From the Archives
of the Rare Fruit Council of Australia, inc.
by Dave Hodge - Cairns Branch
Large Unmanageable Tai So Trees
number of Tai So trees on the property of Mr Pete Brittain of White
Rock have now grown so huge that they are becoming hard to manage. It
is difficult to net them properly against bird and bat damage and hard
to reach the fruit at the top of the tree with the picking elevator.
has been marcotting the large-fruited variety FAY ZEE SIU for sale and
for his own use. This new variety shows considerable market potential
because of its size, small 'chicken tongue' stone and excellent
flesh-to-seed ratio. It is sweeter than Tai So and matures about the
same time. It is claimed to be a regular cropper.
of Fay Zee Siu have been planted back into sites from which large Tai
So trees have been removed, growth has been slow, which is not
It was therefore decided to try to top-work instead
of replanting, by approach grafting marcots onto shoots arising from
cut-down Tai So stumps. After all, with massive Tai So root systems in
the ground, these should force the Fay Zee Siu to grow rapidly and thus
get them into crop a lot quicker.
five or more months between time of marcotting Fay Zee Siu and
eventually planting them out. Other varieties may take longer. Fay Zee
Siu take about 6-8 weeks to root, then spend 1- 3 months in a pot by
which time roots should be appearing through the base of the pot.
Harden off in semi-shade for two weeks and a further two weeks in full
We started to cut down the Tai So on 7.12.92 after harvest.
The marcots would have been done sometime in spring. This is about the
right time to marcot lychees, when the bark is beginning to slip. This
timing synchronised growth of both varieties ready for approach
grafting in April-May.
Stumping the Trees
that everything can be sprinkler-watered, it was decided to remove the
pots and plant the marcots in the ground next to the Tai So shoots.
This would obviate having to water lots of pots individually out on the
block every day and not a stand pipe in sight!
The trick was to
estimate how far to cut down the trees so that the resulting shoots
from the stumps would be about the right height for approach grafting
into the Fay Zee Siu marcots, once they were planted in the ground.
After a bit of head scratching and measuring we decided to cut the Tai
So trees down to around 1.5-2 ft (45-60cm) above ground, as in the
picture. This was done with a chainsaw.
What about Leaving Breathers?
is usual to leave a breather or branch to draw the sap until the shoots
have formed on the stumps. However, in this case, the bases of the
trees had been in deep shade for so many years there wasn't a single
thin branch, shoot or anything left. Just the stumps, which seemed to
produce shoots all right anyway.
The whole stump was painted with white water-based paint against sunburn.
11th March, first shoots to appear now 45cm long. By 1st April the stump was covered in shoots.
Painting the Stumps
cut ends were trimmed and smoothed around the edges, more or less, with
a sharp knife to facilitate healing. A spoke shave would have done a
better job, but we didn't have one.
Wound paint: The cut ends
were immediately painted over with wound paint. This comprised of two
fungicides against disease - Benlate 5g and Bravo 10g and an
insecticide against borers - Lorsban 10ml per litre of white
The stump ends had to be repainted two or three
times, as oozing sap tended to wash it off. Stump ends are vulnerable,
as many were more than 1 foot across.
Sun protection: The whole
stump was then painted with white water-based paint against sun burn.
This has to be done thoroughly, as sun on bark that has been shaded for
20 or more years can burn severely. Whitewash gets washed off, so
always use paint.
The shoots push out through the paint after
about a couple of months. A month after emergence, they grow to about
18 inches (45cm) long. At this stage, make sure marcots go out from the
shade house to adequately harden off before planting out.
Planting out the Marcots
1st April (are we fools??) the hardened-off Fay Zee Siu marcots, now
showing roots through the pot bases, were planted out 4 or 5 per Tai So
stump. The holes were easily dug with a post-hole borer as the stumps
had been watered two days previously. A spade was used to widen the
holes so that potting compost could be placed beneath and around the
roots. A stick was used to compact the compost around the root ball.
The potting compost should have a complete fertilizer mixed through it.
