Crop-damaging wireworms-the soil-dwelling larvae of click beetles-have resurged in Europe over the past 15 years, particularly in French maize crops. There is currently no curative treatment available to control wireworms, and preventive treatments are mainly chemical. We therefore need to better understand factors that rule damage for developing agroecological control strategies. In this investigation, we tested the effect of agricultural practices and local landscape on wireworm damage in maize crops. We surveyed wireworm damage in 341 fields under various conditions in western France in 2011 and 2012. We used in particular a random forest algorithm to impute missing values and an automated model selection routine to select the best beta regression model. Our results show that the occurrence of grassland in the rotation increases wireworm damage. Tillage also shows a high influence, though varying with season and year. Wireworm damage is decreased by the presence of hedges or cultivated crops at the field border, whereas it is increased by the presence of grassland at the field border. Overall, our findings provide some insights to develop preventive solutions for the sustainable control of wireworms, as well as a framework for data processing to analyze a wide range of similar situations involving other crops and pests.

International audience

In order to understand the effect of nuclear transfer technology on the physiology of lactation and milk fatty acid composition in dairy cattle (Holstein breed), the present study compares the milk yield and composition from bovine somatic cell cloned (n=5) and control animals (n=5) at 180 days in milk (DIM) maintained together under the same conditions. All cows were offered the same total mixed ration ad libitum. At 180 DIM, the cloned had a higher body weight (BW; P<0.01) compared with control animals, whereas comparable body condition score (BCS) was observed among the 2 groups. The cloned cows had a lower milk yield and milk protein and lactose yields (P<0.05) and had a tendency (P=0.08) for a lower milk fat yield. Conversely, no differences in milk fat, protein and lactose concentrations were observed in cloned compared with control animals. Similar milk fatty acid (FA) concentrations were observed in cloned and control cows except for two minor FA, cis-9 C10:1 and C17:0 (P<0.05) that were higher in the cloned. The milk fat cis-9 C14:1/C14:0, cis-9 C16:1/C16:0, cis-9 C18:1/C18:0, cis-9, trans-11 C18:2/trans-11 C18:1 concentrations ratios were not different in cloned and control. The milk medium-(C10–C16) and long-(∑C18) chain FA yields were lower (P<0.05) in cloned compared with control animals. The mRNA abundance of genes encoding for SCD1, SCD5, ACACA and FABP3 genes in mammary tissue was similar (P>0.05) in cloned and non-cloned animals. Conversely, cloned animals had a lower (P<0.05) mRNA abundance of LPL and a tendency (P<0.10) for lower mRNA abundance of FASN and CD36 genes compared with control. The absence of major differences of milk constituent concentrations, milk FA composition and of the SCD desaturation indices observed between cloned and conventional animals suggest a comparable nutritional quality of milk for these animals. The noticed differences in milk long chain-FA yields were consistent with modulation of mammary lipogenic pathway as suggested by lower mRNA abundance of LPL gene in cloned compared with control. Otherwise, differences in the partitioning of nutrients between the mammary gland and other tissues cannot be excluded as suggested by the higher BW and lower milk yield observed in cloned. Altogether, these observations may be attributed to different genetic background and/or to epigenetic modifications due to the nuclear transfer technology that may affect the growth and the physiological adaptation to lactation and impact the dairy performances. Further investigations are required to identify the mechanisms underlying these differences.

