Journal articles on the topic 'Trees Calcium chloride'

Investigations were performed in the period 1977-1979 on the apple tree cultivar 'Fantazja', on rootstock A 2, M 7 and MM 106 on the effect of spraying with solution containing calcium on the incidence of bitter pit, breakdown, calcium content in the fruit flesh and other features of the fruits. Threefold spraying with calcium nitrate, calcium chloride or Anti-Stipp significantly limited the appearance of bitter pit and breakdown.

ABSTRACTCalcium increases postharvest conservation of apples. Consequently, several calcium foliar sprays are generally applied to apple trees. Due to the low mobility of calcium in the phloem, foliar sprays may have low efficiency to supply calcium in the fruits. This study aimed to evaluate the efficiency of different sources of calcium applied to the soil, compared to the foliar application, on the content of calcium in the soil, leaves and fruits, on yield and fruit quality of ‘Fuji’ apple trees. The following treatments were tested: control, soil application of calcium chloride, gypsum, Nitrabor®, hydrated lime and pulp sludge, and foliar application of calcium chloride. For all sources in the soil, 80 kg of calcium ha-1 year-1 were applied. For the foliar treatment, ten sprays with 0.4 % of calcium chloride were performed. The experiment was conducted in two seasons (2008/2009 and 2009/2010), in a complete randomized blocks design, with four replicates and two apple trees per plot. Even in a soil with high calcium content, the sources of calcium increase the calcium content in the soil and leaves, as well as the firmness of apples stored for 90 days. The use of gypsum and pulp sludge increase the calcium content in the flesh of ‘Fuji’ apples after two successive applications (2009/2010). The sources of calcium applied to the soil can replace the leaf application commonly used in apple orchards, in order to reduce production costs, provided there is no water restriction in the orchard.

The aim of the study was to examine the effect of calcium chloride (CaCl<sub>2<sub>) spraying at different rates of water on apple (<em>Malus domestica</em> Borkh.) calcium concentration. The examination was carried out in 1997-1998 on 'Jonagold' apple trees grafted on M.26 rootstock and planted in 1990 on sandy-loam soil at a distance of 4 x 2.5 m.The trees were trained as a spindle at 2,4 m and 2 m of height and canopy width, respectively. In the experiment apple trees were sprayed with CaCl<sub>2<sub> at a rate of 7 kg ha<sup>-1<sup> using 250, 500, 1000 and 1500 L of water volumes which gives : 2.8, 1,4, 0,7 and 0.5% CaCl<sub>2<sub> solutions, respectively. Sprays with CaCl<sub>2<sub> solutions were applied 6, 4 and 2 weeks before commercial fruit harvest. The trees unsprayed with Ca served as a control. The study showed that sprays with CaCl<sub>2<sub> at all studied water volumes had not effect on leaf and fruit damages. Regardless of the applied water rates, apples from the middle and the bottom of the canopy had higher calcium concentrations as a result of CaCl<sub>2<sub> sprays whereas this treatment had not effect on fruit calcium concentration from the top of the canopy. However, the laboratory study showed that 'Jonagold' apples from the canopy top had ability to take up exogenous calcium. It was found that efficacy of CaCl<sub>2<sub> sprays at studied water rates in increasing fruit calcium concentration was similar. The study showed as well that young 'Jonagold' fruitlets took up clearly less exogenous calcium compared to mature fruit which suggests that sprays of this cultivar with calcium salts should be applied mainly at late apple development stages.

