Orchard Management Specialist Shares Insights Dr Bruce Lampien Speaks With Local Almond Growers By Ben Brown - Industry Liaison Manager
Dr Bruce Lampinen is an Integrated Orchard Management/Walnut and Almond Specialist who has responsibilities of coordination of extension teaching and research activities for almonds and walnuts on a statewide basis. Dr Lampinen cooperates on three regional almond variety trials in Butte, San Joaquin and Kern Counties. His research expertise and findings all originate from one primary area of orchard management - the role and affect of irrigation management. With a strong background on this topic Bruce’s research has lead him
Some of the main topics of discussion from Bruce’s talk included:
You are losing the potential for 0.78 kg of yield for each square meter of sunlight hitting the orchard floor at midday.
The use of a pressure bomb to provide a plant based measurement of stress. Pressure bombs are very complimentary to water use budgets, crop factors, and soil moisture monitoring equipment. Midday stem water potentials of -14 to -16 bars (i.e. pressure bomb readings) during hullsplit can lead to decreased incidence of hull rot without significant impacts on yield.
Almond production potential is approximately 558kg/ha of kernel per 10% light interception with a theoretical maximum of approximately 5,500 kg/ha to 6,000 kg/ha. The orchard with Salmonella • outbreak in California is a highly productive orchard, has maximum light interception and lots of shading, clay loam topsoil, micro- sprinklers, moderate levels of natural rainfall, and consequently a highly moist environment with very little drying of the orchard floor. The source of Salmonella has never been identified and still exists today. Soil temperature is the most important factor influencing Salmonella survival. Salmonella can migrate from the husk into the shell and kernel. Threshold for potential mould growth is >70% relative humidity in stockpiles (i.e. 0.7 water activity). Mould growth is more of a problem on the north and west facing slopes of a stockpile where water condenses and runs down tarps. Lower edges of stockpiles and unevenly made stockpiles with troughs are more conducive for conditions of mould growth. Long stockpiling of greater than 6 months are more at risk for mould growth.
to investigate the influence and inter-relationship of irrigation management on; a) light interception, canopy coverage (hedging vs non- hedged) and affect on yield, b) light interception, canopy coverage and affect on spur longevity,
"S oil temperature is the most important factor influencing Salmonella survival"
c) light interception, canopy coverage and affect on orchard micro climate and food safety issues such as salmonella, and d) irrigation management and its affect on the moisture level of almond fruit, stockpiling conditions, mould development and potential for aflatoxin.
When an almond tree has
maximised its vegetative growth and filled its allotted space there has to be a decision or trade-off made between; a) slowing vegetative growth, maintaining 90-100% light interception/canopy cover and maintaining yield, and b) maintain vegetative growth
and introduce a pruning/hedging regime which will increase light interception, enable easier orchard access, reduce the risk of food safety issues, improve nut quality but reduce overall yield.