Spray Thinning of Apples

Even when pollination conditions and tree vigour are satisfactory, spray thinning apples always involves calculated risks. Inadequate fruit removal is a more common result than excessive thinning. However, some years natural fruit set may be poor and applying a fruit thinning spray may excessively reduce final fruit set and crop load.

Recommended Thinning Products:

Active Ingredient	Examples	Usage Notes
Naphthalene acetic acid (NAA)	Fruitone L, Fruitone N	Used alone or with Sevin XLR; caution with Red Delicious to avoid pygmy apples.
6-Benzyladenine (6-BA)	Cilis Plus, MaxCel	Effective for thinning and fruit size enhancement; works well with Sevin XLR.
Carbaryl	Sevin XLR	Effective on all varieties; limited to one application per season.
1-Aminocyclopropane-1-carboxylic acid (ACC)	Accede	Supplemental tool for thinning when other treatments are insufficient.

 

All fruit management practices, and spray thinning in particular, may require adjustment to work well in your orchard. Keep careful records of your spray thinning results in order to make appropriate adjustments for each block and to ensure improved fruit quality. When possible, leave some trees untreated for comparison purposes. 

Blossom Thinning

Reducing initial fruit set by blossom thinning will increase the amount of return bloom the following spring as well as improve fruit size and crop load in the current season.  A foliar nutrient spray applied during bloom has proven effective in this regard. Descriptions of the specific effects of the nitrogen and sulphur containing fertilizer, ammonium thiosulphate (ATS) are found under Fruit Tree Nutrition. Note the precautions listed for the use of this chemical.

Post-Bloom Thinning

Post-bloom thinning helps fine-tune the crop load. The table below summarizes the timing and usage of common thinning products:

Timing of Applications:

Product	Timing
NAA products	7-12 days after full bloom; apply when fruit are 8-10 mm in diameter under cloudy, humid conditions.
Sevin XLR	10-25 days after full bloom; best when largest fruits are 10-15 mm in diameter and warm weather follows application.
NAA + Sevin XLR Mixture	15-20 days after full bloom; apply when conditions are most suitable for Sevin XLR.
Cilis or MaxCel alone or in combination with Sevin XLR	7-21 days after full bloom; apply when king fruitlets are 5-10 mm in diameter.
Accede	When king fruitlets are 15-20 mm in diameter; apply early morning or at night for slow drying.

 

The extent of fruit development at the time of spraying is an important consideration and in seasons when post-bloom weather is consistently warm and bright these thinners should be applied early in their recommended period. If the weather is cool and fruit development is slow, they should be applied later.

When used by itself, Sevin XLR results in good fruit thinning when the largest fruits are 10-15mm in diameter and the outlook is for several days of bright and warm weather. Temperatures should reach 20° C or higher within 5 days of application.

NAA products used alone should be applied when the largest fruit are 8 -10 mm in diameter and air temperatures are at least 10° C. Best uptake of NAA occurs under slow drying conditions (cloudy, humid).

When applying the mixture of an NAA product and Sevin XLR, apply when the conditions are most suitable for Sevin XLR.

Accede is a new plant growth regulator that is now registered for apple thinning in Canada. Its active ingredient is a naturally occurring compound, 1-Aminocyclopropane- 1-carboxyllic acid (ACC), the precursor to ethylene synthesis in all plants. Applying Accede when king fruitlets are at the 15-20mm stage promotes fruit abscission of smaller fruitlets through production of ethylene in the plant. Accede should not be used as a replacement for existing post-bloom thinning programs, but as a supplementary tool to manage cropload, especially when earlier treatments were not as effective as desired.

Materials and Strength for Hormone Application

SPRAY THINNING OF APPLES – HORMONE MATERIALS
Materials	Air-blast Sprayer		Dilute	Varieties
	per hectare	per acre	per 1000 L
Sevin XLR	0.5 - 3.22 L	0.2 - 1.3 L		All varieties.  Apply 0.5 - 3.22 L/ha for to spindle to super spindle trees. Apply 0.5 - 2.15 L/ha to all other tree density plantings. Do not spray trees which have not reached full bearing. REI: 12 h - 14 days.
Sevin XLR plus Cilis or MaxCel	0.5 - 3.22 L   2.5 to 6.25 L	0.2 - 1.3 L   1 to 2.5 L	2.35 L to 5.88 L	All varieties.  See rates above.
Sevin XLR* plus  NAA (3.1%)  Fruitone N Fruitone L	50-100 mL     410 g 410 mL	20-40 mL     164 g 164 mL	160 g 160 mL	All varieties. Apply higher rates for hard to thin varieties. McIntosh, Spartan, Golden Delicious, Spur Red Delicious (and hard to thin new varieties)
Accede SG	500-1000g	200-400g	500-1000g	Accede is labeled for application at timings as early as king bloom but is more effective when sprayed at 15-20 mm fruitlet size. Use of a non-ionic surfactant may increase efficacy. See the product label for more guidance

