Papaya

Morphology

Morphology

Habit

  • Papaya is normally a small unbranched soft wooded tree almost like a herb.
  • The whole plant contains latex vessels.

Root

  • Root system is extensive and dense but also rather shallow though the tap root is present.

Stem

  • Stem is unbranched, sometimes branches arise when apical bud is damaged.
  • The stem is hollow with soft fleshy tissue covered with smooth grey bark marked externally by numerous large orbicular leaf scars.

Leaves

  • A crown of large leaves are found in a spiral manner.
  • Leaves are very large upto 75 cm across and deeply divided into about 7
  • palmate lobes, each lobe again being pinnately lobed.
  • Leaves dark green often drooping from the ends of hollow petioles even upto 1m long.
  • Leaves are eventually shed leaving a large scar on the stem.

Sex in Papaya

  • Papaya are usually dioecious though hermophrodite plants do occur as in the case of varieties like Solo.

Flower types

Type I

  • Typical female flower apparently polypetalous, obscurely gamopetalous at the base.
  • No external trace of stamens.
  • Pistil is pentacarpellary syncarpous showing 4 shallow lobes

Type II

  • This is the pentandria flower so called due to the presence of 5 stamens alternating with the petals.
  • Petals are adnate with pistil.
  • Pistil is pentacarpellary syncarpous as in Type I but deeply forward, stamens lying in the grooves or furrows between the lobes.

Type III

  • Intermediate

Type IV

  • Intermediate

Type V

  • Typical male flower
  • The corolla tube carries in its throat ten stamens, arranged in two whorls.

Male flowers

  • Found on long pendulous panicles.
  • Individual flowers are small, 2-3 cm long, sessile.

Calyx

  • Minute calyx, gamosepalous.

Corolla

  • A long corolla tube divided about 1/3 of the way from its mouth into 5 pointed lobes, gamopetalous.
  • The pale yellow corolla is often fragrant.

Androecium

  • At the mouth of the corolla tube, ten epipetalous stamens are arranged in two rows of five each.
  • One row with longer filaments alternating with petal lobes, the other with shorter filaments lying opposite to the lobes. Filaments light yellow, anthers, oblong and pistillode is also present.

Female flowers

  • Solitary, much larger than males, around 4-5 cm long and are more or less sessile on the main axis. They also occur as few flowered, comes in the axils of the leaves.
  • Rachis short and thick.
  • Calyx tube is short with five lobes, yellowish green.
  • Corolla has 5 waxy yellow petals united at the base but free for most of their length and with twisted pointed tips. Yellow linear lanceolate, somewhat oblique with a slightly narrowed base and an obtuse or rounded apex.
  • Gynoecium-ovary large, superior, sessile, globular and green with 5 much branched sessile stigmas.
  • Ovary has five united carpels with a single locule which contains many ovules on parietal placentation.

Hermophrodite flowers

  • Two kinds of hermophrodite flowers, one with long corolla type with 10 stamens and another with a short corolla and only 5 functional stamens.

Blossom biology

  • Anthesis is between 6.30 - 8.30 AM.
  • Anther dehiscence immediately follows the anthesis.

Fruit

  • It is a large fleshy hollow berry elongated or globular.
  • In ripe fruit the smooth skin (epicarp) is yellow or bright orange,.
  • The thick orange, yellow or red flesh encloses a centre cavity containing many seeds which are embeded in a mass of musilage.

Seed

  • Seeds are small, rounded, dark green or brown or black.
  • The seeds are covered with a gelatinous material and attached to the flesh by a gelatinous stalk.

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Taxonomy

Genus: Carica

  • Small rapid growing, unbranched trees, commonly grown in greenhouses as foliage plants and often bearing fruit under such conditions. Juice milky.
  • Leaves large, soft, long stalked, in clusters at the top of the trunk, usually dioecious, the male flowers on long axillary peduncles, funnel shaped, with 10 anthers in the throat, the pistillate flowers larger and with 5 distinct petals and a single pistil with 5-rayed stigma, sessile in the axils of the leaves. Perhaps 20 species, all native to American tropics.
  • But Carica papaya is cultivated throughout the tropics for its delicious edible fruits.

Species

  • Papaya grows to a height of 7.5 m, glabrous, leaves to 0.6 m across, deeply palmately 7 lobed, the lobes pinnately lobed, flowers yellowish, to 2.5 cm long or more, male flowers slenders, long-tubed, long-peduncled, axillary recemes to 0.9 m long, female flowers, broader, solitary or few together, on short peduncles, male plants sometimes bearing a few female or bisexual flowers, flower elongate to globose with central cavity, greenish yellow to orange, to 50 cm long with thick yellow or orange flesh, seeds many, black.
  • Widely cultivated in tropics.

Wild species

  • Carica candamarcensis
  • C. cauliflora
  • C. quercifolia
  • C. pentagona
  • C. pentandra
  • C. goudotiana
  • C. microcarpa
  • C. monoica

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Tamilnadu

Papaya

Papaya Management