MVCB Weekly News - Murray Valley Citrus Board

MVCB Weekly News
13 November, 2012 www.mvcitrus.org.au
Murray
Valley
Citrus
Board
58 Pine Ave
Mildura VIC
3500
PO Box 1384
Mildura VIC
3502
Ph: 03 5051 0500
Fax: 03 5021 1905
Qfly Update
Area # Qfly Action
Buronga NSW 1 Under chemical control
Queensland fruit fly.
Board chair John Tesoriero and CEO Hugh Flett have attended a number of meetings about
the continuation of the Pest Free Area (PFA). Other sectors involved in these meetings
included Victorian Department of Primary Industry (Vic DPI), NSW DPI, table grapes,
summerfruit, biosecurity Australia, Horticulture Australia, VFF and AHEA.
These meetings have been to consider the proposal in front of industry from the Vic DPI to
shift the majority of the costs of management and eradication of Qff within Sunraysia on to
industry (citrus, table grapes and summerfruit). The proposal represents a cost share
arrangement of 70/30, industry/government. Industries preferred position is for a 50/50
split with an across industry HAL project to assist with the funding. Negotiations are
continuing with government in this respect. A number of issues and actions are still being
considered with regards to the proposal and we will update growers when more is known.
MVCB is pleased with the appointment of Lauren Donaldson by Vic DPI as the new Plant
Standards Officer based in Mildura. MVCB welcomes Lauren and is looking forward to
working closely with her on eradicating Qfly in the Sunraysia PFA.
Foliar Nutrient Sprays for Citrus
Nutrient foliar sprays complement soil fertiliser programs, and at critical periods have proven
to be beneficial by enhancing vegetative growth, increasing fruit set and size and reducing skin
disorders such as albedo breakdown. Foliar fertilising is more efficient than applying fertiliser
to the soil. Some studies have shows it to be at least five times more efficient, depending on
the nutrient, soil condition and crop.
At this time of the year, citrus trees require adequate levels of nutrients, especially nitrogen, to
support the spring flush, flowering and fruit set.
Foliar sprays of calcium nitrate after fruit set, (mid to late November), are important to
maximise calcium uptake by the new fruitlets as it can be difficult to get calcium into the fruit.
They are also particularly important to minimise albedo breakdown and fruit splitting especially
if day time temperatures are below normal. Patches and/or varieties that are prone to fruit
splitting and albedo breakdown may need to have a repeat application of calcium nitrate. The
use of low biuret urea will facilitate the uptake of calcium nitrate into the fruitlets. From late
January onward applications of calcium nitrate should be avoided as it will delay colour
development.
Practical notes for foliar spray application are:
• Only use foliar spray grade fertilisers especially calcium nitrate

Diary Dates:
• Alternatively use chelated forms of magnesium, zinc, calcium or manganese for foliar
sprays
• Do not apply foliar sprays in high temperatures (above 32 0 C) especially if humidity is
low or trees are stressed
• Check pH and conductivity. Optimum pH if there is no fruit on trees is between 5.0
and 5.5. If fruit is present optimum pH is between 5.5 and 6.0. Electrical conductivity
should be below 15,000
• Use between 2,000 and 3,000 L/ha volume of water.
For more information contact your agronomist or chemical reseller