Gearing up for 2013

aboriginalconspiracyUrban and Civil

Nov 16, 2013 (3 years and 6 months ago)

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December 2012 E
-
Newsletter




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1

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8

Gearing up for 2013

Dear Reader,

Welcome to another issue of the PINT newsletter. A new year
and it’s time to gear up for raft of agribusiness research,
development and extension activities. This issue includes
articles on papaya


notably the papaya mealy bug, a
devastating insect pest i
n different parts of the globe
-

though;
the news is not all bad.

Plant Industries also has a couple of new projects that have hit
the ground. Better understanding the processes around
nitrogen cycling in tropical crops is the focus of a new program
funde
d by the Australian Dept. of Agriculture Fisheries and Forestry. Nitrous oxide emissions are
significant in the case for anthropogenic climate change; therefore reducing such emissions in
tropical farming systems may have some benefit. However, important t
o farmers on the ground is
that their nitrogen cycling in their cropping system is running as effectively and efficiently as
possible


it just makes good economic sense. Also in this issue is a story on the ever insidious
fusarium, which has in recent tim
es struck the NT’s melon industry. A research project has been
raised to further investigate the strain of the disease in the Northern Territory and how it might be
managed.

I would also like to introduce a new staff member Alan Niscioli who has come on
board as a
Technical Officer to work in
the
nitrogen cycling

study


welcome Alan.

The ‘Upcoming events’
section highlights a range of planned activities associated with the NT mango industry, as well as
a field walk here at Berrimah on ornamentals for the

nursery and cut
-
flower industries. So check
them out and get along.

Regards,



Warren Hunt

Ph


+61 (0)8 8999 2143

Fax +61 (0)8 8999 2049

Mobile: +61 (0)409 809 610

Email:
Warren.Hunt@nt.gov.au




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Papaya mealybug, a new
pest of papaya in SE Asia

By: Dr Brian Thistleton, Principal Entomologist,
Department of Primary Industry and Fisheries,
Northern
Territory.

Papaya mealybug (
Paracoccus marginatus
)
or PMB

is a severe pest of papaya which has
been moving through SE Asia in the last few
years. The pest has caused large scale
damage to papaya plantations but fortunately
it is easily controlled by biolog
ical methods
and is no longer a problem in most countries
where it occurs.

PMB is not currently in
Australia.



Above:
Severe infestations of papaya mealybug in
Java, Indonesia (photos B. Thistleton).

Impact:

Large infestations of PMB occur
along on lea
ves and fruit
,

where they feed by
sucking plant juices and excrete a sticky
substance called honeydew.
S
ooty mould
grows on honeydew
(see top right photo),
and coats the plant
, thereby

impeding
photosynthesis and gaseous exchange. This
leads to the death
of papaya trees within a
few months after infestation.

Distribution:

The pest is native to Central
America and was first collected from Mexico
in 1955 although it was not formally
described as a new species until 1992. Since
1994 it has been recorded in t
he Caribbean
and Florida and was later recorded in Guam
(2002), Palau (2003), Hawaii (2004) and
Northern Marianas (2005). More recently

it
has been recorded in: Java, Indonesia
(2008), Philippines (2008), India (2008), Sri
Lanka (2008), Thailand (2008), Bangladesh
(2009), Maldives (2009), Cambodia (2010),
Thailand (2010) and East Timor (2010). It has
also spread to Africa.

Other hosts:

While the common name is
papaya mealybug, t
he pest has a wide
range
of hosts and
has been reported
on

more than
25 genera of host plants, including many
other
economically important crops such as
citrus, yams, cassava, hibiscus and
frangipani.

Management:


PMB is very difficult to control
with ins
ecticide sprays and in many countries
local parasitoids and predators have not
significan
tly reduced its numbers. Where the
pest occurs naturally in
Mexico
, it is only
in
low populations
. Research
dis
covered that it
was being contro
l
l
ed

by several parasito
ids

(i.e
.

insects that live inside and kill other
insects).
Three of these
are
minute wasps,
Anagyrus loecki, Acerophagous papayae and
Pseudleptomastrix mexicana

and
were
collected from Mexico and cultured and mass
produced in San Juan, Puerto Rico by the
Department of Agriculture in co
-
operation
with the USDA, Animal and Plant Health
Inspection Service (APHIS).


