Ertan Yildirim

Effect of Foliar Salicylic Acid Applications on Growth, Chlorophyll, and Mineral Content of Cucumber Grown Under Salt Stress

ABSTRACT The objective of this study was to determine the effect of foliar salicylic acid (SA) applications on growth, chlorophyll, and mineral content of cucumber grown under salt stress. The study was conducted in pot experiments under greenhouse conditions. Cucumber seedlings were treated with foliar SA applications at different concentrations (0.0, 0.25, 0.50, and 1.00 mM). Salinity treatments were established by adding 0, 60, and 120 mM of sodium chloride (NaCl) to a base complete nutrient solution. The SA was applied with spraying two times as before and after transplanting. Salt stress negatively affected the growth, chlorophyll content and mineral uptake of cucumber plants. However, foliar applications of SA resulted in greater shoot fresh weight, shoot dry weight, root fresh weight, and root dry weight as well as higher plants under salt stress. Shoot diameter and leaf number per plant increased with SA treatments under salt stress. The greatest chlorophyll content was obtained with 1.00 mM SA treatment in both saline and non-saline conditions. Leaf water relative content (LWRC) reduced in response to salt stress while SA raised LWRC of salt stressed cucumber plants. Salinity treatments induced significant increases in electrolyte leakage. Plants treated with foliar SA had lower values of electrolyte leakage than non-treated ones. In regard to nutrient content, it can be interfered that foliar SA applications increased almost all nutrient content in leaves and roots of cucumber plants under salt stress. Generally, the greatest values were obtained from 1.00 mM SA application. Based on these findings, the SA treatments may help alleviate the negative effect of salinity on the growth of cucumber.

Salicylic acid ameliorates the adverse effect of salt stress on strawberry

Strawberry is considered as a salinity sensitive species and is adversely affected in response to the salt stress in terms of growth and yield. Pot experiments were conducted to determine the effect of exogenous salicylic acid (SA) application on physiology, growth, chlorophyll and mineral content of strawberry grown under salt stress and greenhouse conditions. Strawberry plants were treated with SA at different concentrations (0.0, 0.25, 0.50 and 1.00 mM). Salinity treatments were established by adding 0 and 35 mM of NaCl to a base complete nutrient solution. Salt stress negatively affected the growth, chlorophyll content and mineral uptake of strawberry plants. However, plants treated with SA often had greater shoot fresh weight, shoot dry weight, root fresh weight and root dry weight as well as higher chlorophyll content under salt stress. The greatest values were obtained with 1.00 mM SA treatment in both saline and non-saline conditions. Leaf water relative content (LWRC) was reduced in response to salt stress while electrolyte leakage was raised. SA treatments induced increases in LWRC and decreases in electrolyte leakage compared to the control under salt stress. With respect to the nutrient content, SA treatments increased almost contents of all nutrients in leaves and roots of strawberry plants under salt stress. The greatest values were often obtained by the 1.00 mM SA treatment. These findings suggest that the SA treatments can ameliorate the negative effect of salinity on the growth of strawberries.

Foliar and soil fertilization of humic acid affect productivity and quality of tomato

Abstract The objective of the study was to determine the effect of foliar and soil fertilization with humic acid (HA) on quality, growth and yield of tomato under greenhouse conditions in 2004 and 2005. Tomato plants were treated with soil and foliar HA applications at different concentrations (0 ml/l, 10 ml/l and 20 ml/l). Three weeks after planting HA was sprayed four times during the vegetation period at 10-day intervals. Furthermore, 0, 10 and 20 ml/l HA solutions were applied as a drench to the plant root area four times during the vegetation period at 10-day intervals three weeks after planting. HA treatments had no effect on pH and titratable acidity (TA) of tomato. Total soluble solids (TSS) increased with both foliar and soil HA treatments. Foliar 20 ml/l HA application resulted in the highest ascorbic acid (AA) content. Foliar applications of HA led to higher leaf and stem dry matter contents than the control. Both foliar and soil HA treatments positively affected fruit characteristics including fruit diameter, fruit height, mean fruit weight and fruit number per plant. Similarly, HA treatments increased the early yield of tomato compared to control. The yield of tomato was significantly influenced by soil and foliar HA applications. The highest yield occurred in foliar 20 ml/l HA treatment. The study shows that 20 ml/l concentration of HA sprays could be successfully used to obtain better growth and yield in tomato.

