Top 5 Tips for Promalin® Plant Growth Regulator Application on Apples

How does Promalin® Plant Growth Regulator improve fruit characteristics?

Highly profitable apple orchards are often those that have higher yields, larger fruit size and better fruit color. Fruit size potential is typically determined by the number and size of cells in the cortex of the fruit; however, final fruit size will depend on the interaction between genetics, environmental and growing practices.

Promalin Plant Growth Regulator is comprised of two components: gibberellic acid 4 and 7 causes cell elongation, enlargement, and elasticity and 6-benzyladenine promotes cell division. Promalin is designed to increase fruit size, shape, and quality, increasing packout and the percentage of fruit that fall in the large category.

What should I know about applying Promalin?

1. Timing

For an elongated shape (or typiness), apply Promalin at 50% to 85% open flower stage. The greatest increase in length occurs when the calyx or the receptacle surface is still open.

2. Apple Varieties

Promalin can be used in any apple variety where typiness or overall size is desired, e.g., Red Delicious, Gala, Fuji, Golden Delicious, Minneiska, etc.

3. Tank Mixing

Promalin tank-mixed with prohexadione-Ca or streptomycin antibiotic has not shown compatibility issues, phytotoxicity, or lack of efficacy. Adjuvant usage is not recommended at bloom as it may cause thinning.

4. Weather Conditions

Apply Promalin under slow drying conditions to increase absorption by the plant. Do not apply Promalin when air temperatures are below freezing or greater than 32°C (90°F).

5. Crop Load

Promalin should be used in conjunction with other thinning practices to optimize benefits on fruit sizing and finish. The benefits of Promalin are often reduced when trees are over-cropped.

For questions about application rates, please speak to your local representative or consult the label.

Always read and follow label instructions. For label information or SDS, please contact your local distributor.