Reducing Dust at Harvest

Improving air quality in California, especially in the San Joaquin Valley, is a major issue for the state’s growers. Sweepers and pickup machines can create a significant amount of airborne particles (PM10).  Almond Board of California-funded research has developed numerous methods growers can use to reduce dust at harvest, such as changing sweeper head height, reducing the number of blower passes, using metal tines, and reducing pickup machine speed. 

Sweeper heads should be set at the manufacturer's factory level so that wire tines are 0.125 inches off the ground.  If set too low, dust from the pick up is increased substantially.  Wire tines without rubber flaps on sweeper heads can reduce dust, particularly on softer soils.

Adjusting the blower spouts to match the unique conditions in the field can reduce blower passes.  Adding an optional berm brush can also help minimize blower passes under many conditions.

Harvester ground speed should be reduced, depending on field conditions. In orchards with loose soils, slower ground speed allows gravity to drop dirt rather than depending solely on fans.

Under clean orchard conditions, suction fan speed can be reduced on pickup machines to dramatically reduce dust in the field without loss of harvest efficiency.

When operating near roads or homes, use the trees as a natural filter during harvest by blowing rows close to the edge into the orchard to allow dust to filter and settle out.

Refer to Western Farm Press, June 2009,for additional information.  Ag efforts to reduce SJV air pollution