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Following impact risk assessments which
showed

that the parasitoids were host
-
specific and would be unlikely to attack other
fauna, the parasitoids

were introduced into
USA (Florida and Guam),
as well as
Palau,

the

Dominican Republic, Puerto Rico, Sri
Lanka and India.
High levels of control of
PMB

were reported in all cases. Many
indicated
up to 95 to 100%

efficacy

within six
months of introduction o
f the parasitoids
.

Friendly n
eighbours:

One of the
parasitoids,
Acerophag
o
us papayae,

has
established in Indonesia and East Timor, and
the impact of PMB infestations has been
greatly diminished
. This has not only
protected the local industries but has
significantly lowered the risk of the
PMB
reaching Australia from these countries.

Hi
-
tech pest identification
:

Normally the
identification of the parasitoids is made by
rearing
PMB

larvae to adult

stage. However
in the case of the East Timor

detection,

the
only specimens of larvae initially available
were preserved in alcohol.
A

successful
identification was
instead
made by DPIF staff
using DNA analysis.

If you have any other queries on PMB please
contact:

Dr Brian Thistleton

Principal Entomologist, Plant Industries,

Department of Primary Industry and
Fisheries, Darwin

brian.thistleton@nt.gov.au



+
61
(0)
8 8999 2257
.

Action on the ground:
Investiga
ting nitrous
oxide cycling in Northern
Territory farming systems

By: Stuart Smith, Senior Extension Officer,
Berrimah Research Farm.


Above: Pop Jacobson (on tractor) and Stuart Smith
sowing cover crops at Thao Nguyen’s, Humpty Doo

Plant Industries
group
has

secured funding
und
er the Australian Government’s
Carbon
Farming Futures program
. The
A
ction on the
Ground

project is searching for ways to
make
NT farming systems more efficient by
benchmarking
nitrous oxide

(
N
2
O)

emissions
and carbon
sequestration
in

the soil
. This
research is being conducted in
melon, hay
and vegetable crops. Nitrous oxide is a
potent greenhouse gas, around 300 times the
greenhouse warming potential of carbon
dioxide. Three trials

(one in each of the
respective crops),
a
re running o
ver the wet
season and will form the base point from
which modifications to existing farming
practice can be made to improve nitrogen
efficiency and soil carbon retention. A brief
summary of the different trials underway
follows:


Katherine:

Th
is trial is
aimed at
testing the
addition of substances to nitrogen fertilisers
to reduce nitrous oxide production

in a typical
tropical fodder production system
. These

.

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nitrification inhibitors


have been shown to
work in temperate climates, but are yet to be
proven in the
monsoonal dry
tropics
.

The trial
is
based around a
S
abi grass paddock at
Katherine Research S
tation.
Period
ic

s
oil
testing
and
nitrous oxide gas

measurements
are a feature of t
he trial and are being carried
out by
project officer
s

Khamla Mott and
Malcolm Bennett
.

Results should be in by
the end of the wet season.


Above:
Project technical officer Alan Niscioli installing
gas chambers at “The Sweet Life”, Lambell’s Lagoon

Darwi
n:

There are two trials in Darwin
investigating the carbon and nitrogen
dynamics of cover crops

planted in rotation
with
in melons and Asian vegetables
.
The
first is

hosted
with
Sweet Life

at
Lambell

s
Lagoon, and the
latter by
Thao Nguyen, a
vegetable pro
ducer from Humpty Doo. The
carbon and nitrogen dynamics are being
measured by taking soil samples, soil water
samples from Full Stop

(wetting
-
front
indicators)
and

N
2
O
, CO
2

and methane

(CH
4
)

using
purpose built
mini

gas chambers
installed in the soil. This

work is being
undertaken by project officer
s Stuart Smith
and
Alan Niscioli. The cover crops include
Sweet Jumbo

sorghum,
Fumig8or

sorghum
and the legume
L
ab
-
lab
,

and are being
compared to fallow
spray
-
out paddock
s
. The

current

growing
conditions are ide
al for the
production of nitrous oxide in the soil, so the
results should be interesting
.

Measured
root
growth of these cover crops is
high
, with
evidence of
sorghum and lab
-
lab
having roots
down to 40 cm.

