Year: 2004
Type: dissertation
Abstract: productivity will need to increase by 20% in the developed countries and by 60% in the developing countries.In the light of these demographic, agricultural and ecological issues, the threat and effects of salinity become even more alarming.Reducing the spread of salinization and increasing the salt tolerance of crops and improving species or genotypes to salt tolerance, particularly the high yielding ones are, therefore, issues of global importance. Salinity in EgyptEgypt is an arid and semi-arid country, which covers an area of about one million square kilometers in the north-east corner of Africa and the Sinai Peninsula of south-west Asia.More than 69 million inhabitants now occupy only 4% of this area, which is mainly concentrated in the Nile Valley, the Delta and the coastal zone along the Mediterranean Sea.Thus, Egypt has one of the highest population densities in the world with an average of 1700 inhabitants per km 2 .More importantly, Egypt is one of the countries that suffer severe salinity problems.For example, 33% of the cultivated land (Ghassemi et al., 1995), which comprises only 3% of total land area in Egypt, is already salinized.This salinization is mainly due to low precipitation (<25 mm annual rainfall), high temperature (during summer, temperature reaching from 35 to 45°C), high surface evaporation (1500-2400 mm/year), poor drainage system with 98% of the cultivated land under irrigated, rising water table (less than one meter below the soil surface), and irrigating with low quality water (up to salinity of 4.5 dS/m) (Amer et al., 1989).The reduction in production of soils affected by salinity is about 30% (El-Lakany et al., 1986), threatening the livelihoods of the poor farming and having a significant negative impact on the food production of Egypt as whole.Moreover, the Egyptian Government has spent large sums on reclamation, mainly on drainage projects (more than US$ 30 million annually) to solve salinity problems in irrigated area, but the annual average net income from crops grown with drainage system is more limited than for those grown without drainage system (Amer et al., 1989).Therefore, genetic improvement for salt tolerance in major crops, particularly because this approach is less expensive for poor farmers than other, has became an urgent task in dealing with salinity problems in Egyptian agriculture sector. Effect of salinity on plant growthGenerally, Salinity can inhibit plant growth by three major ways (Greenway and Munns, 1980): traits (Schachtman et al., 1989).Therefore, the one objective of the study was to describe the effects of salinity on different physiological traits and how these relate to plant growth analysis. References
Author: Salah El-Hendawy
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2746214909