In order to understand the effect of nuclear transfer technology on the physiology of lactation and milk fatty acid composition in dairy cattle (Holstein breed), the present study compares the milk yield and composition from bovine somatic cell cloned (n=5) and control animals (n=5) at 180 days in milk (DIM) maintained together under the same conditions. All cows were offered the same total mixed ration ad libitum. At 180 DIM, the cloned had a higher body weight (BW; P<0.01) compared with control animals, whereas comparable body condition score (BCS) was observed among the 2 groups. The cloned cows had a lower milk yield and milk protein and lactose yields (P<0.05) and had a tendency (P=0.08) for a lower milk fat yield. Conversely, no differences in milk fat, protein and lactose concentrations were observed in cloned compared with control animals. Similar milk fatty acid (FA) concentrations were observed in cloned and control cows except for two minor FA, cis-9 C10:1 and C17:0 (P<0.05) that were higher in the cloned. The milk fat cis-9 C14:1/C14:0, cis-9 C16:1/C16:0, cis-9 C18:1/C18:0, cis-9, trans-11 C18:2/trans-11 C18:1 concentrations ratios were not different in cloned and control. The milk medium-(C10–C16) and long-(∑C18) chain FA yields were lower (P<0.05) in cloned compared with control animals. The mRNA abundance of genes encoding for SCD1, SCD5, ACACA and FABP3 genes in mammary tissue was similar (P>0.05) in cloned and non-cloned animals. Conversely, cloned animals had a lower (P<0.05) mRNA abundance of LPL and a tendency (P<0.10) for lower mRNA abundance of FASN and CD36 genes compared with control. The absence of major differences of milk constituent concentrations, milk FA composition and of the SCD desaturation indices observed between cloned and conventional animals suggest a comparable nutritional quality of milk for these animals. The noticed differences in milk long chain-FA yields were consistent with modulation of mammary lipogenic pathway as suggested by lower mRNA abundance of LPL gene in cloned compared with control. Otherwise, differences in the partitioning of nutrients between the mammary gland and other tissues cannot be excluded as suggested by the higher BW and lower milk yield observed in cloned. Altogether, these observations may be attributed to different genetic background and/or to epigenetic modifications due to the nuclear transfer technology that may affect the growth and the physiological adaptation to lactation and impact the dairy performances. Further investigations are required to identify the mechanisms underlying these differences.

In order to understand the effect of nuclear transfer technology on the physiology of lactation and milk fatty acid composition in dairy cattle (Holstein breed), the present study compares the milk yield and composition from bovine somatic cell cloned (n=5) and control animals (n=5) at 180 days in milk (DIM) maintained together under the same conditions. All cows were offered the same total mixed ration ad libitum. At 180 DIM, the cloned had a higher body weight (BW; P<0.01) compared with control animals, whereas comparable body condition score (BCS) was observed among the 2 groups. The cloned cows had a lower milk yield and milk protein and lactose yields (P<0.05) and had a tendency (P=0.08) for a lower milk fat yield. Conversely, no differences in milk fat, protein and lactose concentrations were observed in cloned compared with control animals. Similar milk fatty acid (FA) concentrations were observed in cloned and control cows except for two minor FA, cis-9 C10:1 and C17:0 (P<0.05) that were higher in the cloned. The milk fat cis-9 C14:1/C14:0, cis-9 C16:1/C16:0, cis-9 C18:1/C18:0, cis-9, trans-11 C18:2/trans-11 C18:1 concentrations ratios were not different in cloned and control. The milk medium-(C10–C16) and long-(∑C18) chain FA yields were lower (P<0.05) in cloned compared with control animals. The mRNA abundance of genes encoding for SCD1, SCD5, ACACA and FABP3 genes in mammary tissue was similar (P>0.05) in cloned and non-cloned animals. Conversely, cloned animals had a lower (P<0.05) mRNA abundance of LPL and a tendency (P<0.10) for lower mRNA abundance of FASN and CD36 genes compared with control. The absence of major differences of milk constituent concentrations, milk FA composition and of the SCD desaturation indices observed between cloned and conventional animals suggest a comparable nutritional quality of milk for these animals. The noticed differences in milk long chain-FA yields were consistent with modulation of mammary lipogenic pathway as suggested by lower mRNA abundance of LPL gene in cloned compared with control. Otherwise, differences in the partitioning of nutrients between the mammary gland and other tissues cannot be excluded as suggested by the higher BW and lower milk yield observed in cloned. Altogether, these observations may be attributed to different genetic background and/or to epigenetic modifications due to the nuclear transfer technology that may affect the growth and the physiological adaptation to lactation and impact the dairy performances. Further investigations are required to identify the mechanisms underlying these differences.

