MORPHOLOGICAL AND PHYSIOLOGICAL STUDIES ON SOME INDIAN JUJUBE (Ziziphus mauritiana Lamk.) VARIETIES GROWN AT EL- NUBARIA REGION

Abstract

Ber or the Indian jujube is belongs to the family Rhamnaceae that consists of 45 genera and 550 species. It is widely distributed in tropical and sub-tropical climates in the world (Mukhtar et aL, 2004). Ber can be successfully cultivated even in the most marginal lands of the tropics and subtropics with few agriculture inputs and little attention. The cultivated area in Egypt of Indian jujube reached about 1000 feddans distributed in Western El-Nubaria and Al-Ismailia area. The tree propagates freely and resists strees conditions in regions experiencing recurrent droughts. It is suitable to rehabilitate the vast resource-poor regions of the tropics and subtropics and is thus an important tree for integration into the agroforestry systems in the warm desert ecoregions. The tree can provide economic sustenance to the region and insurance against ecological degradation.

The Indian jujube has different names in different languages of the world there are in Arabic; Aunnabe Hindi, Nabig and Sidr; in English; ber, Chinese Date, Indian Cherry, Indian Jujube, Indian Date and Indian Plum; In French; Chicourlier, Croc de chien, Epine a cerises, Guin-doulier, Jujubier, Masson and Massonier; In Hindi, Baer, Ber and Beri.

The Indian jujube is native from the Province of Yunnan in Southern China to Afghanistan, Malaysia, Queenland and Australia. However, ber is now widely distributed and has become naturalized in tropical Africa, Iran, Syria, Sri Lanka and part of Mediterranean (Kaarira, 1998 and Obeed et at., 2008).

The Indian jujube trees are ever green and vigorous grower and have a rapidly developing tap root system within a short period and it can also withstand alkalinity and slightly water-logged condition. Its trees are found even on marginal lands which are otherwise unfit for growing other fruits or even crops. It can in fact, withstand and often do better than most fruits on poor soils (Pareek, 1983). Ber trees can withstand extremely high summer temperatures and are found to grow well in regions having maximum temperatures of 39 to 4Z C and can tolerate temperatures as high as 49-50 C. However, fruits set are adversely affected at temperatures above 35 C. The trees shed leaves and enter dormancy during the extremely hot summers in the subtropics of northern India. In Northern Australia, leaf senescence and leaf fall begins in April as the dry season sets in and the new leaves emerge with the onest of rainfall in September and October (Grice, 1998). This appears to be an adaptive mechanism to escape damage through desiccation during hot weather. Desiccation damage in ber is caused by high cuticular transpiration, which is reported to be associated with high levels of fatty acids and low levels of aldehydes and alcohols in the wax cuticle rather than with the thickness of the cuticle and wax itself (Rao et at., 1981). During the dormancy phase, along with leaf fall, growth ceases. Dark tan-coloured hard and pubescent scales develop on the buds and the bark and buds lose moisture and show lower nitrnqen contents (Singh et at., 1974).

Ber tree may be a bushy shrub 4 to 6ft (1.2 -1.8 m) high, or a tree 10 to 30 or even 40ft (3- 9 or 12m) tall; erect or wide- spreading, with gracefully drooping branches and downy, zigzag branchlets, thornless or set with short, sharp stqtight or hooked spines (Morton, 1987). The leaves are alternate, ovate or oblong elliptic with 3 viens at the base and are usually about 2.5 to 3.2 em long and 1.8 to 3.8 em width. The flowers are yellow, 5-petalled and are usually in two and three in the leaf axils. This quick growning tree starts