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SEEDCANE PRODUCTION

South African Sugar Association

South African Sugarcane Research Institute
170 Flanders Drive, Mount Edgecombe, 4300
Tel: (031) 508 7400 Fax: (031) 508 7597
Website: www.sugar.org.za/sasri
ISBN No. 1-874903-29-8 SOUTH AFRICAN SUGARCANE
RESEARCH INSTITUTE
 Contents

Introduction 2

Establishing a nursery 5

Nursery operations 11

Hot water treatment (HWT) 16

Propagating transplants 18

Published by

South African Sugarcane Research Institute

170 Flanders Drive, Mount Edgecombe, 4300

Tel: (031) 508 7400 Fax: (031) 508 7597

Website: www.sugar.org.za/sasri

ISBN No. 1-874903-29-8

Updated March 2015

Copyright subsists in this work. No part of this work may be reproduced in any form or by any means without the publisher’s written permission. Whilst every effort has been made to ensure that the
information published in this work is accurate, SASRI takes no responsibility for any loss or damage suffered by any person as a result of the reliance upon the information contained herein. The use of
proprietary names in this publication should not be considered as an endorsement for their use.

Page 1
Introduction

T
his manual outlines the procedures for the production
of good quality seedcane. Seedcane is defined as any
sugarcane plant material which is intended for use in the
propagation of sugarcane. Planting good quality seedcane is
crucial for profitable sugarcane production. The potential yield of
a crop will not be attained if seedcane of poor quality is planted. In spite of this,
seedcane production is an aspect of sugarcane management that is often neglected.

The benefits of quality seedcane Where the grower has his own seedcane nursery, he
is guaranteed seedcane of the right variety at the
Reduced pest and disease risk right time and of the right quantity for the replant
programme.
Planting good quality seedcane significantly reduces
the risk of serious pest or disease outbreaks in com- A well-managed certified nursery expedites the
mercial fields. This includes ratoon stunt (RSD), smut, introduction of new varieties by ensuring purity
mosaic and eldana. and providing a controlled environment for rapid
bulking.
Improved germination
Another advantage of good quality seedcane is good Description of the required standards for the two classes of
germination and the improved likelihood of high
yields. Well-grown seedcane not yet mature is most
likely to germinate quickly and evenly. Good germina- Class of Source to establish
Fallow period
tion leads to rapid growth of a uniform stand, and al- seedcane nurseries
lows the variety to realise its full potential. Problems
of gap filling after planting are therefore minimised Certified HWT certified Overall the period to be
and weed control is aided by a full leaf canopy. seedcane whole-stick not less than 12 months
and seedcane with a minimum of 6
Having the plant crop start off on such a strong Certified OR months totally free of
footing and subsequent good management will lead seedcane HWT transplants sugarcane
to prolonged ratooning before replanting, thereby nurseries cut and grown from
significantly reducing production costs. certified seedcane
OR
Varietal purity NovaCane® plantlets

A further benefit of good quality seedcane produced Approved Certified seedcane Overall the period to be
in a well-managed nursery is varietal purity. Seedcane seedcane not less than 9 months
taken from commercial fields is often contaminated and with a minimum of 6
with off-type varieties, including unwanted varieties Approved months totally free of
infected with disease. The production of seedcane seedcane sugarcane
under nursery conditions allows for regular inspec- nurseries
tions and effective eradication (roguing) of unwanted
stools.

Page 2
 Certified and approved nurseries
The Local Pest, Disease and Variety Control
Committee (LPD&VCC) has legal powers, creat-
ed through the provisions of the Sugar Act and
the Sugar Industry Agreement. LPD&VCC reg-
ulations require that all commercial sugarcane
fields be planted with either LPD&VCC certified
or approved seedcane. The terms certified and
approved refer to the two different classes of
nursery (or seedcane) registration described in
the regulations, with certified nurseries having
to conform to a slightly higher set of standards
than approved nurseries, as detailed in the table
below. In addition to the requirements specified
in the table, all seedcane must be well-grown, in
good condition and not water or nutrient stressed.
All movement, use or sale of seedcane has to be
sanctioned by the LPD&VCC.
Good quality seedcane.

nursery (or seedcane) registration.