As a consequence of climate change, forage crops in Belgium are increasingly subjected to late spring water deficits, threatening the autonomy of cropping systems. The goal of this study was to compare the yield performances of forage crops under water deficit conditions, and identify the underlying drought tolerance mechanisms. For this purpose, quantitative and qualitative yield traits along with several gas exchange-related physiological traits were measured in the field on 8 genotypes belonging to 4 different species under both well-watered and water deficit conditions. In addition, whole plant transpiration response curves to water deficit conditions were examined under greenhouse and growth chamber conditions. The investigation showed yield genetic variability under drought, which was not linked to field-based instantaneous measurements. In contrast, whole plant transpiration sensitivity to increasing vapor pressure deficit (VPD) was correlated with the yield performances. This multi-environmental study highlights the importance of the crop sensitivity to VPD as a major player in the yield variability. | À cause du réchauffement climatique, les cultures fourragères en Belgique sont soumises à des déficits hydriques de fin de printemps plus importants, menaçant l’autonomie fourragère des exploitations agricoles. Le but de cette étude était de comparer les rendements de différentes espèces et variétés fourragères en situation de déficit hydrique imposé et d’identifier les mécanismes de tolérance à la sécheresse sous-jacents. Les rendements qualitatif et quantitatif ainsi que plusieurs paramètres d’échanges gazeux ont été mesurés sur 8 génotypes appartenant à 4 espèces en conditions hydrique limitante et bien irriguée. De plus, la réponse de la transpiration de la plante entière à des conditions de déficit hydrique a été évaluée en serre et chambre de culture. Notre étude a révélé l’existence d’une variabilité génétique des rendements en situation de sécheresse, celle-ci n’étant pas corrélée avec les paramètres instantanés mesurés au champ. Au contraire, la sensibilité de la transpiration de la plante entière au déficit en pression de vapeur (VPD) était fortement corrélée avec les rendements. Cette étude multi-environnementale souligne l’importance des réponses des cultures au VPD dans l’établissement de ces performances.

As a consequence of climate change, forage crops in Belgium are increasingly subjected to late spring water deficits, threatening the autonomy of cropping systems. The goal of this study was to compare the yield performances of forage crops under water deficit conditions, and identify the underlying drought tolerance mechanisms. For this purpose, quantitative and qualitative yield traits along with several gas exchange-related physiological traits were measured in the field on 8 genotypes belonging to 4 different species under both well-watered and water deficit conditions. In addition, whole plant transpiration response curves to water deficit conditions were examined under greenhouse and growth chamber conditions. The investigation showed yield genetic variability under drought, which was not linked to field-based instantaneous measurements. In contrast, whole plant transpiration sensitivity to increasing vapor pressure deficit (VPD) was correlated with the yield performances. This multi-environmental study highlights the importance of the crop sensitivity to VPD as a major player in the yield variability. | À cause du réchauffement climatique, les cultures fourragères en Belgique sont soumises à des déficits hydriques de fin de printemps plus importants, menaçant l’autonomie fourragère des exploitations agricoles. Le but de cette étude était de comparer les rendements de différentes espèces et variétés fourragères en situation de déficit hydrique imposé et d’identifier les mécanismes de tolérance à la sécheresse sous-jacents. Les rendements qualitatif et quantitatif ainsi que plusieurs paramètres d’échanges gazeux ont été mesurés sur 8 génotypes appartenant à 4 espèces en conditions hydrique limitante et bien irriguée. De plus, la réponse de la transpiration de la plante entière à des conditions de déficit hydrique a été évaluée en serre et chambre de culture. Notre étude a révélé l’existence d’une variabilité génétique des rendements en situation de sécheresse, celle-ci n’étant pas corrélée avec les paramètres instantanés mesurés au champ. Au contraire, la sensibilité de la transpiration de la plante entière au déficit en pression de vapeur (VPD) était fortement corrélée avec les rendements. Cette étude multi-environnementale souligne l’importance des réponses des cultures au VPD dans l’établissement de ces performances.

