Tag Archives: Water stress

The Effect of Potassium Fertilization on the Tolerance of ‎Bread Wheat (Triticum aestivum var. Sham 6) to Water Stress

Bothena Omran(1) and  Ghiath A. Alloush*(1)

(1). Department of Soil and Water Sciences, Faculty of Agriculture, Tishreen University, Latakia, Syria.

(*Corresponding author: Dr. Ghiath A. Alloush. Email: galloush@scs-net.org).

Received: 21/11/2019                               Accepted: 11/01/2020

Abstract

A pot experiment was conducted at a greenhouse during the growing season 2016/2017 to study the effect of water stress (FC=65 and 75%) on growth and productivity in the presence and absent of K fertilization (0 and 100 mg K/kg soil). Two control treatments at (0 and 100 mg K/kg soil) watered to 100% of FC were also included. Water stress was implemented during the whole life cycle of wheat crop and at three different wheat phonological stages: up to ending of tillering, up to beginning of spike heading, and up to beginning of grain filling. Water stress was then relieved and plants were watered to 100% of FC. Regardless of K application, water stress at 65 and 75% of FC decreased total number of tillers which mostly remained weak and unfertile compared to the control plants. The application of K to plants grown at 100% of FC increased the number of fertile tillers. Wheat plants subjected to 65 and 75% of FC water stress up to grain filling were unable to compensate for the lost fertile tillers after the stress was relieved. Whereas, stressed plants at tillering and spike emerging stages were able to compensate and increased number of fertile spikes not only similar, but even higher than those obtained for control plants. The decrease in grain weight per spike of main stem and tillers less apparent at 75% of FC, and that K application had no significant effect among treatments of the different water stress stages. The effect of water stress at different growth stages and K fertilization on the number of fertile tillers and weight of grain in spikes influenced grain productivity. Imposing continuous water stress led to decrease grain yield from 11.78 to 4.28 and 7.44 ton/ha at 65 and 75% of FC, respectively, in case of no K application. The decrease in grain yield for the same treatments were from 11.94 to 4.89 and 7.75 ton/ha in the presence of K application. In treatments subjected to water stress up to spike emerging stage yielded 7.44 and 8.58 ton/ha at 65 and 75% of FC  and no K application, and 7.77 and 9.16 ton/ha for the same treatments receiving K application. Water stress at 65 and 75% of FC at tillering stage had small reducing effect on grain yield and produced as much as 90 and 97% of the grain yield of the control plants without K application. Grain yield was 91 and 99% of the yield in the control treatments receiving K application.

Key words: Bead wheat,Water stress, Potassium, Grain yield, Grain protein

Full paper in Arabic: PDF

Determination of Selection Indices in Soybeans (Glycine max L.) Genotypes under the Effect of Water Stress

Mohamad Nael Khattab*(1) Nabil Habib(1) and Sahar Hanifa(1)

(1). Crops Field Department, Faculty of Agriculture, Tishreen University, Latakia, Syria.

(*Corresponding author: Dr. Mohamad Nael Khattab. E-Mail: aboalabd876@gmail.com).

Received: 02/05/2018                                Accepted: 01/10/2018

Abstract

The research was carried out in the coastal region (Ashrafieh village of Jibla district) and in the laboratories of the Faculty of Agriculture, Tishreen University, during the season 2018 to study the effect of water stress on five soybeans genotypes (Sb335, Sb337, Sb339, Sb342, Sb344), to determine which of them more resistant to drought through productive indicators and their components, and to study the establishment of selectorial indices for production attributes to determine which of them can be considered as criterion for high productivity under water stress conditions. The experiment was carried out according to the split block design with three replicates. The water stress treatments were applicated in the main plots (from the beginning of the flowering stage and the beginning of the fullness of the pods), while the secondary plots included the five soybeans genotypes. Most of the studied traits showed high GCV values and were associated with a high inheritance coefficient indicating that these traits were relatively less affected by the environment. The results showed that water stress caused a significant decrease in productivity and all its studied components compared to normal irrigation treatment (control). Sb 335 genotype had the lowest reduction in all studied indicators, while the genotypes Sb 337 and Sb 344 were the most sensitive to stress. The decrease was due to the effect of water stress on the characteristics of the studied genotypes with the percentage of increase in the proline content. The productivity of seeds was positively and significant correlated with the weight of pods (r = 0.92 **) and the number of seeds per plant (r = 0.94 **). These traits showed high values of GCV, GA% and H2B. This study indicated the possibility of using weight of pods and number of seeds per plant as selectorial criterion to improve seed productivity.