Foliar application of hormones and nutrients can improve fruit quality, but specific conditions for applying hormones and nutrients may vary among fruit species. The objective of this study was to determine the effects of 6-BA, potassium phosphate (monobasic), and calcium chloride on fruit weight, palatability, and storage quality of 8-year-old pear trees, cv. Hosui. Foliar applications of 1 mg·L-1 6-BA, 0.3% potassium phosphate, 0.3% calcium chloride, or 0.3% potassium phosphate + 0.3% calcium chloride were made at 20-day intervals from June until maturity. All foliar applications increased average fruit weight over the control (distilled water). 6-BA or the combination of potassium phosphate and calcium chloride increased fruit weight more than did potassium phosphate or calcium chloride alone. Fruit palatability, measured as the ratio of sugar content to acid content, was significantly lower in 6-BA, potassium phosphate, and calcium chloride treatments than in the control. All treatments increased vitamin C content over the control. Fruit storage quality in calcium chloride or calcium chloride + potassium phosphate treatments was superior to that in the control. Potassium phosphate alone and 6-BA treatments had no effects on fruit storage quality. We conclude that foliar applications of 0.3% potassium phosphate + 0.3% calcium chloride or 1 mg·L-1 6-BA can increase average fruit weight and improve fruit palatability.

ABSTRACT Studies related with the storage of peach fruits have received great relevance in Egypt. In this study, the effect of pre-harvest sprays of calcium chloride and chitosan, separately and in combination, on quality attributes and storability of peach fruits stored at 0±1 °C was studied. ‘Early Swelling’ peach trees were sprayed twice with 1% or 2% calcium chloride. The first spraying was at pea stage, while the second one was performed at 10 days before harvesting. Chitosan sprays were performed at 0.5 or 1%, alone or in combination with 1 and 2% calcium chloride, at 10 days before harvesting. Untreated trees served as control. Fruits were harvested at maturity stage, then packaged and stored at 0±1 °C and 85-90% of relative humidity. Fruit physical and chemical properties were evaluated at 7-day intervals. Results showed that pre-harvest application with 2% CaCl2+1% chitosan was most effective in minimizing weight loss (%) and decay (%), as well as in maintaining maximum firmness and lengthening shelf life. Fruit color was not affected by any of the treatments, while untreated fruits and calcium chloride treatment alone, at both applied concentrations, maintained higher total soluble solids (TSS, %), total phenolic content, and lower titratable acidity percentage.

Control of bitter pit in `Honeycrisp' apples (Malus ×domestica) from trees treated during the growing season with foliar sprays of trifloxystrobin fungicide and calcium was evaluated in four replicated trials over 2 years. All trials were in commercial orchards of `Honeycrisp' trees that were 3 to 6 years old. The effectiveness of combining boron with foliar applications of calcium chloride (CaCl2) was evaluated in two trials, and effectiveness of harpin protein, used either alone or in alternating sprays with CaCl2 was assessed in one trial. Trifloxystrobin applied twice during the 30 days before harvest reduced bitter pit incidence at harvest in one of the four trials, but the reduction was transitory, no longer being evident when fruit were re-evaluated after 63 days of cold storage. Harpin protein did not affect disorder incidence. Calcium sprays failed to control bitter pit in treatments where the total elemental calcium applied was less than 2.7 lb/acre (3.03 kg·ha–1) per year for tree canopies that were sprayed to drip using 100 gal/acre (935.4 L·ha–1) of spray solution. In the two trials where some treatments involved application of at least 2.9 lb/acre (3.25 kg·ha–1) of elemental calcium per season, the incidence of fruit with bitter pit at harvest was reduced by 76% to 90%. Effectiveness of calcium sprays for bitter pit control was not enhanced by superimposing trifloxystrobin, boron, or harpin protein treatments. Flesh firmness at harvest was lower in calcium-treated than in non-treated fruit, and fruit maturity was more advanced on trees receiving boron sprays than on trees receiving no boron. In one trial, where the first calcium application was made approximately 2 weeks after petal fall and 4 days prior to a fruit thinning spray, crop load of trees that received calcium sprays, measured as number of fruit per cm2 trunk cross-sectional area, was 38% greater than on trees that received no calcium sprays. CaCl2 provided better control of bitter pit in `Honeycrisp' than any of the other materials tested.

