Growth Cycle of Asparagus
Asparagus is a perennial crop with a large storage root system. AspireUS operates on the principle that good management of this system is necessary to obtain high yields. It achieves this by providing a method to estimate root CHO content, identifying deviations from normal CHO patterns, and using the deviations to help diagnose problems and suggest crop management decisions to resolve them.
There are usually three phases in each annual growth cycle of asparagus:
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Dormancy, when the soil temperature is low.
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Harvest, when spear growth is driven by temperature and the availability of CHO in the roots.
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Fern growth, when the spears are allowed to grow and form a fern canopy.
These phases occur in most climates and crop production systems, but their order and timing vary. The usual order in temperate climates is for dormancy in winter, followed by harvest in spring-summer, and then fern growth in summer-fall before the next dormant period. In tropical and sub-tropical climates there is little or no dormant phase and, often, the other two phases are combined in the mother fern management system in which emerging spears are harvested from beneath an established fern canopy.
In all climates and systems, the above-ground growth phases are associated with characteristic patterns of depletion and accumulation of soluble CHO in the storage roots. The sequence for a temperate climate (see CHO Graph) is:
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Stored CHO in the roots is usually at maximum during the dormant period.
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Spear harvest and fern establishment deplete stored CHO.
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CHO is replenished by the established fern canopy during mid-late summer.
These general features of the cycle are well known, and asparagus growers understand that high yield depends on high CHO availability from the roots for spear growth during harvest. However, growers seldom know the CHO status of the roots and, even if they did, they could not easily interpret the information. Therefore, the traditional focus of crop management practices has been on above-ground growth, assuming that production of healthy, vigorous fern will lead to high spear yield and quality in the following season.
AspireUS provides a new way for growers to get higher yields and better long-term crop performance by monitoring and managing root carbohydrate (CHO) content during the crop’s annual growth cycle.