Disease, off-type and pest limits

Maximum Harvests
Smut, Mosaic, age at harvest permissible
RSD Eldana/100
Off-types

Less than local area NIL Less than local area Irrigated North and KZN Plant and 1st
hazard levels when tested (with hazard levels when Coastal <500 m above sea ratoon only
(not exceeding 0.1%) cane being at least inspected within level:
when inspected on nine months old) two months of 9-12 months
the last of THREE harvest date
Midlands > 500 m above
consecutive
sea level:
LINE BY LINE
12 –18 months
inspections

Less than local area NIL Less than local area Irrigated North and KZN Plant crop
hazard levels when tested (with hazard levels when Coastal <500 m above sea only
(not exceeding 0.1%) cane being at least inspected within level:
when inspected on nine months old) two months of 9-12 months
the last of TWO harvest date
Midlands > 500 m above
consecutive
sea level:
RANDOM
12 –18 mnths
inspections

Page 3
Planning for seedcane
Each grower should ideally establish his or her own
seedcane nursery to produce either certified or ap-
proved seedcane. All nurseries must be registered
with the relevant LPD&VCC, who will inspect the
seedcane produced in the nursery and approve its
use either on the grower’s farm or for sale to other
growers.

Growers may opt not to have nurseries on their

farms but must then purchase their seedcane for
commercial planting from LPD&VCC certified or ap-
proved nurseries. If certified or approved seedcane
is sourced from a grower outside of the LPD&VCC
area, then permission must be obtained from both
the sending and receiving LPD&VCCs.

Establishing a nursery and synchronising its outputs

with the seedcane requirements of the farm can
be a complex process. Seedcane production should
therefore be regarded as a core component of all
sugarcane production management planning.

Page 4
Establishing a nursery

S
eedcane can take one of three forms: whole-stick
seedcane, transplants or NovaCane®. Growers will
usually choose a particular option based on availability,
source, ease of handling, labour requirements, quantities
required and the intended purpose of the seedcane.

Types of seedcane

Whole-stick sugarcane
This is the most common form of seed-
cane used in the industry where the entire
sugarcane stalk is planted as seedcane.
The stalk may be cut up into billets, usually
in the furrow, unless the seedcane was
heat treated after harvesting.

Single-budded sett transplants

Transplants are an excellent alternative
source of nucleus seedcane and are clas-
sified as certified seedcane in terms of
industry seedcane rules. They have some
distinct advantages, particularly for the
rapid bulking up of healthy, true-to-type
seed material in nurseries. Transplants can
be easily and inexpensively transported
over long distances, and each stool can
be easily identified when roguing in the
nursery.

They are not recommended for planting

commercial fields. Being less hardy than
whole-stick seedcane, transplants need to
be handled with greater care to ensure a
good stand, and watered if the nursery is
not irrigated.

Transplants are usually obtained from

transplant nurseries. If you wish to prop-
agate your own transplants, follow the
guidelines provided on page 18.

Page 5
NovaCane® plants produced via tissue
culture
NovaCane® plantlets are multiplied by means of tis-
sue culture in a laboratory, thereby enabling a large
number of plants to be propagated using a minimum
quantity of starting material.

At the time of production and before being exposed

to normal field conditions, NovaCane® plantlets are
free of disease and are true-to-type.

The NovaCane® process is particularly useful in elim-

inating viruses such as sugarcane mosaic virus and
sugarcane yellow leaf virus, both of which are not
eliminated by conventional hot water treatment.

After production in the laboratory, the plants are

hardened off and grown in seedling trays for a period
of 3-5 months and the leaves are trimmed monthly.
Plantlets can be easily and inexpensively transport-
ed over long distances, and each stool can be easily
identified when roguing in the nursery.

NovaCane® plants satisfy the requirements to be

classified as certified seedcane and can be harvested
twice (plant and first ratoon crops) as certified seed-
cane provided the cane remains pest and disease free.