Peach fruit and trees are prone to various issues, regarding yield, quality and pest attack. Calcium plays several roles in plant and fruit development. Therefore the current study was conducted to evaluate the response of peach fruit to foliar application. The experiment was laid out in Randomized Complete Block Design with two factors factorial arrangement and three replicates. Calcium chloride was applied at the rate of 0, 1, 2 and 3%. The foliar application of calcium was done at pink bud stage, berry size fruit stage, and then at pit hardening stage of peach. The obtained resulted indicated that foliar application of calcium significantly improved peach fruit quality and yield. The highest fruit weight (142.6 g), yield tree–1 (15.6 kg), ascorbic acid content (6.67 mg‧100 g–1), total soluble solids (11.0°Bx), fruit juice pH (3.98), sugar to acid ratio (45.1), fruit firmness (3.90 kg‧cm–2) and fruit volume (155.6 cm3) was obtained with the application of 3% solution of calcium chloride at pit hardening stage but it significantly reduced the percent titratable acidity (0.3%) and disease incidence (5.8%). It was concluded that 3% calcium chloride applied at the pit hardening stage significantly boosted peach quality and fruit yield.

Flesh softening, skin browning and rotting are chief problems during cold storage (CS) of 'Fuyu' Persimmon. We studied the effects of boron (B) and calcium (Ca) sprayed on the trees during three consecutive years, on the development of skin cracks, grooves and browning in persimmon fruit under CS in Farroupilha, RS, Brazil (29°31' south, 51°21' west, about 750 m altitude). A homogeneous orchard area of 0.5 ha was delimitated and three sets of five plants for each treatment were randomly selected. The persimmon trees were sprayed at a 20 day interval, from 15th January until harvest, for three consecutive years, with: T1) water; T2) calcium nitrate at 0.5% (m/v); T3) calcium chloride at 0.5% (m/v); and T4) boron at 0.3% (m/v). The fruit were harvest with orange-reddish colour; 18-20°Brix, pulp firmness of 45 to 60N, and kept under CS at 0±1°C for 45 days. The fruits were evaluated immediately before CS, after six hours at 23±2°C after removal from CS, and after four days at 23±2°C after removal from CS. Equally boron and calcium sprayed on the trees prevented skin cracks, skin grooves and skin browning. Besides, when boron was sprayed on the trees, the mentioned effects were additive in the following year.

The aim of this study was to examine effect of frequency of calcium chloride (CaCl₂) sprays on 'Jonagold' apple (<em>Malus domestica</em> Borkh.) quality. The experiment was carried out in 1996-1998 in the Experimental Orchard of the Research Institute of Pomology and Floriculture in Skierniewice. Apple trees were grafied on M.26 rootstock and planted in 1992 at a distance of 4 x 2 m on a sandy loam soil with high available phosphorus, potassium and magnesium contents. Four experimental treatments were applied: (i) three sprays with CaCl₂ solutions at 2, 10 and 18 weeks after full bloom, (ii) six sprays with CaCl₂ at 2, 6, 10, 14, 16 and 18 weeks after full bloom, (iii) nine sprays with CaCl₂ at 2, 4, 6, 8, 10, 12, 14, 16 and 18 weeks after full bloom and (iv) control plot - trees unsprayed with CaCl₂. The results showed that fruit Ca concentration increased with the number of CaCl₂ sprays during the growing season. Apples nine-times sprayed with CaCl₂ solutions were smaller, less mature at harvest and after storage, had lower titratable acidity and soluble solids contents after storage and were less sensitive to bitter pit, internal breakdown and Gloeosporium-rot compared to other treatments; however these effects were influenced by the growing season. Six CaCl₂ sprays only in one year of the study increased fruit firmness after storage, fruit resistance to bitter pit and internal breakdown. Three CaCl₂ sprays decreased bitter pit incidence; however this effect was found only in one investigated year.

