Differences in germination response of spores of several species of rust and smut fungi to nonanal, 6-methyl-5-hepten-2-one, and related compounds.

activity. This may lead to some error when calculating K,. Secondly, the potassium salt of the herbicide may produce some ion pairs. The calculation of Tz using line width is not very accurate and thus T2 measurements using the spinecho method may be preferred. The line-width changes in 2,4,5-T resonance peaks at a fixed BSA concentration in solutions of different pH are shown in Figure 4. The decrease in line width with increasing pH may be explained on the basis of a decrease in binding at higher pH values. Such a decrease may be due to denaturation of the protein a t higher pH values. The lH NMR results of herbicide-BSA binding indicate that the CHz*protons are more affected by the binding than the ring protons, suggesting that they are closer to the binding site. This is in agreement with the earlier investigation of the binding of phenoxyacetic acid and proteins (Fischer and Jardetzky, 1965). I t is interesting to note that this is in contrast with the binding of the chlorinated hydrocarbon bis(p-chloropheny1)acetic acid with BSA, where the binding involves the benzene ring (Haque et al., 1974). Such behavior may be due to the large difference in the hydrophobic characteristics of chlorinated hydrocarbons and these herbicides.