Sustainability and multifunctionality in French farms: Analysis of the implementation of Territorial Farming Contracts

Sustainable agriculture and ways to achieve it are important issues for agricultural policy. However, the concept of sustainability has yet to be made operational in many agricultural situations, and only a few studies so far have addressed the implementation process of sustainable agriculture. This paper provides an assessment of the Territorial Farming Contracts (TFC) – the French model for implementing sustainable agriculture – and aims to give some insights into the ways to facilitate the development of sustainable farming. Using a systems approach, the founding concept of the TFC model, an analysis has been made of the TFCs signed in the Midi-Pyrenees Region in south-western France. The results show that the first aspect of sustainability apparent in farmers’ projects referred to economic objectives. The environmental and social aspects were not foremost in the farming changes undertaken. In addition, the territorial dimension of the TFC was under-addressed. The majority of TFCs reveal a moderate or even low convergence with territorial priorities. These results are explained partly by the dominance of professional farming organizations in the implementation of TFC, and they imply that the organizational social dimensions of sustainability must not be neglected. Mohamed Gafsi is an assistant professor of farm management at the National School of Agronomic Training. He received his PhD in management science at the University of Bourgogne. His research interests include farm management and protection of natural resources, corporate environmental management, sustainable agriculture, and African family farms. Geneviève Nguyen is assistant professor in rural economics at the National Polytechnique Institute – National Superior School of Agronomy, in Toulouse. Her research interests include the dynamics of agrarian institutions in uncertain economies, the supply and organization of services in remote rural areas. Her research has been carried out in Europe, Africa, and Asia. She received her MA in Economics and her PhD in Agricultural Economics from the Ohio State University. Bruno Legagneux is assistant professor of farm management at the National Polytechnique Institute – National Superior School of Agronomy, in Toulouse. His research interests include farm management and the entry of young farmers into farming. Patrice Robin is an engineer agronomist. He received his diploma from the National Superior School of Agronomy, in Montpellier. He is currently a doctoral candidate at the University of Toulouse. His research interests include agriculture and rural development, environmental issues, and food quality.     

Catabolism of L-ascorbate by Lactobacillus rhamnosus GG

Catabolism of L-ascorbate by enteric bacteria is well documented, but no study has formally proved that bacteria of the Lactobacillus genus ferment this compound. However, some genes analogous to those of yiaK-S operon and ula regulon, which encoded proteins leading to L-ascorbate degradation by Escherichia coli and Klebsiella pneumoniae , have been identified in the recently sequenced Lactobacillus rhamnosus GG genome. Investigations by HPLC and in vivo (13)C NMR using L-[1,6-(13)C]-ascorbate showed that L. rhamnosus GG, a common probiotic strain, has the ability to catabolize L-ascorbate under anaerobiosis. The main products of the ascorbate degradation have been identified as CO(2), acetate, and lactate. These results are in accordance with the metabolic pathway proposed for the fermentation of L-ascorbate by E. coli.     

Antiprotozoal activities of organic extracts from French marine seaweeds

Marine macrophytes contain a variety of biologically active compounds, some reported to have antiprotozoal activity in vitro. As a part of a screening program to search for new natural antiprotozoals, we screened hydroalcoholic and ethyl acetate extracts of 20 species of seaweeds from three phyla (Rhodophyta, Heterokontophyta and Chlorophyta), sampled along the Normandy (France) coast. We tested them in vitro against the protozoa responsible for three major endemic parasitic diseases: Plasmodium falciparum, Leishmania donovani and Trypanosoma cruzi. The selectivity of the extracts was also evaluated by testing on a mammalian cell line (L6 cells). Ethyl acetate extracts were more active than hydroalcoholic ones. Activity against T. cruzi and L. donovani was non-existent to average, but almost half the extracts showed good activity against P. falciparum. The ethyl acetate extract of Mastocarpus stellatus showed the best antiplasmodial activity as well as the best selectivity index (IC(50) = 2.8 μg/mL; SI > 30). Interestingly, a red algae species, which shares phylogenetic origins with P. falciparum, showed the best antiplasmodial activity. This study is the first to report comparative antiprotozoal activity of French marine algae. Some of the species studied here have not previously been biologically evaluated.     

Genetics and molecular mechanisms of resistance to powdery mildews in tomato (Solanum lycopersicum) and its wild relatives

Powdery mildews (PMs) cause disease in a wide range of plant species including important crops. Taking tomato as an example, here we review findings on the genetic basis and mechanisms of plant resistance to PMs. First, we present a summary of our research on tomato resistance to two PM species, with the focus on Oidium neolycopersici. We discuss the genetics of resistance to this pathogen in tomato. Then, we compare different forms of resistance mediated by different resistance genes based on molecular and cytological data. Also, we provide a comparison between these resistance genes in tomato with those in barley, Arabidopsis and wheat, in order to present a model for the genetic basis of resistance to PMs in plants. We try to accommodate these resistance mechanisms in the current model of plant innate immunity. At the end we discuss possibilities to translate these findings to practical approaches in breeding for resistance to PMs in crops.     