Management of pear (Pyrus communis L.) trees for low N and high Ca content in the fruit reduced the severity of postharvest fungal decay. Application of N fertilizer 3 weeks before harvest supplied N for tree reserves and for flowers the following spring without increasing fruit N. Calcium chloride sprays during the growing season increased fruit Ca content. Nitrogen and Ca management appear to be additive factors in decay reduction. Fruit density and position in the tree canopy influenced their response to N fertilization. Nitrogen: Ca ratios were lower in fruit from the east quadrant and bottom third of trees and from the distal portion of branches. High fruit density was associated with low N: Ca ratios. Nutritional manipulations appear to be compatible with other methods of postharvest decay control.

The recommendations for boron (B) sprays in deciduous tree fruit orchards have changed little over the past 50 years. We conducted two 3-year field studies evaluating the effect of two modifications to the existing recommendation for B maintenance sprays on apple (Malus ×domestica) tree nutritional status. A widely recommended Na polyborate-based commercial B spray product was used as the B source. Postbloom sprays of B applied at the recommended annual B maintenance rate of 0.56 kg·ha-1 to `Scarlet Gala' apple trees consistently increased fruit B concentration but had a weaker effect on leaf B concentration in early August, the recommended timing for sampling leaves for mineral element analysis. Applying half or all of the annual B maintenance rate in a spray at the pink flowering stage increased flower cluster and early-season leaf B concentrations as well as having positive effects on fruit and leaf B concentrations. The pink sprays increased flower cluster Na concentration but had no effect on leaf and fruit Na concentrations. In the second study, one-quarter of the annual B fertilizer requirement was tank-mixed with each of four biweekly CaCl2 sprays applied starting in early June for bitter pit control. This treatment consistently increased `Scarlet Gala' fruit B concentration but had a lesser effect on August leaf B concentration. It did not interfere with fruit Ca status, and increased both fruit and leaf Na concentrations. Leaf Na concentration in all treatments was substantially lower than levels associated with specific Na toxicity of deciduous fruit trees. The results of these experiments indicate that applying B sprays at the pink flowering stage timing and tank-mixing B with CaCl2 sprays applied for bitter pit control are useful practices to enhance B spray efficacy and convenience of application.

Peaches are often grown on sandy, low pH soils which may predispose plants to aluminum (Al) toxicity. Previous research has shown that peach (Prunus persica, L. Batsch) is not tolerant to Al and toxicity may be associated with occurence of peach tree short life syndrome. Current recommendations to control PTSL include soil calcium (Ca) applications to reduce soil acidity and Al availability. However, these applications often result in inconsistent responses. Objectives of this study were to determine if Ca would ameliorate the effects of Al toxicity and whether different Ca compounds would provide different responses.Rootstock were grown in sand culture supplied with Hoagland's solution containing 16.7 mM aluminum Trees received weekly foliar sprays containing 12.5 uM calcium and 0.1% Chevron X-77 as a spreading agent. Calcium compounds tested included calcium chloride, formate, lactate, nitrate, phosphate, and sulfate. Stem dry weights were significantly increased by Ca lactate and sulfate, leaf dry weight by Ca lactate, and Ca formate significantly increased leaf retention. Nutrient concentrations and interactions in leaves, stems, and roots will be discussed.

The experiment was carried out to study the relationship between the soil calcium conditions and the content of this element in fruit and leaves of apple trees at ground fertilization with nitrogen and potassium. The experimental orchard is located in the forest-steppe zone of the Central Russian Upland (Oryol region). The soil of the orchard is Loamy haplic luvisol with a slightly acidic reaction and a high content of organic matter. Fruit plantations are represented by apple trees of ‘Sinap orlovsky’ variety on rootstock 54-118 planted in 2013. Ammonium nitrate and potassium chloride were used as soil fertilizers and applied early in spring at doses of N30K40, N60K80 and N90K120. Annually from 2016 to 2019, the content of exchangeable and water-soluble Ca compounds in the orchard soil and the total element content in leaves and fruits were determined. With the annual application of nitrogen and potash fertilizers the changes in the conditions of apple tree calcium nutrition occured already in the first years after treatments. The changes lay in increasing the calcium mobility and subsequent decrease in the element’s concentration in the root zone. At the same time, there was an annual decrease in the calcium status of fruits. The Ca content in fruits was positively correlated with the content in the soil of exchange (r = 0.43; P<0.05) and water-soluble (r = 0.51; P<0.01) forms of the element. There was no statistically significant relationship between the studied soil calcium forms and element content in apple leaves.

