Silver-leaf ironbark

Eucalyptus melanophloia

Silver-leaf ironbark grows on the granite country of the northern NSW tablelands and southern Queensland. (Clemson, p.55) When ground moisture is high it produces large quantities of pollen and honey. Crops of 20 to 50 kg per hive of honey have been reported. It is a very quick honey flow lasting for only three to four weeks.

Tests on pollen samples collected at Mole River NSW appear to indicate the pollen is of reasonable quality with a crude protein of 20% to 23%. But the essential amino-acid iso-leucine is well below the 4% required, giving a digestible protein level of 16% to 17%. However the large volume of pollen the bees collect may substitute for this shortage of iso-leucine. (Table 34)

Bees that have worked this type of pollen while being on such a heavy honey flow may well be strong hives of bees, but would be greatly stressed and have a reduced body-protein, also silver-leaf ironbark usually flowers during the midsummer heat. The bees would be stressed through hard work and the heat.

If silver-leaf ironbark has been worked for honey, it would be advisable to work a pollen source before going onto another honey flow, or to feed supplementary protein during and after the silver-leaf honey flow.

The pollen would be useful to collect, store and use as feedback to the bees, as a mix with soyflour.

Many beekeepers who work silver-leaf honey flows report that the ground needs to be very wet before the tree will yield good crops of honey. Also silver-leaf ironbark is a tree which needs strong hives to produce a good crop. It is such a short heavy honey flow that bees cannot breed on the flow and collect good crops of honey at the same time.

Table 34: Silver-leaf ironbark Eucalyptus melanophloia

Amino-acid
Minimum % of Amino-Acid from De Groot (1953)
Mole River 

January 1987

Mole River 

January 1993

Threonine 3.0 3.6 3.6 
Valine 4.0 3.75* 4.4 
Methionine 1.5 1.8 1.5 
Leucine 4.5 6.3 5.9 
Iso-leucine 4.0 3.0* 3.3*
Phenylalanine 2.5 3.8 3.3 
Lysine 3.0 5.6 5.0 
Histidine 1.5 2.75 1.7 
Arginine 3.0 5.99 8.3 
Tryptophan 1.0 1.9 -
Crude Protein - 22.9% 19.7%
Fat    1.1%  

* Low level of this amino-acid


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