Layering principles and methods

Layering principles and methods

1. Layering principles and methods 1

2. Layering Method of propagation in which roots are developed on a stem with suitable rooting medium while it is still attached to the parent plant The stem which is rooted is called as layer In layering root is formed in areal part like stem or branches After proper rooting layer is detached and plant as a new plant 2

3. Principles of layering 1. Girdling It is removal of bark and phloem tissues from stem Carbohydrates, nutrients and auxins accumulate at this point and when it touch with soil and moisture it produce roots Main principle in air layering, ground layering 3

4. 2. Etiolation It is development of plant parts in absence of light Absence of light favour initiation of root primordia in stem Basic principle in trench layering, stooling 4

5. Types of layering Simple/ ground layering Tip layering Trench layering Air layering Mound layering Serpentine layering 5

6. Simple/ ground layering/ dab Done in low, flexible shoot which can bend easily All leaves and side shoots are trimmed of leaving 15-20 cm from tip Bend the shoot and burry in soil leaving tip exposed Rooting time: 5-7 weeks Girdling induce profuce rooting Eg : guava, lime, lemon 6

7. Tip layering Done in plants with trailing type shoots Current season’s shoots are selected Tips of shoots are buried in soil In absence of light buried tip get flattened and produce adventitious root New shoot system will develop and come out of soil Detach new plant and transplant Eg. Blackberries, raspberries, dewberries, gooseberries, current 7

8. Trench or continuous layering One year old plant intended to multiply plant in slanting position-40° When plant is established, they are bend over and pegged down in a shallow trench and cover with soil As buds are emerging more soil is fill over Rooted growth are detached and replanted Eg : apple rootstocks- M16, M29, walnut, pear, quince, cherry, plum 8

9. Air layering Chinese layerage , pot layerage , circumportion , goottee , marcottage, Hawaii, dab Fairly long, partially hardened, one to two year old shoots are selected Basal leaves are removed and bark at base strip of in a ring along with cambium Sphagnum moss or moist soil is placed around ringed portion and wrapped with transparent polythene sheet Rooting start in 25-30 days 9

10. Contd …. Rooted layers are removed with in 3 months Eg : guava, litchi, pomegranate, jack fruit, persimmon, mango, sapota Application of auxin in girdled portion enhance rooting Advantages of transparent polythene Retain the inside moisture Allows gaseous exchange Root growth is visible from outside 10

11. Air layering 11

12. Stage wise removal of air layered shoots Help to improve success Make a V shape cut 2 cm below earth ball Deepened cut after 5-7 days After 4- 5 days detach shoot from mother plant Best time for air layering- February- March and June- July 12

13. Mound layering / stooling Plant headed back to 15 cm above ground level during dormant season New sprouts will form with in 2 months Earthing up is done when sprout are about 10- 15 cm long Earthing up is continue as shoot grow till it grow to 35-45 cm Moisturize the soil Rooted shoots can be detach from mother plant in next winter Stool can be used for up to 15- 20 years 13

14. Contd … Success rate of stooling can be increased by following girdling practice and application of IBA( 3000- 5000 ppm) Used in- apple, guava, mango, jackfruit, pear, plum, hazel nut, litchi, ber 14

15. 15

16. Compound or serpentine layering Used in plants with long soft shoot which bend easily Shoots are covered and exposed alternately along the length Slanting cut is given just below node where it is to root Adventitious roots are formed the node buried in soil and new shoot develops from node above the ground When shoot attain considerable size they detached and replanted eg : muscadine grapes 16

17. Factors affecting success of layering Physiological condition of the mother plant Plants deficient in water often show reduced rooting Low N and high CHO balance promote rooting Internal factors of plant- auxin level, rooting co-factors – help in root initiation process Stem treatments Bending, cut, notching, girdling- promote rooting of layers Rooting hormone will enhance profuse rooting –IBA, NAA 17

18. Contd … Light prevention Blanching, etiolation- prevent destruction of auxin and help in root development Juvenile stage of shoot Shoots from juvenile growth phase often root better than from adult phase Climate Depend on crop Layering in temperate crop done in dormant season (winter) 18

19. Contd … Type of the wood lateral shoots root better than the ones taken from terminal shoots as lateral shoots have more stored food more roots are developed in the basal portion of the shoot than mid or top of the shoot, because accumulation of CHO and root promoting substances Presence of viruses Viruses reduce root initiation, rooting percentage and influence the root number 19

20. Contd … Presence of leaves and buds The promoting effect of leaves and buds in root initiation is due to these are the primary source of carbohydrate and auxin synthesis and other root promoting co-factors in the plants Usually, growing buds promote rooting and dormant buds inhibit it Presence of buds in easy-to-root species stimulates rooting but in difficult-to-root species, rooting is inhibited 20

21. Advantages of layering Easy method and does not require much care and arrangement like cuttings The mother plant supplies nutrient and other metabolites as it remains attached while rooting By using large branch we can obtain much larger plant in first instance It can be used in plants in which cutting will not root easily 21

22. Constraints of layering It is costlier method It is a slow process Limited number of plants can be propagated Layered plants are generally shallow rooted Interference with cultivation Required more individual attention The beneficial effect of root stock cannot be exploited 22

23. Thank you 23