The effects of plant density and irrigation interval on forage yield and some physiological traits of Kochia, Quinoa and Forage sorghum in Golestan province

Alireza Saberi ¹ ( 1Assistant Professor, Agronomy and Garden Research Department, Golestan Agricultural and Natural Resources Research and Education Center, AREEO, Gorgan, Iran )
Alireza Kiani ² ( Agricultural engineering department, ,Golestan Agricultural and Natural Resources Research and education Center )

Submited date : 2022-11-13 Accepted date : 2023-01-28

Keywords: Salinity, Forage yield, Chlorophyll, Irrigation frequency,

Abstract :

The productivity of plants is strongly influenced by environmental stresses. Scientists consider soil salinity as one of the major factors that reduce plant growth in many regions of the world (McCarty and Dudeck, 1993; Murdoch, 1987). Sodium chloride (NaCl) is the predominant component contributing to salinity in soils (Jungklang et al., 2003). To overcome this problem, the search for salt tolerant forages has increased (Harivandi et al., 1992). Salt tolerant plants have the capability to minimize these detrimental effects by a series of morphological, physiological and biochemical processes (Jacoby, 1999). Under the variable saline environments, plants have developed different adaptive mechanisms (Rhodes et al., 2002 and Borsani, et al., 2003).Sorghum has tillering characteristics that enable it to completely regenerate the above-ground portions of the plant. Individual sorghum plants have been kept alive for as long as 7 years where the climate is mild enough to avoid winterkill and disease and insect protection have been provided. These important features of sorghum have allowed producers to seek a second crop within the same growing season. This decision, however, must be made at or soon after harvest of the main crop, and re-growth should be managed in the same manner as the main crop (Teutsch, 2006). A new generation of salt-tolerant forage varieties would allow for landscape development in saline environments and where salt water usage is a problem, or where fresh water is limited or not available for irrigation. Forage sorghum development in these areas often requires the use of brackish water from affected wells or other secondary sources. The effect of salinity and water deficit on kochia, quinoa and forage sorghum is not known. Hence, studies are needed to improve understanding on yield of these crops under influence of salt and water stresses. In addition, many factors need to be considered when addressing the suitability of irrigation water with respect to salinity. To our knowledge, there are no published studies on drought and salt water tolerance among these forage varieties. The specific objectives of this study were:To determine yield, biomass partitioning, and morphological responses of kochia, quinoa and forage sorghum varieties to different levels of salinity and irrigation frequency.It is predicted that at least 10 million people will be hungry and malnourished in the world by the end of this century (FAO 2003). Thus, to reduce the food insecurity, crop production will have to be doubled, and produced in more environmentally sustainable ways (Borlaug and Dowswell 2005). This can be achieved by expanding the area of crop production, increasing per hectare yield and improving crop quality. Furthermore, during the second half of the past century, rise in per hectare crop productivity was due to improved or high yield potential (Arous et al. 2004).The relationship between growth of Kochia, Quinoa and forage sorghum under different irrigation frequency and plant density is not well understood. Many changes take place in plants to enable them to compete and maintain photosynthetic activity. Works in the late 1980s demonstrated that yields can be raised two to three-fold by using available improved varieties and appropriate agronomic techniques. These include in the aspects of to what extent of irrigation frequency and plant density affect the yield and morpho-pysiological parameters of Kochia, Quinoa and forage sorghum. In addition, no comprehensive database is available on sorghum under combination of pattern and density in northern Iran. Thus, studies are still needed to improve our understanding of the effects of pattern and density for Kochia, Quinoa and sorghum. Hence, the present study was to design with the following objectives:Objectives1. To determine the performance of Kochia, Quinoa and forage sorghum at different levels of plant density. 2. To study the effect of irrigation frequency on yield and physiological parameters of Kochia, Quinoa and forage sorghum. 3. To identify how interaction irrigation frequency and plant density affect yield and yield components of Kochia, Quinoa and forage sorghum. In order to study irrigation frequency and plant density of Kochia, Quinoa and forage sorghum, a field experiment was conducted during 2015 and 2016 at Salinity Station. The experiment was laid out in a randomized complete block design in form of split plot factorial experiment and replicated four times. At this research effects of irrigation frequency at four levels (irrigation after 5, 10, 15 and 20 days), and plant density at three levels (11.1, 16.7 and 33.3 plants per m2) on Koshia (Birjand and Sabzevar bulks), Quinoa (Santa Maria and Sajama Iranshahr) and verities of KFS3 and Speed feed sorghums were investigated. Sowing date was the time of soil temperature reaching to 12 °C and the harvesting date was the time of 5% flowering of each plot. Each variety was planted in four lines, the length of planting lines were 6 meters and inter row spacing was 60 cm. the seeds were planted in series, then distance of 5, 10 and 15 considered for plant densities of D1, D2 and D3. For yield estimation, after removing borders, 6 m2 harvested. For measurements physiological treats, 10 bushes randomly sampled. Chlorophyll content was estimated using the method of Witham et al. (1986). Free proline concentration was determined by means of a rapid colorimetric method using an acid ninhydrin procedure developed by Bates et al. (1973). Data were analyzed using SAS software. Quantitative experiment results showed that; Sabzevar bulk at irrigation every 5 days interval and 33.33 plants per m2 with yield of 33.99 ton ha-1 had the highest yield and chlorophyll content. With increasing low irrigation stress, amount of proline had increasing trend and Sabzevar bulk had the most amount of proline on its leaves.