Forward planning nursery will ensure that adequate amounts of fresh,

Planning seedcane production needs to start at least well grown seedcane are available when needed. A
two years before the seedcane is actually required permanent nursery site enables seedcane rotation
for planting into commercial fields. to be practised without disrupting the management
of commercial fields.
The nucleus or mother seedcane to be planted in the
nursery should be between 9 and 12 months old in Commercial cane fields, preferably without a history
the irrigated and coastal regions, and up to 18 months of RSD, can be used as nurseries following a break of
in the high altitude areas. Spring planting is the most at least one year, 6 months of which must be free of
suitable time for commercial fields in most areas, so regrowth from the previous crop. These nurseries
the nursery should be planted in the previous spring. can then revert to commercial cane production after
As the mother seed has to be ordered or planted the permissible number of harvests of seedcane have
at least a year before it is required for the nursery, been taken.
producing seedcane for commercial planting takes
Where a nursery is within a commercial field, its
at least two years.
boundaries should be well-defined and clearly
As good seedcane can be cut from a nursery over a marked. The edges of the nursery must be wide
period of several months, some flexibility in planting enough to avoid contamination from neighbouring
dates is possible. cane and to enable easy access. Where several dif-
ferent varieties are grown in the nursery, they must
Nursery site all be clearly labelled.

There are advantages to having a permanent site for There are some obvious cost benefits from growers
a nursery, situated on good, well-drained soil, and in co-operating and producing their combined seedcane
a low-risk area i.e. areas not prone to runaway fires, requirement in a single nursery, in conjunction with
grazing cattle, frost or theft. The ability to irrigate a a shared heat treatment plant.

Page 6
Nursery size Important notes
The size of nursery to produce the required amount of yy Seedcane requirements should always be over-
seedcane depends on the area of commercial cane to estimated and expected yields underestimated
be replanted each year, the expected yield from the in order to allow for poor growing conditions,
nursery, and the planting rate for commercial fields. additional areas requiring replanting and other
All of these will vary from farm to farm but approx- unforeseen circumstances.
imately 2 to 3 hectares of either LPD&VCC certified
yy Seedcane must be planted so that it is available
or approved nursery space is generally sufficient for
at the required time. Attention needs to be paid
every 100 ha of commercial cane with a replant of
to the particular growth cycle of the area and the
10% per year. The size of the nursery can be calculated
seedcane planting date adjusted accordingly (tak-
as shown in the following example:
ing care not to exceed the LPD&VCC seedcane age
limits for the area).
Calculating the nursery area for a 100 hectare
yy Varieties will need to be planted in the nursery in
farm with an average replant percentage of 10%
proportion to the areas of commercial planting
10 ÷ 100 X 100 ha = 10 ha required.
There must be sufficient seedcane to replant 10
hectares of commercial fields every year. yy Varieties with low populations of thick stalks will
require a higher planting rate.
If the seedcane planting rate is 10 tons per
hectare: yy Different varieties need to be clearly marked in
10 t/ha X 10 ha = 100 tons the nursery.
Required amount of seedcane is 100 tons.
If the yield of cane at the nursery site is conser-
vatively estimated to be 80 tons per hectare
per annum:
100 t ÷ 80 t/ha = 1.25 ha
Nursery space to obtain required seedcane
needs to be sourced is 1.25 hectares.

If certified seedcane is purchased every year, the re-

quired area of LPD&VCC approved nursery is 1.25 ha.
Unless otherwise specified, only one harvest of this
seedcane is permitted (plant crop only).
If certified seedcane is produced on the farm and a
three-plot dedicated nursery system is used, then:

1.25 ha represents two of the three plots (to allow

for a one-third fallow), so the whole nursery size
needs to be:
(1.25 ÷ 2) X 3
= 1.9 ha (2 ha, to be practical).
Unless otherwise specified, only two harvests
(plant and 1st ratoon crop) are permitted.

Page 7
Nursery layout and rotations
A standard, permanent nursery is normally divided into three equal portions and cycled on a three-year
rotation so that, in any given year, one-third will be fallow, one-third will carry a plant crop and one-third will
carry a first ratoon crop. Getting the three blocks of a nursery into this rotational cycle can be done in one
of two ways.

First option
This is the most rapid way to achieve the nursery cycle. It involves leaving two blocks (BLOCKS A and B)
fallow for the first year. In year 2 the BLOCKS A and B are planted and BLOCK C is fallowed. At the beginning
of year three, BLOCK A is harvested and ratooned while BLOCK B is harvested, ploughed out and fallowed;
the third block, BLOCK C, which was fallow in the second year, is planted. This means that the nursery gets
into its proper cycle in year three.

