92 



Flag Smut of Wheat. 



were carefully recorded by tlie farmer, so that they are given here in con- 

 nexion with the appearance of the smut. The soil is a rich alluvial red loam, 

 with a sub-soil of clay at an average depth of 3 inches, and holding the 

 moisture well. On analysis it was found that lime was very deficient. 



The land is level, low-lying, but not swampy by any means, and has 

 hitherto generally yielded splendid crops. The seed obtained from per- 

 fectly new land was carefully graded, dressed with bluestone at the rate of 

 4 lbs. to 50 gallons of water, and drilled in on 28th April. This was a very 

 dry month, only .25 inches of rain having fallen, although the preceding 

 month was very wet, having 5.55 inches. It was sown at the rate of 45 lbs. 

 per acre, and Florida superphosphate along with it at the rate of 75 lbs. per 

 acre. The Hag smut was first observed in this paddock in 1903, the year 

 after the dry season of 1902, and it was estimated that the loss due to it was 

 about 8 bushels per acre. The wheat was followed by Algerian oats in 1904, 

 with nitro-super. as manure. Then bare fallow during 1905, being ploughed 

 in August, disced in November, and scarified about the middle of April. The 

 ploughing was 3 to 4 inches deep. Up till about the beginning of October, 1906, 

 the crop looked perfectly healthy and fresh, and then signs of disease began 

 to appear. All through the crop the smutted plants were found generally 

 destitute of ears, alongside of strong vigorous plants just coming into ear. 

 To give an idea of the state of the crop, on 16th November a square yard of 

 the average crop was measured ofE and the wheat plants grown on it care- 

 fully pulled. There were 144 smutted straws producing no grain, and 62 

 clean straws with healthy ears, or 70 jier cent, affected with flag smut 

 (Plate VIZ.). 



The average rainfall is about 18 inches, but this was much exceeded in 

 1906, and distributed as follows : — 



January 



February 



March 



April 



May 



June 



Total 



After the very definite results obtained from sowing on a dry and a wet seed- 

 bed, as regards the appearance of flag smut, it seemed rather contradictory 

 that the heavy rain preceding the sowing of the crop in 1906 should not have 

 tended to reduce the amount of smut rather than increase it. But, as the 

 farmer informed me that the cattle had the run of the whole paddock, both 

 before and after the heavy rain in March, it is evident how the paddock was 

 freshly infected with smut spores in the most suitable condition for germina- 

 tion. Laboratory experiments conducted in pots showed that with wheaten 

 hay affected with flag smut fed to horses, the resulting manure was capable 

 of infecting seed sown in the ground, and the farmer's cattle in this case were 

 fed on such diseased hay straw. 



During 1908 the flag smut was not so bad in this particular locality. On 

 counting the smutted plants in a row 10 chains long it was found that there 

 were about two diseased straws to every square yard, and the yield was 

 13 bushels per acre. At Dookie and Longerenong there were evidences of it 

 being in the soil, but not widely distributed. At Dookie there were ten plots 

 of 1 acre each on which selected wheats were sown. The seed was treated 

 with bluestone, and the varieties were as follows : — Yandilla King, Marshall's 

 No. 3, Austrahan Talavera, College Purple Straw, Dart's Imperial, Jumbuck, 