 

Naphthalene Acetic Acid (NAA)

• Effectiveness:
  • NAA alone is less effective than Sevin XLR but enhances thinning when mixed with Sevin XLR.
  • Suitable for all varieties but requires caution with Red Delicious and spur-type varieties due to potential over-thinning and pygmy apple formation.
• Application Details:
  • Use at least 2250 L/ha (900 L/acre) with a surfactant. Ensure thorough coverage.
  • Apply earlier than Sevin XLR or Sevin XLR plus NAA mixture for adequate thinning where Sevin-induced mite build-ups have been experienced.
  • Adjust rate based on variety and tree vigour (higher rates for hard-to-thin varieties and lower rates for easy-to-thin varieties).

Calculating Spray Concentration

What is PPM?

• Parts per million (ppm) is a measure of concentration, representing the number of parts of a substance (e.g., active ingredient) per one million parts of the solution. It is commonly used to describe the strength of sprays or chemical solutions.

Steps to calculate PPM

• Step 1: Gather Necessary Information
  • Desired PPM: The target concentration for your application, as recommended on the product label or by local guidelines.
  • Tank Water Volume: The total amount of water in your spray tank, measured in liters (L).
  • Product Concentration: The concentration of the active ingredient in the product, typically found on the label, expressed in grams per liter (g/L) for liquids or grams per kilogram (g/kg) for solids.

• Step 2: Calculate the Amount of Product to Add to Sprayer
  • Formula:
    
  • Example: To achieve a 100 PPM concentration using a product with a concentration of 150 g/L in a 400 L tank:
    
• The PPM of the solution remains constant regardless of the spray volume applied per hectare or acre.
• Adjust the amount of product added to the tank based on the total water volume to maintain the desired PPM concentration.
• If the product concentration is given in percentages, convert it to g/L by multiplying the percentage by 10. For example, a 3.1% concentration equates to 31 g/L.

Carbaryl (Sevin XLR)

• Effectiveness:
  • Suitable for all varieties.
• Application Details:
  • Apply at least 1700 L/ha (680 L/acre) for thorough coverage.
  • Re-entry interval: 12 hours to 14 days depending on orchard activity.
  • Pre-harvest interval (PHI): 75 days for thinning rate applications.
  • Thinning effect may take 3-4 weeks to be fully evident.
• Precautions:
  • Can harm predatory mites.

Sevin XLR + NAA Mixtures

• Effectiveness:
  • Highly effective for thinning varieties like Spartan, McIntosh, Golden Delicious, and Spur Red Delicious.
• Application Details:
  • Apply 15-20 days after full bloom.
  • Use at least 2250 L/ha (900 L/acre) for good wetting and coverage.
  • NAA rate can be adjusted for desired thinning intensity. Do not alter Sevin XLR rate.

Cilis or MaxCel

• Effectiveness:
  • Fruit size enhancement and mild thinning.
  • Enhances carbaryl’s (Sevin XLR) thinning activity when mixed.
  • Cilis or MaxCel can be used with NAA, but caution should be exercised with Fuji and Red Delicious varieties to prevent retention of pygmy fruits.
  • When used alone, two applications are often necessary for effective thinning and fruit size enhancement.
• Application Details:
  • Begin applications at petal fall or when king fruits are 6 mm in diameter.
  • Follow-up applications may be needed when king fruits are about 10 mm in diameter (7-10 days later).
  • Use rates above 100 ppm for significant thinning.
  • Use during slow drying conditions (early morning or late evening) to improve absorption.

Accede

• Effectiveness:
  • Best used as a supplementary thinning tool following other thinning sprays.
  • Contains ACC (ethylene precursor) to promote fruit abscission of smaller fruitlets.
• Application Details:
  • Apply when king fruitlets are 15-20 mm in diameter.
  • Use a non-ionic surfactant like Agral 90 for consistent performance.
  • Spray volume: 1000 L/ha (400 L/acre).
  • Apply under slow drying conditions (early morning or night) for best results. Avoid temperatures about 30 °C.