In the fourth year, the BLOCK A is harvested, ploughed out and fallowed, BLOCK B, which was fallow, is
planted, and BLOCK C harvested and ratooned.

Year 1 Year 2 Year 3 Year 4

Harvested and Harvested, ploughed

BLOCK A Fallow Planted ratooned and fallowed

Planted Harvested, ploughed

BLOCK B Fallow and fallowed Planted

Harvested and
BLOCK C Fallow Planted
ratooned

Second option
This is a more gradual process of implementing the full nursery cycle. In year one, only one block (BLOCK A)
is fallowed. In year two, BLOCK A is planted and BLOCK B is fallowed. In year three, BLOCK A is harvested and
ratooned, BLOCK B is planted and BLOCK C is fallowed. This system will achieve its full production in year four.

Year 1 Year 2 Year 3 Year 4

Harvested and Harvested, ploughed

BLOCK A Fallow Planted ratooned and fallowed

Planted Harvested and

BLOCK B Fallow
ratooned

BLOCK C Fallow Planted

On an average sized farm, commercial fields can be planted with seedcane taken directly from the nursery.
Because the risk of infection by diseases is increased with additional harvests, only the plant and first ratoon
crops may be taken from a nursery.

On large farms and estates, a bulking phase will enable a larger amount of seedcane to be produced, but only
the plant crop from the bulking phase may be used for as seedcane for commercial planting.

Page 8
 Certified Cane
(from Plant or First Ratoon only)

Hot Water Treatment

Whole Stick Transplants NovaCane

Certified
Fallow Plant First Ratoon Seedcane
Nursery

Approved
Bulking Phase Nursery

Plant
Crop
only

Commercial Fields

Flow diagram of seedcane showing a three-block nursery rotation and a bulking phase.

Page 9
Using commercial fields
Sometimes, establishing a dedicated nursery site may not be practical. Growers may then opt to use com-
mercial fields as temporary nurseries as they come up for replanting.

In order to be registered as either certified or approved nursery sites, these fields need to be subjected to the
standard requirements for fallow and general suitability (soils, irrigation, low-risk etc.). Once the permitted
number of harvests for seedcane is completed, the nursery reverts to a commercial field and the next nursery
site is identified from within the normal area under fallow on the farm.

The advantages of this system are that the grower does not have to eradicate relatively high-quality seed
material after only one ratoon, and the benefits of good seedcane are then maintained for the rest of the
crop’s life.

The disadvantages of this approach are that it might not be possible to choose the best site, and control could
be compromised with having the nursery site or sites in different parts of the farm each year.

Commercial fields may be used as temporary nurseries where dedicated nursery sites are not
practical.

Page 10
Nursery operations

N
urseries should be managed to create the
most favourable conditions for optimum growth.
The costs of the additional management practices
required to produce good quality seedcane are negli-
gible in relation to the benefits obtained from using good
seedcane to establish a healthy commercial crop.

Seedcane sources

Certified nurseries
For a LPD&VCC certified seedcane nursery, only
certified seedcane from another certified nursery
may be used as nucleus seedcane. This cane must
be hot water treated at an approved facility before
planting into the nursery. Once the nursery system is
operational, nucleus seedcane can be obtained from
the previous nursery crop each year and subjected to
hot water treatment. Alternatively, hot-water treated
single-budded sett transplants or NovaCane® plant-
lets may be used as nucleus material.

Approved nurseries
For a LPD&VCC approved nursery, only certified
seedcane from a co-operator approved by the
LPD&VC Committee may be used as nucleus seed.
This seedcane does not require further heat treat-
ment and, if kept disease free and approved by the
LPD&VCC, it may be used to establish commercial
fields the following year.

