Ahmet Esitken

The effect of spraying a growth promoting bacterium on the yield, growth and nutrient element composition of leaves of apricot (Prunus armeniaca L. cv. Hacihaliloglu)

Experiments were conducted during 2000 and 2001 to determine the effects of floral and foliar application of the bacterial strain Bacillus OSU 142 on the yield, growth and nutrient element composition of leaves of the apricot cultivar Hacihaliloglu grown in the Malatya province of Turkey. In 2000, trees were sprayed with a bacterial suspension at full bloom, and 30 and 60 days after full bloom. This experiment demonstrated significant differences in yield, shoot length and nutrient element composition of leaves only on trees treated at the full bloom stage. In view of this, the bacterial application was performed only at full bloom in 2001. The average increase in yield in 2000 and 2001 was 30% and 90%, respectively, compared with the untreated control. Shoot length development was significantly higher when trees were treated with OSU 142 at full bloom stage in both years. Similarly, N, P, K, Ca and Mg contents of leaves were higher on OSU 142-treated trees than on the untreated control. The results of this study suggest that OSU 142 has the potential to increase the yield of apricot trees.

Alternating magnetic field effects on yield and plant nutrient element composition of strawberry (Fragaria x ananassa cv. camarosa)

A magnetic field is an inescapable environmental factor for plants in the soil. However, its impact on plant growth is not well understood. In order to learn how magnetic fields affect plants, the effects of alternating the magnetic field (MF) on the yield and ion accumulation in the leaves of strawberry (Fragaria x ananassa) was studied. Short day strawberry cv. Camarosa plants were treated with magnetic field (MF) strengths of 0.096, 0.192 and 0.384 Tesla (T) in heated greenhouse conditions. Fruit yield and fruit number per plant, and average fruit weight were higher at low MF strength than control and high MF strength. Increasing MF strength from control to 0.096 T increased fruit yield per plant (208.50 and 246.07 g, respectively) and fruit number per plant (25.9 and 27.6, respectively), but higher MF strengths than 0.096 T reduced fruit yield and fruit number. All of the MF strengths increased average fruit weight as compared with the control, although the largest fruit weight (8.92 g) was obtained at 0.096 T strength. Increasing MF strength from control to 0.384 T increased contents of N, K, Ca, Mg, Cu, Fe, Mn, Na and Zn, but reduced P and S content.

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.

Salinity effects on growth, proline and ion accumulation in strawberry plants

High salinity in soil is one of the major factors limiting plant growth and productivity. Strawberries are very sensitive to salinity (Larson, 1994), and salinity reduces leaf number, leaf area, shoot dry weight and number of crowns, leading to low yields (Ehlig & Bernstein, 1958; Awang et al., 1993; Awang & Atherton, 1994). Moreover, salinity causes physiological and biochemical changes in plants. In the plants, these changes appear, depending on the effects of ions and solutes in the root zone on water activity in the cell and physiological and biochemical functions of the cell (Greenway & Munns, 1980), reducing turgor, limiting photosynthesis (Schwarz & Gale, 1981; Walker et al., 1981) and increasing ion deficiency due to inadequate transport mechanisms (Hasegawa et al., 1986). Plants have specific mechanisms which aid tolerance of these harmful effects of salinity, and osmotic adjustment is the most important of these mechanisms. Under salt stress conditions, osmotic adjustment is obtained by the production and accumulation of compatible organic solutes such as proline, glycerol, sugars and glycine betaine in the cytoplasm, while mineral ions are localized in the vacuole (Hellebust, 1976; Weimberg, 1986). With osmotic adjustment mechanism, plants may lower water potential of the cells than saline media in the root zone, and thus the osmotic inhibition effect of salinity could be negated. In addition, proline can inhibit toxic effects of NaCl by stabilizing proteins and enzymes in the cell (Ahmad et al., 1982). However, Zhang & Archbold (1993) found that amounts of proline were not significantly changed under water deficit conditions in Fragaria . Although numerous studies have been conducted on the impact of salt stress on proline accumulation in different plants (Zhu et al., 1998; Aziz et al., 1999; Alian et al., 2000), no attempts have to date been made to study proline accumulation in strawberry plants under salinity conditions. The objective of this study was to determine the effects of salinity on the growth, proline and ion accumulation in leaves of two strawberry cultivars (Fern and Camarosa).

Adventitious root formation of kiwifruit in relation to sampling date, IBA and Agrobacterium rubi inoculation

During the winters of 2001 and 2002, the effects of three strain of Agrobacterium rubi (A1, A16 and A18), a range of IBA concentrations (0, 2000, 4000 and 6000 ppm) alone and in combination with three strains of Agrobacterium rubi and date of cutting collection on the rooting of hardwood stem cuttings of kiwifruit cv. Hayward were evaluated. Treatments of hardwood stem cuttings of kiwifruit cv. Hayward with the bacteria, IBA and IBA plus bacteria were found to promote rooting. Highest rooting percentage was obtained from cuttings treated with 4000 ppm IBA plus A18 in cv. Hayward in both years. Higher rooting percentages were observed when shoots were collected in February rather than in January.

