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Seed Production
8.1 Plant Type
The papaya seed production requires technical knowledge due to its complex genetic
make-up and cross-pollinated nature. The monoecious papaya needs cross-fertilisa-
tion, and therefore, segregates very rapidly when male plants of different varieties
are found at one site. In order to harvest genetically pure seeds, it is necessary to
ensure varietal purity. This is achieved by removing any unidentified male plant in
the proximity of the plantation. When seed results from open pollination, it becomes
impossible, in most cases, to obtain selections which are reasonably uniform in
flower type and fruit characteristics. Depending upon the sex type and parental com-
bination, papaya varieties fall under two broad groups as mentioned below.
8.1.1 Dioecious Varieties
Varieties which produce male and female plants separately are called dioecious.
The proportion of male and female is generally 1:1 with male population slightly on
higher side which is a genetical character. The prevalent varieties which fall under
this group are Pusa Dwarf, Pusa Nanha, CO-1, CO-2, Washington, etc.
8.1.2 Gynodioecious Varieties
The gynodioecious varieties comprise female and hermaphrodite plants and both
are productive, thus, these varieties possess only productive plants and are preferred
because of the absence of unproductive male plants. The varieties coming under this
group are Pusa Delicious, Pusa Majesty, Coorg Honeydew, Solo (Hawaii), etc.
8.2 Seed Production Method
The seeds in dioecious varieties are produced by pollinating the female flowers with
male flowers of the same variety, known as sib-mating. The seed in gynodioecious
varieties are produced by crossing the female flower with the hermaphrodite. Since
variation in sex in hermaphrodite plants occurs under different environmental condi-
tions, selection of regular and prolific bearing hermaphrodite plant(s) for seed pro-
duction in each generation is essential. In gynodioecious varieties, the proportion of
female and hermaphrodite plants will depend upon the technique used. If the female
plant is crossed with the pollen of hermaphrodite plant, the population of females
and hermaphrodites will be in equal proportion. If the hermaphrodite plant is selfed
or intercrossed, the proportion of female and hermaphrodite in the plant population
will be 1:2. The female plant is preferred because of the higher yield. Hence, the seed
is produced by crossing the female flower with the pollen of a hermaphrodite plant