A new approach for controlling low boron concentration on nutrient solutions
It has always been a problem for research workers to control low external boron concentrations in the nutrient solutions to study the boron deficiency effects on plant growth. Limitation of conventional solution culture techniques led to a range alternatives for the controlled study of plant nutrition including flowing culture, programmed nutrient addition and chelated-buffered nutrient solution. From a literature review it was found that a range of substances form chelates with boron including poly hydric alcohols like mannitol, sugars and phenolic compounds. However, none apart from hydrofluoric acid formed chelates with formation constant comparable to iron chelates like OTPA or EDDHA. Moreover, most chelating substances had deleterious side effects which reduced their suitability for use in water culture: many of the compounds are substrates for bacterial growth, some were toxic' or harmful to handle, and others are toxic to plants. Current investigations center around the use of the Boron-specific resin, IRA 743 which strongly complexes H3B03 on its N-methyl glucamine functional groups. The boron sorption capacity of the resin varies with the supply batch from 2.2 to 5.0 mg B/ml resin. Boron saturated resin maintains an equilibrium boron concentration in solution of 0.5 mg B/L when added at the rat~ of 2 ml of resin to 1 L of boron free triple deionised water. Current investigations are to study loading and unloading techniques of resin with boron, lowering the boron concentration in solution when the exchange resin is used as a boron source and comparing the plant growth when the boron is supplied by two different ways ie. boron exchange resin and 0.1 mg boron solution.
|Publication Type:||Journal Article|
|Murdoch Affiliation:||School of Biological and Environmental Sciences|
|Publisher:||Asian Network for Scientific Information|
|Copyright:||© Capricorn Publications 2000|
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