outperform either material sprayed alone. Interestingly,
zinc applied alone was not found to increase yields.
Other trials have found limited to no benefits from the
application of other micronutrients at bloom unless
nutrient deficiencies are present.
Be Careful with Bees
There has been a lot of concern about honey bee
health related to fungicide, surfactants and insecticide
applications within orchards. More is being learned every
year about the impacts of pest management practices on
hive health.
When applying bloom sprays, always proceed with
caution and err on the side of bee safety. Avoid the
fungicides Rovral, Captan, or Ziram at during bloom.
These fungicides negatively impact bee hive health.
Do not add any additional surfactant unless indicated
by the fungicide label as these chemicals have been
shown to impact bee health. Apply fungicides later in
the afternoon or evening when bees and pollen are less
present. It is important to also not spray too late that
the fungicide does not have a chance to dry before the
next foraging day. When spraying, cover or remove the
bee’s water source. Avoid spraying the hive directly with
any pesticides. Finally, remove bees as soon as petal
fall occurs as this will reduce exposure of bees to later
fungicide timings.
To further help with fungicide selection, the University of
California Agricultural and Natural Resources Integrated
Pest Management Program has developed a website
that provides toxicity information of various pesticides
(ipm.ucanr.edu/beeprecaution/). Precaution rankings (I, II,
III) have been created based on the currently available
scientific studies. The table does include effects on
bee brood if research is not available. Lack of toxicity
data for honey bee brood means that there is no data
currently available, not that the material has no impact.
Proper Tree Planting
When planting a new orchard, it is important to take
the proper precautions to avoid tree loss. Trees should
be planted as soon as possible after delivery. Prior to
delivery, make sure the field is prepared, which includes
ensuring that soil fumigants have completely dissipated,
soil clods are broken down and workable, and large
amounts of organic material (e.g. grass clippings,
compost) are not present in the planting areas. Berms are
recommended for most soils to prevent crown infections
by Phytophthora. Berms may not be needed in soils with
high infiltration rates. If planned, berms should be pulled
prior to tree planting. Do not pull berms as an after-
thought: soil covering the graft union will increase the risk
of Phytophthora.
To prevent root drying, keep the roots moist and cover
with a tarp when being transported within the field. Do
not prune tree roots unless they are broken. Holes should
be dug at the time of planting if possible, but if not, as
Plant trees carefully! Make sure holes are large enough to fit the
entire root system. Avoid wrapping or bending roots in order to
fit into a smaller hole as this will cause “J-rooting.”
IN YOUR ORCHARD
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A L M O N D F A C T S