Forage species to associate in multispecies grasslands, in order to both productivity, perenniality and quality for farmers, are better known in the various conditions of soils and climate of French territory, based on regional experiences obtained by experiments fields. For the suckling cattle breeding area of north Massif Central and for cutting, the presence of adapted species as cocksfoot, lucerne and red clover is more important than number of species or seeds quantity. | Les espèces fourragères à associer dans des prairies multi-espèces apportant à la fois productivité, pérennité et qualité aux éleveurs, se précisent dans les conditions variées de milieux du territoire français, grâce à l’expertise régionale acquise au travers d’essais. Pour la zone d’élevage allaitant du nord du Massif Central et pour la fauche, la présence d’espèces adaptées comme le dactyle, la luzerne et le trèfle violet, apparaît prépondérante au nombre d’espèces ou à la dose de semis.

Forage species to associate in multispecies grasslands, in order to both productivity, perenniality and quality for farmers, are better known in the various conditions of soils and climate of French territory, based on regional experiences obtained by experiments fields. For the suckling cattle breeding area of north Massif Central and for cutting, the presence of adapted species as cocksfoot, lucerne and red clover is more important than number of species or seeds quantity. | Les espèces fourragères à associer dans des prairies multi-espèces apportant à la fois productivité, pérennité et qualité aux éleveurs, se précisent dans les conditions variées de milieux du territoire français, grâce à l’expertise régionale acquise au travers d’essais. Pour la zone d’élevage allaitant du nord du Massif Central et pour la fauche, la présence d’espèces adaptées comme le dactyle, la luzerne et le trèfle violet, apparaît prépondérante au nombre d’espèces ou à la dose de semis.

Plusieurs espèces légumières sont des plantes grimpantes, soit par des vrilles comme le pois ou les Cucurbitacées (melon, concombre, courge, pastèque…), soit grâce à une tige volubile comme le haricot ou, parmi les espèces tropicales, l’igname et plusieurs espèces de Vigna. Les formes sauvages de ces espèces sont à longue tige grimpante mais, à la suite de la domestication, au cours de la diversification, des mutants ont été sélectionnés. Ils sont caractérisés par des entre-nœuds plus courts, la perte de la volubilité de la tige et éventuellement la disparition des vrilles.

Plusieurs espèces légumières sont des plantes grimpantes, soit par des vrilles comme le pois ou les Cucurbitacées (melon, concombre, courge, pastèque…), soit grâce à une tige volubile comme le haricot ou, parmi les espèces tropicales, l’igname et plusieurs espèces de Vigna. Les formes sauvages de ces espèces sont à longue tige grimpante mais, à la suite de la domestication, au cours de la diversification, des mutants ont été sélectionnés. Ils sont caractérisés par des entre-nœuds plus courts, la perte de la volubilité de la tige et éventuellement la disparition des vrilles.

Key messageBud burst disruption, carbon depletion and tree dieback in spring were experimentally linked to N shortage the previous autumn. Dieback occurred despite tree N concentrations were compatible with plant survival: their N stores being blocked in the roots and woody axes.ContextTree dieback is generally linked to hydraulic failure or carbon (C) starvation but seldom to poor nitrogen (N)resources.AimWe provide here an experimental evidence linking autumn N shortage, C depletion and tree dieback in spring.MethodsYoung peach trees were either N deprived or fertilised in autumn, and then fed in excess in spring. Springsupplies were 15 N-labelled. The effects of the deprivation on tree development, N uptake and C status were then assessed by coupling in situ measurements of shoot development with organ biochemical and isotopic determinations.ResultsAll deprived trees died within 3 months after burst. Bud burst was severely disrupted, and vegetative growth limited to the expansion of a few leaves. The dead trees absorbed between 39 and 117mg 15N in spring, and their roots and axes contained 758 mg more nitrogen than the fertilised trees, suggesting that they did not mobilise their N reserves in spring.They also had lower non-structural carbohydrate concentrations (<3.9 % DW) than the fertilised trees (>15.4 % DW), which were below the threshold accepted for plant survival.ConclusionTwo possible causes of total non-structural carbon (or TNC) depletion are discussed: insufficient storage due to advanced leaf senescence or increase in the C costs regarding winter embolism recovery