Important notes
yy Seedcane should not have flowered, nor should it have swollen buds which are prone to damage and will
lead to gaps in the nursery.

yy All seedcane to be planted in a nursery should be treated with a fungicide to protect against pineapple
sett rot and infection by smut (refer to SASRI Information Sheets 2.7 Pineapple sett rot and 2.11 Smut).

yy If high levels of eldana are present and no alternative seedcane can be sourced, or if the seedcane is to
be moved to another farm, it should be hot water treated (50°C, 30 minutes) to ensure that any eldana
present is killed.

Page 11
Planting
Ideal planting times are Septem-
ber, October and March. Avoid
planting mosaic susceptible
varieties from end of September
through to the end of February
to reduce the risk of acquiring
mosaic.

Planting into a nursery must take

place only after the previous
cane crop or nursery has been
completely destroyed. This is
best achieved using glyphosate
or imazapyr-based herbicides
that are registered for cane de-
struction, followed by a 12 month
break. During this break, the soil
can be left fallow, or a low-grow-
ing crop can be grown. This will
enable the easy recognition and
eradication of any sugarcane re- The ideal time for planting sugarcane is September, October or
March.
growth from the previous crop.
Suitable fallow crops could be either a cash crop or Planting transplants and NovaCane®
a green manure crop. plantlets
In their final stages, NovaCane® plantlets are similar
To obtain good germination and rapid establishment
to transplants grown from single-budded setts (SBS).
of the seedcane crop, plant using water (2 to 3 litres
The following planting guidelines therefore apply to
per metre of row) or apply a suitable composted
both SBS Transplants and NovaCane® plantlets.
organic material in the furrow if the nursery cannot
be irrigated.
yy Order plants 12 months before planned planting
date.
Seedcane nurseries should not be ‘gapped up’ to com-
pensate for patchy germination, unless further nucleus yy The number of plants planted per hectare differs
seedcane of identical variety and quality is available. depending on the row spacing. Plants are planted
either 40 or 50 cm apart.

Planting whole-stick seedcane yy Vehicles should be covered and the plants should
not be exposed to high temperatures. If there
With good soil conditions, the setts or stalks of
are delays in delivery, the consignment should be
seedcane can be spaced slightly apart in the planting
removed from the delivery vehicle if possible, and
furrow, thus allowing the most economical use of
stored in a cool place and kept moist.
the valuable seedcane and also to facilitate roguing
operations in the nursery. yy Plant within 24 hours of delivery (especially if
plants are received bulk-packed in plastic bags).
Heat treated cane has no apical dominance. Whole Plants that are hardened in trays with plastic
stalks should therefore not be cut into setts when sleeves should be kept in the sleeves up to the time
being planted as this could re-introduce diseases. of planting if possible to further reduce stress.

Page 12
yy Always plant in the best soils with some form of yy The depth of planting should be just below the
irrigation available. lowest leaf of the plant to ensure that tillering
occurs below soil level. This will give the roots a
yy The soil should be clod-free to avoid air-pockets
good start and reduce stress to the plant.
forming around the roots, regardless of whether
ploughing or minimum tillage has been used as a yy Gentle foot pressure needs to be applied around
form of cultivation. the plants after planting.

yy Fertiliser (P and K) should be applied and incorpo- yy Apply a nematicide in sandy soils if necessary for
rated into the soil prior to planting to avoid the nematode control. Bandit® (imidacloprid) should
possibility of root scorch. Nitrogen fertiliser should be applied to control thrips if planting in summer.
be top-dressed after the plants are established.
yy The field should be irrigated after planting.
yy A wooden peg and hammer are required to make
the hole for each plant. There are also both hand Nutrition
and tractor-mounted implements designed spe-
cifically for planting trees and other seedlings Nutritional requirements should be determined from
and these can be used to speed up the planting the analysis of soil and leaf samples submitted to
process if necessary. SASRI’s Fertiliser Advisory Service.

yy If the soil is dry and friable (easily crumbled), a

small amount of water will be required to allow the
Weed control
planting hole to remain open long enough while
Fields can be either hand-weeded or sprayed with
the plant is positioned and planted. It is also a good
herbicides within a week of planting. Regular weed
idea to water each plant after planting. There are
control is necessary in the nursery, until the crop has
also commercially available water-retaining gel
canopied.
products which can be applied in the planting hole
that will enable water to be made available to the
Transplants and NovaCane® are very sensitive to her-
plant during the very early stages of growth.
bicides. Herbicide damage is minimised when leaves
are trimmed and the plants are planted deep. Early
application of products such as metribuzin + diuron
are safe for use if directed into the interrows so that
the spray swath covers only the base of each plant.

