Tropical and subtropical fruits (2+1)

Sex determination in Papaya

• Papaya is a polygamous species, many forms of inflorescence have been reported by Frankel and Galun, 1977.
In general there are 3 important types of flowers.

Staminate or male flowers Spleder spoon shaped buds with long, narrow tubular flowers on long peduncles, from leaf axil petals fused at base and contains stamens but no ovary, it cannot develop in to fruits
Pistilate/Female flowers Large yellow, borne singly or in groups of three in the leaf axils, close to the trunk. These flowers have five large twisted and fleshy petals, surrounded ovary, which swells and develops in to a papaya fruits.
Hermophrodite flowers These are bisexual flowers, having both female and male organs, they are creamy white in colour, big sized flowers no peduncle. The bisexual flowers are also borne in the same manner as of female flowers i.e. closer to the trunk in leaf axils.
• In papaya change in the sex expression is influenced by environmental factors like, low temperature favoring production of perfect flowers on the male tree. It was observed that fertile hermaphrodite types had some pistillate flowers which showed male tendency in summer and female tendency in winters. Seedless fruits are developed from the pure female flowers which are not cross pollinated.
• After flowering the fruits mature within 5 months after flowering; Under adverse climatic condition flowers & fruit drop is very common, to avoid this problem spraying of planofix @ 1ml/liter. Fruit thinning is suggested to get good size and quality.