Class 12 Agriculture and Floriculturist Chapter 2 Cultivation of Commercial Flower Crops — II

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Class 12 Agriculture and Floriculturist Chapter 2 Cultivation of Commercial Flower Crops — II

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Cultivation of Commercial Flower Crops — II

Chapter: 2

A. Fill in the Blanks:

1. Approximately _________ species of roses are native to India. 

Ans: 11.

2. Rose hips are a rich source of vitamin _________. 

Ans: c.

3. Rose hips contain __________ times more ascorbic acid than those of oranges.

Ans: Three.

4. The result of crossing between Dwarf Polyantha and early HT roses is _____________.

Ans: Floribunda.

5. The resultant class developed by crossing HTs with Floribunda is known as __________.

Ans: Grandiflora.

6. Quite cold-hardy low-growing rose, bearing large clustered smaller flowers is _________.

Ans: Polyantha.

7. The roses growing on its own roots are known as _________________. 

Ans: Miniatures.

8. Complete or partial failure of rose bud opening is known as _________________. 

Ans: Rose balling.

9. A phenomenon where new shoots emerging from the axillary buds of the previous floral stem having no floral bud is known as ____________________.

Ans: Blindshoot.

B. Multiple Choice Questions:

1. Proper harvesting stage of rose is ______________.

(a) Tight bud.

(b) Slightly loose. 

(c) Half open.

(d) None of these.

Ans: (a) Tight bud.

2. Bluing of rose petals is due to ______________.

(a) The accumulation of ammonia. 

(b) More salt.

(c) Less sugar.

(d) Bacterial infection.

Ans: (a) The accumulation of ammonia.

3. Which of the following is less sensitive to chilling injury?

(a) Rose.

(b) Bird of paradise.

(c) Gaillardia. 

(d) Marigold.

Ans: (a) Rose.

4. Which flower is acclaimed as the ‘King of Flowers’?

(a) Tulip.

(b) Rose. 

(c) Carnation.

(d) Gladiolus.

Ans: (a) Tulip.

5. The time for budding in roses in North Indian plains is ____________.

(a) September–October. 

(b) November–December.

(c) April–May.

(d) July–August.

Ans: (b) November–December.

6. Wintering of roses in India is done normally in the month of ________________.

(a) July.

(b) October. 

(c) January.

(d) April.

Ans: (b) October. 

7. Which of the following is a long stem cut rose grown in India?

(a) Raktagandha.

(b) Anurag.

(c) Dr. Homi Bhabha.

(d) Mother Teresa. 

Ans: (a) Raktagandha.

C. Subjective Questions:

1. What are the deficiency symptoms of the following nutrients?

(a) Nitrogen. 

Ans: It causes the leaves to turn from light green to yellow so lime may be applied when the soil pH is below 6. Nitrogen is to be applied to such plants only when pH in the field is optimum.  

(b) Phosphorus.

Ans: It causes dark red to purple colouration of leaves so P2 O5 at optimum pH may be applied, though in the case of lower pH, lime should be applied. 

(c) Potash.

Ans: It appears as drying of the leaf edges, in this case 10 g KNO3 /5 litres of water/plant should be applied and if pH is less, Ca should be applied. 

(d) Boron.

Ans: It causes light green colouration of the leaves at the base along with their twisting coupled with the death of terminal buds which can be corrected by applying 5 g borax per bush.

(e) Zinc.

Ans: It causes large areas of dead tissues at tips and between the veins which may be corrected by correcting the soil pH and by applying zinc chelate.  

 2. Discuss the classification of rose plants according to their utility.

Ans: (i)  Prostrate roses: These are a small group of hardy deciduous plants with a short flowering season. These form the low hummocks or mats and make a dense cover so are quite useful for planting on the banks and on the old tree stumps. Some of the most popular varieties are Rosa luciae wichuraiana, ‘Max Graf’, ‘Raubritter’, etc.

