Walnut cultivars in the sub-carpatian area of Oltenia
negative from ‚Franquette’ (180.5 m3), with the exception of ‚Tehama’ (165.8 m3) which is significantly different.
After 16 years from planting (16th leaf) the lateral bearing cultivars have less than the control cultivar which has terminal bearing,
‚Franquette’. These varieties begin their annual growth cycle (bud break) during April (April 7th to 19th), almost same time like terminal
bearing walnut cultivars and usually after the appearance of spring frosts. Blooming time is distinguished as period between flowering
of female flowers (15.04 – ‚Serr’ and 7.05 – ‚Fernor’) and male or catkins flowering time (from 14.04 – ‚Lara’ and ‚Payne’ to 29.04 –
‚Fernor’), which occurs between 14.04. and 17.05. The limit of female flowering time extends from 15th of April till 16th of May and the
limits of male flowering time occurs from14th of April till 17th of May. The control cultivar ‚Franquette’ is the latest flowering walnut
variety (from 28.04 to 09.05 the male flowers blooming occurs from 28.04 to 09.05 and in the case of female ones from 03.05 to
21.05). Compared with ‚Franquette’, the lateral bearing varieties bloom earlier (same time with the Romanian walnut cultivars), or
simultaneously with it. All these varieties have proved to be protandrous under the climatic conditions of sub-Carpathian area of Oltenia.
In some years the temperature conditions may change the walnut cultivar flowering dichogamy.
Entry into fructification of these cultivars can occur from third or fourth year after planting. Fruit production in the 3rd leaf is low (28-83
kg / ha) and in the case of ‚Franquette’ is none. Starting with the 4th leaf the fruit yield reaches 153 kg / ha (case of ‚Tehama’) and goes up
to 500 kg / ha (‚Vina’). In the 5th year the yield limits varied from 278 kg / ha (‚Payne’) and 848 kg / ha (‚Vina’). ‚Franquette’ walnut cultivar
achieved much lower yields in those years (respectively 83 and 278 kg / ha).
The yielding was increasing slowly for all the cultivars, same time with the growth of crown and fruiting elements. The cumulative yield in
the first nine years was relatively low (7.29 t / ha for ‚Tehama’ duet o to 8.45 t / ha for ‚Ferjean’), but much higher than the control cultivar
‚Franquette’ (6.56 t / ha) (Table 3). The average annual yield for 5 years was of 0.81 to 0.94 t / ha / year in the case of cultivars with lateral
bearing habits and only 0.73 t / ha for ‚Franquette’.
During the 10th to 14th fruit bearing years (12-16 years after planting), the average yield reached 1.74 t / ha / year (case of ‚Tehama’)
duet o to 2.40 t / ha / year (for ‚Ferjean’). The cultivar ‚Franquette’ achieved an average annual output of 1.70 t / ha, much lower than
most varieties with lateral bearing.
Exceptions to this rule are the varieties ‚Serr’ and ‚Tehama’ which do not differ significantly compared with ‚Franquette’ from point of
view production. The most productive varieties were found to be: ‚Ferjean’ (2.40 t / ha), ‚Vina’ (2.26 t / ha), ‚Hartley’ (2.24 t / ha), ‚Fernor’
(1.94 t / ha) and ‚Lara’ (1.88 t / ha), all with very significanty different yields compare with the control.
Starting with the 12th leaf of fructification, since the tree crowns have the tendency to cover almost all the orchard soil with their
projection, all varieties are increasing their yield by 145-212% compared to the yields recorded in the10th leaf.
Terminal bearing cultivars have 40% less productive potential than the lateral bearing ones. The lateral bearing walnut cultivars’ fruits
can be grouped into the category of large size fruits (Size index = 34.9 to 39.9 mm) and average weight of 10.9 g (‚Fernor’) to 13.9 g
(‚Pedro’). The degree of uniformity of the walnuts is medium uet o the values of the coefficients of variation (S %) which range from
16.5 to 21.3%) and the kernel efficiency situated between 46.8% (‚Tehama’) and 53.0% (‚Serr’). The cultivars ‚Ferjean’ (50.8%), ‚Lara’
(50.3%) and ‚Serr’ (53.0%) have highest kernel ratios.
The fruit shell is thin (0.9 to 1.4 mm) for all cultivars from this study and this facilitates the breaking and easy deployment of the kernel.
Kernel tegument color is yellow of various shades, and the taste is pleasant. There are no very significant quality differences between
the fruits of lateral bearing cultivars and the terminal bearing ones.
Lateral bearing walnut cultivars proved more susceptible to bacterial blight (Xanthomonas campestris pv. Juglandis) and anthracnose
(Gnomonia leptostyla) in the ecological conditions of sub-Carpathian region of Oltenia. In the rainy years the bacterial attack goes on
fruits from 8.5% (‚Ferjean’) to 14.1% (‚Vina’) compared with 4.8% (case of ‚Franquette’). Anthracnose attack on leaves riches 4.7%
(‚Fernette’) to 5.9% (‚Tehama’), versus 4.2% in the case of ‚Franquette’. Levels of attack of these diseases were recorded when five
phytosanitary treatments were performed per year with copper based products.
4. Conclusions.
Growing of lateral bearing walnut cultivars in the sub-Carpathian area of Oltenia and other similar regions is limited by low temperatures
during winter and late spring frosts which can occur after budbreak and flowering.
During the study period (1994-2009) the lateral bearing cultivars had normal growth and bearing being not affected by temperatures up
to – 22.7°C (2006) recorded in the area. All the 10 lateral bearing walnut cultivars studied emphasized a lower growth vigor then control
(‘Franquette’). Coming into fructification occurred 3 to 4 years after planting in the case of lateral bearing cultivars, these means 1-2
years earlier than 'Franquette'.
Productive potential of the lateral bearing cultivars is 40% higher then the terminal bearing walnut cultivars. High yields were recorded
in the 14th leaf for 'Ferjean', 'Vina', 'Hartley' and 'Lara'. The lateral bearing cultivars tested in the sub-Carpathian area of Oltenia
conditions proved to be more susceptible to bacterial blight and anthracnose then the terminal type cultivars, for this reason their
pathogen control program is more demanding.
Advantages and disadvantages offered by growing lateral bearing walnut cultivars in the sub-carpatian area of Oltenia.pdf