Fifty in vitro cassava (Manihot esculenta Grants.)
varieties produced by tissue culture were obtained from
IRRT, San Carlos. California, USA. From those, only 12
varieties were well adapted to Egyptian climate. The acclima
tization process and the experiment were carried out in
the Vegetable Research Division. Agric. Res. Center, Giza,
Egypt during 1984 and 1985. After 2 months the plants were
transplanted into a well watered field in March 1984 for
propagation tu get enough cuttings for next season. Cuttings
were obtained from 12 months old plants and were planted
on ridges. The evaluation of the 12 varieties for some
of the agronomic characters related to yield was undertaken
in 1985. Data on growth and yield characters (8 months
age) were recorded at harvest.
The tested varieties differed gratly in plant height.
branching levels, number of leaves/plant, leaf area, petiole
length and petiole colour. Tuber length ranged between
12 to 45 cm, tuber diameter between 2.5 and 6 ca’, number
of marketable tuber varied from zero to 11, tuber colour
varied from white crear’ to dark brown, yield of leaves
varied from 5 to 21.6 t/f ad.. tuber yield/plant reehed
a maximum of 4.4 kg for var. 12 and varieties number 7, •
lo and 12 were the three leading with an average yield
of about 19 tIled. Root to top ratio ranged from 0.015
to 1.11. Content of HCN in tubers varied from 10 ppm to
218 ppm and HCN in leaves ranged from 143 to 514 ppm.
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