Influence of Kaolin Clay Applications on
Blueberry Yields during Low-Chill
Seasons in West-Central Florida
Bielinski M. Santos
Gulf Coast Research and Education Center
IFAS, University of Florida

Reduce transpiration and sun scalding.

Based on calcium carbonate, kaolin
clay or wax.

Surround WP.

Degradable.
Previous Studies with Kaolin
a
b
b
c
a
a
b
Early Fruit Weight (ton/acre)
4
3
2
a
a
a
b
Control
8 d + kaolin
6 d + kaolin
4 d + kaolin
1
0

Previous study: Kaolin clay application
reduced bud temperatures.

What happens during low-chilling winters?

Would kaolin increase the number of
chilling hours?
Determine effects of foliar application
programs of kaolin clay on the marketable
yield of southern highbush blueberries.

Two-year study: 2011-12 & 2012-13.

Gulf Coast REC, Balm, Florida.

3-year-old ‘Jewel’ (1500 plants/acre).

Pine bark beds.

No hydrogen cyanamide.

Surround (25 lb/acre).

Regular sprayer (100
gal/acre of water).

Non-treated,
Weekly applications,
Biweekly applications.



Application from Sept. 15 to
Dec. 15.

Eight harvests starting in
early March.

Early and total fruit weights.

160 h ≤45oF between Sept. 1
and March 1 of each season.
Treatment
October
November December
None
48
44
35
Weekly
42
39
33
Biweekly
47
43
35
Treatment
October
November December
None
45
40
36
Weekly
41
36
33
Biweekly
45
39
35
Treatment
Early
Total
ton/acre
None
Weekly
Biweekly
Significance
1.30 b
1.68 a
1.31 b
*
2.16
2.47
2.20
NS

Surround seems to decrease bud
temperatures.

Weekly applications (6 to 8) of Surround
improved early yield (+29%).

More research needed in large fields.

What about regular winters?