(ii) Hedge roses: These are a group of roses quite suitable for planting either on a boundary or at a corner of the garden in the form of informal hedges. These are planted at usual spacing but to keep these in proper shape, these are pruned lightly. All the compact Floribundas are excellent for hedging and these are Chinatown, Dainty Maid, Frensham, Iceberg, Masquerade, Shepherd’s Delight, etc. Among the old shrub roses, the Hybrid musks are quick spreading but make excellent hedges, such as Cornelia and Penelope. From the modern shrubs, Heidelberg and Queen Elizabeth (requiring regular shaping) are the best.

(iii) Shrub roses: These are strong, hardy, variably thorny or bristly deciduous hybrids chiefly between the species and old roses. These bear glossy pale to mid-green leaves with 5–7 ovate and toothed leaflets. Flowers are single or semi-double, some being fragrant, and borne as solitary or in small clusters. These grow up to 1.5 m in height and are suitable for hedging, for planting on the back of the herbaceous borders, among other shrubs and as specimen plants. Some of the popular varieties are Constance Spry, Fred Loads, Fritz Nobis,  Fruhlingsmorgen, Golden Chersonese, Golden Wings, Heidelberg, Iceberg, Joseph’s Coat, Kassel, Munster, Uncle Walter, Wilhelm, Will Scarlet, etc.

(iv) Standard or tree rose: This is a man-made rose created by grafting a bush rose on a tall, sturdy and upright-growing rose plant so that it may mimic a small tree form, that is from 90 to 180 cm. Such plants provide a spectacular scene. 

3. Describe the cultural operations in rose.

Ans: Cultural operations in rose:

(i) T-budding (shield budding): Make a T-shaped incision about 2.5 cm long on the rootstock just below a node. Open the incision to facilitate the insertion of the budding eye. Insert the budding eye in a T-shape cut properly. Secure the eye by wrapping polythene tape, leaving the eye unwrapped.

(ii) Wintering (for Indian conditions): Wintering of roses in India is done normally in the month of January.

(iii) Pinching, pruning, and training: They are practiced to regulate flowering and shape.

4. Describe the important insect-pests and diseases of rose.

Ans: (i) Rose balling: Complete or partial failure of the opening of the rose buds is called rose balling. In this case, outer petals on an unopened or partially opened bud become pale-brown, papery, and dry. Inner petals are initially unaffected but later on they may also die after the invasion of the secondary organisms. This occurs generally in damp weather when entire bud is covered with a grey mould. Possible cause is due to rains followed by bright and hot sunlight which causes scorching of the petals. To minimise this problem, only basal watering is to be done during the evening hours and not during hot sunny days. Such buds should immediately be pruned off.

(ii)  Blindshoot: It is a phenomenon where new shoots emerging from the axillary buds of the previous floral stem, are without a floral bud. This occurs due to insufficient light intensity, lower temperature, and poor nutrient status of the medium.

(iii) Bent neck or Neck drooping: It is the bending of the floral buds on one side of the pedicel from the neck which occurs due to the weakening of the tissues at the neck because of the air blockage, or microbial plugging of water-conducting vessels, thereby the water absorption is unable to match the transpiration rate, hence this problem.

(iv)  Petal blackening: It occurs mostly in the case of red to maroon roses where the outer petals show blackening when exposed to strong sunlight, or in greenhouse roses when the covering sheet has no UV-B radiation protection. This occurs as the yellow pigments in red roses wither due to UV-B radiation, hence the red pigments become darker.

D. Match the Columns:

Ans:

A. Fill in the Blanks:

1. Gaillardia flowers are also known as __________. 

Ans: Blanket flower.

2. Gaillardia can be grown in gardens for __________ or __________. 

Ans: Bedding or borders.

3. Commercially gaillardia is propagated by __________. 

Ans: Seeds.

4. Gaillardia seeds have no dormancy and remain viable up to __________. 

Ans: 31 months.

5. Gaillardia seeds germinate within __________. 

Ans: 10 days.

6. Gaillardias start flowering in __________ to _________ days after seed sowing.

Ans: 90, 120.

B. Multiple Choice Questions:

1. Seed sowing in gaillardia during summer season is done in ________________.

(a) October–November.

(b) February–March.

(c) June–July. 

(d) Any month.

Ans: (b) February–March.

2. Gaillardia is generally propagated through ______________.

(a) Seed. 

(b) Roots.

(c) Cutting.

