Search

Grasslands and forage crops are major components of the agri-food systems worldwide and must provide a wide range of ecosystem services, from the production of feed and food to the preservation of the environments. This paper presents the stakes associated to the three pillars of sustainability, with special attention given to the farmers and their expectations regarding farming systems. We suggest that risk aversion of farmers must be especially taken into account for the definition of new production systems and for the implementation of innovations. Implementation of production systems combining annual grain crops and perennial forage crops or associating plant and animal productions either at farm or territory scales make it possible to maintain production and economical performance and to improve environmental performances. The production systems as well as the breeding and registration systems are involved in lock-in situations that are a complex equilibrium of stakeholders and their activity around a series of standards of production and utilisation. These situations hinder the implementation of “disruptive” innovation that could move the systems to higher levels of productivity and environmental service. The conditions to escape from such situations are explained. Innovative conception theory provides a frame for identifying new concepts and for searching knowledge to support those who are creating the innovations. Adoption of innovations by farmers is a critical issue and tools to facilitate the implementation of innovation by farmers are identified, especially work in farmers groups, advisory systems and, on a long term perspective, training and education. It is also necessary to consider the heterogeneity of farmer communities. The early adopters must be targeted as they are opinion leaders who will first implement the innovations and disseminate them to neighbours and partners.

Plant structure was shown to limit the seed yield of Lupinus mutabilis through low dry matter production. The genetic and environmental variations of architectural and phenological traits of indeterminate Andean lupin were evaluated. Twelve genotypes were sown at 6–8 dates at 5 locations in Europe in 1994 and 1995. Wide variation was observed for phenological and architectural characters. The variation in the number of mainstem leaves was partly explained by the temperature. The mainstem height and flowering date were related to the number of mainstem leaves but flowering time was also affected independently by the enviromental conditions. The mainstem structure determined the potential number of first-order branches through the number of axillary buds. The actual number of branches was also determined by the prevailing environmental conditions during branch growth. The number of leaves on the second first-order branch was less susceptible to the environmental conditions than the number of leaves on the mainstem. Heritabilities were high for all characters except for the number of leaves on the second first-order branch, and the interactions between genotype and environmental condition were low. Breeding for architecture modification would thus be possible in L. mutabilis.

Despite the high oil and protein content of the seeds, the agronomic potential of Lupinus mutabilis Sweet, a South American lupin species, is limited because of its low seed yield and its uncertain maturity. Dry matter accumulation and partitioning, and seed yield, of 2 genotypes (early-maturing LM34 and late-maturing LM268) were studied in 2 seasons at 2 densities at Lusignan, France. Total dry matter at harvest was, on average, 680 g/m2. The mainstem and first-order branches mainly contributed to total plant biomass but pods were only produced on the mainstem. On average, across the different crops, the maximum leaf area index (LAI) was 2· 8. The duration of LAI above 2·5 was short and not correlated with the total dry matter production. The partitioning of the dry matter varied according to the genotype. LM34 showed enhanced pod growth, its harvest index (HI) was 0·32, and seed yield averaged 1·28 t/ha. LM268 showed enhanced vegetative growth, both HI and seed yield were lower (0·16 and 1·13 t/ha, respectively), and whole plant maturity was never reached. For both genotypes during the pod filling, no remobilisation of assimilates occurred from stems to pods.

SUMMARYThe effect of dwarfism on leaf number and size was investigated on six pairs of tall and dwarf nearisogenic lines of indeterminate autumn-sown white lupins (Lupinus albusL.). Dwarfism reduced mainstem height by 41% and first-order branch length by 22%. It also slightly decreased the number of leaves on the mainstem and first-order branches without affecting the time of flowering. Leaf size was not reduced. Logistic equations were used to analyse differences in the patterns of light interception by leaf canopies relative to thermal time from sowing during the growth of seven dwarf lines and three tall cultivars sown on different dates. The genotypes studied had long periods of low light interception during their early growth. No differences were found between most of the equation parameters for dwarf and tall genotypes. Only the proportion of light intercepted at flowering differed and this was explained by differences in flowering time. The dwarf character did not limit the ability of the crop canopies to intercept light. It is concluded that the character can be introduced into a wide range of genetic backgrounds without deleterious effects.