Spray Thinning Pollinizer Trees

Trees planted strictly for pollination may be thinned more severely and otherwise managed to insure reliable flowering. Since crab apple pollinizers flower mainly on one year wood, pruning shortly after bloom helps to maximize return bloom and can be used to control the size and shape of these trees.

Spray Thinning for Pears

Chemical thinning can be used in pear orchards to manage crop load, enhance fruit size and ensure consistent annual yields. In Canada, the primary chemical thinners registered for use on pears are 6-benzyladenine (6-BA) products, specifically MaxCel and Cilis Plus. As described above, these plant growth regulators (PGRs) promote cell division, aiding in fruit thinning and size enhancement.

Registered Products and Application Guidelines:

Product	Active Ingredient	Application Timing	Application Rate	Pre-Harvest Interval	Notes
MaxCel	6-benzyladenine (6-BA)	When fruitlets are 8-14 mm in diameter	125–200 ppm;  6.25-10 L/ha (2.5-4 L/ac.) (consult label for specific rates)	86 days	Ensure thorough coverage; avoid application during high temperatures.
Cilis Plus	6-benzyladenine (6-BA)	When fruitlets are 5–10 mm in diameter	50–200 ppm; (consult label for specific rates)	28 days	Similar guidelines as MaxCel®; refer to label for detailed instructions.

Stop-Drop Sprays for Apples

ReTain- A Harvest Management Tool for Apples

Active ingredient: Aminoethoxyvinylglycine (AVG), which inhibits ethylene production in plants.

Benefits:

• Reduces preharvest drop in McIntosh and Spartan.

• Delays preharvest fruit drop for all apple varieties by approximately 10 days.
• Slows fruit ripening processes such as softening and starch degradation.
• Reduces fruit cracking in Gala and other varieties.
• Delays water core development and improves fruit firmness.
• Reduces storage scald after controlled atmosphere (CA) storage.

ReTain is applied four weeks before normal anticipated harvest (i.e., this timing may be as early as 3 weeks before actual harvest). Experience has shown that applications slightly later than 4 weeks before harvest do not significantly affect performance. Note that in some years the development of red colour is delayed after the application of Retain in treated Galas and Spartan blocks.

Each package of ReTain contains 333 grams of material, or 50 grams active ingredient. The label rate for all apple cultivars is 125 g active ingredient (2.5 packages) per hectare (50 g/acre = 1 package/A) applied with enough water to thoroughly wet the fruit and foliage (about 900 L/ha, 80 gallons imp/acre). To achieve good coverage and efficient use of the product, tree row volume principles should be used. A properly calibrated and maintained sprayer and the addition of an organosilicone wetting agent, (e.g.: Sylgard 309) at 0.05%-0.1% by volume (500 - 1000 ml/1000 L) are essential. When high temperature (in excess of 32 degrees C) weather conditions prevail or are anticipated, the 0.05% v/v rate is recommended. Absorption of ReTain is improved by slow drying conditions. Avoid weather conditions where spray drift onto non-target crops could occur. Do not spray if rain is forecast within the next 8 hours.

Since the benefits of ReTain relate to the inhibition of natural ethylene production, it should not be mixed with NAA or ethephon, which increase ethylene production in apple fruits.

Summary:

Application Guidelines	Details
Timing	Apply 4 weeks before anticipated harvest (can be adjusted slightly later without affecting performance).
Rate	125 g active ingredient per hectare (2.5 packages) or 50 g per acre (1 package) in 900 L/ha (80 gallons/acre) of water.
Wetting Agent	Use Sylgard 309 (organosilicone wetting agent) at 0.05%-0.1% spray volume.
Spray Conditions	Apply during slow drying conditions; avoid spray drift and rain within 8 hours of application.
Precautions	Do not mix with NAA or ethephon, as these promote ethylene production and counteract efficacy of ReTain.

 

STOP-DROP APPLICATION FOR APPLES *
Material	Quantity per			Time to Apply	Duration  Effectiveness from Time of Application
	Medium Volume		High Volume*
	1700 L/ hectare	680 L/ acre	Per 1000 L
Retain (AVG) Plus Sylgard 309	445 -832 g   0.05-0.1%	180-333 g   0.05-0.1%		4 weeks before the start of the anticipated harvest of the treated fruit	37 to 40 days after application (7-10 days after the beginning of normal harvest of untreated fruit)

 

Perlan and Promalin

Perlan and Promalin are plant growth regulators combining 6-benzyladenine (6-BA) and gibberellins A4 and A7 (GA₄+₇). They are widely used in apple and cherry production to improve fruit shape when applied as king blossoms are opening and to promote lateral branching. 