(d) Bulb.

Ans: (a) Seed. 

3. Gaillardia is native to ___________________.

(a) Japan.

(b) Korea.

(c) China.

(d) Central United States. 

Ans: (d) Central United States.

4. Blanket flower is harvested when they are _______________.

(a) Fully open. 

(b) Half open.

(c) At bud stage.

(d) Showing flower colour.

Ans: (a) Fully open.

5. The colour of gaillardia var. ‘The Bride’ flower is ____________________.

(a) Red.

(b) Yellow.

(c) Cream-white. 

(d) Orange-yellow. 

Ans: (c) Cream-white. 

C. Subjective Questions:

1. Discuss the climatic requirement for cultivation of gaillardia.

Ans: Gaillardia requires sunny spots for better performance. It is a long day plant but requires short days (10–12 hours) for a good vegetative growth, while long days (12–16 hours/day) with high light intensity for flower initiation, so in winters it requires supplementary lighting. It stands well to heat and drought conditions. It grows well at the temperature range of 20–30°C. The perennial types are quite hardy and tolerate temperatures as low as –4°C. It can be grown throughout the year in plains.

2. Write about the important varieties of gaillardia.

Ans: Baby Cole (red flowers with yellow margin), Burgundy (wine red), Copper Beauty (orange yellow), Dazzler (bright orange-yellow petals, centre maroon-red), Firebrand (orange and maroon), Goblin (yellow and red), Golden Goblin (golden-yellow), Ipswich Beauty (orange and brown-red), Kobold (red, margined yellow), Lollypops (red or red and yellow, free-flowering), Mandarin (flame-orange and red), Picta (brown-red and golden-yellow), Picta Aurea (yellow), Red Plume (bright red), The Bride (cream-white), The Sun (golden-yellow), etc.

3. Write about the planting of gaillardia.

Ans: Some 15 cm raised seedbeds should be prepared for growing gaillardia. Soil should be thoroughly mixed with 4–5 kg/m² FYM or vermicompost, and then the soil should be made to a fine tilth through repeated ploughings, and then all the perennial rootstocks should be taken out along with other hard materials such as wood pieces, stone, crocks, polythene shreds, etc. In heavy soils, fresh coarse sand should also be mixed. The soil should be sterilised by drenching with 2% formalin and then covering it with black polythene sheets for 2–3 days and then exposed fully for a minimum of one week further before planting. Beds of convenient sizes (normally 60–100 cm width and the length as per requirement but not more than 6 metres) should be prepared and properly levelled.

4. How is gaillardia propagated?

Ans: Commercially, gaillardias are propagated by seeds, whether it is annual or perennial types, though a few of the perennial types are also multiplied through division, and root or stem cuttings. Gaillardia seeds have no dormancy, and remain viable up to 31 months, provided moisture content has been brought down to less than 9%.

 5. Describe the methods of bed preparation for planting gaillardia.

Ans: Some 15 cm raised seedbeds should be prepared for growing gaillardia. Soil should be thoroughly mixed with 4–5 kg/m² FYM or vermicompost, and then the soil should be made to a fine tilth through repeated ploughings, and then all the perennial rootstocks should be taken out along with other hard materials such as wood pieces, stone, crocks, polythene shreds, etc. In heavy soils, fresh coarse sand should also be mixed. The soil should be sterilised by drenching with 2% formalin and then covering it with black polythene sheets for 2–3 days and then exposed fully for a minimum of one week further before planting. Beds of convenient sizes (normally 60–100 cm width and the length as per requirement but not more than 6 metres) should be prepared and properly levelled.

6. How are the flowers of gaillardia harvested?

Ans: Blanket flowers are harvested when they are fully open.

7. What are the different insect-pests of gaillardia and how are they controlled?

Ans: Root rot or Damping off: It is caused mostly at seedling stage due to pathogens (Alternaria alternata, Botrytis cinerea, Aspergillus, Curvularia pallescens, Dreschslera, and Fusarium) present in the soil, former two causing foliar infection while others affecting seeds and seedling mortality. Dithane M-45 at 0.3% seed treatment is quite effective against all these pathogens.