Five chemical elicitors––6-benzyladenine (BA), ethephon (ETH), methyl jasmonate (MeJA), hydrogen peroxide (H2O2) and calcium chloride (CaCl2)––were used to treat 1- and 5-year-old sandal trees (Santalum album L.) to assess their effects on growth, heartwood formation and concrete oil synthesis. The results showed that some newly formed branches in stems that were induced by BA and ETH displayed leaf senescence and developed new smaller and light-green leaves. The relative percentage of concrete oil from the heartwood of water-treated trees (0.65%) was significantly lower than that from trees treated with 4 mM H2O2 (2.85%) and 4 mM BA (2.75%) within one year. Four mM BA, H2O2 and CaCl2 induced a significantly higher level of sesquiterpenoids than heartwood treated with 2 mM of these elicitors. Four mM MeJA induced significantly less sesquiterpenoids than heartwood treated with 2 mM MeJA. Morphological, physiological, and chromatographic–spectrometric technologies were integrated to trace the potential function of these exogenously applied chemical elicitors. The results may have important applications and provide a better understanding of the molecular mechanism of heartwood formation and hardening in young sandalwood trees.

The aim of this study was to examine the effects of tryptophan (L-TRP) sprays on calcium (Ca) distribution within mature ‘Red Jonaprince’ apple (Malus domestica Borkh.) trees and on fruit quality. Trees were sprayed with L-TRP before flowering (at the green and pink bud stages and when 5% to 10% of flowers were open), after flowering (at petal fall and 14 and 28 days later), and both before and after flowering. In each spray treatment, 50 g of L-TRP per ha was applied. Other trees were sprayed with calcium chloride (CaCl2) six times during the growing season at rates ranging from 6 to 9 kg⋅ha−1. Plants that were not sprayed with L-TRP or CaCl2 served as controls. The results found that the studied spray treatments did not affect yield, mean fruit weight, apple skin russeting and blush, seed set, mean seed weight, or acidity of fruit at harvest. Prebloom L-TRP sprays enhanced the concentrations of both free indole-3-acetic acid (IAA) in fruitlets (by ≈230% compared with those of the control plants) and Ca in fruitlets and fruit (on average by 18% compared with the control combination) but did not affect the leaf Ca concentrations. Apples from trees sprayed with L-TRP before flowering had lower starch index (SI) values at harvest than those of the control plants. Postbloom L-TRP sprays increased leaf Ca concentration, but had no effect on apple Ca concentration or fruit quality at harvest. Combined pre- and postbloom L-TRP sprays did not improve the effectiveness of this amino acid. Overall, preharvest CaCl2 sprays increased leaf and fruit Ca concentrations and decreased fruit SI. Apples sprayed with CaCl2 had lower soluble solids concentrations (SSCs) and were firmer than fruit from control trees. Prebloom L-TRP sprays are effective in improving apple Ca concentration, at least for triploid varieties that have small seed numbers.

To find out the formation time of stone cell, drought stress, isolated from water by plastic house, was inflicted on pear trees at 30 days before full bloom, full bloom stage, 30 days after full bloom and 60 days after full bloom during 30 days, respectively. Adhesiveness, gumminess, cohesiveness and chewiness increased suddenly in fruits contained stone cell more then 28.0mg/g in flesh and hardness was higher in pear fruit with higher stone cells, but the changes of the springiness as contents of the stone cells showed no difference. By optical microscope, stone cell observed first from 14 days after full bloom. The adjacent cells to stone cell was first showed spherical type on initial forming stage but showed radial form at 90 days after full bloom. The shape of stone cell inspected by SEM was like a cluster and its size was various. By using TEM, components of stone cell, such as nucleus and vacuole, and secondary cell wall thickening were observed, so it could consider that the stone cell is living thing. The largest amount of stone cell clusters existed beneath fruit skin. The stone cell in flesh enlarged by drought stress compared to control, and then stone cell per areas was the largest at 30 days after full bloom. Therefore, it seems that the drought stress became a cause of inducing stone cell. The stone cell was decreased by the application of calcium chloride 0.5 %, on 30 days after full bloom. Also, fruit firmness was increased compared to control on harvest time. Calcium chloride application showed a possibility for the inhibition of stone cell formation