Plant growth-promoting rhizobacteria improved growth, nutrient, and hormone content of cabbage (Brassica oleracea) seedlings

Metin TURAN, Melek EKİNCİ, Ertan YILDIRIM*, Adem GÜNEŞ, Kenan KARAGÖZ, Recep KOTAN, Atilla DURSUN Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Yeditepe University, Kayışdağı, İstanbul, Turkey Department of Horticulture, Faculty of Agriculture, Atatürk University, Erzurum, Turkey Department of Soil Science, Faculty of Agriculture, Erciyes University, Kayseri, Turkey Department of Plant Protection, Faculty of Agriculture, Atatürk University, Erzurum, Turkey

EFFECTS OF PLANT GROWTH PROMOTING BACTERIA ON YIELD, GROWTH, LEAF WATER CONTENT, MEMBRANE PERMEABILITY, AND IONIC COMPOSITION OF STRAWBERRY UNDER SALINE CONDITIONS

Plant growth promoting effects of Bacillus subtilis EY2, Bacillus atrophaeus EY6, Bacillus spharicus GC subgroup B EY30, Staphylococcus kloosii EY37 and Kocuria erythromyxa EY43 were tested on strawberry cv. ‘Fern’ in terms of fruit yield, growth, chlorophyll reading value, leaf relative water content (LRWC), membrane permeability and ionic composition of leaves and roots under saline conditions. Compared with 0 mM sodium chloride (NaCl) treatment, the average decrease of yield and LRWC were 51.6% and 21.0%, respectively, when 35 mM NaCl was applied. However, EY30, EY37, and EY43 treatments under saline condition (35 mM NaCl) significantly increased fruit yield (54.4%, 51.7% and 94.9%) compared with 35 mM NaCl treatment without plant growth promoting bacteria (PGPB). The LRWC increased from 72.0% in 35 mM NaCl treatment to 88.4%, 86.6%, 84.2%, 83.5%, and 86.2% by EY2, EY6, EY30, EY37, and EY43 applications, respectively. The lowest membrane permeability among the bacterial strains was obtained from EY37 treatment (37) while it was 33 and 58 in 0 mM NaCl and 35 mM NaCl treatments, respectively. The concentration of all plant tissue nutrients investigated [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)] with the exception of root phosphorus (P) and Mg concentration significantly decreased with 35 mM salt treatment. Nitrogen content of leaves varied between 3.04 and 3.14% in bacterial treatments under saline conditions while it was 2.71% in 35 mM NaCl treatment. In contrast sodium (Na) and chloride (Cl) of leaves and Cl content of roots were significantly decreased by root inoculation with all bacterial treatments in comparison to 35 mM NaCl treatment with no inoculation. Treatment with Bacillus EY30, Staphylococcus EY37 and Kocuria EY43 to strawberry plants can ameliorative the deleterious effect of salt stress on fruit yield, growth and nutrition. These results demonstrate that PGPB treatment could be offer an economic and simple means to increased plant resistance for salinity stress.

Effects of Boron Fertilizer on Tomato, Pepper, and Cucumber Yields and Chemical Composition

In many parts of the world, boron (B) levels are insufficient for potential production. Boron deficiency is also widespread in the Anatolia region of Turkey. Boron deficiency could impact production and quality of tomatoes (Lycopersicon esculentum L.), pepper (Capsicum annum L.), and cucumber (Cucumis sativus L.). A two-year greenhouse experiment was conducted to study yield and quality response of three vegetables to B addition (0, 1, 2, 3, and 4 kg B ha−1). The optimum economic B rates (OEBR) were 2.3, 2.6, 2.4 kg B ha−1, resulting in soil B concentrations of 0.33, 0.34 and 0.42 mg kg−1. Independent of plant species, B application decreased tissue nitrogen (N), calcium (Ca), and magnesium (Mg) but increased tissue phosphorus (P), potassium (K), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) concentrations. We conclude that a B addition of 2.5 kg ha−1 is sufficient to elevate soil B levels to nondeficient levels. Similar studies with different soils and initial soil-test B levels are needed to conclude if these critical soil test values and OEBR can be applied across the region.

Increasing Productivity with Intercropping Systems in Cabbage Production

ABSTRACT This study was carried out to determine the effect of different intercropping systems on growth, mineral contents and yield of cabbage (Brassica oleracea L. var. capitata) under field conditions in 2000, 2001 and 2002. LER (Land Equivalent Ratio) and economic net income of different cropping systems based on cabbage as an index of intercropping efficiency were also evaluated. In the study, cabbage was used as a main crop, and cos lettuce (Lactuca sativa L. var. longifoila), leaf lettuce (Lactuca sativa L. var. crispa), radish (Raphanus sativus L.), onion (Allium cepa L.) and snap bean (Phaseolus vulgarism L. var. nanus) were used as intercrops. Each of the intercrops was planted in between cabbage rows in separate plots. Cabbage and all intercrops were also grown as sole crops. There was no significant effect of different intercropping systems on growth characteristics and yield of cabbage compared with sole cabbage cropping except for radish as an intercrop, which affected adversely the yield and some growth characteristics of cabbage. Net income was increased significantly when cabbage was intercropped with cos lettuce, bean, leaf lettuce or onion. The values of LER appeared to be greater than 1 under intercropping systems. Cropping systems did not significantly affect nitrogen, phosphorus, potassium, calcium, magnesium and iron content of cabbage. The results obtained in this study pointed out that intercropping systems based on cabbage might increase total yield, productivity and profitability.

