Results 91 to 100 of about 252,481 (245)

Seeds of change: The impact of Ethiopia's direct seed marketing approach on smallholders' seed purchases and productivity

American Journal of Agricultural Economics, EarlyView.
Abstract While multiple factors explain low adoption rates of improved varieties by small‐scale farmers in sub‐Saharan Africa, a key supply‐side constraint is the limited availability of seed embodying new traits in the volume, quality, price, and timeliness required by farmers. This constraint is partly attributable to classical failures in the market
Dawit Mekonnen, Gashaw T. Abate, Seid Yimam, Rui Benfica, David J. Spielman, Frank Place   +5 more
wiley   +1 more source

Vulnérabilité territoriale et impacts climatiques dans le bassin du Mono (Togo)

Revue Congolaise des Sciences et Technologies
Dans un contexte d’intensification des aléas climatiques avec des pluies extrêmes, sécheresses prolongées et feux de végétation, cette étude propose une analyse intégrée de la vulnérabilité des populations riveraines dans la partie septentrionale du ...
Ndigridema Narouwa, Essossimna Magamana, Lamboni Payéne, Fousséni Foléga, Robijaona Rahelivololoniaina Baholy, Marra Dourma, Koffi Tozo, Atsu Kudzo Guelly, Komlan Batawila, Koffi Akpagana   +9 more
doaj   +1 more source

Modern pollen rain–vegetation relationships along a forest–steppe transect in the Golestan National Park, NE Iran [PDF]

, 2009
Pollen rain-vegetation relationships were studied over a forest-steppe transect in Golestan National Park, NE Iran. The surface pollen percentages were compared to the vegetation composition of the respective vegetation types in 18 sampling points using ...
Akhani, Akhani, Beer, Beug, Bottema, Bottema, Braun-Blanquet, Budnar-Tregubov, Davis, Davis, Dolédec, El-Moslimany, Faegri, Follieri, Goeury, H. Akhani, Heim, Herzschuh, J.-L. de Beaulieu, Janssen, Klein, Kvavadze, Kvavadze, Leestmans, Leroy, Leroy, Liu, M. Djamali, Markgraf, Moore, Moore, Nakagawa, Neilson, P. Campagne, P. Ponel, R Development Core Team, Ramezani, Reille, Reille, Reille, S.A.G. Leroy, Saadi, Sales, Stuchlik, ter Braak, ter Braak, V. Andrieu-Ponel, Van Zeist, Vincens, Woldring, Wright, Yazvenko   +51 more
core   +1 more source

Climate change and perennial crop production: Evidence of yield impact and adaptation in California

American Journal of Agricultural Economics, EarlyView.
Abstract Perennial crops are economically important. They contribute to food security, providing essential nutrients that are often lacking in annual crops, and provide additional environmental benefits compared with annual crops. Despite their importance, empirical research on the impacts of climate change and adaptation on perennial crops remains ...
Yuanyuan Wen, Wei Zhang, Julian M. Alston   +2 more
wiley   +1 more source

Forest vegetation management: France (chap.4) [PDF]

Current practices and problems of forest vegetation management in France are described in the context of research on alternatives to herbicides.FORET;PEUPLEMENT FORESTIER;VEGETATION;CONCURRENCE VEGETALE;LUTTE;MODE DE TRAITEMENT;LUTTE PHYTOSANITAIRE ...
H. Frochot, P. Balandier, P. Van Lerberghe, R. Michalet   +3 more
core  

Variations écologiques et chorologiques de la végétation macrophytique des rivières acides du Massif armoricain et des Vosges du Nord (France) [PDF]

, 1990
La végétation macrophytique des rivières acides d'Europe occidentale présente une grande unité, marquée par la constance d'un ensemble floristique de base, dont certaines espèces (Callitriche hamulata, Myriophyllum alterniflorum, Potamogeton ...
Haury, J., Muller, S.
core   +1 more source

Drivers of insect herbivory resistance and tolerance to plant damage in the Brachypodium distachyon species complex

American Journal of Botany, EarlyView.
Abstract Premise Insect herbivory is a major biotic factor shaping plant populations and driving the evolution of defensive traits. Polyploidy (whole‐genome duplication) often induces substantial phenotypic and genotypic changes that may affect species interactions, including herbivory.
Antonio J. Manzaneda, Luisa M. Martínez, Ana Fernández‐Ocaña, Teresa Salido, Pedro J. Rey   +4 more
wiley   +1 more source

Résultats d’un délai d’application du dégagement mécanique en plantations d’épinettes blanche et noire dans un scénario de reboisement hâtif

The Forestry Chronicle, 2018
La maîtrise de la végétation concurrente est essentielle afin que les plantations présentent les rendements escomptés, mais ses effets dépendent de son moment d’application.
par Morgane Urli, Martin Barrette, Alain Leduc, Nelson Thiffault   +3 more
doaj   +1 more source

Shaped by context: Evolutionary trajectories of desiccation tolerance in land plants

American Journal of Botany, EarlyView.
Abstract Desiccation tolerance (DT), the ability to survive near‐complete cellular dehydration, is widespread in diaspores but rare in the vegetative tissues of land plants. The patchy and punctuated phylogenetic distribution of vegetative desiccation tolerance (VDT) suggests that the trait is both ancient and recurrent, yet the evolutionary ...
Rose A. Marks, R. Shawn Abrahams, Jenna T. B. Ekwealor   +2 more
wiley   +1 more source

Flower color variation in Digitalis purpurea: Pollination and soil influences across native and introduced populations

American Journal of Botany, EarlyView.
Abstract Premise Flower color, a key trait influencing plant–pollinator interactions, may be influenced by abiotic factors such as soil. We investigated association between pollinators, soil characteristics, and flower color variations in Digitalis purpurea across native populations in Sweden and introduced populations in Bolivia.
Sissi Lozada‐Gobilard, Pamela Espinoza Peñaloza, Giovanni Pascucci, Zainab Aliwi, Emilia Larsson, Mikkel Brydegaard, Øystein H. Opedal   +6 more
wiley   +1 more source