Key messageBud burst disruption, carbon depletion and tree dieback in spring were experimentally linked to N shortage the previous autumn. Dieback occurred despite tree N concentrations were compatible with plant survival: their N stores being blocked in the roots and woody axes.ContextTree dieback is generally linked to hydraulic failure or carbon (C) starvation but seldom to poor nitrogen (N)resources.AimWe provide here an experimental evidence linking autumn N shortage, C depletion and tree dieback in spring.MethodsYoung peach trees were either N deprived or fertilised in autumn, and then fed in excess in spring. Springsupplies were 15 N-labelled. The effects of the deprivation on tree development, N uptake and C status were then assessed by coupling in situ measurements of shoot development with organ biochemical and isotopic determinations.ResultsAll deprived trees died within 3 months after burst. Bud burst was severely disrupted, and vegetative growth limited to the expansion of a few leaves. The dead trees absorbed between 39 and 117mg 15N in spring, and their roots and axes contained 758 mg more nitrogen than the fertilised trees, suggesting that they did not mobilise their N reserves in spring.They also had lower non-structural carbohydrate concentrations (<3.9 % DW) than the fertilised trees (>15.4 % DW), which were below the threshold accepted for plant survival.ConclusionTwo possible causes of total non-structural carbon (or TNC) depletion are discussed: insufficient storage due to advanced leaf senescence or increase in the C costs regarding winter embolism recovery

• KEY MESSAGE : Bud burst disruption, carbon depletion and tree dieback in spring were experimentally linked to N shortage the previous autumn. Dieback occurred despite tree N concentrations were compatible with plant survival: their N stores being blocked in the roots and woody axes. • CONTEXT : Tree dieback is generally linked to hydraulic failure or carbon (C) starvation but seldom to poor nitrogen (N) resources. • AIM : We provide here an experimental evidence linking autumn N shortage, C depletion and tree dieback in spring. • METHODS : Young peach trees were either N deprived or fertilised in autumn, and then fed in excess in spring. Spring supplies were ¹⁵N-labelled. The effects of the deprivation on tree development, N uptake and C status were then assessed by coupling in situ measurements of shoot development with organ biochemical and isotopic determinations. • RESULTS : All deprived trees died within 3 months after burst. Bud burst was severely disrupted, and vegetative growth limited to the expansion of a few leaves. The dead trees absorbed between 39 and 117 mg ¹⁵N in spring, and their roots and axes contained 758 mg more nitrogen than the fertilised trees, suggesting that they did not mobilise their N reserves in spring. They also had lower non-structural carbohydrate concentrations (<3.9 % DW) than the fertilised trees (>15.4 % DW), which were below the threshold accepted for plant survival. • CONCLUSION : Two possible causes of total non-structural carbon (or TNC) depletion are discussed: insufficient storage due to advanced leaf senescence or increase in the C costs regarding winter embolism recovery.

Meat supply chains have to face 3 major global stakes for their sustainable development: health (animal and human), equity and environment. Rising demand for meat and livestock sector development have serious consequences in terms of natural resources depletion, animal health, public health, structure of production and access to markets. In the same time, amenities of livestock production should be strengthen and better acknowledged in policies. We suggest 5 principles that will allow the sector to successfully improve its sustainability: efficiency in using natural resources, conservation of resources, protection of rural livelihoods, resilience of communities and ecosystems and governance of private and public initiatives.

Meat supply chains have to face 3 major global stakes for their sustainable development: health (animal and human), equity and environment. Rising demand for meat and livestock sector development have serious consequences in terms of natural resources depletion, animal health, public health, structure of production and access to markets. In the same time, amenities of livestock production should be strengthen and better acknowledged in policies. We suggest 5 principles that will allow the sector to successfully improve its sustainability: efficiency in using natural resources, conservation of resources, protection of rural livelihoods, resilience of communities and ecosystems and governance of private and public initiatives.