zahra ghahremani

In order to evaluate the effect of water deficit stress on growth and fruit yield of some Iranian melons, the experiment was set out in a split plot design with three replicates in research filed of University of Zanjan. Treatments consisted arrangement of three irrigation levels (starting irrigation at 100, 66 and 33% ETc) and 11 accessions of Iranian melons (Khatouni, Kali, Orshang, Mouri, Mozi, Zarde-Paeize, Shirazi, Shiardar, Ezmir, Eyvanaki and Suski-e-Sabz). Results showed that irrigation treatment had a significant effect on plant length, fruits number per plant, fruit weight, leaf area, leaf dry matter, yield, total chlorophyll and carotenoids. The water deficit stress 33% ETc caused 1.9% increases of leaf dry matter and reduced 34.4 and 59.75% of fruit weight and yield, respectively. The lowest values of plant length, number of fruits per plant, fruit weight, leaf area and the highest leaf dry matter was obtained in the sever water stress (start point of 33 ETc). Melon acce...

To evaluate the effect of water-deficit stress on the yield, antioxidant activity, and physiological traits of four Iranian melon genotypes (“Khatooni,” “Suski-Sabz,” “Zarde-Tabriz,” and “Shiari”), an experiment was conducted. The irrigation levels were: (1) control (100%ETc); (2) deficit irrigation 66% (66%ETc); and (3) deficit irrigation 33% (33%ETc). The results showed that the yield and relative water content (RWC) significantly decreased in response to an increase in water-deficit stress. The highest yield reduction (60.7%) was measured in Khatooni under 33% ETc deficit irrigation. Water deficit had no significant effect on the Vitamin C content. Among genotypes, the highest value of Vitamin C was seen in Suski-Sabz. Water-use efficiency (WUE) increased under water-deficit stress conditions with higher WUE values recorded in the Suski-Sabz and Shiari genotypes. Significant proline accumulation was detected with increasing water-deficit stress and the highest value of proline wa...

The field experiment was conducted to evaluate the effect of foliar spray of calcium lactate (Ca) on fresh yield and biochemical attribute of lettuce (Lactuca sativa L.) under water deficit stress, in a split plot form based on a randomized complete block design with three Irrigation regimes (70, 85 and 100% ETc) and three calcium lactate treatment levels (0, 0.75 and 1.5 g L-1) in three replicates. Results revealed that water deficit stress significantly reduced the growth and yield of plant, leaf relative water contents, excised leaf water retention and N, P and Mg absorption while led to increase anthocyanin, phenol and flavonoids contents, antioxidant activity, peroxidase and catalase activity and water use efficiency. The results of our research indicated that the application of CaL 1.5 g L-1 is capable of increasing lettuce yield, under field conditions with 30% less than optimal irrigation. CaL treatment showed a clearly protective effect in stressed plants, enhancing their l...

In order to investigate the effect of plant growth regulator paclobutrazol and hydrogen peroxide on growth, yield and fruit quality of melon (cv. Khatooni), this experiment was set out in a randomized complete block design with three replications in the research farm of University of Zanjan. Treatments included pruning (control), thinning, three levels of hydrogen peroxide (2.5, 5 and 7.5 mM) and paclobutrazol at three levels (10, 20 and 30 mg.L ˗1 ) in 4 -6 leaf and fruit set stages. The results showed that foliar application of hydrogen peroxide increased the total soluble solids content. Thinning treatment had no significant effect on growth and fruit quality but increased yield compared to the control plants. Foliar application of paclobutrazol reduced growth but increased yield fruit and total soluble solids content compared to the control plants. According to results, the highest fruit weight, fruit yield and total soluble solid and the lowest number of stem and plant length w...

Abstract In this study, the effects of four concentrations of humic acid (0, 0.5, 1, and 1.5 kg ha−1, HA applied to the soil) and kinetin (0, 25, 50, and 75 mg L−1, KT, foliar sprayed) on vegetative growth, yield and biochemical attributes of radish cv. Watermelon, grown in two seasons of spring and autumn, were investigated. Results showed that, the number of leaves per plant, leaf area and chlorophyll content increased with application of HA and KT in both seasons, while the high levels of treatments had no significant effect on leaf number per plant and chlorophyll content in spring season. The root diameter, fresh weight and yield increased significantly with application of HA and KT in both seasons, though, this increase was noticeable in the autumn season. Our results also showed that radish root treated by HA and KT exhibited higher root firmness, vitamin C, anthocyanin content and total soluble solids (TSS), especially in autumn cultivation. Macronutrient contents of root including magnesium (Mg), phosphorus (P), potassium (K), nitrogen (N), and calcium (Ca) were significantly enhanced by HA and KT, however high concentration of KT in combination with high concentration of HA decreased some nutrient contents. Generally, the results of this study demonstrated that cultivation season is one of the most important management tools to minimize the negative effects of high temperature during root development. In addition, the benefits of KT spray combined with HA were inconsistent between both seasons, but showed more in the autumn crops.