Root and Stem rot: It occurs due to the infection of Pythium, Sclerotinia, Thielaviopsis, or Rhizoctonia where the lower portion of the stem becomes tan to dark brown, sometimes with white webbing of the fungal growth. Mulching that is too thick and close to the plant, as well as overwatering, should be avoided. Sphaerotheca and Erysiphe cichoracearum cause powdery wilt and in this case, both sides of the leaves are covered with powdery coating. This can be controlled through sulphur dusting and use of colloidal copper fungicide. Potassium sulphide at 0.2% spraying is also quite effective. Entyloma causes white smut on gaillardia plants, first appearing as light green spots on the foliage or with coloured spots in the centre, which  become dark brown at a later stage. To avoid further infection, all the plant debris and fallen leaves should be destroyed. Septoria gaillardiae causes brown-flecked leaf spots with reddish-purple borders which afterwards turn ash-grey, followed by shot-holes. Infected leaves should be collected and burnt and such plants should be sprayed with Bordeaux mixture or dusted with copper fungicide. Pseudomonas causes interveinal leaf discolouration and bacterial leaf spots, followed by foliage turning dark-brown and the collapse of the entire plant. Aerial irrigation should be avoided and infected plant parts should be removed and burnt. If viruses such as impatiens necrotic spot, tomato spotted wilt, and CMV infect this crop, they must be uprooted and destroyed. 

D. Match the Columns:

Ans: 

A. Fill in the Blanks:

1. Botanical name of French marigold is ______________. 

Ans: Tagetes patula.

2. Marigold belongs to family ______________. 

Ans: Asteraceae.

3. Planting marigold in the field reduces the population of ______________ in the soil. 

Ans: Root-knot nematodes.

4. Marigold can be vegetatively propagated through _____. 

Ans: Tip cuttings.

5. Commercially marigold is propagated through _________. 

Ans: Seeds.

6. About ______________ kg seeds of marigold are required for planting one hectare of area.

Ans: 0.7–1.0 

B. Multiple Choice Questions:

1. Among the following, who is associated with Marigold breeding in India?

(a) B. Singh.

(b) R.L. Misra.

(c) M.L. Choudhary.

(d) S.P.S. Raghava. 

Ans: (d) S.P.S. Raghava.

2. Nugget is a cultivar of ______________________.

(a) Marigold. 

(b) Rose.

(c) Tulip.

(d) Carnation.

Ans: (a) Marigold. 

3. Native place of Marigold is _____________________.

(a) Russia.

(b) South Africa.

(c) Mexico. 

(d) India.

Ans: (c) Mexico. 

4. Recommended seed rate of marigold is ____________.

(a) 0.7–1.0 kg/ha. 

(b) 2–3 kg/ha.

(c) 3–5 kg/ha.

(d) 7–8 kg/ha.

Ans: (a) 0.7–1.0 kg/ha. 

5. Optimum temperature required for Marigold cultivation is _______________.

(a) 6–14ºC.

(b) 15–28ºC. 

(c) 30–42ºC.

(d) All of these.

Ans: (b) 15–28ºC. 

6. Among the following, which one is the African marigold variety?

(a) Orange flame.

(b) Melody.

(c) Bolero.

(d) Golden climax. 

Ans: (d) Golden climax.

C. Subjective Questions:

1. Differentiate between African marigold and French marigold. 

Ans:

2. How useful is pinching in marigold?

Ans: Marigold plants are initially straight growing but afterwards due to emergence of many lateral branches these expand horizontally. If the terminal shoot is removed after 40 days of transplanting, side branches start emerging earlier and more number of good quality uniform flowers are produced. If the flowering is required to be delayed, the tips of all these axillary shoots are also removed which will force these shoots to form precocious tertiary shoots so more flowers will be produced, albeit the flowering will be delayed by about 10 days.