The Effects of Nitrogen Fertilization on Intercropped Strawberry and Broad Bean

ABSTRACT To determine different aspects of intercropping strawberry (Fragaria xananassa L. Duch.) with broad bean (Vicia faba L. cv. Lara) and their similarities to different nitrogen concentrations, this field study was conducted for three years. The overall efficiency of intercropping was measured by using Land Equivalent Ratios (LERs). In intercropping plots, broad bean seeds were sown in the middle of strawberry rows. Meanwhile strawberries and broad beans were also grown as sole crops based on identical experimental design. Nitrogen was applied at three different rates (0, 80, and 160 kg/ha) in both sole and intercrop plots of strawberry. Sole cropping broad beans grown with no fertilizer-N application were considered the control. As a result of these studies, it was reported that the chemical characteristics such as ascorbic acid, total soluble solid, and titratable acidity of strawberry fruits were not significantly affected by either intercropping or nitrogen fertilization. While cropping system did not have any negative effects on fruit weight, fruit weight per plant, and yield of strawberry, nitrogen application rate did significantly affect these parameters. The 80 kg/ha nitrogen application gave maximum amount of marketable fruits for strawberry in both sole cropping and intercropping. Cropping system interaction with nitrogen application showed significant differences in fruit weight per plant and total fruit weight of strawberry. Intercropping caused some phenotypic alteration such as increasing height and growth habits of broad bean. However, there were no significant reductions in pod numbers, pod weight per plants and total yield of intercropped broad bean at 80 kg/ha nitrogen application as compared with sole cropping. Strawberry intercropped with broad bean at 80 kg/ha nitrogen gave the best LER values, indicating that intercropping might be more productive than sole cropping especially in case of 80 kg/ha nitrogen application.

Roles of glycine betaine in mitigating deleterious effect of salt stress on lettuce (Lactuca sativa L.)

This study was conducted to evaluate the roles of glycine betaine (GB) in mitigating deleterious effect of salt stress on lettuce. Lettuce plants were subjected to two salinity (0 and 100 mmol l−1 NaCl) and four GB levels (0, 5, 10, 25 mmol l−1). Salinity resulted in a remarkable decrease in growth parameters, relative leaf water content and stomatal conductance. Plants subjected to salt stress exhibited an increase in membrane permeability (MP), lipid peroxidation (MDA), leaf chlorophyll reading value, H2O2 and sugar content. Exogenous foliar applications of GB reduced MP, MDA and H2O2 content in salt-stressed lettuce plants. Salt stress increased Na and generally decreased other nutrient elements. GB reduced Na accumulation, but significantly increased other element contents under salinity conditions. The study showed that gibberellic acid (GA) and salicylic acid (SA) content in salt-stressed plants were lower than those of nonstressed plants. However, salinity conditions generally increased the abscisic acid content. GB treatments elevated the concentrations of GA, SA and indole acetic acid (IAA) at especially 10 and 25 mmol l−1 GB under salt stress conditions. It could be concluded that exogenous GB applications could ameliorate the harmful effects of salt stress in lettuce.

Exogenously applied glycine betaine regulates some chemical characteristics and antioxidative defence systems in lettuce under salt stress

We investigated the effects of exogenous glycine betaine (GB) applications on antioxidant enzyme activity, dry matter, and the contents of organic acids, amino acids, total antioxidants, and total phenolics in lettuce, Lactuca sativa, under salt stress. The treatments included four concentrations of GB (0, 5, 10, and 25 mM) and two levels of salinity (0 and 100 mM of NaCl). The 25 mM GB treatment increased dry matter and the content of total phenolics in lettuce plants compared to the non-GB-treated plants under salt stress. Salinity (100 mM NaCl without GB) significantly reduced dry matter, total phenolic content, and total antioxidant content in the plants. However, the lettuce plants grown under salt stress generally had higher amino acid and organic acid contents than those grown under non-salinity conditions. GB treatments had different effect on amino acid and organic acid contents under salinity conditions. Superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) activities were elevated under the 100 mM NaCl and 0 mM GB treatments, whereas higher concentrations of GB decreased them under salt stress. The 25 mM GB treatment mitigated the negative effect of salt stress and increased the dry matter by 44% compared to the plants that were treated with 100 mM NaCl and 0 mM GB. The results suggested that exogenous GB treatments could ameliorate the tolerance of lettuce to salt stress by increasing the total antioxidants and total phenolics, and regulating antioxidant enzyme activity, and altering the contents of organic acids and amino acids.