Assessment of hedgerow species for seed size,stand establishment and seedling height

The relationships between seed size, emergence, stand establishment and seedling height were examined in a trial comparing tree and shrub species as hedgerows for alley cropping in four environments in Haiti. Logarithmic functions relating % emergence, % stand establishment and seedling height to seed weight were positive and significant. These relationships were stronger when species weighing > 10 g 100⁻¹ seed were excluded from the analysis. Higher R² values were obtained regressing % stand than regressing % emergence on seed weight. Although exceptions were noted, a majority of species having seed weights between 2.5 g and 10 g 100⁻¹ had good stands. Establishment was poor or inconsistent for species with seed < 2.5 g 100⁻¹. The effect of seed size on height was more important for seed weights < 5 or 8.8 g 100⁻¹, depending upon the site, than for larger seed. Species with < 2.5 g 100⁻¹ seed are unsuitable for direct seeding where the chance of drought is high.