II.2. SQUASHES, PUMPKINS, ZUCCHINIS, GOURDS (CURCURBITA SPECIES) – 115
climate. C. ficifolia can only be grown from seed, and can be used as a rootstock for
grafts of other Cucurbita due to its hardy root system and virus resistance. C. ficifolia
may be found in cultivation in high elevations from Mexico to northern Chile and
Argentina, and in other parts of the world (e.g. France, Germany, Japan and the
Philippines).
Cucurbita maxima
Within its native distribution, there are variants or local races of Cucurbita maxima
cultivated in places within a wide altitudinal range, from 100 metres (in some Brazilian
localities) to 3 000 metres (in Bolivia). A frost tender, annual plant, C. maxima is primarily
cultivated in regions with temperate climate, and very rarely in warm and damp regions
(Robinson and Decker-Walters, 1997). C. maxima requires a rich, moisture-retentive
well-drained soil and a warm, sheltered, sunny position. Many forms require a temperature
range of 20-27ºC during the growing season, although there are some forms that tolerate
cooler conditions. C. maxima is the most tolerant of the cultivated Cucurbita of low
temperatures. C. maxima is cultivated in temperate and subtropical regions worldwide.
Cucurbita moschata
In botanical literature, C. moschata is reported as being grown mainly in areas of low
altitude with a hot climate and high humidity (Esquinas-Alcazar and Gulick, 1983;
Whitaker, 1968). However, while it is true that this species is preferentially grown within
these limits, they do not appear to be strictly adhered to, as variants have been found
above 2 200 metres, e.g. in Oaxaca, Mexico. For example, Bukasov (1981) fixes
2 200-2 300 metres as the top altitudinal limit for this crop in Colombia and Mexico, and
this information has recently been corroborated by means of collections of fruits and
seeds of the variants growing above 2 200 metres within the region of the Mixteca Alta in
the state of Oaxaca, Mexico (Lira, Andres and Nee, 1995). In general, C. moschata is the
cultivated Cucurbita least tolerant of low temperatures, but is relatively drought tolerant.
C. moschata is cultivated in subtropical and tropical regions worldwide, but can also be
cultivated sporadically elsewhere.
Cucurbita pepo
C. pepo can grow in a variety of ecological conditions. C. pepo tolerates a fairly wide
range of altitudes ranging from 8-2 300 metres. This species includes variants which are
cultivated at altitudes above 2 000 metres (during the rainy season or even during the dry
season on land that remains wet), and still others can grow near the sea and in even more
extreme conditions (i.e. those found on the Yucatan Peninsula). For example, in Mexico
there are native varieties that grow close to sea level in semi-dry climates and limestone
soil (i.e. the “tsol” in the Yucatan Peninsula), while others are managed at altitudes above
2 000 metres, with colder climatic conditions and sometimes highly eroded soil (i.e. the
“güiches” in the state of Oaxaca) (Lira, 1991; 1988; 1985). In Guatemala the varieties or
native races commonly called “güicoy” are grown above 1 800 metres, while those called
“tsol” are managed in the low and warm-humid areas of the Petén, below 500 metres
(Azurdia-Pérez and González-Salán, 1986). C. pepo grows best when day temperatures
are between 24°C and 28ºC and night temperatures between 16°C and 24ºC, although
it can tolerate monthly average day temperatures of 18-28ºC. It needs six to eight hours of
sunlight a day and has some level of drought tolerance. Many of the commercial cultivars
are widely spread around the world, demonstrating the ability of varieties to adapt to
different environments. Cucurbita pepo may be grown in temperate, subtropical and
tropical regions worldwide.