YIELD / FRUIT-SET On Citrus (Grapefruit)

Study Investigator: John Curtis, PhD

Location of Study: Indian River District, FL, USA, Open field

Study Period: May - June 2014

App 1

1 Quart/Acre


App 2

1 Quart/Acre


App 3

1 Quart/Acre


App 4

1 Pint/Acre


App 5

1 Pint/Acre

Color Break

1 Qt/acre

Bloom 50%

+1 Qt/acre

Bloom 50%

2 Qts/acre Bloom 50% total

1 Qt/acre


+1 Qt/acre


2 Qt/acre Post-Bloom total

  • Block of 25 acres located Indian river district, FL USA


  • 1 row is 47 trees
  • 5 rows per treatment
  • 235 trees per treatment for 1 replicate
  • Rows: a;b;c;d;e
  • Treatments :
    • T1) Program (Qt per acre and Pint/acre)
    • T2) Program (2 Qts per acre)


  • Replicated x5 times per treatment
  • The 5 rows per treatment are randomized each time
  • Example, T1, replicate # 1 and the 5 rows are as follow:
    • R1 = Row Grower Standard
    • R2 = Row T1
    • R3 = Row T2
    • R4 = Row T1
    • R5 = Row T2
  • Each replicate then present a different order of the row via a scientific randomization.

 Total tree monitored:

  • 1,175 trees per treatment replicated 5 times
  • 2,350 trees total (2 treatments replicated 5 times) 
  • It is recommended to spray Cyan 365® 1 week before natural fruit competition (summer) and 1 week before color break (fall)
  • At 1 Pint per acre for each spray for moderate fearing of early fruit drop.
  • At 1 Quart per acre for each spray for fearing of important early fruit drop.
  • Also interesting for the wind season in september-october (fall at pre harvesting)

All raw datas + individual photos can be asked under special request.


Treated trees:

  • 20 Trees in total randomly selected within Program A 
  • Trees selected tranverse in the middle of each row

Untreated trees:

  • 10 trees in total randomly selected within the grower std row (not treated)


  • The collection of the premature drop made with a rake.
  • Only the heavy fruit have been counted (present season). Dry fruits considered as from previous season
  • Once collected placed in a zip lock bag with tree ID
  • 2 measurement then have been operated: 
    • Weight count
    • Fruit count
  • 3,078 Early fruit drop collected in the radius of each tree selected (30 trees total)
  • Operated with a quadron of 4 Ft x 4 Ft
  • Placed in the middle of the canopy as per same angle and orientation each time.
  • Remaing viable fruit count were the pieces comprised into the quadron and in depth until the front trunk limit.
  • This study Has been realized within the same trees selected for the Citrus perennial yield agronomic study.

Study Results

x 3

More early drop for very tiny fruits on treated trees (small fruit, size of kumquats)


More viable remaining fruit count on the trees with Cyan 365® (prog A)


Cyan 365® is zero Phyto-toxicity

  • x3 times more early early fruit drop of very tiny fruits (size of kumquats) for the treated trees with Cyan 365®.

Once the natural fruit competition occurrred (usually summer), we observed,

  • +114% More viable remaining fruit on the trees for the treated trees. (counted at fall season)


  • Cyan 365® generates a more profusional blooming with a better conversion of flowers into fruit. 
  • Cyan 365® improves the fruit-set by also the quality of the blooming.

Objectives: In real conditions within the same block, back to back, grower standard untreated versus grower standard treated with CYAN 365®, just one variable added: To show and demonstrate how CYAN 365® applied by foliar spray, can help to reduce the early fruit drop and to improve the volume of bearing fruits. Main parameters monitored: weight count and fruit count for early fruit drop and fruit count for remaining fruits on the tree.

For a better view of the graphs and charts, reposition your mobile device into landscape mode.

Progression rate in % of the Early Fruit Drop for very tiny fruits compared to the Untreated trees

Trees selected across means all trees in row #4, row #8, row #24, row #33 and row #44

Then all trees # 4 and #8 per row for each treatment selected

In the treated rows we found an average increase in Early fruit drop of 302%. This early drop is countered by later data received, giving an average increase of +114% in remaining viable fruits at harvest (regardless of the droppings).

Less remaining viable fruits in the untreated trees with a higher rate in the treated trees
  • 3,078 Early fruit drop collected in total and among the 30 trees selected in total.
  • 17% of this amount is the share of the un-treated trees
  • 83% is the share of the treated trees
  • This graph demonstrates the capacity of Cyan 365® to promote and improve the fruit-set

3,078 premature fruit drop total counted over the 30 trees selected. Out of this number 17% are coming from the checks in total and the remaining so 83% from the treated rows, trees.

Progression of the remaining viable fruits on the trees Vs. the Grower Std.

Better quality fruit-set makes more quality fruits, better sizes, more uniform fruits at the end.

As you may see, with CYAN 365® you have more premature drops, but the key is that you have an average of over 114% more viable fruits in the trees at harvest. In row 8, we have even reached 3 times more remaining viable fruits Vs. the check. Furthermore, growers have noticed more uniformity in fruit size and almost zero small fruits.