|D.R. Wilson, S.M. Sinton, R.C. Butler, D.T. Drost, P.J. Paschold, G. van Kruistum, J.T.K. Poll, C. Garcin, R. Pertierra, I. Vidal, K.R. Green
|carbohydrate, yield, roots, biomass, physiology
The physiology of yield determination in asparagus (Asparagus officinalis L.) is complex.
Above-ground growth of spears and ferns is the ultimate indicator of performance.
However, growth is driven by soluble carbohydrate (CHO), which has a well-known pattern of gain and loss in the storage root system during the crop’s annual cycle.
Root CHO content is a better performance indicator, now that the relationship between above-ground growth and CHO changes is better understood.
Recent research has improved the definition of the root CHO pattern, and of benchmark CHO contents at key times during the growth cycle.
Detection of deviations from the ‘ideal’ pattern can help with early diagnosis of problems.
The research has also led to a simple method for assessing the CHO content of roots and to an internet-based system for delivering interpretations of CHO content data.
Together, these components constitute the Aspire decision support system.
In this paper we review this research.
In particular, we explore four topics that are crucial for the viability of the concept: (a) evaluate whether Brix% of root sap can be used as a surrogate for analytical root CHO content; (b) compare root CHO content patterns in different countries, with different climates and management systems; (c) analyse the significance of root system size; and (d) analyse the physiological capacity of crops to produce CHO during fern growth.
We conclude that, provided the implications of these factors are recognised, the approach can deliver benefits to asparagus growers.
The Aspire system is becoming available to increasing numbers of growers around the world.
Already it is being used by growers in New Zealand and North America, supporting them in making management decisions to improve yields and the long-term sustainability of their crops.
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