Effects of soil suction and salinity of water on yield and yield components of cotton

In arid and semi-arid regions¡ salinity is a serious and chronic problem for agriculture. Due to the improved methods of irrigation and mechanization this methods to increase water use efficiency and enhance the uniformity of water distribution in the field¡ is very important. Main area of farming cotton in Iran is about 150000 ha¡ which in Kerman province mostly is in Orzoueyeh region by the area of 2500 ha and capability of 2.5 ton ha-1. Therefore¡ Due to a shortage of good quality water resources in the province¡ the aim of this study was to evaluate the combined effect of irrigation and salinity on the yield of cotton.
in order to investigate the effect of salinity on yield and yield components of cotton under soil suction¡ a field experiment was carried out during 2011 and 2012 growing seasons at an experimental farm in Orzoueyeh territory of Kerman province. The treatments were laid out in Randomized Complete Block Design with three replications. The treatments were comprised of four soils potential including 45¡ 55¡ 65 and 75 Kpa tension in main plot and sub plot consisted of three salinity of irrigation water including 1.5¡ 4.5 and 7.5 dS.m-1.
The results showed that in comparison to 45 and 55 Kpa tension¡ parsimony of water usage equal 1150 m3 ha-1 achieved. Moreover yield¡ height of plant¡ number of bolls per plant and bolls weight decreased 7.3¡ 11.4¡ 7.7 and 11.4 percent respectively but water use efficiency increased 4.8 percent. Also¡ In comparison to 1.5 and 4.5 dS.m-1 salinity of irrigation water¡ yield¡ water use efficiency¡ bolls weight¡ number of bolls per plant and height of plants increased 8.6¡ 4.2¡ 8.4 and 4.1 percent respectively. But from statistically point view all mentioned traits in both treatment of study placed in one statistic group.
ccording to the results¡ it can be said that in arid and semi-arid areas of the country¡ increase irrigation efficiency in furrow irrigation systems can play a role in saving water and energy costs. Also¡ due to the increased salinity of water resources¡ applying the 55 Kpa potential point in using salinity water with 4.5 dS.m-1 can have efficient role in increase yield¡ water use efficiency and area of cotton cultivate. According to the results¡ it can be said that in arid and semi-arid areas of the country¡ increase irrigation efficiency in furrow irrigation systems can play a role in saving water and energy costs. Also¡ due to the increased salinity of water resources¡ applying the 55 Kpa potential point in using salinity water with 4.5 dS.m-1 can have efficient role in increase yield¡ water use efficiency and area of cotton cultivate.