Walloon Agricultural Research Centre

Dynamics of the synthesis of the biomass and the nitrogenized compounds and their mobilisation and accumulation in the grain of winter wheat (Triticum aestivum L)

Context

Socio-economic context of the Walloon agricultural policy with the regulations of the EC (1799/1992, 824/2000 and 178/2002) as well as the Belgium royal decree of the 07/02/1997, changed the system of production of winter wheat. The farmers are confronted with several constraints : to respect the environment by the reduction or the limitation of their inputs (nitrogen fertilizers and pesticides), and to obtain high quality to fulfill the requirements increased of the outlets (SYNAGRA normes) and to maintain the profitability of their production. The Unit of “Phytotechnie des Régions Tempérées” (FUSAGx) and the Departement of the Crop Production (CRA-W) Gembloux collaborate in studies on the optimization of the output and the quality of the wheat product by the improvement of the cultivation methods, in particular of the nitrogen fertilization. The present project is integrated to these studies. Grain protein concentration, is an important characteristic determining the valorisation of winter wheat, it’s directly influenced as well by the availability of nitrogen for the plant as by its remobilisation from the vegetative organs towards the grain. The origins of the nitrogen accumulated in wheat grain are the immobilized nitrogen (which was taken up during the vegetative growth) and the nitrogen assimilated during grain filling whose transfer to ear is very fast. A large number of studies underline a lack of information about the mechanisms of grain filling in relation to nitrogen absorption and transfer. Some physiological aspects remain still badly elucidated. Plant mechanisms such as remobilisation and absorption of nitrogen in post-anthesis phase and senescence of the vegetative apparatus (organs) prove to be important in the accumulation of nitrogen in the grain. These mechanisms are regulated by the relationship source/sink.

Objectives

Work aims at determining the share of the dry matter and nitrogen of the grain coming from the matter remobilization present in the vegetative parts of the plant at anthesis and that originating from absorption or the late synthesis. Particular attention is devoted to level and spliting of nitrogen fertilization and to wheat genotypes.

Expected results

A better understanding of the grain filling phase is expected and can lead to optimization of nitrogen fertilization taking into account of varietal choice.

Contribution

Installation the experiments of isotopic tracing - Analysis of the nitrogen samples (soil and plant) - Analysis of the nitrogen 15N samples.

Statistical processing of data - Acquisitions of the weather data

Partners

Unit « Phytotechnie des Régions Tempérées » (FUSAGx) Gembloux

CRAW off coordinator

BOULELOUAH Nadia (Doctorante) Département Production végétale Rue du Bordia, 4 B-5030 Gembloux Téléphone direct :62 50 19 Téléphone département :+ 32 (0) 81 / 62.50.00 Fax département :+ 32 (0) 81 / 61.41.52 E-mail :boulelouah@cra.wallonie.be

Funding

CRA-W - Walloon Agricultural Research Centre
FUSAGx - Faculté Universitaire des Sciences Agronomiques de Gembloux

Dynamique de la synthèse de la biomasse et des composés azotés, de leur mobilisation et leur accumulation dans le grain du blé d’hiver (Triticum aestivum L)