
%0 Journal Article
%A Maier, NA 
%A Dahlenburg, AP 
%A Twigden, TK 
%T Effect of nitrogen on the yield and quality of irrigated onions (<I>Allium cepa</I> L.) cv. Cream Gold grown on siliceous sands
%J Australian Journal of Experimental Agriculture
%D 1990/12/01
%V 30
%N 6
%P 845-851
%K 
%R https://doi.org/10.1071/EA9900845
%U https://www.publish.csiro.au/paper/EA9900845 
%X The effect of nitrogen (N), at rates up to 590 kg N/ha, on the yield and quality of Cream Gold onions grown on siliceous sands was investigated in field experiments conducted during 1987-88 (1 site) and 1988-89 (2 sites). As the rate of applied N increased there was a significant (P<0.001) increase in the fresh weight of tops harvested when the largest bulbs were 25-30 mm in diameter. Fresh weight of tops was significantly (P<0.001) correlated with final marketable yield of bulbs. Nitrogen application accelerated top senescence. Nitrogen-deficient plants had erect green tops at harvest. Marketable yield was significantly (P<0.01) increased and the yield of culls (unmarketable bulbs) was significantly (P<0.01) decreased as the rate of N increased at all sites. Nitrogen rates in the range 299-358 kg N/ha were required for 95% of maximum yield. Scale thickness increased significantly (P<0.05) and glucose and fructose concentrations decreased significantly (P<0.05) at 2 sites as the rate of applied N increased. Soluble solids and dry matter of bulbs were not affected by N. Bulb size increased as the rate of applied N increased, however, the magnitude of the effect varied between sites. Number of days to 10% sprouting during storage at 15 ¦ 0.5¦C was significantly increased as the rate of applied N increased up to 40 kg N/ha at 2 sites. We have concluded that for the cv. Cream Gold grown on siliceous sands, the high rates of fertiliser N required to maximise marketable yield and bulb size were not detrimental to quality. 