Fields with a history of problems with creeping grass-

es should not be planted to NovaCane® or transplants.

Page 13
Pest and disease inspections

LPD&VCC teams inspect nurseries regularly for pests, diseases and off-types. In addition, farm staff
should also be trained to conduct their own inspections.

All nurseries should be registered with the LPD&VC SASRI publications such as the Pest & Disease Guide
Committee, whose teams will then inspect them and the various SASRI Information Sheets on diseases.
regularly for pests, diseases and off-types. The LPD&VCC teams will routinely inspect for the
more common and important pests and diseases such
Inspections are performed in young cane (when as smut, mosaic, MSV, RSD and eldana.
the canopy is knee to shoulder high – about
1.5 m) by walking between the cane lines and carefully
Roguing
examining the plants. Line by line inspections are con-
ducted and diseased stools and off-types are marked It is the grower’s responsibility to remove diseased
for roguing. Certified nurseries require at least three stools (clumps of infected shoots) and off-types that
line by line inspections by LPD&VCC while approved have been identified by LPD&VCC. These stools can
nurseries require two random surveys by LPD&VCC be dug out and left to dry in or beside the field (stool
in order for the seedcane to be registered. roguing). They may also be chemically rogued in the
field by spraying with 10 ml of a 10% glyphosate solu-
Growers are advised to supplement the required
tion sprayed over as much of the unwanted stool as
LPD&VCC inspections by conducting their own inspec-
possible. Care should be taken to avoid spraying the
tions. On request, the LPD &VCC or instructors from
the Shukela Training Centre will train farm staff to surrounding stools. Sprayed stools will die off after
recognise and eradicate diseased and off-type stools. four to eight weeks.
It is important for every farm to have its own trained
staff to manage nurseries and carry out the necessary If smut is observed, emerging whips must first be cut
field hygiene procedures. from the infected plants and placed in bags so that
the spores are not spread while the whips are being
For comprehensive information on the many pest and collected and removed from the field. The bags of
disease threats facing our industry, please consult whips should be closed and taken as far from the field

Page 14
as possible for burning. Whips should not be left in
or beside the field. In the case of chemical roguing, it
is important to remove both incipient and emerging
whips by cutting about halfway up the stalk before
spraying with glyphosate.

Harvesting
When harvesting any seedcane, new knives must be
purchased and whilst in use they must be cleaned and
scrubbed frequently in a disinfectant such as Jeyes
Fluid (1 part to 9 parts water) to minimise the risk of
spreading RSD. Each cutter should be issued with at
least two knives.

Seedcane harvested from the nursery should be

handled carefully to avoid damage to the buds and
it should be planted without delay.
Cane knives used in the nursery should be
disinfected frequently.

Loading and transport

Vehicles used for moving the seedcane from nurseries to the fields for planting should be thoroughly
cleaned before use, in order to minimise the risk of varietal mixing or pest transmission and disease infection.
This is particularly necessary if the transport is also used for haulage to the mill.

Loading of seedcane should preferably be done by hand and handling should be kept to a minimum. Mechan-
ical grab-loaders may cause significant damage to buds. Once loaded, the trailer should move slowly over
rough surfaces to avoid further damaging the buds.

Page 15
Hot Water Treatment (HWT)

H
WT is an essential feature of seedcane production, and
ensures that seedcane stocks are free of RSD, as well
as certain other diseases and pests. The process must be
managed with extreme care to be effective.

Procedure
The time and temperature combi-
nation for HWT is a compromise
between the need to eliminate
RSD and to achieve good germi-
nation.

A short treatment (30 minutes

at 50ºC) will eliminate smut,
Fusarium, chlorotic streak and
most insect pests including ses-
amia and eldana. It is essential
to treat seedcane for at least 30
minutes if it is being transported
from high to low eldana risk areas.

