications. It confirmed that INRA plays an active role in the field of fruit and vegetable research.
Computers and Electronics in Agriculture, 2006
SERRISTE is a decision making system that generates daily climate set points for greenhouse grown... more SERRISTE is a decision making system that generates daily climate set points for greenhouse grown tomatoes. The system is based on the mathematical formalisation of expert practices and scientific knowledge, as a constraint satisfaction problem. The structure of SERRISTE is presented, as well as the knowledge used to describe the relationship between the crop behaviour and the greenhouse climate, and the relationship between set points and the resulting greenhouse climate. The performances of the system have been tested in three different locations in France by applying a blind reference management and SERRISTE management to two identical greenhouse compartments at each location. The main results are that SERRISTE maintains higher day to night temperature differences and lower vapour pressure deficit than the reference management, and leads to energy savings in the range of 5-20%. The SERRISTE crop yields at least the same harvest as the reference one. Moreover, the crop behaviour in summer is enhanced by the use of SERRISTE, because the plants are more vegetative and more able to endure high temperatures.
Biological Control, 2005
Collaborative research was conducted in the south of France to assess constraints related to both... more Collaborative research was conducted in the south of France to assess constraints related to both climate heterogeneity and ventilation systems on the control potential of a Lecanicillium muscarium-based formulation against whiteXies in Mediterranean greenhouses. Four series of small-scale greenhouse trials were performed in 2001 and 2002. Two applications at 4-5 day intervals of Mycotal were conducted on young larvae of the greenhouse whiteXy, Trialeurodes vaporariorum, at the rate recommended by the manufacturer (ca. 10 10 viable spores per liter of water suspension). The climatic heterogeneity was taken into account by comparing the fungus-induced mortality of nymphs located on lateral row plants to that of nymphs on center row plants. In spite of signiWcant diVerences in air Xows (0.7-1.2 and 0.3 ms ¡1 , respectively) there was no eVect on fungus eYcacy (53-76% mortality). When comparing the inXuence of greenhouse equipment (sophisticated glasshouse vs. polyethylene-covered greenhouse), the fungus was not aVected (89-96% mortality) in spite of signiWcant diVerences in ventilation rates. The results conWrmed that entomopathogenic Hyphomycetes have a strong potential for microbial control of whiteXy larvae infesting tomato crops at moderate ambient humidity in Mediterranean greenhouses in spite of windy periods. These investigations conWrmed that microclimatic conditions prevailing in the targeted insect habitat (under-leaf surface boundary layer) are greatly disconnected from that of both outside and inside the greenhouse. In northern Mediterranean greenhouses, non-stressed tomato crops provide unexpected favorable conditions for mycoinsecticide use against a phyllophagous insect. 2004 Elsevier Inc. All rights reserved.
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Papers by Benoit Jeannequin