Promising native summer apple (Malus domestica) cultivars from north-eastern Anatolia, Turkey

Abstract This study was conducted on summer apple (Malus domestica) trees growing wild in the Çoruh Valley, north‐eastern Anatolia, Turkey. The research material consisted of uncultivated summer apple trees. Out of 250,10 trees not infected by apple scab (Venturia ineaqualis) were selected. Fruit characteristics of these superior types were evaluated. The ranges of fruit characteristics determined for the selected types were: 49.5–152.2 g fruit weight, 42.8–65.3 mm fruit length, 52.3–75.7 mm fruit width, 10.3–13.8% total soluble solids, 4.88–7.44 mg vitamin C/100 g, 0.19–1.43% total acidity (as malic acid), 9.33–12.06% total sugar, and 6.31–8.94% reducing sugar. Some selections ripening in mid July should be compared with common summer apple cultivars for their agronomic characteristics or used as breeding partners for further breeding efforts.

Effects of magnetic fields on yield and growth in strawberry ‘Camarosa’

Summary This study was carried out in a heated greenhouse on the short-day strawberry ‘Camarosa’ as experimental material. Strawberry plants were treated with magnetic flux density fields (MF) of control (natural), 0.096, 0.192 and 0.384 Tesla (T). Fruit yield per plant and average fruit weight were greater at low MF strengths than the control and the high MF strength. Increasing MF strength from control to 0.096 T increased fruit yield per plant (208 and 246.g, respectively), but MF strengths higher than 0.096 T reduced fruit yield. All the MF strengths increased average fruit weight compared with the control, although the largest fruit (8.92.g) were determined at 0.096 T. On the other hand, MF had positive effect in terms of number of leaves, fresh and dry root weight but crown per plant and leaf area was not significantly affected by MF. In addition, high MF strength had a negative effect on plant growth.

Hydro- and osmopriming improve chickpea germination

Abstract The effects of different priming treatments and durations on germination percentage, speed, synchrony and thermal time requirement of the seeds of chickpea were investigated. Seeds were osmoprimed in four water potentials (−0.5, −1.0, −1.5 and −2.0 MPa) of polyethylene glycol (PEG) or in 4% mannitol in addition to hydropriming for 12 or 24 h at 25±1°C in darkness. Following priming, the seeds were subjected to germination tests at ten different constant temperatures ranging from 5 to 32±0.5°C. In general, there was no significant effect of priming treatments on germination percentage. However, compared to unprimed seeds, hydropriming and osmopriming treatments induced faster and more synchronous germination at all of the temperatures tested and also significantly decreased thermal time requirements. These reductions in thermal time requirements ranged between 18.1°C d and 30.3°C d for 50% germination. Seeds treated with water for 12 h generally produced the highest germination speed and the lowest thermal time requirement values. Among the osmopriming treatments, seeds treated with −0.5 MPa solution of PEG for 24 h gave the best results. Consequently, hydropriming for 12 h or osmopriming (PEG −0.5 MPa) for 24 h may be recommended for a better germination of chickpeas under cold soil conditions.

Use of Plant Growth Promoting Rhizobacteria in Horticultural Crops

Horticulture is one of the areas where agricultural technologies are widely and intensively used. Horticultural crops may grow both in the open and closed space such as greenhouse and tunnel, and there are several practical applications such as propagation with cuttings and grafting, pruning, and soilless culture; plant growth regulators that have little or no use with other agricultural crops were used largely in horticultural crop production. In addition, to make sure of sufficient plant growth and development and high fruit yield and quality, these treatments should be inhered in horticultural production. Therefore, horticultural crops require more input than the other agricultural crops and sustainability maintenance is also quite significant. For these reasons, there is a need for different techniques that increase the input efficiency, and plant growth promoting rhizobacteria (PGPR) have proved to be a major tool. PGPR can affect on plant growth by production and release of secondary metabolites, lessening or preventing deleterious effects of phytopathogenic organisms in the rhizosphere and/or phyllosphere, and/or facilitating the availability and uptake of certain nutrients like N, P, and Fe from the root environment. In accordance with these action mechanisms, PGPR can be used for various purposes such as rooting of cutting, grafting union, fruit setting and thinning, lateral root formation, increasing tolerance against abiotic stress as well as growth, development, and biological control with root inoculation and/or spraying. These screening approaches and practical applications of PGPR in horticultural crops are the major focus of this review.

Boron application improves on yield and chemical composition of strawberry

Abstract Boron (B) is an essential micronutrient required for normal plant growth and development. Boron management is challenging because the optimum B application range is narrow and the application rates vary from one soil to another. Boron deficiency is widespread in the Anatolia region of Turkey. This may impact on yield and mineral contents of leaves and fruits of strawberry (Fragaria×ananassa cv. Fern) especially in B-deficient calcareous Aridisols in Eastern Anatolia, Turkey. A 2-year field experiment was conducted to study yield and quality response of strawberry to B application. Boron fertilizer application affected plant yield and chemical composition. B application decreased tissue nitrogen (N) and calcium (Ca) but increased tissue phosphorus (P), potassium (K), manganese (Mn), zinc (Zn) and copper (Cu) content. We conclude that a B addition of 5.5 kg ha−1 is sufficient to elevate soil B levels to non-deficient levels.