MANAGEMENT OF SPEAR NUMBER, SIZE, QUALITY AND YIELD IN GREEN ASPARAGUS THROUGH CROWN DEPTH AND POPULATION

The effects on spear characteristics and yield of crown densities of 19 000, 33 000 and 44 000 p/ha and depths of 50, 100, 200 and 300 mm obtained by planting at depth or ridging 50 mm deep crowns were studied.

Density and depth effects were independent.
Over 5 years the highest density reduced spear weight by 10% and head quality by 3% but produced 40% more spears and 30% more saleable yield.

Increasing planting depth from 100 to 300 mm increased spear weight by 20% and head quality by 9% but reduced numbers by 20%. Changes in spear number offset those in weight and saleable yield was directly proportional to total yield.
Ridging resulted in similar changes but depth for depth these were not as great as in practice equal depth cover was not achieved.

Linear relationships between depth, density and spear butt diameter and head quality were identified.
Knowing the varietal characteristic of spear size, quality and the height the spear opens, the depth and density required to maximise saleable yield to market specifications of spear length, size and head quality are predictable.

VII International Asparagus Symposium

S.J. McCormick, D.L. Thomsen

https://doi.org/10.17660/ActaHortic.1990.271.19