Morphology and Growth

Morphology Stages of Growth Growth Regulators


  • Chillies are dried ripe fruits of the species of genus capsicum and family solanaceae.
  • Though 20 wild species have been reported only 5 species are cultivated viz., C.annum, C. baccatum, C.frutescens, C.Chinense and C.Pubescense.
  • Capsicum annum var. annum is the most widely grown and economically important of the domesticated chilli peppers.
  • It is the only species commercially cultivated outside the America.


  • Capsicum annum var. annum is distinguished with the presence of calyx teeth and the single white large flower at each node.
  • Flower is solitary, extra axillary, some times occurs in pairs, actinomorphic, pedicellate, bisexual and hypogynious.
  • Calyx is capanulate, sepals usually five, gamasepalous and is shorter than fruit. Corolla is bell shaped rotate 5 to 6 lobed twisted in bud.
  • Lobes are thin veined and incured in tips. Androcium consists, instrose, non-convesmient.
  • Anthers dehis Longitudinally by lateral sutures.

  • Carpels2, syncarpous, obliquely place.
  • Ovary superior 2 or 4 celled with numerous ovules in each locule on swollen axile placentation. Style is slender, terminal , linear.
  • Stigma is subcapitate and faintly bifid.
  • Majority of flowers open at 5a.m.
  • Stigma is receptive from a day earlier to anthesis and continued for 2 days after anthesis.
  • The pollen grains are fertile a day before anthesis with maximum fertility on the day of anthesis.
  • In chilli plant emasculation and hybridisation can be done simultaneously.
  • Chilli plant is often cross-pollinated crop, and is visited by pollen carrying insects.
  • Natural cross pollination may go upto 50 per cent depending upon extent of style exertion, time of dehiscence of anthers, wind direction and insect population.
  • To maintain purity of chilli variety, a minimum isolation of 500 m is considered safe.
  • Selfing the unopened buds a day prior to anthesis gives satisfactory result.
  • For crossing, a bud one day prior to anthesis is ideal for emasculation.
  • It can be pollinated on the same day and the bud may be wrapped by thin sheet of cotton which is slightly tightened by giving a side twist.
  • Days required for flowering in chilli crop mainly depends upon the cultivar, temperature, light intensity and duration, soil moisture, fertility status and the age of seedling at transplanting.
  • Percent fruit set in chilli ranges around 20% of the flowers prorduced.


  • Fruit in chilli is a berry. Unlike the usual berries, the seeds are not embedded in fleshy pericarp.
  • Fruits vary in shape, colour and pungency.
  • Pericarp in chilli fruit is leathery or succulent which turns from green to purple or red, orange or orange red.
  • The placenta carries numerous seeds
  • When fruits ripe pericarp begins to dry
  • After anthesis and pollination fruits gradually increase in size and shape. Seeds start developing 15 days after anthesis.
  • Fruits attain full maturity around 35 days after anthesis and then fruit colour turns from green red or purple depending on variety.
  • After maturity of fruits there is loss of moisture.
  • At full maturity, fruits (around 40 days after anthesis) contain nearly 70 per cent moisture.
  • Some chilli cultivars have waxy pericarp and do not loose moisture quickly and retain shiny moisture for a long period.
  • This character is desired especially when chilli is marked for green purpose.
  • Guntur selections G-3 and G-4 have waxy coating and remain fresh for a long time when marketed for green chilli purpose.
  • The first picked fruits have longer fruits than late pickings and similar trend follows in weight also.
  • Fruit weight at maturity varies according to cultivars, time of harvest, soil fertility and cultural management.
  • Weight of fresh fruit ranges from 1g to 300g as per the variety or hybrid.
  • Seed content influence shape and size of fruits. Night temperatures influence seed content. Seed number / fruit also depends on the variety.
  • Major fruit components are seeds, pericarp, placenta and pedicel. There is a great variation in the fruit components mainly due to cultivars and climate conditions.
  • The most important quality character in chillies is the pungency and the colour. The pungent principle is capsaicin C17H27O3N. A major gene determines the pungency but the polygenes acting in a cumulative manner, both positive and negative, determines the various degrees of pungency.
  • The pericarp contains almost all the pungency whereas the chilli seeds contain only traces of pungency with a capsaicin content of 0.005 per cent. The capsaicin content in red dry chillies varies between 0.7 to 0.9%. Over 90 percent of the capsaicin found in the pericarp is found in the dissepiment.
  • Red colour in chillies is mainly due to the carotenoid pigments. Nearly 37 pigments have been isolated from capsicums, of which capsanthin is the major red pigment of chillies contributing towards 35 per cent of the total pigments. The other major carotenoids which contribute to red colour are capsolubin (6.4%) and zeaxanthin (2.3%).
  • Colour of chillies under storage is affected by moisture content, temperature light and fat content of chilli seeds. 9-10% of moisture is optimum for stability of colour.
  • Storing chilli at higher temperature increases the rate of colour degradation. Sunlight exhibits pronounced effect in bleaching of colour and brings about maximum dis-colouration of the red pigments in chillies.
  • The presence of higher amounts of unsaturated fat in chillies seeds leads to quicker deterioration of colour due to oxidation.


