SUMMARYPhotosynthesis and resistance to rust infection were studied in upper, uninfected leaves of broad bean, Vicia faba L., where the lower two leaves were infected with rust, Uromyces viciae‐fabae (Pers.) Shroet. Following inoculation of the lower leaves, rates of net photosynthesis were significantly increased in the upper, uninfected, fully‐developed leaves and the young developing leaves, compared to controls. In contrast, photosynthesis was substantially reduced in the lower, rusted leaves. When 14CO2 was fed to the upper, uninfected leaves of rusted plants, there was a considerable increase in labelled assimilate in those leaves, compared to controls. In addition, there was substantial movement of labelled assimilate into lower, rusted leaves, into young, developing leaves and into roots. On the other hand, there was a substantial reduction in labelled assimilates moving into shoot apices.Upper, uninfected leaves of rusted beans exhibited Increased resistance to rust infection. Thus, the percentage leaf area covered with rust and the number of pustules per cm2 were reduced in these leaves compared to controls. This resistance to rust infection was greatest when the upper leaves were challenged 1 d after inoculation of the lower leaves with rust and decreased with increasing time after inoculation of the lower leaves. Young, developing leaves on rusted beans also exhibited increased resistance to rust infection. When photosynthesis in the upper leaves was reduced to near control values or well below control values by shading, resistance to rust infection in those leaves was also reduced, although not in proportion to the reduction in photosynthesis. It is suggested that the increased photosynthesis in upper, uninfected bean leaves probably facilitates maximum expression of resistance to infection in those leaves.

Resistance in the upper leaves of broad bean (Vicia faba) plants to infection by the rust fungus, Uromyces viciae‐fabae, was increased following treatment of the lower leaves with 10 mm potassium phosphate or 5 mm EDTA. Increasing the interval between treatment of the lower leaves and inoculation of the upper leaves had little effect on rust infection. Thus rust infection was reduced by 50 and 34% if the upper leaves were inoculated 1 day after treatment of the lower leaves with potassium phosphate or EDTA, respectively, while there was a 75% reduction in infection if the interval between treatment and inoculation was increased to 12 days. Application of calcium nitrate (10 mm) after the phosphate or EDTA treatments prevented the induction of systemic resistance. Calcium nitrate applied alone to the lower leaves had no significant effect on rust infection of the upper leaves.

A laboratory continuous mixed suspension salting out crystallizer was designed and constructed to test the dynamic crystallization model proposed by Randolph and Larson. The model relates the crystal size distribution to nucleation and growth kinetics and operating conditions. The ammonium alum-ethanol-water system was selected because of its ease of operation and control. The results of this work were in agreement with the steady state model. Under the conditions of these experiments, it was found that the nucleation rate dN o / dt was related to the growth rate r by dN o /dt = k 1 r 2 . The crystallizer was also operated under unsteady state conditions which resulted from variations in the production rate. The theoretical model with experimentally determined parameters was simulated on an analog computer and solved for production rate changes. The results indicated that the model was in agreement with the dynamic data for production rate upsets.

AbstractFurther studies with the isobutene‐aluminum chloride‐methyl chloride system has led to a better understanding of the dependence of degree of polymerization on monomer concentration and on temperature. Polymerizations were also carried out in C14‐labeled methyl chloride to determine solvent incorporation in the polymer. A quantitative kinetic theory has been developed which explains the behaviour of the isobutene–aluminum chloride system in polar solvents such as methyl chloride, vinyl chloride, and ethyl chloride. The rate‐determining step in propagation is polymer activation, presumably by ion separation. The DP of the polymer is determined principally by two competing chain‐breaking processes; namely, chain transfer to monomer and/or chain breaking involving the solvent. The latter reaction becomes important in polar solvents at higher temperatures. The influence of phase separation has also been studied. The results indicate that the polymer molecule precipitates after it has under gone either a chain breaking or a chain termination reaction.