3. Describe the harvesting of marigold.

Ans: Flowers in marigold are harvested manually at fully-open stage, though still compact, usually by the evening when the weather has become cool but dew has completely dried up. Depending upon the varieties planted, prevailing climatic conditions and cultural practices adopted, yield of flowers in African marigold ranges from 11–22 tonnes/ha (1.5–2.5 millions/ha) and 6–15 tonnes/ha (8–12 millions/ha) in French marigold. To avoid dehydration, after harvesting the flowers are covered with moist hessian cloth/gunny bags when stored only for a night and next day taken to the market, however, at 8°–10°C these can be stored for up to three days. For local markets, these are either taken in large polythene or gunny bags but for distant markets, they are taken in the baskets of various sizes. The shelf life of loose flowers can be extended by soaking them in 0.1% Aluminium sulphate [Al2(SO4)3] for two hours.

4. Write about the bronze speckling of marigold.

Ans: It appears on African marigold cvs ‘First Lady’ and ‘Voyager’, probably due to iron toxicity, where chlorosis and necrosis, along with the downward curling and cupping of leaves takes place. The iron level in the leaf tissue should not exceed 500 ppm to avoid iron toxicity.

5. Give the symptoms and causes of leaf burn in marigold.

Ans: Symptoms:

(i) The tips and margins of the leaves start turning brown.

(ii) In severe cases, the whole leaf may dry up.

(iii) Leaves look burnt or dried out, mainly when the weather is very hot and dry.

Causes:

(i) Excessive accumulation of salts in the soil due to overuse of fertilizers.

(ii) Irregular or improper irrigation practices.

(iii) High temperature combined with low humidity conditions.

(iv) Direct exposure to hot, dry winds makes the leaves lose too much water, which causes stress and burning.

D. Match the Columns:

Ans:

A. Fill in the Blanks:

1. In India, about _______________ species of jasmine are found. 

Ans: 20%

2. For its concrete, ______________ has an international market. 

Ans: Jasminum grandiflorum.

3. Jasmine is propagated by _____________________. 

Ans: Simple layering and stem cuttings.

4. Dormancy in most of the Jasminum species is observed during __________________. 

Ans: Winters.

5. The easiest way of propagating jasmine is ________________. 

Ans: Cuttings.

6. Seedlings of jasmine can be planted during the _________________. 

Ans: Rainy season.

7. Yield of Jasmine flower is _______________ tonnes/ha.

Ans: 8–10

B. Multiple Choice Questions:

1. Among the following, which one is the substitute for saffron?

(a) Jasmine.

(b) Tulip.

(c) Rose.

(d) Carnation. 

Ans: (a) Jasmine.

2. Climate requirement for jasmine is _____________.

(a) Temperate.

(b) Tropical.

(c) Sub-tropical.

(d) All the above. 

Ans: (b) Tropical.

3. For jasmine oil extraction, which stage of flower is suitable for plucking?

(a) Tight. 

(b) Half open.

(c) Fully open.

(d) None of these.

Ans: (b) Half open.

4. Jasmine is propagated through ____________.

(a) Soft wood cutting.

(b) Semi-hardwood cutting. 

(c) Hardwood cutting.

(d) Seed.

Ans: (b) Semi-hardwood cutting.

C. Subjective Questions:

1. Write down the importance of jasmine.

Ans: However, J. arborescens, J. calophyllum, J. flexile, J. humile, and J. pubescens also have high ornamental value.

2. Describe jasmine propagation.

Ans: Jasmine can be propagated through seeds, though seed-setting is very rare and also seed-raising is the job of a breeder for developing new varieties. It is commercially propagated through cuttings and layering. 

Commercially, cuttings are the easiest way of producing a number of plants from one plant. Softwood central cuttings having at least two leaves and 15–20 cm length are taken mainly in March and also in June, July, September, or October and inserted in the propagation media [sand, vermiculite, sphagnum moss, peat, or various combinations of these, best being coarse sand, followed by sand + moss (1:1 to 1:3)] at an illuminated place. It takes 6–10 weeks for rooting, depending upon the species or cultivar chosen and prevailing climatic conditions. In case of layering, it is simple layering, practised from June/July to October/November, and it takes 90–120 days for removal. Since, it is time-consuming and only a few plants are prepared from one plant, as after bending the shoots are buried in the soil and pegged to remain in the position so one shoot yields only one layer. As in Jasminum auriculatum and J. grandiflorum, the propagation through cutting, is not so successful, these are propagated through grafting and patch budding.

