ENVY Chemical Thinning Orchard Walk 10 th October 2016

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1 ENVY Chemical Thinning Orchard Walk 10 th October 2016 Today s field walk is about doing everything possible to pamper the star- "Envy". This includes making sure the Class1 yield is good, the majority of fruit are packed as High Grade colour, and ESP A&B. This requires a full management approach as illustrated in the growing jigsaw below. In this field walk we will discuss a number of the jigsaw positions that relate to spring management. Make this variety your number one priority every week. Achieve optimisation of each of the 13 pieces of the puzzle.

2 Chemical Thinning The key to growing good Envy lies in getting the thinning and crop loading correct. Envy has high production potential but there is a fine line between optimum crop and over cropping. The penalty for over cropping is: Biennial bearing Poor colour development Low dry matter and brix levels Poor eating quality If conditions are not correct for fruit set there can be heavy fruitlet drop in the absence of blossom stage chemical thinners. Factors responsible for erratic fruit set appear to include: Poor provision for cross pollination Wet feet Inadequate nitrogen levels in early season, i.e. leaf nitrogen less than about 2.7% for a spring leaf sample If these conditions exist be very careful with blossom thinners. Preferred blossom thinner programmes include ATS, ethephon or ATS/ethephon combinations. Ethephon is known to be very effective in promoting return bloom. However, in 2014 we witnessed several blocks treated with ethephon that suffered excessive primary drop. Relative to other varieties, Envy has very large petals and as petals are the uptake mechanism for ethephon this probably explains its elevated sensitivity to ethephon blossom thinning sprays. If you re using ethephon, we recommend using only moderate rates of both ethephon and the spreader sticker. Also take care with water rates on dwarf canopies that don t have high Tree Row Volumes. Ethyphon should be used after king bloom are open to selectively take out te lateral flowers and the later flowers. ATS should not be started until the king blooms have set. Take care with application conditions as blossom thinners applied in poor conditions will increase levels of russet. Many Envy blocks receive only post blossom thinning programmes, usually benzyladenine (BA) plus NAA and this has predominately done a good job in regard to return bloom. As blocks become more mature and lower vigour, they will become harder to thin, so while BA/NAA programme combined with early hand thinning has given very good return bloom in the past, there are situations where a more aggressive chemical thinning programme would markedly reduce the hand thinning task and will assist with return bloom and evenness of the block. Adding Carbaryl to the BA/NAA fruitlet thinning spray, whilst successful as a thinner, is very detrimental to predator populations and is it to be discouraged. Where additional thinning is required we recommend you consider adding bloom thinning products as discussed above. For young blocks BA plus NAA is still the best option.

3 Minimising Russet The following summarises a russet management strategy for Envy. Russet can be caused later in the season especially where leaf quality is poor but the primary time for russet control on Envy is during flowering and early fruitlet development. Several management techniques have shown to reduce russet: 1. Maintain an open canopy that will dry quickly in the spring. AgFirst saw evidence last year of canopies that were too dense in the bottoms suffering increased levels of russet. 2. Apply a GA4+7 program over bloom and early fruit set. Apply GA 4+7 (50-100ml/100L) + Umbrella 120 mls per 100l + tank acidifier anytime from balloon blossom, repeated every 7 days. 4 applications in total. Water volume is important to ensure full coverage of the fruitlet, (1000 L/ha recommended for full canopy dwarf trees). Acidify the tank mix to ph. Umbrella spreader sticker has shown significant improvement in russet control over GA 4+7 alone. The higher rate of GA is more effective than the low rate however overuse of GA can cause reduced bloom levels the following year. More often is better than a few at a higher rate. There is a low potential that Umbrella (or Nufilm) may interfere with pollen transfer/viability due to their mode of action, so it may be wise to use 100mls/100l plus Regulaid or Spray Aid for the application around full bloom. Definitely add the Umbrella to late bloom and young fruitlet applications. 3. Keep tank mixes simple, no more than 2 products/tank, combining products increases the volume of surfactants in each tank which can increase russet. 4. Only use pesticides that have a scientific record of not inducing russet. Don t take risk with unproven generics. 5. Quick drying conditions are favourable to minimise russet. Always spray Envy above 10 0 C and with temperatures increasing. Also consider using concentrate vs dilute spray application particularly over the russet sensitive period. 6. Healthy leaves early: Applying 5/kg per hectare of low biuret Urea up to 2-3 times from mid-september starting once the initial leaves are 3-5 cm can provide extra tree health and better overall leaf condition which could help reduce russet. Low Biuret Urea applications the day before frosty conditions can also reduce the severity of minor frost events. 7. Frost protection is critical. Have wind machines coming on at a minimum of +0.8 o C degrees. Keep grass sward mown short, herbicide strip clean and free of active weed growth. Operating the under tree irrigation can provide C protection in areas where the wind machines are not 100% effective. 8. Powdery mildew can influence russet levels therefore maintain excellent control throughout the season. Ensure sprayers are accurately calibrated and sufficient spray is reaching the tops of trees. We have seen lots of mildew appear around Christmas time which should have been controlled by the product being applied but coverage was lacking. 9. Monitor nutrition and water inputs throughout the season. Trees must be kept healthy as leaf health is critical to good fruit finish. Monitor magnesium leaf levels as Envy are prone to magnesium deficiency and this element is critical for healthy green leaf and colour development.

