International Symposium on
Drylands Ecology and Human Security

Go to Arabic site :-)

© 2006 NDRD        Imprint        Disclaimer


Determination of the Best Seeding Time for Atriplex Seeds
(Atriplex conescens) in the Drylands of Tehran, Iran

Hamid Madani 1, Gholamreza Naderi Broojerdi 1, Ebrahim Farahani 2

1 Faculty of Agriculture, Arak Islamic Azad University, Arak, Iran
Presenting Author: Dr. Hamid Madani

2 Agriculture and Natural Resource Center, Tehran Providence, Tehran, Iran


Atriplex is one of the plants that have a good response to saline soils, cold environments, dry lands and semi arid ecosystems. These tree limiting ecological parameters are the main stressors for arid and semiarid ecosystems, such as the center regions of Iran. The climate of the great Tehran region has two ecological limiting factors for shrubs planting, plant growth and development. In addition to recurrent drought periods in dry summers, there may as well be freezing temperatures during cold winters.
In this investigation, that we are conducting in Bijin Natural Source Research Center (26˚,51' latitude with 1160 meter elevation above sea level) on 2000-2004 we use of complete randomized design with 3 replications in 50 pots as a experiment unit. The objectives are to determine the best sowing time for Atriplex seedlings and the production of developed shrubs. Tehran location has according to Domarten method a semi arid environment. Temperatures below-zero were recorded on about 80 days per year, while an average mean of 240 days could be considered dry. The time frame for sowing for this experiment included 9 different time intervals from the first of June until the end of September. The maximum air temperature during the study period was 45° C during July and the lowest temperature was -8° C in October.
The percentage of emerging plants, height, root length and number of branches per plant was determined at each plot that included 50 B sizes of plastic pots according to ISTA rules and the row results were analyzed with MSTAT-C software. The results show that the best sowing time for a healthy growth of Atriplex conescens seedling was in the end of August (p<5%) and relay from this time can make more branches per plants that are non essential character for small shrub production (p<1%). Other sowing times resulted in a reduced main root length (p<1%). However the main root length of small shrubs is a vital characteristic for the acclimation of the plant to freezing temperatures and drought tolerance in the given natural semiarid planting condition.

Key words: Atriplex conescens, small shrub, sowing time, root length