  • Seeds are compressed, obicular and minutely pitted.
  • Diameter of seed varies from 3 to 4 mm weighing around 6 mg.
  • Seeds start developing in fruit rapidly during 14-21 days after anthesis.
  • A kilogram seeds contain 120-170 thousand seeds.
  • Increased seed yield was observed with higher nutrition.
  • Phosphorus is known to increase seed size than nitrogen and potash.
  • Seeds remain viable for longer period in fruit than when seeds extracted and stored.


  • Leaves are simple, alternate, exstipulate, elliptic, lanceolate, glabrous with unequal margin.
  • Leaf area per plant varies from 1000 to 3000 cm2.
  • Leaves are shed either due to foliar diseases especially due to powdery mildew infestation, moisture stress or due to senescence.
  • Chilli plants infested by mites have long petiole and leaves curl downward.
  • Thrips infested leaves have cup shaped appearance.
  • Leaf thickness has bearing on pest tolerance especially thrips.
  • Chilli leaves contain nitrogen 3 to 5 per cent, phosphorus 0.5 to 0.6 per cent, potash 3 to 5 percent, calcium 0.9 to 1.3 per cent magnesium 1 to 1.5 percent on dry weight basis.


  • Chilli plant is a highly branched herbaceous plant having height ranging from 50-100 cm.
  • Branching mainly depends on cultivar, soil fertility, soil moisture and season.
  • High branching is preferred in chilli for easy picking of fruits and for effective inter cultivation and to prevent rotting of fruits.


  • Root system of chilli plant is restricted to upper soil layer of 30 cm depth.
  • Application of organic manures and fertilizers enhances root activity.
  • Root system of chilli crop is highly branched with a tap root at centre. Root system resembles that of grasses.
  • Chilli plants withstand drought better than excess soil moisture.
  • It is observed that chilli crop is more drought hardy than sorghum.
  • Moreover, chilli crop picks up its growth after receipt of rains.
  • Water stagnation or saturated condition of soil for more than 24 hours is highly detrimental to the chilli crop at any stage of its growth.


Stages of Growth

  • Total duration of chilli crop is 150-180 days depending on variety, season and climate, fertility and water management.
  • Duration of chilli broadly divided into two phases:
  • (a) Vegetative growth phase
    (b) Reproductive phase.

  • The vegetative phase is sub divided into
    • Germination
    • Seedling
  • The reproductive phase is sub - divided into
    • Stem elongation
    • Branching
    • Flowering
    • Fruiting
    • Fruit development
    • Fruit maturity.
  • Varieties of tropical environment spend 80-85 days in vegetative phase and about 75-90 days in reproductive phase.

