Out in the field - Matthew Carter

Happy New Year!

This is how I started Fresh Focus 12 months ago – “The dry weather is really starting to hit home now. As I write this, there is a hint of rain for later today and the weekend, but I suppose we will see when/if it gets here”. From 1^st – 17^th January 2017 we recorded just 4.2mm of rain at the First Fresh Weather Station in College Road. For the same period this year (2018) it has recorded 99mm!

However, this rainfall has been very localised, and dominated by thunderstorms and very heavy rain. One time when College Road received 40+mm in one downpour, only 1.5mm was recorded at Muriwai. Most areas have now received a good soaking, giving relief to farmers, growers and orchardists alike.

Summer is still here and it looks like there are going to be some hot and dry days coming up, so if you have irrigation, make sure it is in use to keep soil moisture levels up.

The First Fresh weather stations (and some others) are accessible via the www.Harvest.com website. Just click on “Live Data Portal”, and then follow the directions to get to Gisborne and the various weather stations.

The warm weather and plentiful moisture has meant that fruit size is looking better than I would expect for this time of year. Crops and trees are looking healthy, and under less stress than we often see in January. Take advantage of this by continuing with foliar nutrition, and lets keep this fruit growing to optimum size.

Many blocks are in an “on” year, and so the fertiliser recommendations that I did for many of you including the February “if required” application, will need to be applied. For many, this is a top up of something like Nitrabor (field grade calcium nitrate with boron). This is a nitrate based fertiliser with both nitrogen and calcium available directly to the plant. Calcium is obviously very important for fruit size, cell structure, and rind quality.

Plenty of reminders and suggestions this month – so here they are.

Gibberellic Acid Applications – Navel Oranges

G.A. (Gibberellic Acid) is a growth regulator which should be applied to all navel orange blocks. A G.A. spray is recommended to reduce creasing (albedo breakdown) water spotting, oleocellosis, and post-harvest breakdown. It also strengthens the rind of the fruit. Used in conjunction with a calcium programme, the application of G.A. helps improve packouts, both domestically and when fruit is repacked overseas. Used in autumn, a G.A. application can delay rind colour, however, a summer application made before the end of February will have minimal effect on rind colour, whilst strengthening the rind.

One issue for export crops can be poor out turns overseas, mainly due to rots and blue/green moulds. Blue/green moulds can only be caused by physical damage to the fruit. This is why, in an export carton, there are often affected fruit surrounded by good, intact fruit. In New Zealand, there are no post-harvest chemicals (fungicides) applied to the fruit, which gives a point of difference in the market, but also increases the chances of rots. Where a G.A. has been applied the increased firmness and reduction in general rind disorders usually means far better outturns overseas.

All export blocks must have a GA applied. Navel Orange crops that have had a G.A application and a robust nutritional programme will be prioritised for export over those that have not.

During the 2017 season, Newhall and Navelina oranges were also sprayed with GA. There was no colour delay and quality was better, so once again this season, ALL export navels need to have a GA applied.

Key points for G.A. Applications

• Apply to all Navel varieties when they are at “Golf Ball” size (30-50mm diameter) during the summer. This is generally from late January to mid-February – but certainly looking earlier this season – some has already been applied.
• The rate is 10 ppm (parts per million) used at the 30-50mm size.
• Use with a non-ionic spreader such as Spray Aid, Contact Xcel, or Spreadwet 1000.
• pH of Spray water – Consult label, as they do differ. Rule of thumb is that water may need to be acidified slightly to between pH 5.5 – 7.0 (slightly acidic to neutral)
• Good penetration into the canopy and around the fruit is required.
• Apply in warm, slow drying conditions.
• Do not apply for 4 weeks after an oil or copper spray as oil can affect the uptake of the G.A. and copper can react with G.A.
• Thorough coverage is essential; this can be up to 2,000 l/ha for small trees, and up to 3-4,000 l/ha for larger dense trees.
• Trees must be sprayed to runoff.
• Don’t apply to waterlogged, water stressed, or unhealthy trees.

Gibberellic Acid Applications – Satsumas

There is also a recommendation to apply to satsumas for rind strengthening. Rind strengthening only is applied at 5ppm at colour break. To delay harvest, 10ppm is used in March. The decision bout delaying harvest will occur later when we have a better idea of crop forecasts from Northland and Gisborne.

The 5ppm rind strengthening application is recommended for all but the very earliest blocks. This allows a little more leeway if harvest needs to be slowed down, the fruit will hold better on the trees if it has had a G.A application.

Thinning

Many satsumas blocks had an NAA application to chemically thin fruit. This has worked well, although there are still bunches in most blocks which need to be hand thinned. Do this asap, as fruit size is increasing quickly.

There are also a few bunches of fruit in Meyer lemons, again, it is a good idea to try and thin down the larger bunches to promote fruit size and reduce incidence of marking and safe havens for Greenhouse Thrip.

Pest Pressure

The crop monitors are currently seeing very high pest numbers, due I believe to warm and wet weather. Mealybug and thrip are the main ones so far, including a resurgence of Kelly’s Citrus Thrip in many crops.

Buprofezin (Applaud/Ovation) with Wetcit is recommended as an IPM friendly approach to controlling mealybug (plus whitefly and scale crawlers). Two applications are required, 14 days apart, and although the numbers are slow to drop, they stop causing damage quite quickly.

Success, Sparta, and Movento are all being recommended depending on the situation, for thrips.

Citrus Flower Moth – especially in Yen Ben, is just starting to show up a little more on monitoring reports. Using BT (Dipel, Biobit) every 10-14 days will help keep the problem down. Success, and Sparta are also effective against CFM, so are useful when undertaking thrip control. 

Please get onto spraying crops asap after monitoring recommendations are made, as pest numbers have been increasing rapidly, and will cause damage to fruit.

Valencia and Encore

Many Valencia and Encore blocks are coming to the end of harvest. Some Valencia’s were able to be strip picked pretty early, which will certainly help grow the larger crop of next year’s fruit.

As these summer varieties are harvested, make sure they get pruned, and nitrogen applications are made when the weather allows. The earlier these activities are undertaken, the better the crop will be next season.

Maintain the fungicide and pest control programmes. Sooty mould is often an issue on Valencia, so use Movento and or Buprofezin for control of whitefly crawlers and reduce the population.

Give me a call if you need any further nutritional information or pruning tips on these varieties.