Plantation Crops

Top working in cashew

The technique of top working was first standardized at ARS Ullal. It is for the rejuvenation of uneconomical cashew trees. It involves following steps;
1. Selection of trees:  The selected cashew for rejuvenation should be
   a. Low yielding trees: Trees yielding less than 2 kg per tree are selected.
   b. Trees bearing small sized nuts: Trees producing nuts which weigh less than 200 nuts per kg of raw nut. (i.e., less than 5 g per nut)
   c. Trees which are highly susceptible to tea mosquito attack.
   d. Age: Age between 10 to 25 years are suitable.
   e. Trees free from stem borer infestation.
2. Beheading of trees:

   a. Time and season of beheading : December to February
   b. Remove branches :
   c. Stumping: Cutting stump at 0.50 m to 0.75 mabove ground level with saw to avoid bark splitting.
   d. Smearing cut portion : Smear the cut portion with BM – 10 % paste or cow dung slurry and red soil.
   e. Basin rectification : Prepare a basin of 1.50 m radius
   f. Plant protection : Paste sevin dust + Blitox ( 50 g sevin dust + 50 g blitox per liter of water)
   g. Provide shade.
3.  Sprouting of beheaded trees:

   a. Sprouting: New sprouts appear in 30 to 40 days after beheading.
   b. Remove shade
   c. Thinning: Retain 10 to12 healthy shoots/sprouts for grafting and remove others.
   d. Periodical removal of new sprouts to facilitate the growth of selected sprouts.
4. Selection of Scions:

   a. Select scions from high yielding varieties
   b. Pencil thick and 12 to 15 cm long scion stick with a sprouted bud should be selected from shoots of 3 to 4 months growth.
   c. Preconditioning: Remove all the leaves 7 to 8 days before grafting.
   d. Fresh scion is always preferred for better success.
5. Grafting:

   a. Select 10 to 12 sprouts for grafting.
   b. Cut the sprout 5 to 6 cm from the top and split it in the middle to 3 – 4 cm depth with the help of a knife.
   c. Technique of grafting : Wedge grafting
   d. Select the scion of the same thickness and give a cut to form a wedge or “V” shape.
   e. Insert the scion: Firmly tie with the help of polythene strip.
   f. Cover the grafted portion with the help of polythene bags./ caps
6.  After care:

   a. Sprouting in 10 to 15 days. About 5 to 6 successful grafts are sufficient per tree.
   b. Remove excess and unsuccessful shoots.