Treatment with Gonadotropin Releasing-Hormone in Prepubertal Gilts at Two Different Ages

To study the effect of GnRH in prepubertal gilts, seven crossbred gilts were treated with saline solution and 250 fig GnRH. In connection with saline and GnRH treatments blood was sampled every 15 min for 4 h, thereafter every 30 min for 2 h and every 60 min for 3 h, and finally every 3 h for 6 days. The ovaries were inspected by laparo-scopy just before and 6 days after GnRH treatment. The first GnRH treatment was undertaken when the gilts had a mean age of 141 days and mean body weight of 66 kg. One gilt was in prooestrus at this treatment. In the other 6 gilts the mean LH level was around 0.5 μg/l during a 4 h period after the saline injection. After the GnRH treatment a LH peak was seen with a mean duration of 4 h and a mean maximum level of 9.2 ± 2.07 μg/1. None of the gilts ovulated or showed oestrus within a week after GnRH treatment, which was confirmed by laparoscopy. The seventh gilt which was in prooestrus had high levels of oestradiol-17β (> 40 pmol/1) at GnRH treatment and no LH peak was seen during a 4 h period after treatment.Two gilts which had not shown oestrus at an age of 173 days and a mean body weight of 93 kg were treated a second time with 250 μg GnRH. The LH peak had a duration of 4 h and a mean maximum level of 5.3 ± 3.04 μg/l. Neither of these 2 gilts showed oestrus or ovulated within a week after GnRH injection. It was concluded that a single injection of GnRH results in a LH peak but is not enough to stimulate ovulation or oestrus in prepubertal gilts at a mean age either of 141 or 173 days.Key words: GnRH-treatment, prepubertal gilts, LH, oestradiol-17β     

Technosol genesis: identification of organo-mineral associations in a young Technosol derived from coking plant waste materials

Background, aim and scope  

Technosols form a new soil group in the World Reference Base for Soil Resources (WRB) (FAO, World Soil Resour Rep 132:145, 2006) mainly characterised by anthropogenic parent material of organic and mineral nature and which origin can be either natural or technogenic. The increasing number of sites affected by technogenic materials and their impact on the environment as growing media for plants or as source of pollutants requires an understanding of their functioning and evolution. Among the parameters describing soil functions, the structure is a key property, encompassing physical, chemical and biological soil processes, which is not yet usually studied in Technosols. The presence of high levels of complex technogenic materials and pollutants (polycyclic aromatic hydrocarbons [PAHs] and trace elements) is likely to determine aggregation and induce a specific soil structure. This work was undertaken to test this hypothesis and assess whether technogenic material would contribute to the formation of water-stable aggregates in Technosols.     

Influence of dissolved gases and heat treatments on the oxidative degradation of polyunsaturated fatty acids enriched dairy beverage

The combined effect of dissolved gas composition and heat treatment on the oxidative degradation of a dairy beverage enriched with 2% linseed oil was studied. The dairy beverage was saturated with air, nitrogen, or a nitrogen/hydrogen mixture (4% hydrogen) before pasteurization or sterilization. Saturation with either nitrogen or a nitrogen/hydrogen mixture decreased the dissolved oxygen concentration in dairy beverages (Delta = 7.7 ppm), and the presence of hydrogen significantly reduced the redox potential (Delta = 287 mV). Heat treatments also reduced the oxygen content and redox potential, sterilization being more effective than pasteurization. Both pasteurization and sterilization induced the oxidative degradation of the beverages. On average, the propanal concentration increased by a factor of 2.3 after pasteurization and by a factor of 6.2 after sterilization. However, during storage, sterilized beverages resisted light-induced oxidation better than unheated or pasteurized beverages. Furthermore, saturation with nitrogen or a nitrogen/hydrogen mixture significantly reduced oxidative degradation and provided some protection against color changes during storage.     

A simple stem taper model with mixed effects for boreal black spruce

We simplified Kozak’s taper model by setting the inflection point at 1.3 m (dbh) without losing accuracy and precision. The simplification was required to facilitate the estimation of the covariance parameters when using a mixed-effects method. This method was necessary to take into account the correlation among multiple diameter measurements on an individual stem. The simple stem taper model was fitted to an extended data set collected across the province of Quebec, Canada. Comparison of the predicted stem taper and the derived stem volume with those obtained using existing models showed a comparable predictive power for the simple model. Including a prediction of the tree random effects based on supplementary diameter measurements of the bole improves the predictive ability of the model around the extra diameter observation. This model offers welcome simplicity as a means of predicting tree taper at coarse resolution for planning tree harvesting.     

Artificially applied plant volatile organic compounds modify the behavior of a pest with no adverse effect on its natural enemies in the field

The use of volatile organic compounds (VOCs) derived from plants to manipulate insect pest behavior can be applied in an integrated pest management strategy (IPM) using a combination of attractive and repulsive stimuli. The “push–pull” strategy was developed on this idea in order to disturb and modify the distribution and abundance of pests to protect crops and reduce the use of agrochemicals. This field experiment investigates, in a “push–pull” context using broccoli as a target crop and Chinese cabbage as a pull component, the stimulo-deterrent effect of five synthetic VOCs (dimethyl disulfide, linalool, geraniol, eucalyptol and citronellol) on the oviposition of the cabbage root fly Delia radicum. With the exception of linalool, all compounds tested had a significant effect in the field and eucalyptol showed the most promising results, reducing oviposition on broccoli by 45 %. Moreover, eucalyptol was the only VOC able to reduce the final infestation of D. radicum, i.e., the number of pupae. The other VOCs reduced oviposition by 20–30 %. No adverse effect of the treatments was found on major parasitoids (Trybliographa rapae and Aleochara bipustulata) and potential predators of D. radicum. This study highlights the potential of VOCs as deterrent stimuli against agricultural pests in the field.