Scheduling winter barley crop management using a growth stage model [Hordeum vulgare]
1993
Hough, M.N. (Meteorological Office, Bracknell, Berkshire (United Kingdom)) | Chalmers, I.F. | Flockhart, I. (Crops Monitoring Ltd., Inglemire Lane, North Humberside (United Kingdom))
A model of autumn-sown barley is described which calculates leaf number and development stage from site and weather data. The site data needed are from location, altitude, latitude and details of crop variety and sowing date. The weather variable needed is daily mean air temperature. The crop development model is based upon observations of crop emergence and leaf growth which are related to accumulated air temperature measured in a standard meteorological screen. The maximum main shoot leaf number is correlated with mean temperature and daylength in the 5 weeks following sowing. The crop apex development stages, double ridges and maximum primordia, are assumed to correspond to fixed fractions of the maximum leaf number (0.5 and 0.7, respectively). The appearance of nodes, anthesis and maximum grain dry weight is related to thermal time. Some allowance is made for the effects of cultivar since some develop at slower/faster rates than others. The output from the model is the dates at which the following stages are reached: three leaves, floral initiation, double ridges, glumes, maximum primordia, mid stem extension, flag leaf, anthesis and maximum dry weight. This output is intended to be used as a planning tool for farmers to aid the management of crops. Recently, agrochemical companies have used it to determine customer priority and sales opportunities. Reports are issued with projections into the future using climate data and with the next imminent growth stage underlined
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