Seedcane must be treated for

two hours at 50ºC for acceptable
control of RSD. It should be noted
that treatment for two hours at Seedcane being lowered into an Upfold hot water treatment tank.
50ºC provides little control of
leaf scald, and may increase the
susceptibility of certain varieties Standard sizes of HWT tanks.
to smut and mosaic.
Water Number Interval Output per
Treatment for two hours at 50ºC Model capacity of between 10 h shift
may not entirely eliminate RSD (litres) baskets baskets (min) (kg)*
from severely infected cane. To
ensure that all traces of RSD are 3 ton 3 300 9 15 2 800
removed, it is preferable that
5 ton 4 800 13 10 4 700
seedcane should first be tested,
and only selected for treatment if (* Assuming 70 kg seedcane per basket and no downtime)
found to be free from RSD. Recy-
cling previously heat treated seed-
cane stocks through the nursery
system is the best way to ensure
that RSD is not re-introduced.

Page 16
Hot water tanks yy The two-hour treatment period should commence
only when the water temperature has reached
A continuous output HWT plant comprises a tank and 50ºC. The time should be strictly controlled and a
a number of baskets, each of which holds 60-70 kg of constant temperature maintained.
seedcane. Baskets are added successively to the tank
yy Loose dead leaf material should be removed before
at appropriate intervals (10–15 min, depending on the
HWT, but it is not necessary to strip the seedcane
tank size) and are slid on rails from the input to the
completely. Leaving the leaf-sheath bases at the
output end of the tank as treatment progresses. When
nodes gives some protection to the buds which
the longest immersed basket has been in the tank for
become soft during hot water treatment.
two hours, it is removed and a new basket is added.
By adding relatively small baskets at short intervals, yy Seedcane should be handled carefully after HWT.
the large temperature fluctuations which result from Softened buds are easily damaged after removal
adding large loads of cold seedcane are avoided. from the tank, and this often results in poor ger-
mination.
Heating is achieved by electric elements (usually 18
kW) and temperature is controlled by a thermostat yy Where smut is common, HWT of smut-susceptible
assisted by good water circulation which avoids hot varieties may result in the rapid re-infection. To
and cold areas within the tank. counter this effect, seedcane of susceptible vari-
eties should be treated with a registered fungicide
A major advantage of this type of tank is that damage when these varieties are planted in areas where
due to excessive handling of the seedcane is mini- smut is prevalent. Bayleton is currently the only
mised. If enough baskets are available, they could fungicide registered for use against smut in sug-
be used to transport seedcane directly to the field arcane. Refer to SASRI for updates.
after treatment, thereby further reducing handling
and possible damage. yy Some varieties are sensitive to HWT and may germi-
nate slowly after treatment, particularly under cool
conditions. It is important to treat these varieties
Sizes of Upfold HWT tanks
with a fungicide before planting. Refer to SASRI
Two standard sized models of continuous output Variety Information Sheets for details.
HWT plants are available commercially. For details
of distributors visit SASRI’s website at www.sugar. yy Heat treated cane has no apical dominance. Seed-
org.za/sasri. cane treated as whole stalks should not be cut into
setts when planted in the nursery as this could
Smaller tanks of 1 000 litre capacity, suitable for re-introduce diseases.
treating single-budded setts, can be made to order.

Important notes
yy While large batch tanks are available for HWT,
SASRI recommends the use of the continuous
output HWT plant. With this system, the time to
reach the required temperature is reduced and a
fairly constant temperature is maintained during
the process.

yy Seedcane germination is eventually reduced after

prolonged operation of the HWT plant, as the
water becomes contaminated. It is therefore nec-
essary to empty the tank and refill. The refilling
interval depends on the rate at which fouling of the
water occurs, but is normally necessary after 40 to
50 hours of operation. An Upfold tank should be
drained and refilled with clean water after treating
no more than four hundred 70 kg baskets.

Page 17
Propagating transplants

G
rowers can propagate their own transplants relatively
cheaply in the hot months when no special germination
facilities are required and off-season labour can be used.

Transplants established in seedling trays during

January can be planted out in March. The trays can
then be replanted immediately and those plants
can be kept in the trays until spring.

Under favourable conditions, plants will be ready

for transplanting into the field after 50 days in sum-
mer, and up to 100 days or more in winter. Good
management and adequate nutrients will ensure
the development of a firm root plug. This can be
checked by examining the root plug periodically.

