Factors Affecting Wheat Quality

Press, Volume CIV, Issue 30937, 18 December 1965, Page 9

Factors Affecting Wheat Quality

At some time in the future it is likely that wheat will be purchased on a quality basis. It is therefore a matter of some importance to farmers if it can be determined in advance what aspects of farm practice have an influence on quality. This was the subject of a report by Mr G. M. Wright, a cereal breeder at the Crop Research Division of the Department of Scientific and Industrial Research, to last week’s meeting of the Wheat Research Committee. According to the report there are conditions under which heavy applications of nitrogenous manures would be economic in terms of increased yields and would give a reasonable improvement in baking quality. This, however, applies to a relatively small proportion of crops grown on soils with a low nitrogen content Tests to determine low soil nitrogen levels would be useful to show where applica-

tions of nitrogen would give increased yield and baking quality. Dr. H. C. Smith, director of the Crap Research Division, said thia week it was hoped that the Department of Aqrirwitaire might be able to develop a nitrogen testing service so that nitrogen levels could be determined before ptougiing Of U peddocfc at during the growing period. Substantial improvements in grain protein content can be obtained by late spraying or topdressing. according to Mr Wnfnt, Mtt ear>Brui unimt Of tbaae applications is needed if there is to be any associated yield improvement. The Im-

provement in protein quantity may not, however, always be matched by an equivalent increase in baking quality. Mr Wright says that all New Zealand studies have shown that with the present high level of soil fertility the cropping history of the paddock in which wheat is being grown is more important in determining quality than soil type, cultivation practices, or, within limits, climatic factors.

Drought and disease can improve quality, while reducing yields, but the effects on quality are not marked, he says. The application of extra nitrogen can be detrimental, particularly where there is a high level of soil nitrogen, and if this occurs under conditions of drought or disease yield can be reduced. Late sowing, says Mr Wright, also leads to improved quality and lower yields. Investigation of nitrogen topdressing of stubble before ploughing tor a second crop of wheat might be rewarding. The danger of using unnecessarily high sowing rates in a dry season also needed to be brought to the attention of farmers, said Mr Wright. This was something that affected yield more than quality. The report M to be referred to toe research division of the Department of Agriculture wMi the ronert tost it collaborate wMk the Crop Research Division in further wort aimed .at improving the qnahty and yWd of wheat Dr. Smith said that further trials were envisaged in which the rote and timing of nitrogen applications in relation to the previous cropping history of an area would be studied. These woted be trials in which the Crop Research Division and Department of Agriculture would be cooperating.