Tropical and Sub-Tropical Fruit Trees

Inflorescence-based micropropagation holds great potential for the multiplication of recalcitrant male and female date palm individual trees and culti-vars of commercial interests with limited populations. This can be accomplished in a short time with minimal effort as compared to the traditional practice of using shoot-tip explants. The aim of this technique is to pave the way to use inflorescence explants to micropropagate date palm by direct formation of organs (somatic embryos or shoots) and avoiding most of the constraints that face the shoot tip like high percentage of contamination in the establishment stage, heavy browning, a long time for first cluster initiation, using a considerable number of offshoots and inability to micropropagate the elite palms in case no offshoots are available. The way to excise the immature inflorescence without damage to the mother tree, composition of the nutrient medium for direct organ initiation have remained hindrances to this technique over recent decades, in addition to the technicalities for proper handling of cultures inside the laboratory and successful shifting of plants to the greenhouse. We report for the first time an innovative method used to excise the immature inflo-rescence at a suitable stage for successful culture initiation. Spikelet explants are induced to produce shining globular structures without a callus phase. Also, explants were exceptionally able to develop direct shoots. Two types of organs developed on the differentiation medium, green shoots and intact somatic embryos. Only green shoots and multiple somatic embryos were subjected to proliferation at the multiplication stage. Well-rooted plantlets were hardened and successfully established in soil.

THE SUITABILITY of white greenhouse net cover for growth of mango (Mangifera indica. L.) cv. Keitt cultivar was tested at the El-Bosaily governmental farm at the North West of the Nile Delta, Egypt. The treatments were cover the greenhouse by white net and conventional open field treatment (control). This study aims at investigating the effects of white net on the growth and production of mango trees from the interception of light, temperature, humidity and plant growth were evaluated over two seasons (from 2007 and 2008). The nets demonstrated their efficiency for orchard decrease maximum temperatures and increase minimum temperatures and relative humidity compared with open field treatment. The use of white net resulted in a significant increase of number of leaves, plant height and stem diameter per plant compared to open field orchard. The net was superior for plant growth, flowering and yield. Data revealed that microclimate under the white net make proper microclimate for tropical fruits under Egyptian conditions.

The present work aimed at improving pineapple (Ananas comosus (L.) Merrill) cv. Smooth Cayenne production throughout the tissue culture technique. Some factors affect this process were studied. The method of surface sterilization, the adventitious and axillary bud formation versus N6-Benzyladenine (BA) concentration, type of medium (liquid or solidified), rooting and acclimatization were evaluated. Explants have been surface sterilized with sodium hypochlorite (NaOCl) at 0.5 %, then with mercuric chloride (Hg Cl2) at 0.1 % both for 5 minutes, with survival percentage of 95%. All explants were cultured onto MS basal medium supplemented with different concentrations of BA and 1.0 mg l-1 Kinetin (Kin). All cultures were maintained in a growth room at a 16 h photoperiod (40 mmol.m-2 s-1), 27 ± 2°C. After eight weeks, number of initiated shoots was counted and the cultures were transferred for multiplication on the best treatment, 2.0 mg l-1 BA and 1.0 mg l-1 Kin. Therefore, using the liquid medium during multiplication stage speed up the growth of proliferated shoots compared to solidified medium. Utilizing 1.0 – 3.0 mg l-1            α-Naphthaleneacetic acid (NAA) or Indole-3-butyric acid (IBA) enhanced the root formation of individual shoots. Finally, the well rooted plantlets, around 12 cm in length, were transplanted onto the Peat moss as a soil bed under the greenhouse. After 4 weeks, the survival percentage was 100 %. By this improved protocol, more than 10000 pineapple plants were produced from one initial plant in less than 9 months.  Introduction

THE SUITABILITY of white greenhouse net cover for growth of mango (Mangifera indica. L.) cv. Keitt cultivar was tested at the El-Bosaily governmental farm at the North West of the Nile Delta, Egypt. The treatments were cover the greenhouse by white net and conventional open field treatment (control). This study aims at investigating the effects of white net on the growth and production of mango trees from the interception of light, temperature, humidity and plant growth were evaluated over two seasons (from 2007 and 2008). The nets demonstrated their efficiency for orchard decrease maximum temperatures and increase minimum temperatures and relative humidity compared with open field treatment. The use of white net resulted in a significant increase of number of leaves, plant height and stem diameter per plant compared to open field orchard. The net was superior for plant growth, flowering and yield. Data revealed that microclimate under the white net make proper microclimate for trop...