General Commission for Scientific Agricultural Research-
Tartous Research Center
Faculty of Agriculture, Tishreen University,
This study has been done at Citrus Research Section’s orchards in Tartous during 2007-2009 at 15 years non grafting rootstocks under same orchards and same soil. Five rootstocks were studied (i) sour orange; (ii) carrizo citrange; (iii) Citrumelo 4475; (iv) Cleopatra 4; and (v) Trifoliata orange mandarin.
The results showed:
1.The most roots mass gathering for citrus were under the foliage edge directly at high significant differences.
2. Citrumelo 4475 gets over all other rootstocks in roots mass, while Trifoliate orange was the least.
3. The rate of root diameter under 0.1 m.m gets over other roots.
4. In vertical distribution as general average between rootstocks the roots were distribution from up to down between sectors as little by little in clear significant differences but it is concentrated at (0-25cm).
5.Sour orange has the most root deepening, however no roots at depth >100 cm for Poncirus trifoliate or Carrizo citrange .
6.For each rootstock three root flashes (spring -summer- autumn) and all rootstocks various each other on date of beginning and end of root flashes.
7. There were three foliage flashes (spring-summer- autumn) and all root stocks various each other on date of beginning and end of flashes.
8. The spring flashes were the most important and bigger than other flashes in clear significant differences.
9.The results show that southern side of tree overcomes all sides for all rootstocks except Sour orange and Cleopatra mandarin which show that west and south sides overcome other sides.
10. Citrumelo has the strongest growth (steam cut), and the lower one was trifoliate, and all rootstocks overcome trifoliate in the foliage volume.
11. There is a relationship between ability of rootstocks to gather elements at root and gathering elements at leafs and this relationship differs by rootstock and elements.