sentence: Reduced sucrose production in the leaf could lead to reduced ovary initiation , lower ear growth rate , and increased ovary abortion ( Jacobs and Pearson , 1992 ; Andrade et al ., 2002 ) , as well as delayed flowering , slow silk emergence , and increased anthesis – silking interval ( Hanway , 1962 ; Lafitte and Edmeades , 1994 ; Lemcoff and Loomis , 1994 ) , which further limits sink strength during grain filling , and imposes a sink to source feedback regulation on leaf carbon accumulation and export.It is clear that photosynthesis is under feedback control , and that the C to N balance is more important than C status per se to understand C metabolite feedback control of photosynthesis ( Paul and Pellny , 2003 ) .