Waterlogging and fungal disease characterised conditions on many northern paddocks in 1998. The way varieties performed under these conditions is outlined below.
Most crops were affected by yellow leaf spot which took out the flag leaf prematurely, reducing grain fill and causing the small grain problem. Take-all and crown rot disease were also evident. Melanism, or false black chaff disease, was aggravated by yellow leaf spot in SR2 varieties (Suneca, Sunbrook, Sunstate, Kennedy, Dollarbird, Hartog, Batavia, Diamondbird).
Wheat-following-wheat situations were worse because of earlier infection from stubble, and waterlogging situations aggravated the problem. Wheat on fallow and break-crop paddocks was also affected because masses of spores spread through the atmosphere, but infection was later and effect on yield not nearly as severe.
Varietal susceptibility rating
Worst (reduced yield and pinched grain): Janz, Sunmist, Hartog, Batavia, Sunland, Banks, Sunbrook
Moderate (reduced yield): Sunstate, Sunvale, Sunco, JM73, Diamondbird, Sunbri, Rosella, SunSoft 98
Best (minimal effect): H Apollo, H Mercury, H54, Silverstar, Sunlin, Cunningham, Whistler, Currawong (Leichhardt), Kennedy. Durum varieties - Kamilaroi, Wollaroi, Yallaroi
The varieties in the 'worst' category had substantial pinched grain, whereas varieties in the 'moderate' group were able to hold their grain size.
Overall, durum performed well last season. All three varieties were tolerant of yellow leaf spot and small grain was not a problem. Grain yields were good. Most was received into DR2 and DR3 because of protein problems, black point problems, or both.
Major diseases were leaf net blotch (spot form), scald and waterlogging. Very little malting barley was received due to discoloration and low grain weight.
Varietal susceptibility to net blotch in 1998:
Worst: Gairdner, Franklin, Lindwall
Moderate:Skiff, Tantangara, Sloop, Schooner
Best: Tilga, O'Connor, Wyalong
* This material was taken from a Grains Research Update (seminar series sponsored by growers through the GRDC) by Col Mullen — NSW Agriculture, District Agronomist Dubbo.
Contact: Mr Col Mullen 02 6881 1276; email: firstname.lastname@example.org