Relationship between yield and tree growth in almond as influenced by nitrogen nutrition

Abstract

Understanding the relationship between nitrogen (N), tree growth and yield, can maximize productivity and sustainability. This study analyzed the effect of N on canopy development and its relation with yield in a super-intensive almond orchard in Spain over two seasons. The treatments included 50 kg N ha−1, 100 kg N ha−1, 150 kg N ha−1, and 100 kg N ha−1 applied between 3.1 and 7.7 Growth Stages, and their combinations with a nitrification inhibitor, DMPSA. The canopy was measured using LiDAR technology after pruning in spring and before harvest. Differences were found in canopy parameters comparing early N (Nstop) against N applied along the season. The treatments N50, N100 and N150 resulted in higher cross sections and widths, less porosity and higher yield, fruit set and hull weights. In contrast, Nstop gave higher porosity and higher flower density. DMPSA produced more homogeneous canopies and improved N use efficiency, combined with N100 or N150. These findings provide evidence to support the management of N in super-intensive orchards.