Agriculture Reference
In-Depth Information
fore growing in the same bed after an infection. Bacterial leaf spot disease (
Pseudomonas lachrymans
)
is seed-borne and also enters the plant through injuries on leaves and stems. Angled, yellowish brown
spots appear, which may be slimy or crusty on the underside. Rain, wind, and garden maintenance can
help spread this disease. Other seed-borne diseases include cucumber scab and anthracnose (for symp-
toms and treatment, see melon). Powdery mildew (
Erysiphe cichoracearum
and
Sphaerotheca fuli-
ginea
) is not seed-borne and is mostly seen on the tops of leaves; in wetter locations, powdery mildew
can cause crop failure, especially in mid to late summer. Seed-borne downy mildew (
Peronospora
spp.) often appears when dew forms nightly for prolonged periods.
Different cucumber varieties, all overripe and ready to have their seed harvested
CULTIVATION HISTORY
The cucumber originally comes from India. Its bitter-tasting wild ancestor can
be found in the subtropical valleys of the Himalayas. This bitterness is still found in some cultivated
varieties, especially in the portion near the stem. Cucumber cultivation in India appears to be a very
old practice, having likely begun by 2000
BC
or earlier. From there it spread west (Iraq by 700
BC
) and
east to China, where mainly long-fruited varieties were bred. Europe and the USA are now the most
important breeding centers, and the development of hybrid cucumbers, many parthenocarpic, is well
advanced.
Cucumber seeds—the older, the better?
Classic German-language seed literature suggests that cucumber seed quality increases with age:
“It is not the case for all vegetables that the most recently harvested seeds are best; some crops,
like cucumbers and melons, produce fruits earlier when grown from three- to six-year-old seed
than when grown from one- or two-year-old seed. This is an exceptional case, however, as other-
wise the freshest, most robust seeds yield the most vigorous plants” (Lucas 1905).
And from another source: “Many gardeners, especially older ones, claim that five- to six-year-
old seed is best. Others believe further that they get the best results when the seeds are first car-
ried around in their pants pockets for several days. … My experiments have shown that two- to