Bitter rot is an apple fruit disease most commonly caused in New Zealand by the fungus Colletotrichum acutatum The timing of fungicide applications to manage this disease was investigated during two seasons Fungicides applied during October (carbendazim) or November and December (tolyfluanid captan and mancozeb) reduced incidence of rots expressing on trees in the orchard Fungicides (halfstrength copper oxychloride Bacillus subtilis QST 713 and tolyfluanid) applied during January and February reduced the incidence of postharvest rots Bacillus subtilis QST 713 applied regularly throughout the season reduced incidence of field rots but was not effective when the number of applications was reduced Calcium chloride (CaCl2) or copper oxychloride applied during November and December reduced the incidence of sprinkler rots caused by Phytophthora cactorum

Calcium (Ca) is a major plant nutrient that affects cell wall and plasma membrane formation and plays a key role in plant growth, biomass production, and function. Ca can be used to decrease fruit decay and increase firmness and shelf life. Different sources and concentrations of foliar-applied Ca were examined for the effects on nutrient concentration and growth of ‘Eksotika II’ papaya (Carica papaya) plants. Papaya seedlings were established in pots and irrigated with a standard nutrient solution in a net house. Four preharvest sprays were applied as foliar applications with three different sources of Ca {calcium chloride [CaCl2], calcium nitrate [Ca(NO3)2], and calcium propionate [Ca(C2H5COO)2]} at four concentrations (0, 60, 120, and 180 mg·L−1). Plant Ca concentration was unaffected by the different Ca sources. However, increased Ca concentration applied to the leaves enhanced plant accumulation of phosphorous and Ca in the plant, but decreased potassium (K) and magnesium (Mg) concentrations in the tissues. Plants that received Ca at 180 mg·L−1 had greater height and diameter than control plants. In a field trial with mature trees, preharvest applications of Ca (0, 4000, and 5400 mg·L−1) in the form of CaCl2 showed that increasing concentrations improved fruit Ca concentration, texture, and flavor; and decreased weight loss, Mg content, and apparent disease incidence of the fruit.

‘Honeycrisp’ apple trees are highly prone to biennial bearing and predisposed to bitter pit. The hypothesis that tank mix sprays of ethephon (ETH), naphthaleneacetic acid (NAA), and 1-aminocyclopropane carboxylic acid (ACC) combined with calcium chloride (CaCl2) can mitigate these production problems was tested in a 3-yr study. Mature ‘Honeycrisp’ trees were treated with either three or six summer applications of 150 mg L−1 ETH or 5 mg L−1 NAA, all tank-mixed with and without CaCl2, or two or five applications of 150 mg L−1 ACC (without CaCl2). Treatments were applied at 10-d intervals and initiated between 21 and 26 June. All treatments had little effect on enhancing return bloom of ‘Honeycrisp’. NAA, ETH, and CaCl2 all influenced fruit maturity and quality at harvest to varying degrees and across years. Fruit treated with NAA were firmer compared with untreated fruit in 2 out of 3 yr, whereas overall, fruit treated with six sprays of ETH had lower fruit firmness and were more mature. NAA had less influence on fruit quality attributes at harvest than did ETH, and decreased pre-harvest fruit drop (PFD). PFD increased with ETH in 1 out of 2 yr, whereas ACC and NAA both decreased PFD in 1 out of 2 yr. Overall, ETH and NAA, with or without CaCl2, had significant but inconsistent effects on fruit quality and maturity, all dependent on the year and number of applications. Adding CaCl2 decreased fruit firmness in 2 out of 3 yr.

