Expl Agric. (2000), volume 36, pp. 369±378 Printed in Great Britain Copyright # 2000 Cambridge University Press RELATIONSHIP OF FLOWER AND POD NUMBERS PER INFLORESCENCE WITH SEED YIELD IN LENTIL By H. A. A. TAMBAL{, W. ERSKINE{, R. BAALBAKI{ and H. ZAITER{ {American University of Beirut (AUB), PO Box 11-0236, Beirut, Lebanon, and {International Center for Agricultural Research in the Dry Areas (ICARDA), PO Box 5466, Aleppo, Syria (Accepted 25 January 2000) SUMMARY This study, quantifying variation in ¯ower and pod production in lentil (Lens culinaris), aimed to answer the question: Will selection for more pods per in¯orescence increase seed yield? In Season 1 (1992±93) all open ¯owers were tracked to maturity in a ®eld experiment with two lentil genotypes sown on two dates. Genotype Talia 2 had a higher rate of ¯ower abortion than pod abortion, in contrast to genotype ILL 2581 which showed the reverse. Flower abortion accounted for 15% of ¯owers opened in early sowing and increased to 22% in the late sowing. Pod abortion was 19% (of ¯owers opened) in early sowing and 23% in the late sowing. These are the ®rst quantitative estimates of ¯ower and pod abortion in lentil. From the data, a rapid sampling method was developed to estimate the average number of pods per in¯orescence at maturity. In Season 2 (1993±94) an experiment was conducted at two locations to estimate the average number of pods per in¯orescence of 81 genotypes and to relate this to seed yield. Although the broad-sense heritability (h 2 ) of the number of pods per in¯orescence was 0.68 and its phenotypic correlation with seed yield was r = 0.71, the highest-yielding genotypes were not those with the most pods per in¯orescence. Selection for the number of pods per in¯orescence cannot be recommended for increasing seed yield in lentil. INTRODUCTION Lentil (Lens culinaris) is an important food legume in West Asia, South Asia, North Africa, Ethiopia, and North and South America. Its seed has a high nutritive value for human consumption and the straw is an important animal feed (Bhatty, 1988). Since lentil is primarily a rainfed crop, yield stability is a major objective in any breeding programme. This could be achieved through a better understanding of the components contributing to ®nal yield. However, these components vary from year to year and from location to location, even for the same lentil genotype (Muehlbauer et al., 1985). Negative correlations are often found between morphological components of yield in crop plants. They probably arise primarily from developmentally-induced relationships. This happens when two developing structures of a plant body compete for a {Corresponding author: W. Erskine. Email: w.erskine@cgiar.org