Improving Fruit Shape in Apples:

To improve fruit shape, apply Perlan or Promalin at a rate of 1.25 - 2.3 L/ha (500 - 900 mL/acre) in a medium volume spray (2250 L/ha) (900 L/acre) or 125 mL/100 L (567 mL/100 gal imp) during bloom. Addition of a registered surfactant may enhance efficacy. The treatment promotes cell division and elongation, resulting in more pronounced calyx lobes and overall improved “typiness”.

PRECAUTIONS

1.  Thinning effects: Perlan and Promalin are known to thin apple blossoms. Weak or frost-injured flowers appear to be particularly susceptible. On such trees, Perlan or Promalin usage may also increase the amount of thinning achieved with a subsequent blossom thinning spray.

2.  Spur vigour: In trees where spur vigour is low or where the king blossoms have been damaged by frost, the fruit lengthening response to Perlan or Promalin may be negligible.

3.  Spray conditions: Do not apply Perlan or Promalin if rain is expected within 6 hours.

Promoting Branching in Apples and Cherries

Promalin is effective in inducing lateral branching in young apple and cherry trees. Studies indicate that applying Promalin in conjunction with bark-injury methods, such as notching or scoring, can enhance lateral branching.

Foliar Application: For nursery and orchard trees, apply Promalin at concentrations of 125 to 500 ppm (62.5 to 250 milliliters per 10 liters of spray solution) when new terminal growth reaches 1 to 3 inches.

Latex Paint Application: Mix 100 to 165.6 milliliters of Promalin with 500 milliliters of latex paint and apply in the spring when terminal buds begin to swell but before shoots emerge. 

ReTain- Extend Flower Viability in Cherries

ReTain is a plant growth regulator that has been shown to extend flower viability in cherries by reducing ethylene production in cherry flowers and delaying flower and stigmatic senescence. Due to this effect, flowers that last longer have a higher likelihood to be successfully pollinated, and increased pollination results in a higher yield. Research has shown that ReTain works best if used before poor pollinating conditions, including wet, cool, windy weather or low honey bee activity, or on varieties that tend to be shy-bearing.

For Sweet Cherry fruit set, use 1 pouch/0.4 ha (1 pouch/ac.). Make a single application of ReTain during bloom. Efficacy requires thorough coverage of the product on the flower buds and flowers. Use appropriate water volume based on tree size. Applications between balloon stage to first bloom are more effective than earlier or later applications. Do not apply after petal fall. Do not apply when fruit are present. ReTain on cherries is not meant to be used as a harvest management aid.

Gibberellic Acid Use on Sweet Cherries

The normal harvest period for sweet cherries can be delayed 5 to 7 days and several aspects of fruit quality can be improved by a single spray of gibberellic acid applied about 3 weeks before normal harvest (the straw-yellow stage of fruit maturity).

This treatment delays red colour development, increases fruit firmness and fruit size, and delays the period of maximum sensitivity to rain splitting. Gibberellic acid-treated fruit is less likely to develop the postharvest disorder known as “cherry pitting”.

There are  four registered products containing gibberellic acid: Activol, Falgro, Florgib 4L and ProGibb 40 SG.

Activol

Activol contains 0.92 g of gibberellic acid per tablet. Dissolve 20 tablets in 1000 L water (20 ppm) and apply as a foliar spray 21 days before expected harvest. The fruit is usually in straw-coloured stage. Do not harvest with 21 days of harvest. Research in BC has shown ripening is delayed 4-5 days.

Falgro

Falgro contains 1g of gibberellic acid in each tablet. To prepare the recommended spray concentration of 20 ppm active ingredient, dissolve 20 Falgro tablets in 1000L of water (9 tablets per 100 gal imp). Add 250 ml of Agral 90 non-ionic surfactant per 1000L (113ml/100gal imp). Apply as a high-volume spray (see page 11-15) to full foliage wetness.

GroSpurt GS-4

Make one application of 20-50 ppm (50-125 mL/100 L) when the fruit is light green to straw coloured in sufficient water to ensure thorough wetting (to point of run-off). PHI - 7 days.

ProGibb 40 SG

ProGibb contains 40 percent active ingredient or 1 gram of active ingredient (GA) for every 2.5 grams of product. To make a 20 ppm concentration spray mixture, add 50 grams of ProGibb for every 1000 litres of water (22.5 grams per 100 gal imp). Apply as a high volume spray (see page 11-15) to full foliage wetness.

