In most areas the start to the season on Eyre Peninsula is unprecedented. The winter pattern of southern changes arriving with wind and rain, have finally started.
Decisions based on nutrition can be extremely hard given that we are realistically dealing with a shorter growing season. Nitrogen aside and with phosphorous decisions made prior to seeding the trace element decisions still need to be addressed as the season develops.
In my experience, nutrition decisions are still very important in dry years because of the roots inability to source everything it needs in a constantly changing and drier than normal soil profile. Foliar applications of mineral elements can circumvent the root issue and supply the plant with some of its needs. Up to 80% of foliar nutrients can reach their intended target.
Zinc – responsible for enzyme systems associated with growth regulators and therefore tiller development.
Manganese – crucial for chlorophyll production and cell wall strength.
Copper – important for flowering, pollination and seed formation.
These plant physiologies still need to function in plants forming the basis for a light crop as a high yielding crop.
A shorter growing season means opportunities for applications are reduced given frosts, dry spells, active leaf area etc. Therefore, whilst zinc requirements are generally needed earliest, with manganese and copper a little later, the trace element blends provide the opportunity to spray once when conditions are most suitable.
The sulphates deliver high levels of nutrients quickly into the plant where deficiencies occur in an extremely economical fashion, and the chelates can offer a more sustained availability where a more optimistic view of the length of the growing season occurs.
Given limited opportunities do not compromise on water rates if you wish to get the best leaf coverage and absorption rates possible.
Tim van Loon