Spike dry matter and nitrogen accumulation before anthesis in wheat as affected by nitrogen fertilizer: relationship to kernels per spike

abonos nitrogenados amande de la graine azote contenido de materia seca crop yield deficiencia de minerales dry matter content espigas facteur de rendement factores de rendimiento floraison flowering germen kernels mineral deficiencies nitrogen nitrogen fertilizers rendement des cultures rendimiento de cultivos spikes triticum aestivum yield factors