When applying either Falgro, Fruitsize or ProGibb apply at least 2250 L/ha (900 L/acre) of the spray mixture. Harvest the fruit at the desired shade of red skin colour. Falgro and FruitSize have a pre-harvest interval of 21 days; ProGibb has a pre-harvest interval of 28 days.

Gibberellic Use on other Tree Fruits

GroSpurt GS-4

Peach - Apply 200 ppm (500 mL/100 L) twice per season (full bloom and fruit set) in sufficient water to ensure thorough wetting (to point of run-off). 

Prune plum - Apply 40-125 ppm (100-312 mL/100 L) only once 4-5 weeks before expected harvest in sufficient water to ensure thorough wetting (to pint of run off). 

Other stone fruit - Apply 40-80 ppm (100-200 mL/100 L) only once 3 weeks before expected harvest in sufficient water to ensure thorough wetting (to point of run-off).

Apple and Pear - Apply 10-50 ppm (25-125 mL/100 L) once only at early fruit set in sufficient water to ensure thorough wetting (to point of run off). 

Apogee

Apogee (27.5% prohexadione calcium) is registered growth control product for apples.  Apogee acts within apple trees to inhibit the biosynthesis of gibberellin, which results in reduced vegetative growth.  Suppression of growth may last from 2 – 5 weeks following application and does not affect growth in the following year.  Apogee may cause the tree to retain more fruit, so more aggressive thinning programs may be required.

Application

Apply Apogee with enough water to thoroughly cover the tree foliage.  Apply the first spray at 5 cm growth stage, followed by a second application 14 -21 days later.  Refer to the following table for application rates. Consult the label for more detailed information:

APOGEE APPLICATION - APPLES
Application Timing	Apogee rate per 100L of dilute spray	Apogee rate per hectare
Medium to high vigour (split applications) (fire blight suppression)	45 grams	1350 grams
Low to medium vigour (split applications)	27 grams	810 grams
Low vigour trees (single application)	27-45 grams	810 – 1350 grams

Fire blight Suppression

To reduce fire blight secondary infections (shoot blight), apply Apogee at 2.5cm to 7.5 cm of shoot growth and apply at intervals of 14 – 21 days up to a maximum of 4 applications per season.  Rates are the same as medium to high vigour growth in the table above. Apogee does not prevent blossom infection.

Prevention of Sunburn and Heat Stress in Apples and Pears

Raynox

Raynox is a foliar product specifically designed to control sunburn. Raynox must be applied on its own and applications of pesticides, nutrients or ReTain should be made just prior to application or reapplication of Raynox, as the fresh coating of Raynox may interfere with absorption. Raynox dries in about one hour, avoid drift onto vehicles and housing, and wash machinery immediately after applying Raynox. Do not apply Raynox if the temperature will exceed 29°C during application. Apply at a rate of 23 L per hectare in 1000 L of water. or 9.5L /acre in 450L of water. The first application should be applied prior to a sun burning event or at the golf ball fruit size (42 mm) and reapplied every 2 to 4 weeks.

Surround WP Crop Protectant 

When Surround WP is applied to plants, a white particle-film is formed which is infrared- and UV-light reflective. Plant surfaces treated with Surround WP are cooler under summer heat-load. As a result, Surround WP may reduce sunburn and heat stress on fruit and foliage.

Application:

Begin applications of Surround WP soon after crop thinning and before the onset of hot conditions.  Make initial applications at the high rate, 4 bags per 1000 L water per hectare (50 kg in 1000 L water, a 5% solution).  To ensure thorough and even coverage, make follow-up applications at the lower rate, 2 bags per 1000 L (25 kg in 1000 L water, a 2.5% solution).  Surround WP dries to a white haze on plant surfaces.  Make low-rate applications to maintain the visible film.

Purshade and Purshade-O

Purshade is a new calcium carbonate (Lime) based spray product. Purshade leaves a protective film after application that reflects Ultra-Violet and Infra-Red radiation, lowering both plant and fruit surface temperatures, which in turn reduces sun induced disorders, such as sunburn. Begin applications once the fruit reach 19 mm, with follow up applications every 2 to 3 weeks. The first application should be made at the high rate, 30 L per hectare (12 L per acre); follow up applications can be made at the lower rate, 20 L per hectare (8 L per acre). Purshade should be applied as a low volume spray, as high spray volumes may cause pooling of the product and reduce efficacy.

