Diseases and Management of Crops under Protected Cultivation

(Diseases and Management of Crops under Protected Cultivation)
ground level. Polyethylene strip is used for keeping the buds close to the stock. When the bark
adheres tightly to the wood, budding is usually successful. After about 2-3 weeks of budding the
polyethylene strip can be opened to examine the success.
Stooling
Stooling is the easiest and cheapest method of guava propagation. This method can be
used for quick multiplication of desired varieties and also rootstocks. In this method, self-rooted
plants (cuttings and layers) are planted 0.5 m apart in the stooling bed. These are allowed to grow
for about three years. Then these are cut down at the ground level in March. New shoots emerge
on the be headed stumps.A 30-cm wide ring of bark is removed from the base of each shoot
rubbing the cambium of the exposed portion in May. All the shoots are mounted with the soil to a
height of 30 cm. The soil is covered with mulch to conserve the moisture. After a period of two
months of the onset of monsoon, the shoots are detached from the mother plant at ringed portion
and planted in the nursery. The shoots are headed back to maintain the root and shoot balance
before planting in the nursery by following the technique of ringing and mounding of the shoots,
second time stooling is done on the same mother shoot in the first week of September.
Air layering
Air layering is one of the most important commercial method in practice for guava
propagation. Rainy season (preferably July-August) is the most suitable period for air layering. In
this method, limbs of about 1.2cm or more in diameter are girdled by removing a strip of bark with
a width of about 2cm. The girdled area is bound with a ball of moistened sphagnum moss of about
7 cm in diameter and 10-13cm long, which is then wrapped with polyethylene film and tied loosely
over the wrap to prevent bird damage and also to prevent the moistened moss from overheating.
Roots usually start developing in three to five weeks. When they grow through the ball of moss,
the stem may be detached from the mother plant below the girdled area. The polyethylene film is
removed and the new plant is potted in manured soil in pot/polyethylene bags and kept in the
shade until new leaves appear.
Soft-wood /Wedge grafting
Soft-wood /Wedge grafting, a technique for rapid multiplication has been perfected at
Central Institute for Subtropical Horticulture (CISH), Lucknow. This technique has a tremendous
potential for multiplying guava plants rapidly throughout the year both in greenhouse and under
open conditions. Presently, the institute is producing quality materials of guava through wedge
grafting technique round the year in greenhouse as well as in open conditions. The technique
involves growing of seedlings in polyethylene bags, grafting, capping and hardening of grafts.
Seedlings are raised for rootstocks in the nursery for approximately 6 to 8 months. When the stem
diameter of seedling is of pencil thickness (0.5-1.0 cm) they are chosen for wedge grafting. In this
technique, proper selection and preparation of scion sticks is very important for obtaining higher
success. Shoot with growing apical portion (terminal growth) which is 3 to 4 months old is ideal for
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