Lec- 7 & 8 Grafting, budding.pptx horticulture

Agriculture

1. Vegetative Propagation – Merits and Demerits – Cutting, Layering, Budding and Grafting – Stock-scion Relationships

2. Vegetative Propagation Asexual propagation or vegetative propagation or clonal propagation refers to the multiplication or perpetuation of any plant from any vegetative parts of plants other than the seed. Vegetative propagation is possible as the vegetative organs of many plants have the capacity for regeneration.

3. For instance, Stem cuttings have the ability to form adventitious roots. Root cuttings can generate new shoot system. While leaves can regenerate new roots and shoots.

4. Vegetative propagation is also known as clonal propagation since this kind of propagation is the rule to maintain a clone . A clone may be defined as genetically uniform materials derived from single individual and propagated exclusively by vegetative means.

5. Bartlett pear , a clone originated as a seedling in England during 1770 has been propagated ever since by vegetative means. The leading cultivars of Tea in South India namely Sundaram and Pandian have been exclusively propagated by cuttings ever since they were identified as superior seedlings in a plantation.

6. Advantages of vegetative propagation The progenies are true to type of the cultivars. Vegetative propagation is the only rule where no seed is formed Or Germination of seed is very slow or no viable seed is formed. Eg . Banana, Pineapple and Roses.

7. Certain rootstocks have the capacity of resisting or tolerating the adverse environmental factors such as Frost Adverse soil factors like salinity and alkalinity. Frost resistance – Poncirus trifoliata . Almond and Myrobolan plum roots tolerate excess boron.

8. The ability of certain rootstocks to resist pests and diseases can be advantageously exploited. Apples when grafted to rootstocks like Merton 778, 793 and 779 are resistant to wooly aphids.

9. Vegetatively propagated plants are generally dwarf in stature than the seedlings. Dwarf trees facilitate pruning, spraying and harvesting. Besides more number of plants can be accommodated in a unit area.

10. To replant an undesirable existing tree due to ; Its poor quality Susceptibility to pests and diseases Pollination requirement It is expensive and time consuming. This defect can be overcome easily by vegetative propagation through grafting or budding of desirable scion to the existing tree by top-working techniques.

11. Many plants are propagated by vegetative means because of the speed and ease of multiplication . For instance in Date Palm, which can be grown to maturity from large off-shoots. The size of which would require several years if to be produced from seeds.

12. Disadvantages of Vegetative Propagation Vegetative propagation is sometimes more expensive than seed propagation. Vegetative propagated plants are comparatively short-lived. The chances of carrying viruses from one generation to subsequent generation are more.

13. Genetic Variation in Asexually Propagated Plants Genetic variation is clonally propagated plants occurs due to gene and chromosome (mutational) changes which can occur within somatic cells. It may lead to a permanent changes in the clone. Some of these changes are of Horticultural curiosities or Economically important.

14. When mutations that occur within a plant often affect only a segment of the meristem and as a result, give rise to sectors or layers of the mutated tissues. Thus, a plant propagated from such meristem is composed of two or more genetically distinct tissues growing adjacent to each other. Such plants are called chimeras.

15. Plants with variegated leaves as found in Coleus, Crotons, Euonymous , Bougainvilleas are example of chimeras. Depending upon the extent of mutated cells lying adjacent to non-mutated cells in a meristem . Three kinds of chimeras are recognized viz. Sectorial chimera, Periclinal chimera and Mericlinal chimera

16. Sectorial chimera In this type, the growing point of the shoot is composed of two genetically different tissues situated side by side occupying distinct sectors of the stem. Leaves and lateral buds arising from such a shoot may be composed of two tissues combined in various ways, depending upon their location.

17. Periclinal chimera In this type, tissue of one genetic composition occurs as a relatively thin skin. Usually with one or several cell layers in thickness over a genetically different core.

18. This is most common and relatively stable chimera type. Such chimeras will revert back if they are propagated by seed or Root cuttings arising from the adventitious roots which originally arise from non-mutated layer.

19. Mericlinal chimera This is similar to periclinal chimera. Except that the outer layer of a different tissue does not extend completely around the shoot. Only occupying a segment of the circumference.

20. Budsport If a branch which shows changes from the rest of the plant in one or more inheritable characters. That can be perpetuated by vegetative means is called a budsport .

21. Many of these budsports are only chimeras and are detected when a lateral shoot develops from a mutated area. Many Horticultural cultivars originated due to budsports . Deep red coloured Starking and Richa Red apple cultivars are sports of the original Delicious apple cultivar.

22. METHODS OF VEGETATIVE PROPAGATION The various vegetative propagation methods are: Cutting/ cuttage Layering/ layerage Budding/ buddage Grafting/ graftage

23. Cuttings Any vegetative plant part, when detached from the parent, is capable of regenerating the missing organ or organs Root cutting - Seedless breadfruit Leaf cutting - Bryophyllum Stem cutting - Rose, Grapes, Hibiscus

24. Seedless Breadfruit Root cutting The true roots of any plant species 10 – 12 cm long planted horizontally

25. Leaf cuttings Sansevieria Peperomia Begonia Bryophyllum

26. Bryophyllum

27. Leaf-bud cuttings Leaf bud cutting consists of leaf blade petiole and a short piece of stem with the attached axillary bud Axillary bud gives raise to the shoot and the roots are initiated from the basal end of stem piece Tea, Camellia and Rhododendron