For Suppression of Splitting in Cherry Blocks

Parka

Apply 8 - 16 L of Parka in 800 - 1600 L of water per hectare (1% solution). Do not exceed 1600 L/ha per application. For best results, apply Parka in a two- application program with the first application at late straw color. Reapply in 7 – 10 days after the first application. Timing between first and second application may be lengthened depending on occurrence of rain events. Do not apply when the air temperature exceeds 29°C.

VaporGard

Applications of VaporGard form a protective barrier on the surface of the fruit that prevents or reduces the absorption of water into the fruit. Begin applications of VaporGard at pit hardening, 3 - 4 weeks prior to harvest, apply 9.4 L per hectare (3.75 L per acre), and make repeat applications on a 7 - 10 day schedule, as the activity of VaporGard is best within a few days of application. VaporGard must be applied during daylight hours and needs at least one hour of drying time prior to a rainstorm to be effective. VaporGard can be applied right up till harvest, as VaporGard has a zero day pre-harvest interval.

RainGard

RainGard is a fruit protection product developed at Washington State University. The activity of RainGard is best within a few days of application, as full fruit coverage is necessary for adequate fruit protection, and coverage diminishes as the fruit grows. Begin applications at pit hardening, apply 23 L per hectare (9.5 L per acre), making follow up applications on a 7 day schedule. Raingard should be applied in 475 L per hectare (42 gal imp per acre), if applications of RainGard are made in higher water volumes per area, raise the application rate to maintain a 5% solution or 5 L per 100 L (23 L per 100 gal imp). Do not apply Raingard to fruit with visible residues (ie from certain nutrients, Wettable Powders, etc). Applications of  other spray products should be made either prior to the application of RainGard or at least 4 days after the application of RainGard.

	Vapor Gard	RainGard	Parka
Purpose	Anti-transpirant, split protection. Retards normal moisture loss without interfering with plant growth or normal respiration	Split protection	Split protection. Binds with the lipid layer of the cherry skin
Timing	3-4 weeks before harvest. Apply Vapor Gard at least one hour, during daylight, before rain – sunlight is need for the protective film to set. Re-apply every 7-10 days for maximum protection. 0 PHI.	Begin application as 4 weeks PHI or straw; re- apply every 7-10 days for a total of 3 applications. Effective when dry.	Apply at late straw color. Repeat 7-10 days later (may extend timing depending on rain). Do not apply within 5 days of harvest.
Application volume	Apply at 200 u.s. gallons/ acre	Apply at 100-200 u.s. gallons/acre	Apply at 100-170 u.s. gallons per acre. Do not exceed 170 u.s. gallons/acre.
Chemistry	Pinolene (pine resin extract). Water emulsifiable concentrate.	Fatty acids & vegetable esters.	Phospholipids, carbohydrates & calcium
Tank Mixes	Do NOT spray with pesticides. No surfactant needed.	Can be tank mixed with pesticides. Do not tank mix with organosilicon surfactant.	Do NOT add surfactants or stickers. Can be tank mixed with some fungicides. Do NOT tank mix with pinolene based products.
Container size	10 L	24.2 L	9.5 L
Rate	3.8 L per acre	0.8 u.s. gallons (3.0 L) for each 100 gallons/ acre. Keep a 0.8 % v/v dilution	3.8 L or 1 u.s. gallon per acre. Do not exceed 1% V/V final concentration. The rate could be halved for the second application if there is a concern about MRL.
Notes	It does not expand with the fruits.	Do not apply to fruit with visible residues. Coverage becomes thinner as cherries are growing.	Somewhat permeable film. Does impair nutrient uptake. Do not apply when air temperature exceed 290C. Rainfast 24 hours.

For more detailed application instructions and precautions, refer to the product labels.

Fruit Colour Management

Exposure of fruit to sunlight with good pruning practices will always give the best colour development. Other horticultural practices such as over-head irrigation and balanced nutrition can sometimes be helpful in apple colour development (see Fruit Tree Nutrition). Discuss the use of over-head irrigation with an irrigation specialist or horticulturist before applying this practice. Also consult a horticulturist if considering installing reflective ground fabric to aid in colour development.

BLUSH

BLUSH (5.25% prohydrojasmon) is a plant growth regulator for use on red apples to promote fruit colour development. Make 1-2 applications of 100-200 ppm at 7-14 day intervals, 7-28 days prior to anticipated harvest. It works best if climatic conditions allow an extended drying period. Apply in the morning or evening when temperatures are lower and humidity tends to be higher than during the day. Read the product label for more instructions on preparing concentrations (ppm) and application.