Influence of Kaolin Clay Applications on Blueberry

Yields during Low-Chill Seasons in West-Central

FloridaBielinski M. Santos

Gulf Coast Research and Education CenterIFAS, University of Florida

Crop ProtectantsReduce 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

Control 8 d + kaolin 6 d + kaolin 4 d + kaolin0

1

2

3

4

Early Fruit Weight (ton/acre)

a a a b

Why Surround and Blueberries?

Previous study: Kaolin clay application reduced bud temperatures.

What happens during low-chilling winters?

Would kaolin increase the number of chilling hours?

ObjectiveDetermine effects of foliar

application programs of kaolin clay on the marketable yield of southern highbush blueberries.

Materials and MethodsTwo-year study: 2011-12 & 2012-

13.

Gulf Coast REC, Balm, Florida.

3-year-old ‘Jewel’ (1500 plants/acre).

Pine bark beds.

No hydrogen cyanamide.

Materials and Methods

Surround (25 lb/acre).

Regular sprayer (100 gal/acre of water).

Non-treated, Weekly

applications,Biweekly

applications.

Materials and MethodsApplication 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.

Bud Minimum Temp. 2011 (oF)

Treatment October Novemb

erDecemb

erNone 48 44 35

Weekly 42 39 33Biweekl

y 47 43 35

Bud Minimum Temp. 2012 (oF)

Treatment October Novemb

erDecemb

erNone 45 40 36

Weekly 41 36 33Biweekl

y 45 39 35

Treatment Early Totalton/acre

None 1.30 b 2.16Weekly 1.68 a 2.47

Biweekly 1.31 b 2.20Significanc

e * NS

SummarySurround 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?

Thanks!bmsantos@ufl.

edu813-468-6322