Resistance to rust (Puminia arachidis Speg.) and late leafspot (Cercospridium personaturn (Berk. & Curt.) Deighton) in some peanut genotypes was studied under field conditions. Late leafspot development was also assessed in the glasshbuse and the parameters lesion diameter, defoliation percentage and sporulation gave highly significant correlations with the field disease scores. Several genotypes were found to be resistant to both rust and late leafspot and should be useful sources of multiple diseaseresistance in a breeding program.

7'hcc~ulti~utedpc~a,r1~/ (Arachis hypogaea. Fubaccac) is belic~ved to have orlginutcjd ulorrg I/?(, C~U S I C~I I slo/)c,s (?f ihr ..lnrl(s in Bo111.ia und northerr1 Argentina. The crop 1s t~orc groLt,tr thronghout i r o~~i c~u l utid warm tonpiJralr regron.c. .4rnong diseases uttac.krn,q pc,ut~lrrs, rlitr cwlr.,c~/ hjl Puccinia arachidis arid larr, Ieuf'spot cuuscd hj, Phaeoisariopsis personata urea flic r?io.sl rt?iportan/ and dcstrurttvc~ on a ~, o r l d~, i d r .\c,olc. noti? pa//iogc,tr~, rr,stric./cd rn host run@, to Arachis, prohahly originated and c,oc,vol\,ed irl .Siiut/r .,ltnrriiu alclt~y ~i'ith thrir /~ost.s. In rcwnr years there has heen 1?11i(./r ~rtlphusr.\

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SUMMARY Twenty groundnut genotypes were grown with various spray treatments which controlled either, only rust, or only leaf spot diseases, or all of these diseases or none of them. The genotypes varied in their resistance to these diseases, some having resistance to only one disease and some having resistance or susceptibility to all the diseases. Chemical control of the diseases resulted in variations in leaf area protection and in yield which were specific to each genotype. For some genotypes the diseases had little influence on yield and foliage, while for others yield and remaining green leaf were varied greatly by the control of diseases. For many of the genotypes the yield achieved was well related to variations in the green leaf remaining at maturity as a result of the spray treatments. Genotypes with good levels of genetic resistance did not have high yield potentials while those with the best yields when diseases were controlled were the most susceptible to these diseases.

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