Agriculture Reference
In-Depth Information
chromosomes) and primarily derived from
Prunus avium
. Tart cherries are
tetraploid (four sets of chromosomes) and are classified as
Prunus ceras-
us
, although they probably originated as complex natural crosses between
sweet cherry and European ground cherry species. (Duke cherries are hy-
brids between sweet and tart cherries and have largely fallen out of favor as
better-quality cherries have been developed.) Several species of bush cher-
ries are used for fruit production, including the cold-hardy Nanking bush
cherry,
Prunus tomentosa
, which is used as an ornamental and sometimes
for fruit. Other bush cherries and hybrids have been developed for specific
growing conditions, such as the Canadian Prairie Provinces.
Although cherries have been grown for millennia, there have been some
recent improvements that are largely confined to Europe, including system-
atic breeding and the use of genes for pest and disease resistance and cli-
matic adaptation. There are relatively few cherry varieties available in North
America, and fewer still that are worthy of cultivation.
Climate concerns.
Despite their long popularity, cherries are among the
more challenging tree fruits to grow. Cherries have rather limited cold hardi-
ness; wood, bark, and bud hardiness limit winter survival and crop production
in Canada and the northern United States. Depending on variety, cherries
typically need 800 to 1,300 hours of chilling and are difficult to produce in
southern areas with limited chilling. Cherries bloom very early and are highly
susceptible to spring frost damage everywhere they are grown.
Site selection is particularly critical with cherries. Avoid planting in a
frost pocket and plant on deep, well-drained soil. Benches and gentle slopes
above temperature inversion layers are often the best sites for cherries.
Loam and sandy loam soils provide good drainage and adequate water-hold-
ing capacity. Planting in areas near large bodies of water helps reduce spring
frost damage.
Pests and diseases.
Pseudomonas blight, brown rot, viruses, and other
fungal, bacterial, and viral pathogens cause serious disease problems, par-