The nursery site must be in full sunlight but shel-

tered from the wind.

Preparing seedcane
A twin blade circular saw is used to cut 25 mm
single-budded setts (SBS) from the cane stalks.
The blades should be sterilised frequently with
10% Jeyes fluid.

Transplant producers should ensure that young,

good quality seedcane for the production of
transplants is available at all times to ensure good Single budded setts are prepared using a twin blade
germination and vigorous plant growth. circular saw.

SBSs that are damaged by borer or infected with To prevent this, SBSs should be planted into trays half-
stalk rot must be discarded. The remaining SBSs filled with growing medium. The SBS should not be cov-
must then be treated with a registered fungicide. ered with growing medium at this stage and trays must
be stacked on top of each other in a warm (28 - 32°C)
Setts can be pre-germinated in humid conditions germination room. After two to three days and once
at a temperature of 28 - 30°C for a few days be- most of the buds have germinated, any un-germinated
fore planting those that have germinated into the SBSs are discarded and replaced with germinated ones.
trays. However, when temperatures are too high The SBSs must then be covered with medium before
or the conditions too humid, fungal and yeast being left in the germination room for another day or
infections can infect whole batches, resulting in two. The trays must be watered daily. When most buds
no germination. have germinated, the trays are placed outdoors.

Page 18
Growing media Trimming
Composted pine bark or composted bagasse Transplant leaves should be trimmed 4-6 weeks after
can be used. Composted bagasse has good planting. Trimming during the growing period can be ben-
physical and chemical properties and is well eficial by slowing down the stronger plants and allowing
suited to the propagation of transplants. the weaker ones to catch up, making them more uniform. A
Prepare the compost as follows: to one cubic light trimming a day or two before transplanting facilitates
metre of fresh bagasse, incorporate 3 kg of handling and reduces transplant stress. As cutting tools
freshly ground dolomitic limestone and 2 kg of can spread RSD, it is important that the instruments are
2:3:4(24) fertiliser. Mix thoroughly and moisten regularly dipped in Jeyes fluid (10 % solution) or methyl-
the stack. Turn over every two weeks for the ated spirits 75%.
first six weeks. Enrich with further nutrients
at a rate of 2 kg 2:3:4(24) per cubic metre of
decomposing bagasse. Continue aerating the
stack by turning at least once a month. After
about four to five months the bagasse will have
shrunk considerably, turned black and will be
ready for use.

Planting into trays

Multi-cellular seedling trays are recommended
for propagating transplants. All trays must be
thoroughly washed after each use. If polysty-
rene, trays must be treated with a copper-based
root-pruning solution before use and re-dipped
if necessary.

The trays must be raised at least 300 mm off the

ground to allow light to penetrate underneath,
which prevents roots from growing through the
drainage holes in the tray cells.

Fertigation
Trays must be irrigated 4 times daily for 3-7
minutes. Although the cane sett acts as a
nutritional buffer during the early stages of
growth, supplementary feeding will be neces-
sary because of the high degree of leaching.
The following nutrient concentrations are rec-
ommended when fertigating: N: 90 - 120 ppm;
Ca: 30 - 50 ppm; P: 50 - 60 ppm; Mg: 20 - 30 Multi-cellular seedling trays should be raised at least
ppm; K: 50 - 60 ppm; S: 20 - 30 ppm; pH 4.5 - 6.0; 300 mm off the ground to allow for light to penetrate
underneath.
EC: <200 mS/m.

Various commercial liquid fertiliser formula-

tions are available for use in fertigation. An inex-
pensive 5:1:3 NPK formulation may be prepared
from commonly available fertiliser carriers.
Fertigate at least twice weekly during summer
and once a week during the winter months.

Page 19
 NOTES

Page 20
 SEEDCANE PRODUCTION

South African Sugar Association

South African Sugarcane Research Institute
170 Flanders Drive, Mount Edgecombe, 4300
Tel: (031) 508 7400 Fax: (031) 508 7597
Website: www.sugar.org.za/sasri
ISBN No. 1-874903-29-8 SOUTH AFRICAN SUGARCANE
RESEARCH INSTITUTE