Vegetative phase

  • The Vegetative phase is characterised by increasing in plant height with profuse branching.
  • Chilli plant is highly branched herbaceous plant with primary, secondary and territory branching.
  • Height varies from 50-100 cm and maximum dry matter accumulation takes place during this period.
  • Branching mainly depends on variety, fertility status of soil, fertilizer and irrigation management.
  • Plant growth, branching and dry matter accumulation adversely affected by excess irrigation.
  • Heavy branching is preferred for better aeration and sunlight infiltration into the canopy over compacted varieties.
  • This also helps in preventing the fruit rotting.
  • During this period maximum rooting takes place.
  • Excess nitrogen prolongs vegetative growth period.

Reproductive phase

  • Flowering starts from 80-85 days of the crop or 40-45 days after transplanting.
  • Days required for flowering in chilli crop mainly depends upon the cultivar, temperature, light intensity, duration, soil fertility, soil moisture and the age of seedlings at transplantation.
  • Chilli plant is often cross pollinated crop with 50% of natural crossing.
  • For fruit development and maturity about 40 days time is required after anthesis and pollination.
  • Crop is ready for harvesting ripe fruits in about 90 days after transplanting.
  • About 5-6 pickings are taken annually for dry chilli and 8-10 pickings for green chilli.
  • Anthesis normally occurs around 5 A.M. stigma is receptive from a day earlier to anthesis and continued for 2 days after anthesis.
  • Percent fruit set in chilli ranges from 20-30 percent of the flowers produced.
  • At full maturity, fruits contain nearly 70 per cent of moisture.
  • Fruit weight at maturity varies according to the cultivar, time of harvest, soil fertility and cultural management.
  • Yield in chilli measured in terms of weight of green or dry fruits.
  • Weight of chilli depends on size of fruit, number of fruits per plant, and seed content of fruit.


Growth Regulators

In chilli crop Growth regulators are used for

  • Production of male sterile flowers
  • Induce early flowering
  • Preventing flower and fruit drop
  • Uniform ripening of fruits
  • Increase or decrease seed content in fruits

Growth regulators used in chilli are,

  • Naphthalene acetic acid (NAA)
  • Indole acetic acid (IAA)
  • Gibberallic acid (G.A)
  • Tri - iodo benzoic acid (TIBA)
  • Kinetins
  • Ethylene
  • Phenoxy acetic acid
  • Sterols
  • Long chain aliphatic fatty acids etc.,
  • "Naphthalene Acetic Acid" (NAA) is used to prevent flower and fruit drop and "etherel" for uniform maturity of fruits are commercially used.

For production of male sterile flowers

  • Hand emasculation is costly and time consuming.
  • Application of growth regulator to chilli plant either before bloom or at flowering suppress stamen formation leading to male sterility.
  • Application of Morphactin at 1 PPM before flowering produces stamen less flowers. But higher concentrations produce epinasty.

For early flowering and reduce flower drop:

  • Chilli plants have 2-3 peaks of blossoming which is influenced by soil moisture, nutrient supply, incidence of pests and diseases
  • Any stress at blossoming leads to flower and fruit drop.
  • Fruit set in chilli crop varies from 30-40% only.
  • Flower drop is maximum on cloudy days.
  • Spraying of NAA @ 2-3 ml/10 litres of water at 45 and 60 days after transplanting induce early flowering and prevents flower and fruit drop.

Production of parthenocarpic fruits

  • Cattle urine, indole acetic acid (IAA) and phenoxy acetic acid (PAA) not only produce parthenocarpic fruits but also increase fruit size.
  • Application of PAA or IAA @ 10 PPM at pre-anthesis stage results in production of 40-60% parthenocarpic fruits.

Uniform ripening fruits

  • Red ripe fruits are valued for colour and flavour. Uniform ripening reduces harvesting period and labour requirement
  • 2 - Chlorophenyl phosphoric acid (Etherel or Ethephon) is applied @ 500 PPM when the first fruit on the plant begins to turn slightly red.


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