It is hoped that this work will clarify the effe
ct
that cover crops have on
N
2
O

emissions
in
these tropical farming systems.
It is
postulated that cover crops can take up
nitrogen left over from vegetable and melon
crops, therefore making it inaccessible to the
soil bacteria that would
otherwise
metabolise
it

into
N
2
O
.
It is also a
good
action
-
learning
activity
for the farmers

as they begin to
investigate how they might best retain

nitrogen in the cover crops
so
that
they
can

be

incorporated
into the soil

and provide
maximum nutrient benefit to th
eir next cash
crop.

Short
-
circuiting fusarium

By: Lucy Tran
-
Nguyen, Barry Conde and Stuart
Smith, Plant Pathology, Berrimah Research Farm.

Fusarium wilt is one of the most severe
diseases of watermelon and is caused by
Fusarium oxysporum f. sp. niveum (Fo
n).
This form of the disease is only pathogenic
on watermelons. Symptoms include damping
-
off, seedling wilt or general wilting during any
stage of plant development. The fungus can
survive many years in the soil as
chlamydospores and is spread by soil, pla
nt
debris, and farm machinery and on seeds. In
the Northern Territory both seedless (round)
and seeded (long) melon varieties are grown,
however
;
more than 90 % of watermelons
sold are seedless
, a
nd it is the seedless
varieties that have proven to be highl
y
vulnerable to this disease. Grafting
watermelon seedlings onto resistant cucurbit
rootstocks is common practice in many
countries as a management option. In
Australia, using grafted watermelon is
becoming a more common commercial
practice in Queensland,
New South Wales,
and Western Australia and the Northern
Territory.



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Plant Industries has initiated a research
project into the disease as there appears to
be subtle differences to the expression of the
disease in the NT situation which may
indicate that it

could be of a different race (or
races) of Fusarium, to those found interstate.
This investigation has been supported by
Horticulture Australia Limited (HAL),
the
University of Sydney
(
as part of a post
-
graduate research project
),

Monsanto
Australia and
Rijk Zwaan
Australia.

In
addition, in
-
kind support will also be provided
by other seed companies and growers.
It will
undertake
research

to identify the

particular
race
s

infecting NT watermelons

using the
latest DNA molecular technologies. The
efficacy of
c
ontrol measures such

as grafting
on resistant rootstocks will
also
be

studied
.
The outcomes of this work could mean
specific tailoring of different rootstocks to
mitigate the effects of specific strains of the
disease.

Project officers include Lucy Tran
-
N
guyen, Barry Condé, Lois Ulyatt, Stuart
Smith, Mark Traynor and a project
-
funded
Technical Officer.

Figure 1







Figure 1: Watermelon plant growing in the field
showing wilt symptoms caused by Fusarium
oxysporum f.sp. niveum (a)
;

symptomless
watermelon plant (b)
;

field sample displaying
vascular colouring (c
-
cross section, d


longitudinal section); watermelon seedlings with
Fusarium welt and leaf blotch symptoms
(e);
in
oculated watermelon seedling from
pathogenicity tests (f). Images by B Cond
ē

and
L.Ulyatt

(Images from Tran
-
Nguyen et al 2012. Outbreak of Fusarium wilt in seedless watermelon seedlings in the Northern Territory, Australia. Australa
sian
Plant Disease Notes. DOI 10.1007/s13314
-
012
-
0053
-
y)



.

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Intro
ducing Alan Niscioli


Welcome Alan!

Alan is a born and bred Territorian having
completed tertiary studies at CDU in both
environmental and biological sciences.

Alan
has
a strong research background. He has
recently joined Plant Industr
ies

after some
five years as a researcher with the
Australian
Bureau of Statistics
.
Alan has worked across
a range of scientific disciplines including
medical diagnostics and medical en
tomology.
Alan also has a wealth of h
orticultur
al
research experience
h
avin
g spent
six

years
working for the

former

CSIRO Plant Industry
unit in Darwin,

where he worked on a range
of projects examining limitations to yield
s

in
m
ango cro
ps including projects spanning
mango breeding, physiology and molecular
biology.


Useful Links

Australian Pesticides and Veterinary
Medicines Authority



APVMA


Public Chemical Registration
System



APVMA Permits



APVMA


Dimethoate Review



APVMA



Fenthion
Review

Bureau of Meteorology services



Weekly climate note



Madden
-
Julian Oscillation

Department of Agriculture

and Food
(DAFWA)



Horticulture Publications

QLD Department of Agriculture,
Fisheries and Forestry (DAFF)



Mango
Information Kit

NT Department of Primary Industry
and Fisheries



Agnotes and Fact sheets



Primary Industr
ies Publications




.