Key words: Soybeans, Water stress, Proline, Genetic variation, Correlation.

Full paper in Arabic: PDF

The Combining Ability for Grain Yield and Some Secondary Traits of Some Maize Crosses under Water Stress Conditions

Majeda AL- Rwaily*(1) Ayman Shehada AL-Ouda(2) Samir AL-Ahmad(1) and Rshad ALobaid(1)

(1). Crops Research Administration, General Commission for Scientific Agricultural Research (GCSAR), Damascus, Syria.

(2). Crops Department, Faculty of Agriculture, Damascus University, Damascus, Syria.

(*Corresponding author: Dr. Majeda Al-Rwaily. E-Mail: r.majeda@gmail.com).

Received: 09/07/2016                       Accepted: 10/10/2016

Abstract                 

Half diallel cross among six inbred lines was conducted at the Scientific Agricultural Research Center in Deir Ezzor, during the growing season 2010. The fifteen crosses and the two local checks Ghoota82 and Basel-1 were evaluated during the growing season 2011, after being exposed to water stress during flowering and grain filling stages, in order to study the genetic behavior through estimating the general and specific combining ability of some secondary traits determining the grain yield i.e., anthesis silking interval, number of ears and per plant, number of grains per ear, 100 grain weight and harvest index, and to determine the response of maize genotypes for water stress through flowering and grain filling stages. The trial was conducted according to randomized block design, with tree replications. Results showed that GCA and SCA mean square of both lines and crosses were highly significant for most of the investigated traits indicating that inbred lines had variation and genetic diversity. The ratio σ2 GCA /σ2 SCA indicated the importance of the non-additive gene action for grain yield under water stress conditions during flowering and grain filling stages, while the non-additive gene action dominated of all other traits under water stress during the grain filling stage and full irrigation. The two lines p3 (IL344T.C-2007) and p2 (IL1081T.C-2009) revealed the best GCA. The hybrids p2×p3 (IL1081-2009×IL344-2007), and p1×p3 (IL441-2009×IL344-2007) showed the best SGA for grain yield trait.

Keywords: Maize. Combining ability, Water stress, Grain yield, Half diallel cross.

Full paper in Arabic: PDF

The Effect of Water Stress on Some Physiological Characteristics of Two Sugar Beet (Beta vulgaris L.)  Monogerm Hybrids

Entessar AL-Jbawi* (1) Fadi Abbas (2)

(1). Sugar beet Research Department,  Crops Research Administration, General Commission for Scientific Agricultural Research  (GCSAR), Damascus, Syria.
(2). Scientific Agriculture Research Center of Homs, (GCSAR). P.O.Box 626, Homs, Syria.

(*Corresponding author: Dr. Entessar Al Jbawi, E-mail: dr.entessara@gmail.com).

Received: 02/02/ 2015                                     Accepted: 17/06/ 2015

Abstract:

The experiment was carried out in the General Commission for Scientific Agricultural Research (GCSAR) at Homs Agricultural Research Center, Homs, Syria, during 2009-2010 seasons, at winter time, to study the effect of early water stress on some physiological characteristics of sugar beet. Two genotypes (Brigita and Dorotea), were subjected to water stress by withholding water for 40 days after rainfall ceased. A split plot design with three replicates was used. Results showed that, early drought stress had a significant effect on the studied parameters. Water content (WC%) and relative water content (RWC%) were decreased in all plant parts under drought condition as compared to control.  However, WC% in taproot decreased more than blades and petioles. RWC% decrement was less in mature leaves than in old and new leaves. Under drought stress, fresh and dry weight of tops and roots were decreased. Sugar beet genotypes showed the capability to regulate its osmotic potential by increasing sodium, potassium, and soluble sugars in both, tops and roots. Results also Indicated that drought stress caused an increasing value of fluorescence origin (fo), decreasing the values of fluorescence maximum (fm), and maximum yield of quantum in photo system-II, (fv/fm). The reduction in Dorotea genotype was more drastically compare to Brigita.

Key words: Water stress, Physiological characteristics, Sugar Beet.

Full paper in Arabic: تأثير الإجهاد المائي في بعض الصفات الفيزيولوجية لهجينين وحيدي الجنين من الشوندر السكري (Beta vulgaris L.)