4 Biennial Bearing Variation in flowering is a significant issue, causing year to year, tree to tree, and within tree variation. The impact of this being uneven crop loads, lower dry matter, poor colour development, later picking, many multiple picks and the potential to increase internal browning risk. Key strategies to ensure strong consistent flowering Appropriate crop loads for the canopy size. Achieving the optimum crop load early in the season. Good chemical thinning and hand thin Envy as soon as practical. Break the cycle by using Ethrel as a chemical thinner Consider a summer NAA program in the On crop Learning from the ENZA Cup Envy winner : Graeme Watson Last year the average colour split was 54% HG, 43% EG and 3% AG. The results of all the blocks run by T&G East are shown in the figure below. 100% HB Envy Colour splits 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% HG TCE % SG TCE % Graeme Watson and his team grew the best coloured Envy in One of his blocks young blocks achieved 92% HG, the mature blocks 82% and 67% HG. Watson blocks are all well above average for colour. What made their colour so much better than everyone else? What can we learn? AgFirst have done a bit of digging to try and unearth the "Watson secret". We believe it is due to 3 primary factors: 1. Branch angle on the Watson trees is closer to o below the horizontal. Compare that to many dwarf blocks in the district, where branch angle at harvest is closer to o. We think these extremely pendant

5 branches are creating too much inter-branch shade and would be better tied up or even shortened to a better angle. 2. Crop Load on the Watson blocks were only moderate at 90t/ha. We know high crop loads dont colour as well. 3. Nutrition (see discussion below) Graeme is running a much higher level of P and K in the leaf than most other growers We know these 2 major elements and their ratio to N has a big impact on colour. By chance Graeme undertook intensive leaf testing in 2015/16 on two of his Envy blocks, the year he won the ENZA Envy cup. We think this data is highly useful to all Envy growers and we're keen to discuss it at the fieldwalk. Figure 1 G Watson Envy leaf test results C&D4 Figure 2 G Watson ENVY MM106 Compare Graemes leaf tests with current industry late January targets: N ( ) P ( ): K ( )

6 Mg ( ) The results that look very interesting to Agfirst are Graemes P and K results and their relationship to N. Both nutrients are known to have an impact in promoting colour. We would like to be able to discuss how Graeme achieved these unigue leaf tests however from analysis of these results our current thinking is that by mid March on Envy you want to be targeting: N P K Mg > 0.20 To achieve these targets you will need the correct soil levels, an active leaf monitoring program and strategic use of foliar fertilisers. Remember balance is the key as excess levels of any one element can cause fruit quality issues.

7 Omahuri Heathcote Envy Bud Counts Row 17 Tree Row 17 Tree

8 Coldstream Main Envy CG202 Bud Counts Row 4 Tree Row 4 Tree Coldstream MM116 Envy (2014) Bud Counts Row 10 Tree Row 10 Tree Row 10 Tree

9 ENVY CHEMICAL THINNING SURVEY Grower Block Rootstock Chemical Chemical rate (per ha) Spreader Sticker & (Rate/100l) Water Rate (l/ha) FB Date Date applied Describe Thinning Effect Return Bloom Yield (t/ha) Sunpeach THO M9 M9 Ethrel 360 mls/ha Reg Oct 7-Oct ATS 1.50% Growett BA 6.4 l/ha Reg Excellent Good 120 Rainbow CG202 CG202 Ethrel 300 mls/ha Reg Oct 10-Oct ATS 1.50% Growett Oct ATS 1.50% Growett Oct Heavy thin but still good yield No secondary Good 90 Coldstream Only secondary thinning on Envy Main CG202 Bapsol 1.4L/ha Oct 1-Nov Good Very good 80 ANA 7ml/100L plantings MM116 Meteor 25g/100L Regulaid Nov Excellent Very good 2015 plantings M9 Cepiland ATS 1.50% 10-Oct Average Very good ATS 1.50% 14-Oct ATS 1.50% 18-Oct RJ Flowers BBA CG202 NAA 240 mls/ha Regulaid Oct 25-Oct Happy, moderate result Very Good 99 R1565 Elexis 7.2 l/ha BBD (Hicane 13/08/15) CG202 NAA 200 mls/ha Regulaid Oct 16-Oct Very Good Very Good 90 Elexis 6.0 l/ha Ridgeview CG202 CG202 Ethrel 600 mls/ha Reg 150ml Oct 10-Oct ATS 1.50% Growett 100ml Oct Top half only sprayed No secondary Good job had some russet? Good 81

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