Eggplant is one of the most popular and vital vegetable crops in the world. Various plant bio-regulators have been used in different crops to increase uptake of nutrients thereby leading to improvement in growth, flowering, fruit quality, storability and yield. The scope of this study was to evaluate the effects of calcium lactate and salicylic acid foliar application on growth parameters, physiological characteristics and shelf-life of eggplant fruit. Obtained results showed that the highest applied concentrations of calcium lactate (4 mM or 0.8 g l-1) and salicylic acid (1.5 mM or 0.2 g l-1) foliar application led to the highest values of measured growth parameters and yield. Applying of calcium lactate and salicylic acid foliar treatments could increase tissue firmness and ascorbic acid content of fruits. Foliar application of calcium lactate 4 mM (0.8 g l-1) and salicylic acid 1 mM (0.13 g l-1) was the best treatment to decrease percentage of fruit decay. In conclusion, our resu...

Some of the most cultivated commercial cultivars of asparagus are susceptible to abiotic stresses. Different species of asparagus plant are distributed in different regions of Iran which could be useful genetic resources for applying in asparagus breeding programs. The purposes of the current study were to evaluate morphological variation of A. azerbaijanensis accessions and drought tolerance assessment of Iranian asparagus in order to introduce superior accessions. Two different accessions of A. azerbaijanensis species were collected. A number of 30 plants were selected and 22 morphological traits were then evaluated. A factorial experiment based on completely randomized design was performed in order to drought tolerance assessment of 9 Iranian asparagus accessions. The average of spear length and diameter in Ahar and Makou plants were 48.94 cm and 4.70 mm, respectively. Based on results, plants of Ahar accession produced short and thick spears but on the other hand, Makou accessio...

Cucumber and other Cucurbitaceae plants have a high transpiration rate and sensitivity to water deficit stress. Ascorbic acid (AsA) and gamma aminobutyric acid (GABA) participate in a variety of plant processes and increase plant resistance to different stresses. The current study was aimed to assess the efficacy of the foliar application of AsA (100, 200 and 300 mg l −1 ) and GABA (20 and 40 mM) on growth, physiological parameters and water use efficiency related properties of cucumber plants under deficit irrigation (DI) strategy (0, 25 and 50%). Results showed that the highest values of measured morphological properties were recorded in plants treated with GABA at 40 mM and AsA at 100 mg l −1 . The highest water use efficiency was observed in plants sprayed with GABA at 40 mM. Also, foliar spraying of GABA at 40 mM was the best treatment to improve the free proline content of leaves and the activity of antioxidant enzymes under drought stress conditions. Findings of this study showed that foliar application of AsA and GABA can be a useful and inexpensive treatment to improve morphological, physiological and water use efficiency related properties of cucumber plant under water deficit stress. Gurken- und andere Cucurbitaceae-Pflanzen haben eine hohe Transpirationsrate und reagieren empfindlich auf Stress durch Wassermangel. Ascorbinsäure (AsA) und Gamma-Aminobuttersäure (GABA) sind an einer Vielzahl von Pflanzenprozessen beteiligt und erhöhen die Widerstandsfähigkeit der Pflanze gegen verschiedene Belastungen. Ziel der aktuellen Studie war es, die Wirksamkeit der Blattapplikation von AsA (100, 200 und 300 mg l −1 ) und GABA (20 und 40 mM) auf das Wachstum, die physiologischen Parameter und die mit der Wassernutzungseffizienz zusammenhängenden Eigenschaften von Gurkenpflanzen unter Defizitbewässerung (DI; 0, 25 und 50 %) zu bewerten. Die Ergebnisse zeigten, dass die höchsten Werte der gemessenen morphologischen Eigenschaften bei mit 40 mM GABA und mit 100 mg l −1 AsA behandelten Pflanzen verzeichnet wurden. Die höchste Wassernutzungseffizienz wurde bei Pflanzen beobachtet, die mit 40 mM GABA besprüht wurden. Auch war die Blattbesprühung mit 40 mM GABA die beste Behandlung, um den Gehalt an freiem Prolin in den Blättern und die Aktivität der antioxidativen Enzyme unter Trockenstressbedingungen zu verbessern. Die Ergebnisse dieser Studie zeigten, dass die Blattapplikation von AsA und GABA eine nützliche und kostengünstige Behandlung sein kann, um die morphologischen, physiologischen und mit der Wassernutzungseffizienz verbundenen Eigenschaften der Gurkenpflanze unter Wasserdefizitstress zu verbessern.