Production Practices and Quality Assessment of Food Crops. Vol. 1

126 S. Pereira-Lorenzo and A. M. Ramos-Cabrer
4.1.1. Hybrids as direct producers
Recently French researchers have focused in the breeding of interspecific hybrids
resistant to ink diseases as direct producers (Bergougnoux et al., 1978, and Breisch,
1995). In Spain, hybrids are considered an alternative in Atlantic areas where they
show very good adaptability (Fernandez et al., 1992) and with sufficient quality
as size and mono-embryony, and harvesting before 20th September. In United States,
the use of hybrids such as Colossal are highly recommended in new orchards due
to the high incidence of blight in United States (Vossen, 2000).
4.2. Main cultivars in nut production
Although variability in chestnut cultivars is very high, some of the cultivars
have increased their importance because of their superior quality in the present
market as the size of the nuts and ‘marron’ type, i.e. less than 12% of polyembryonic
nuts. In some areas of Spain, growers do not collect nuts smaller than
10 g.
Some cultivars in Spain such as Parede (Pereira-Lorenzo et al., 2001a) have
been propagated profusely during last 200 years but it is difficult to explain their
popularity because they produce quite small nuts. Perhaps Parede presents a better
adaptability to areas where temperatures are too low to bear fruits or it is more resistant
to natural conservation.
Fresh market demands big size of nuts and mono-embryonic. Peeling can
be solved with modern machines. Most of the best cultivars combine these characteristics,
but they are localised in specific areas where they were selected
since little experimentation has been performed in this crop to promote the best
clones.
Most of the best cultivars recommended in France for new plantations are C.
sativa cultivars, producing nuts between 12 and 18 g and most of them ‘marron’
type (Table 8). Some cultivars as Comballe and Marron Comballe produce a high
percentage of poly-embryonic nuts but they are the most important in the French
production due to the quality of the kernel. Five out of 26 recommended cultivars
are hybrids between C. sativa and C. crenata, one a clone from C. crenata and
one from C. mollissima. They are planted in combination with European cultivars
(Figure 8). In France the cultivars recommended for altitudes lower than 500 m,
are all hybrids or Asiatic species resistant to spring frost.
In Northern Spain, the most popular cultivars are Amarelante, Negral, Famosa,
Longal, Ventura, Garrida, Loura and Luguesa (Table 9). In Extremadura, Central
Spain, Injerta and Verata are cultivated and in Southern Spain, Planta Alajar,
Temprana and Pilonga are the best. In Canary Islands, the most widespread cultivars
are Mulata in Tenerife and Jabuda in La Palma (Pereira-Lorenzo et al., 2001b).
Arafero, Castagrande, Picudo and Polegre produce biggest nuts.
In Portugal, Longal has been promoted as the best cultivar for fresh market and
industry. The production of this important cultivar can be found in the international
market. Normally it is combined with Judia but other alternatives can be
selected such as Amarelal and Verdeal (Table 10). Although denominations of