Cucumbers are annual, mostly monoecious plants with unisexual flowers, requiring insects for pollination. Bees are the primary pollinators of cucumber flowers. Female flowers are typically solitary (rarely in pairs or more on short stalks), while male flowers are arranged in clusters with multiple flowers.
Cucumber Root
The root system is shallow, penetrating the soil up to 30 cm deep, and rarely reaching 50 cm. The stem is a vine. The leaves are simple, large, and hairy, with a five-lobed shape. Secondary vines develop from the leaf axils, and depending on the cultivation method, tertiary and higher-order vines can also develop.
Cucumber Fruit
The cucumber fruit (peponis) develops from the ovary and the receptacle. It is cylindrical, ranging from dark green to light green, with more or fewer protrusions on the surface, which may have black or white spines. The size of the fruit varies depending on the cultivar. A peponis can contain 100 – 400 seeds. Parthenocarpy, the formation and development of fruit without prior fertilization and without seed formation, is common in cucumbers. Under favorable conditions, cucumbers grow very quickly. The growth of the fruit is also influenced by the number of fruits on the plant; if there are more fruits, they grow more slowly, but if one or more fruits are harvested, the growth of the remaining fruits will accelerate. In favorable outdoor conditions, fruiting can last up to 90 days, and this period is extended in protected environments.
In favorable temperature conditions for germination (25-35°C) and with sufficient moisture, cucumber seeds will germinate in 2 to 3 days, which can extend to 15 – 20 days if the temperature is minimal (12°C). A temperature of 15°C is needed to maintain vegetative growth, while the fastest growth occurs at 25 – 27°C. Growth stops at 40°C, and the plant quickly dies at 0°C. Low positive temperatures (3 – 10°C) are unfavorable for cucumber crops, and if they persist for 2 to 3 days, signs of damage appear (leaves lose turgor and turn yellow, first the older leaves, then the younger ones). Flowering begins at around 15°C, with the optimal temperature for pollination being around 20°C. For optimal cucumber growth, plenty of moisture is needed in the soil (70 – 100% of field capacity) and air (70 – 90% relative humidity).