3. Discuss flower harvesting of jasmine.

Ans: Flowering in jasmine may start in the first year of its planting but usually it starts from the second year, though economic yield is obtained usually from the third year. The stage of flower harvesting depends upon the purpose for which flowers are required. Picking is always carried out early in the morning. For use as fresh flowers, fully developed but little opened flower buds are picked, whereas fully opened flowers are picked for extraction of concrete. In India, jasmine flowers are harvested through the hand picking method though in other countries these may be harvested through suction harvester. For marketing, these are packed loosely in small bamboo baskets for local markets, and in corrugated cardboard boxes for distant markets.

4. Describe jasmine pruning.

Ans: It regulates plant growth and flowering. For pruning, the watering is first withheld and then, all the past season shoots are pruned along with straggling and diseased branches to promote the emergence of new shoots on which flowers are produced. Immediately after pruning, the injured plant parts should be pasted with Bordeaux paste so that no pathogen may enter through the pruned parts. Bordeaux paste should be applied on the cut ends to check the entry of the pathogens. For pruning, certain defoliants such as paraquat dichloride, pentachlorophenol, potassium chloride, and sodium chloride can be used to some extent. Jasminum auriculatum should be pruned prior to 15 days of it taking new growth, that is the middle of February, while in case of J. grandiflorum, the pruning may be carried out in any month to obtain a good flower yield, however, the best time being the last week of December. J. sambac can be pruned from October to January for harvesting to get the highest flower yield. Pruning is carried out from 15 to 90 cm from the base having 3 to 13 nodes intact on the plant, and pruning at 90 cm length from the base with 13 nodes produces more number of branches with improved yield in case of J. grandiflorum. However, J. sambac requires only low pruning.

5. Explain planting spacing for different jasmine species

Ans: Usually the planting is carried out during the rainy season when the soil has sufficient moisture and air is quite humid so that plants are saved from casuality. Density of the plant depends upon the species, cultivar, and the soil and environment of the growing area. The spacing provided for various popular species and their varieties are 1.2×1.2 m for Jasminum sambac, 1.5×1.5 m for J. grandiflorum, and 1.8×1.8 m for J. auriculatum. 

D. Match the Columns:

Ans:

A. Fill in the Blanks:

1. Crossandra is commonly known as _________________. 

Ans: Firecracker plant.

2. A high yielding variety of crossandra is ___________. 

Ans: Lakshmi.

3. Seed rate of crossandra is ______________ per hectare. 

Ans: 2.0–2.5 kg

4. Triploid crossandras can be propagated by ___________________. 

Ans: Ground layering.

5. Crossandra commences flowering after ______________ days of planting. 

Ans: 70–75 days

6. Crossandra flowers are ______________ sensitive. 

Ans: Ethylene.

B. Multiple Choice Questions:

1. Crossandra belongs to _______________ family.

(a) Asteraceae.

(b) Rosaceae.

(c) Acanthaceae. 

(d) Irridaceae.

Ans: (c) Acanthaceae.

2. Among the following, which one is the native place of Crossandra?

(a) Asia. 

(b) Europe.

(c) Australia.

(d) Mexico.

Ans: (a) Asia. 

3. Which of the following climate is suitable for crossandra growing?

(a) Temperate.

(b) Tropical. 

(c) Sub-tropical.

(d) All the above.

Ans: (b) Tropical. 

4. Mona Wallhead variety of Crossandra was introduced in India from which country?

(a) USA.

(b) Brazil.

(c) Sweden. 

(d) Sri Lanka.

Ans: (c) Sweden.

5. Crossandra is planted at spacing of ______________.

(a) 20 × 20 cm.

(b) 30 × 30 cm. 

(c) 50 × 50 cm.

(d) 75 × 75 cm.

Ans: (b) 30 × 30 cm.

6. Shelf life of Crossandra flower is ______________.

(a) 2–3 days. 

(b) 5–6 days.

(c) 7–8 days.

(d) 9–10 days.

Ans: (a) 2–3 days. 

C. Subjective questions:

1. What is the importance of the crossandra flower?

Ans: (i) Beautiful flower: It is used to decorate gardens and homes because it blooms in bright colors.