28. Leaf-bud cuttings - Tea Leaf-bud cuttings – Tea

29. Stem cutting Hard wood cuttings Cuttings are made from fully matured past season shoot with stored food materials Hard wood cuttings should be about 15 – 25 cm long with atleast 2 – 3 nodes Basal end of the cuttings should be slanting and just below the basal node while the top cut end should be straight and 2 – 3 cm above the last node Roses, Grapes and Pear

30. Hard wood cuttings - Grapes

31. Semi-hard wood cuttings Cutting is made from evergreen species during summer and the wood is partially matured Leaves are retained on this type of cuttings usually on the top side Duranta , Hibiscus and Crotons

32. Semi hard wood cuttings - Hibiscus

33. Soft wood cuttings The cutting are taken from woody plants prior to lignification when the tissues are still relatively soft It is also known as green wood cuttings Root easier and quicker than other types, but require more attention Jasmine, Hibiscus

34. Soft wood cutting – jasmine

35. Straight cutting is the commonly used stem cutting Mallet and heel cuttings are used for plants that might otherwise be more difficult to root Heel cutting or torn – A small section of older wood is included at the base of cutting Mallet or Hammer cutting – An entire section of older stem wood is included

36. Heel or Torn cutting Normal cutting Mallet or hammer cutting

37. Herbaceous cuttings Cutting is made form succulent herbaceous plants will not develop woody tissues This will root relatively in a shorter period Geranium, Chrysanthemum and coleus

38. Herbaceous cuttings

39. Coleus

40. Layering Layering is the development of roots on a stem while it is still attached to the parent plant It is easy to perform Any clone which cannot be easily rooted by stem cuttings may be made to root through layers Desired size of plants can be obtained by layering

41. Ground Layering Simple layering - Rose, Jasmine, Guava Compound or Serpentine layering: Jasmine, American grapes, Peperomia Trench layering or etiolation methods: Cherry, Plum Apple rootstocks

42. Tip layering : Blackberry, Raspberry Mound layering or stooling : Rootstocks of Apple, Pear

43. Air Layering It is also known as gootee or marcottage In air layering roots form in the aerial part of the plant where the stem has been girdled or slit at an upward angle Ficus elastica Guava and Crotons

44. Air Layering - Ficus

45. Grafting is the art of uniting or combining tissues of two individual living plant pieces in such a way that they will unite and subsequently grow and develop as one single individual plant. Here the two pieces are Rootstock and Scion. Grafting

46. Scion Graft union Rootstock

47. ROOTSTOCK It is the lower portion of the graft combination which develop roots and become the base and root system of the plant. It absorbs nutrients and water from the soil. It provides anchorage to the resultant graft. Rootstock is otherwise known as stock or under stock.

48. Seedling rootstock Mango, Plums and Peaches Clonal rootstock Apple, Pear and Citrus

49. SCION It is the upper portion of the graft combination It consists of several buds ready to sprout and develop into new shoots which forms the stem and branches Develops in to the top of the tree (Canopy)

50. Techniques of Grafting Inarching or approach grafting Side grafting Epicotyl or stone grafting whip grafting (splice grafting) Whip and tongue grafting Saddle grafting Cleft grafting Bark grafting Bridge grafting Buttress grafting

51. Whip (splice) grafting

52. Whip (splice) grafting

53. Whip and tongue grafting

54. Whip and tongue grafting

55. Successful Whip and tongue grafting Apple

56. Saddle grafting

57. Approach grafting

58. Approach grafting - Mango

59. Approach grafted Mango

60. Side grafting

61. Bark grafting - Mango

62. Bridge grafting It is used when the root system of the tree has not been damaged but there is injury to the bark of the trunk Scion is selected from one year old growth, 0.5 to 1.5 cm in diameter of the same or compatible species Trim the wounded area back to healthy undamaged tissue by removing dead or torn bark Scion is inserted at both upper and lower ends into live bark at every 8 to 10 cm

63. Bridge grafting

64. Bridge grafting

65. Propagation tools

66. Natural Grafting Tree branches and more often roots of the same species will sometimes naturally graft – Inosculation Inosculation occurs where two stems on the same tree, shrub or vine make contact with each other – Oak, Blackthorn, Neem . Transmission of diseases from one plant to another plant

67. Natural grafting Oak tree

68. Natural grafting Blackthorn Prunus spinosa

69. Hardening of Grafts The newly produced grafts are maintained in nursery by providing sufficient water, manures etc. They are protected from pests and diseases attack. In case of pest infestation and disease infection, necessary plant protection measures are taken up. Hardening period for grafts varies from 3 to 6 months.

70. During hardening, some of the plants show wilting symptom. It indicates that there is failure in the union of rootstock and scion The hardened plants are used for planting

71. Budding Art of inserting a bud on the rootstock plant in such a manner that both will unite and continue to grow as a single individual plant Bud wood – shoots of mother tree from which buds are taken for use as scion materials

72. Methods of Budding 1.Shield budding or ‘T’ budding Sweet oranges, Roses, Plums and Peaches 2. Patch budding Citrus, Mango, Rubber and Annona 3. Flap or forket budding Plums and Peaches

73. Shield budding or ‘T’ budding

74. Shield budding or ‘T’ budding Rose

75. Patch budding

76. 4. Ring budding Cinchona 5. Flute budding Rubber, Cinchona 6. Chip budding Grapes

77. Chip budding