BULLETINS
& ARTICLES
New Zealand
Tomato Sector Report - March 2005
Executive officer: Ken Robertson
Article reproduced with permission
of David Peterson and Peter Cooper, Vegfed NZ
EXPORTS
The figures in for December show that 428,061kgs
of tomatoes were exported with 359,000 kilos of them going to Australia.
The total compares well with December 2003 where 370,511kgs were exported.
For the year ending December 2004, almost 2 million
kgs were exported with an FOB value of NZ$7.5 million. The volume
is up 11% and the value is up 33% on 2003.
IMPROVING ENERGY EFFICIENCY IN GREENHOUSE VEGETABLE
PRODUCTION
Elly Nederhoff from Technolutionz Ltd is one third
of the way through this energy efficiency project. It is being funded
jointly by MAF’s Sustainable Farming Fund, VegFed’s Fresh Tomato Sector,
Solid Energy, Natural Gas Corporation and Heko Ltd. In terms of technical
data, the project extends over 3 years so the first winter’s data (2004)
from 10 greenhouse operations has been partly assessed.
In her end of year report to SFF Elly made a long
list of findings, and several comments about heating that are worth repeating
here.
Some boilers had insufficient burner capacity,
whereas others were over-dimensioned. Insufficient burner capacity
makes it impossible to maintain the required temperature during cold weather,
which can lead to humidity problems and hence plant diseases.
Over capacity, especially in a coal burner, leads
to excessive energy use.
It seems there is a lack of awareness that settings
in the burner can be changed for transition from low to high flame and
to low flame again (at certain temperatures of the boiler water).
Elly suggests that improvements can be made here.
Similarly, the boiler capacity (or water content)
is critical. Too small a capacity causes temperature fluctuations
in the boiler and heating pipes and hence in the greenhouse. It also
makes a gas burner switch on and off or alternate between low and high
flame very frequently.
The technical people working with Elly on this
project have suggestions about how to overcome these shortcomings, e.g.
by installing a 3-way valve and/or burner controller and/or a (small) neat
storage tank (buffer). The growers involved in the project have now
been asked for specific information on their burners and boilers.
The other very direct message coming through as
a result of this project and also keeping the Government’s Carbon Tax in
mind, is that growers should be recording their energy use (in megajoule
per sq.m per year) and their production (in kg per sq.m per year).
These two figures can be combined to give the “energy
efficiency” (in kg/MJ). This energy efficiency figure will
be very useful as an energy benchmark and one that can be used to monitor
progress on the efficient use of energy on an individual property.
A more detailed report on this project is to be
written by Elly Nederhoff by mid-year and will be available directly to
growers.
RE-USING ROCKWOOL
Dr Brill Bussell at UNITEC reports that the trial
to study how Hebe plants grow in potting mix containing various percentages
of recycled used rockwool produced an interesting outcome.
It was found that the root growth was much more
extensive in the potting mix containing rockwool than in the control pots
that didn’t contain any. Bill says “more root growth in rockwool
treatments might be of importance in some situations where rockwool and
potting mixtures might be used, e.g. establishing young plants in rockwool
treatments might also enable young plants to be dug earlier from nurseries”.
The project is due to complete by mid-year and
it is expected to produce some useful and economic after life for rockwool
that is past its used-by date in the greenhouse.
ENERGY EFFICIENT WAYS TO IMPROVE THE ECONOMIC
BOTTOM LINE OF YOUR GREENHOUSE CROP BUSINESS
Fresh Tomato Sector, in conjunction with CRL Energy
Ltd, will shortly be releasing a “toolkit of information” via the website
and directly to growers who want it. The information Kit will provide
information on energy use and energy efficiency in the protected crop sector.
Measures to improve the energy efficiency of your greenhouse operation
are suggested and potential energy savings estimated. Growers will
be able to estimate the potential savings in relation to their own greenhouse
operation by completing the simple calculations that are part of the kit.
Some case studies are provided as examples. To complete the calculators,
growers will need to have available a calculator, annual energy consumption
from power and fuel bills and the prices paid per unit for the various
types of energy used, e.g. natural gas, coal, and diesel.
While the Information Kit will provide case studies
on the effect of various measures on energy consumption and energy related
costs on an average basis, the costs of implementing such measures and
associated pay-back periods are not included.
Some information on where to find various technologies,
products, contractors and consultants will be listed at the back of the
kit.
THIS SUMMER’S TOMATO MARKET
I have had several enquiries from growers around
the country this summer asking what has happened to the tomato market compared
with last summer. For growers to be contacting me sitting in an office
in Wellington generally indicates that all is not well as far as production
and returns to growers are concerned.
The country has certainly seen an indifferent start
to summer this year but since mid-January it has been quite normal and
certainly much more normal than the summer we experienced in 03/04.
Perhaps last summer was an aberration but it seemed
to convince quite a few greenhouse growers of other crops to switch to
tomatoes this season. This would indicate that production is up while
consumer demand appears to be way down on normal expectations.
I understand that retailers are not particularly
interested in what they pay for tomatoes, so long as it is no more than
what their competitors are paying. Right now it I pretty obvious,
even with very low prices at retail, that consumers do not seem to be interested
in purchasing more tomatoes.