After planting, the root ball should be about an inch below soil level
for watering. Marcots must be thoroughly watered in to exclude all air
pockets. The adventitious root system of a marcot is only required to
keep it growing until the approach graft has taken. Once taken, the
vigour will come from the Tai So root system.
Take advantage of the vigour:
Each Tai So had two or more stumps as can be seen in the pictures. To
ensure that both sides of a stump are kept alive for adequate healing
and to avoid die-back, the marcots should be placed on either side of
each stump. Hence there are likely to be a minimum of four marcots per
stump. This takes full advantage of the Tai So tree's considerable
vigour to rapidly build up strong and well placed Fay Zee Siu scaffold
limbs. A large tree can be formed very quickly in this way, resulting
in earlier and heavier yields once cropping commences. In temperate
fruit trees and vines, it is common practice to top-work so why not
with tropical fruits?
Placing the marcot:
Position the marcot stems as close as possible to the strongest shoots,
tree roots permitting. Actually this was easier than we anticipated.
Any Tai So shoots that were thick enough to approach graft were grafted
immediately ofter planting. The remainder will be grafted in two to
four weeks time, or whenever they are long enough. Be careful not to
waggle the marcot about too much, if grafting soon after planting, in
case you break the roots off underground.
An approach graft completed immediately after planting.
method of approach grafting is well enough known without the need for
diagrams. It is simply a matter of, in this case, cutting about an
8-cm-long cut on the Tai So shoots and a similar cut on the Fay Zee Siu
marcot and tying them together with tape.
Cambiums must match up:
First hold the two branches together to see where to make the cuts.
Cuts obviously should match each other in length and it is important
that they are also of exactly the same width so that the cambiums,
which lie just under the bark, can combine quickly to form a strong
union. On the thicker stems, I always cut 1.5-2cm tongues on both side
in the centres of the cuts and then fit one into the other before tying
Cut down to form the tongue on the Tai So (rootstock) and cut up to
form the tongue on the Fay Zee Siu (scion variety). This always forms a
good union as it increases cambium contact (similar idea to whip and
I like to use clothes pegs or, better still, short lengths of soft wire
which are easier to use, to hold the two stems firmly together for
tying They make the job a lot easier, otherwise you need two pairs of
hands! Make sure the two sides of each cut match up together exactly as
you wind around the tape, (2-cm-wide plastic tape is normally used).
Try to keep it from creasing up and maintain some tension on it to hold
the two cut surfaces firmly together. I usually start tying at the
bottom of the graft and work up. Remove the pegs or wire when finished.
Three months later:
I leave the tape on for about two and a half months. Never mind if the
grafted area swells up underneath as the tape will stretch. I then
remove the tape but still leave the Tai So (rootstock) top on for a
further two weeks to allow the grafted area to harden up before
removing it altogether.
Leave the Fay Zee Siu plants in the
ground, no need to remove them. Their roots will help to boost growth
and provide stability to the developing tree in the event of cyclones.
about all the suckers? The numerous other shoots which have not been
grafted are allowed to grow on. These will draw the sap, feed back
nutrients and keep the stumps active enough to start healing over the
There may be a possibility of cleft or bark grafting
these in the spring. Spring is the best time to cleft graft according
to some authorities. The problem of doing this in the open air, instead
of in a protected nursery, is desiccation of the grafts. I intend to
try painting over the grafts with white water-based paint as is used a
lot in vine grafting down south. Scions will be defoliated so they can
be painted over. Could be a complete failure, but we won't know that
until we've tried. Budding may also be a possibility.
fails, then once the approach grafts are growing away strongly, all
those suckers will have to be removed. Cut off cleanly to eliminate
base buds, could be a hammer and chisel job. Further suckering may be a
problem, but should be less so as the four or more approach grafts per
tree take up the vigour.
The Dollar is What Counts
the subsequent tree will have more than the desirable one main trunk.
But higher and earlier yields will bring in more dollars and the dollar
is the name of the game!
Future pruning to avoid weak crotches
and for good tree shape, as is normally done, would have to be adapted
to the four or five stem tree. Perhaps some approach grafting of limbs
later on within the tree might give internal support against cyclonic