(ii) Used in temples: People offer it to gods and use it in religious functions.

(iii) Garlands and hair: Women wear it in their hair and make garlands from it.

(iv) Gives money: Farmers grow it and sell it in the market to earn income.

(v) Medicinal use: In traditional medicine, it is used for small health problems like headache and skin issues.

2. How is propagation of crossandra done through seeds?

Ans: Crossandra is propagated through seeds, stem cuttings, and layering. Triploid varieties are propagated only through cuttings as these do not set seeds. For one hectare of planting it requires 2.0–2.5 kg of seeds as in one gramme, it contains some 140–200 seeds. A spacing of 50 × 50 cm has been reported as ideal for seed production. Physiological maturity in crossandra seeds is attained in 55–60 days after flowering and these can be stored for up to six months after treating with Captan at 2g/kg of seeds, otherwise these will remain viable only for three months. However, fresh extracted seeds are the best for nursery raising.

3. How is ground layering done in crossandra? 

Ans: Triploid crossandras do not set seeds hence, can be propagated only through ground layering. Well-conditioned layers can be planted from June to July in pits of 15 × 15 × 15 cm at a spacing of 90 × 90 cm. About 12,500 layers are needed to cover one-hectare. Plants will start flowering within a month of planting.

Detailed procedure:

(i)  Select the flexible branches which can reach the ground level.

(ii) Bend down the flexible branch.

(iii) Make a 2 cm slit with the help of a knife under the node.

(iv) Insert a matchstick in the slit.

(v) Remove the leaves of the portion that goes underground.

(vi) Place the operated portion (slit-tongue) below the soil.

(vii) Follow the recommended practices for nutrition and irrigation to the mother plant.

(viii) Layered plant is detached after the formation of sufficient roots.

(ix) Layered plant is placed in a polythene bag with the soil mixture for growing.

(x) Light irrigation is provided to the new plant.

4. How is planting of crossandra done?

Ans: The land is thoroughly ploughed twice or thrice after mixing about 25 tonnes of FYM in the soil at the time of first ploughing, all the foreign materials are taken out, field is levelled, and beds of convenient sizes are made with proper provision of bunds for walking and trenches for watering.  Seeds are sown at the rate of 2.0–2.5 kg/ha in the nursery beds in June–July on 10 cm raised beds having 1 metre width or in polythene bags, and lightly covered with 3 mm of medium. Temperatures at this time being 26oC day and 21oC at night are quite congenial and there these germinate within 3–4 weeks though optimum temperature range for better growth is considered 18–20oC. Cabaryl 15% dusting of the seed-sown beds will protect the seedlings against cutworm infestation in the nursery beds.  Thirty days old seedlings are transplanted in the prepared field when these attain 4–5 leaf stage in the nursery. For better growth cum development along with  higher flower yield, these should be planted with proper spacing. Spacing of a plant depends on the growth and spread of a variety, though commonly, those having normal spread at 50 × 30 cm spacing while others with more spread at 60 × 40 cm distances, where in the former case some 66,666 seedlings per hectare are accommodated, though in latter case some 41,667 plants are grown. Latter spacing is being practiced in Andhra Pradesh. However, the spacing of 45 × 30 cm is recommended for rooted cuttings of cv. ‘Delhi’. In yellow crossandra, the spacing followed is 90 × 90 cm. For pot culture, as is being done in Denmark, seedlings and cuttings are transplanted into 6.25 cm pots singly, and the liners which are transplanted into 10 cm, 11 cm or 15 cm pots with final spacing of 16.5 × 18.0, 18.0 × 118.0 or 23.0 × 23.0 cm respectively, are kept pot-to pot, commercially, until shipped. 

5. Describe flower harvesting of crossandra.

Ans: Crossandra commences flowering 70–75 days after planting and continues to flower throughout the year with a drop in production during the rainy season. Flowers start appearing from the base of the spike, and at the same time, two diagonally opposite flowers open on the plant and it takes about two days for complete opening. Flowers are harvested on alternate days in the early morning by pulling corolla out of the calyx. The flowers are ethylene sensitive. After flowering is over, dried spikes are removed.

D. Match the Columns:

Ans:

Parimol

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