There is a general trend towards using controlled-release fertilisers (CRFs) in ornamental horticulture because they deliver many benefits, including precision to optimise quality and yield while minimising environmental impact through leaching.
CRFs are also convenient and result in labour savings. Their use provides base-level steady feeding, which growers can top up as necessary and at key crop stages by using water-soluble or foliar feeds.
Having pioneered CRFs almost 50 years ago, ICL's Osmocote products continue to evolve thanks to innovative new technologies and increasing scientific knowledge.
A recent development from the company is a software programme that calculates nutrient demand.
With more than 900 individual recommendations tailored to specific ornamentals as well as some fruit crops, AngelaWeb 2.0 takes into account crop type, variety, growing media and growth phase to display the nutrient demands.
By inputting information regarding water source and how it is applied, and selecting fertiliser product, the programme calculates a regime to the crop's exact needs.
ICL is also establishing trials for two new CRFs. Limited product is available for grower trials this year. One is Osmocote-coated CalMag. It has been developed for calciumor magnesium-demanding container nursery stock such as Rosa, Buxus, Taxus, junipers, magnolias and hydrangea. It can also be used on calcium-demanding pot plants such as poinsettia and cyclamen, in soft-water locations or where growing media contains little lime. After the trials, Osmocote-coated CalMag will join the standard range of Osmocote Exact or Pro products.
The other new product is Osmocote Iron. With threeto four-month longevity, this fertiliser contains 17.8 per cent controlled-release iron. Daily release of small portions of iron has been shown to promote better leaf colour and help optimise photosynthesis. A full product launch is expected in 2017.
The table details CRF products available in the UK. Omission of any company or product does not imply criticism.