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Upcoming events

NT Post
-
season Mango Workshop

The Northern Territory Mango Industry
Association is hosting a workshop to address
quality issues from the 2012
-
13 season.

The
workshop will be held on Friday 1
st

February
at Whitewood Hall,
Howard Park Reserve,
Whitewood Rd, Howard Springs.


Starting at
2pm the workshop will highlight independent,
retail and wholesale perspectives, and allow
participants the opportunity to discuss
potential solutions.


The workshop will
conclude at 5:30pm wit
h a BBQ.


For further
information, or if you would like to attend,
please contact Grant Fenton at NT Farmers,
on (08) 8983 3233 or
grant.fenton@ntha.com.au
.

NT Mango Industry Small
-
group
meetings

Small
-
group meeting


Darwin Region (all
welcome)

Date:



Monday, 18
th

February.

Venue:

Skliros’s shed, Hopewell Rd., Berry
Springs.

Time:



10.00am


12.30pm

Topics:



Revision of small group process from
2012. (i.e., what happened, priorities
listed
etc.).



Back to the group: Report on research
activity


Assessing the effect of foliar
calcium applications on reducing lenticel
damage in KP mangoes (Chelsea
Moore).



Back to the group: Post
-
harvest handling
issues


update on 2012 activities and
discussio
n around major problems
encountered in the 2012 season


will
include a session specially focussed on
‘resin canal’.



Back to the group: The problem of
‘derelict’ neighbouring orchards
(facilitated discussion involving
participants from NT Farmers’
Associat
ion, NT DPI Biosecurity group,
NT Bushfires and NT Dept. of Land and
Resource Management).



Back to the group: New NMBP varieties
-

October visit to Kununurra. Feedback to
group from Ross Maxwell.





Back to the group: Manipulating mango
floral induction


u
pdate on project
development (Cameron McConchie).



New or emerging issues
-

facilitated
discussion and identification of additional
areas for advancement.

Small
-
group meeting


Katherine Region (all
welcome)

Date:



Tuesday, 19
th

February.

Venue:

Ian Curti
s’s shed, Fox Rd Katherine.

Time:



Time:


10.30am


1.00pm

Topics:



Revision of small group process from
2012. (i.e., what happened, priorities
listed in the initial process, what remains
relevant/important).



Back to the group: Report on research
activity


Assessing the effect of foliar
calcium applications on reducing lenticel
damage in KP mangoes (Chelsea
Moore).



Back to the group: Post
-
harvest handling
issues


update on 2012 activities and
discussion around major problems
encountered in the 20
12 season


will
include a session specially focussed on
‘resin canal’.



Back to the group: New NMBP varieties
-

October visit to Kununurra. Feedback to
group from Ian Curtis.





Back to the group: Manipulating mango
floral induction


update on project
deve
lopment (Cameron McConchie).


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New or emerging issues
-

facilitated
discussion and identification of areas for
advancement based on last year’s
discussion session + additional thoughts.

*Please
RSVP

to me by Tuesday 12
February so that that we have an idea on
catering for smokos and lunches.

Email:

Warren.Hunt@nt.gov.au


Showcasing New Ornamentals

Plant Industries extends an invitation to the
local nurser
y and cut
-
flower industries to
learn more about a project supported by the
Rural Industry Research and Development
Corporation aimed at delivering a set of new
genetics and management systems for
tropical gingers and heliconias.

4.00pm to 5.30pm, Thursday
21
st

February at
Berrimah Research Farm Horticultural block.

For more information contact: Megan
Connelly at
Megan.Connelly@nt.gov.au

.

Northern Territory RD&E Forum

NTMIA and the Northern Territory DPIF are
busy organising the annual NT mango R&D
forum. This year, the forum will be held in
Katherine on
Thursday 14th & Friday 15th
March
. Further details, including program
details, will be available in the near future.

9th Australian Mango Conference

The time for the mango conference is rapidly
approaching.


The final program will be
available by the end of February.


If you have
any suggestions for topics or speakers,
please let us know within the next few
weeks.


T
he conference is being held in
Cairns and Mareeba from the evening of
Tuesday, 14 May to Friday, 17 May 2013.
Program and
registration

details are available
on the AMIA website.