Not AvailableSequential and open field planting at monthly intervals (starting from June to November) of two quantitatively short day marigold species (Tagetes species) was conducted. The results revealed that 50% yield could not be compensated due to differential accurnula- tion of heat degree days. The remaining 50% of the flower yield is differentially compensated either by increase in flower number (10%) or by reduction ill flower fresh weight (50%). The African marigold on an average accumulated 10% lower ADD compared to the French type. Genotypic differences in the accumulation of heat degree days by 38% and 15% at 50% flowering and post- flowering ill African and French types might have influenced the flower quality. The mean accumulated degree days were 10% more in French marigold species in comparison to the African marigold. Genotypic differences regarding the accumulated heat degree days at flowering and post-Ilowerlng stages were most important for quality flower production.Not Availabl
