Big range dryland wheat yields
The yield range of the 15 Finley Discussion Groups dryland wheat yields in 2017 was 1.5t/ha to 5.6t/ha. The average yield was 3.5t/ha. The yields were linked to the wide crop rain range based on fallow, growing season rainfall and evaporation.
Jerilderie had crop rain of 123mm compared to 191mm for Oaklands.
The crops were biased to the higher rain Berrigan group.
The 5 highest yields 4.2 to 5.6t/ha had very high water use efficiencies (WUE) of 30- 34kg/ mm indicating these crops benefited from extra subsoil moisture from 2016 waterlogged crops.
The WUE for most of the crops was high good practices were used.
Varieties - the high yielding varieties were Condo, Suntop and Lancer with moderate yields and good WUE 18-24kg/mm from Corack and Suntop. Suntop is still performing on dryland.
Rotation - Six of the high WUE crops were sown into canola stubble although the 5.1 and 5.6 tonne stubbles was burnt. Condo was sown into burnt barley stubble.
Two Corack crops which have moderate resistance to yellow leaf spot were sown into retained wheat stubble and one Suntop sown into pea stubble. Canola still dominates rotations.
Sowing date - The higher yields were sown in the first two weeks May.
All crops were sown at 70-80kg/ha in May and emergence was mainly in May.
This is the first time there were no crops sown in late April because of the rain timing and no Gregory.
Fertiliser - DAP and MAP were common at sowing with zinc linked to the higher yields. All crops were topdressed with 80-150kg/ha urea and the total nitrogen applied in urea terms was 104-170kg/ha. Copper and zinc liquids were applied to 4 higher yielding crops.
Weed control - Fallow, pre and post emergence weed control of most crops were good.
Flowering moisture - Most crops only had poor of fair soil moisture so the late rains must have assisted yields.
Harvest selling - There is a new trend through all the winter crop results of more and more farmers not selling at harvest with eight crops not or partly sold or warehoused.
Farmers said yield increases were from washed out areas, weed control, direct drilling, nitrogen after peas, Gaucho® / Vibrance® Emerge®, seed dressings, zinc on fertiliser and will pre-drill more nitrogen in good seasons.
Farmers said their yield decreases were from crown rot (with a lot of wheat in rotation), armyworms, random and late frost damage and rain cutting out in spring.
The information in this article has been prepared in good faith based on available information and farmer feedback.
John Lacy (pictured) is an independent agriculture consultant based in Finley.