April 2018

Grower talk

What’s top of mind for you in the orchard over the next three weeks – are there two or three things that have to get done? 

  • Start to get ready for picking and pruning
  • Keeping and eye on soil moisture, applying phosphonic acid
  • Apply stop drop and copper sprays (David Arnold, S.A.)
  • Apply stop drop and prepare for a GA spray in a few weeks time (Frank Mercuri, Riverina)
  • Finish copper sprays, apply the cling spray and irrigation do some maintenance (Daniel Lazar, Sunraysia)

Is there any pest, disease or weed you’re targeting? What management practices are front of mind? 

  • Thistles and grasses (David Arnold, S.A.)
  • As soon as reasonable rainfall is predicted apply residual herbicide on late maturing blocks (Frank Mercuri, Riverina)
  • Spot spraying for fleabane and milk thistle (Daniel Lazar, Sunraysia)

What would you like to get done if you had more time? 

  • More irrigation maintenance
  • Prune as soon as the blocks become harvested
  • General machinery and tractor maintenance (David Arnold, S.A.)
  • Conduct irrigation uniformity test (Daniel Lazar, Sunraysia)

Climate update and outlook

Slightly warmer than average conditions (day and night maximum temperatures) are expected for May through to June. This might hasten the internal maturity of fruit but could delay colour development. There is a good chance that average rainfall will occur May through to June.  Average maximum temperatures for March were about 2 °C above average and minimum temperatures were near or slightly above average.  So far April temperatures have been significantly above average. Very dry conditions have been experienced and an irrigation application volume is expected to be above average.

Crop status and management

Phenology and crop development

All varieties are going through the various stages of colour break. M7 and Navelina have 20 to 50% colour. Brix levels in Sunraysia are good (11 ° Brix) with average acid levels; the eating quality should be good.  Some isolated blocks in the Sunraysia and Riverland might be ready for degreening at the last week of April and should be at full capacity by early May.  Riverina are about two to three weeks behind in maturity to Sunraysia. Anecdotal crop loads reports indicate that the Riverina will probably have a below average crop of navels with good size. Sunraysia and the Riverland crop load will probably be slightly below average with good fruit size; similar to the 2016 crop. Imperial mandarin crop are significantly below average throughout the regions. The crop loads are very variable throughout the southern regions; some blocks have low crop loads and some are above average and there is variation between trees.  The official Citrus Australia crop estimate reports should be available in late May.

Copper and cling spray timing is late April to early May.  GA is an option for delaying fruit colour and rind development.

Pests, diseases and weeds

Firstly, a short 100-word update on pests and diseases in the region, including any urgent notices or calls to action.

Secondly, a dot-point list of pests and diseases to look out for in the upcoming month for your region. Just the names will suffice – we will link names to the relevant sections of the Citrus plant protection and management guide 2017.

Insects: Late generations of red scale are the only main concern and this can be easily identified by monitoring the orchard, especially headlands and other dust prone areas. Chemical options are still available.

Fullers Rose weevil: Detections of weevil is at its peak and growers must be extra vigilant to endure all controls are applied and monitor carefully.

Fruit fly: As fruit mature they will have a heightened risk if fruit fly susceptibility. Monitoring and bait spraying programs need to be implemented in Sunraysia and the Riverina. A quick guide and I.D. chart is available from NSW DPI website, NSW LLS and Citrus Australia.

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This Seasonal Update for the Murray Valley, Riverlands and the Riverina has been prepared by Steven Falivene, NSW DPI.