01842naa a2200145 a 450000100080000000500110000800800410001910000160006024500590007626000090013552014280014470000180157270000160159077300900160614677942005-06-30       2004    bl ---       0--  u    #d1 aHITSUDA, K.  aDiagnosis of sulfur deficiency in soybean using seeds.  c2004  aThe objectives of this study were to obtain a reliable index for the evaluation of the S nutrition status in soybean [Glycine Max (L.) Merr.] and to identify the critical S level in relation to seed yield and quality. Two Oxisols were used: A-horizon soil from Serra dos Gerais, and A- and B-horizon soils from Sambaiba in Maranhão State, Brazil. Soybean plants in pots were grown in a greenhouse with the supply of 0 to 80 mg S kg-1 soil. The seed S concentration was a more reliable index of seed yield because of the higher correlation between S concentration and yield. In the plants with visible symptoms of S deficiency, the seeds contained 1.5 g S kg-1, and the seed yield was 60% of the control. Electrophoresis analysis indicated that the critical seed S concentration for deficiency of protein components was 2.0 g kg-1 when the yield was 80% of the control. The S concentration was 2.3 g kg-1 or higher for &gt90% yield when the composition of the protein components was identical with that in the original seeds obtained under sufficient S fertilization. We classified the S concentration in the seeds as: deficient (S &lt 1.5 g kg-1), very low (1.5  S &lt 2.0 g kg-1), low (2.0  S &lt 2.3 g kg-1), and normal (2.3 g kg-1  S). Because of stable S concentration, easy sampling, and sufficient time for planning of fertilizer application for the subsequent cropping, seed analysis is preferable to leaf analysis.1 aSFREDO, G. J.1 aKLEPKER, D.  tSoil Science Society of America Journal, Madisongv. 68, p.1445-1451, July/Ago. 2004.