Abstract Trees play a crucial role in the urban environment. They fulfil aesthetic, sociocultural, ecological, health-promoting and economic functions. Urban development and related human activity bring many risks to green areas within urban space. Plants are exposed to stress connected with water, soil and air pollution. Living space, harmful light and thermal conditions, drought, high density and changeable soil pH with excessive salinity are further disadvantages. European and Northern American cities have to cope with a serious danger of tree death. A leading cause is the use of de-icing chemicals in winter, particularly sodium chloride, applied due to its cost-effectiveness and availability. The paper describes traditional de-icing chemicals used in urban areas (NaCl, solid aggregates, CaCl2, MgCl sulphates MgSO4, (NH4)2SO4, urea alcohols and glycols isopropyl alcohol, ethylene glycol, methanol) and newly developed sodium chloride substitutes (calcium magnesium acetate CMA), sodium formate and acetate NaFo/NaAc, potassium carbonate K2CO3). Moreover, prophylactic methods aimed at preventing the negative impact of de-icing campaigns, rules of planning and design of urban landscape, and reasonable management measures and pro-ecological modern technologies reducing and reversing the consequences of harmful actions are presented

Albedo breakdown is a rind disorder of orange fruit that results in significant economic cost to the Australian citrus industry. The effectiveness of calcium sprays as a control measure for albedo breakdown of navel orange fruit was investigated in a series of experiments in which single fruit, 1 m2 quadrats of tree canopy or whole trees were treated with different calcium sprays. Repeated spraying (24×) of single Bellamy navel orange fruit throughout the season with 1% calcium solutions increased the proportion of unaffected fruit from 30 to 65-80%. Repeated applications (15×) of 1% calcium as CaCl2 and Ca(NO3)2 to quadrats increased the proportion of unaffected fruit from 43 to 70-95%. The effect of anion was in the order Ca(NO3)2 CaCl2 >CaCO3. Repeated spraying (15×) of a commercial CaCl2 formulation (Stopit) at a calcium concentration of 0.33% increased the proportion of unaffected fruit in quadrats from 17 to 47%. Generally, early and mid-season calcium sprays were equally effective and tended to be marginally better than late-season sprays. Spray-applications of calcium at a concentration of 0.33% were more effective than calcium sprays at 0.11% applied early in the season. Calcium sprays were less effective than gibberellic-acid sprays based on the number of sprays but calcium treatments did not affect rind quality characteristics such as rind colour; in contrast, gibberellic acid induced regreening of fruit. Calcium sprays (as CaCl2) applied early in the season at 0.33% caused unacceptable fruit drop. CaCl2 (0.33%�calcium) treatment (5×) resulted in leaf chloride concentrations as high as 100 mmol/L in leaf-tissue water (0.7% on dry weight basis) - a level sufficiently high to substantially reduce photosynthesis. Ca(NO3)2 is the preferred calcium source in citrus because it is (i) as or more effective than CaCl2, (ii) does not result in leaf damage and fruit drop and (iii) may provide a small controlled nitrogen supplement to leaves and fruits.

Clonal micro-propagation is of particular importance in the transition to virus-free gardening. The problems of in vitro cultivation are closely related to mineral nutrition, presence of growth hormones and varietal features of plants. The purpose of the research was to study the patterns of responses of the studied genotypes of fruit and berry crops to the effect of various nutrient media. The objects of the study were varieties of garden strawberries, blackberries, pears and apple trees. Single shoots were planted on a modified medium of MS, Boxus, QL, B5, Pierik, Ly de Fossard, Fardzinova. The number of developed buds per explant, the height of micro-shoots, the general appearance and development of micro-plants were taken into account. It was found that exclusion of ammonium nitrate (NH4NO3) and replacement of calcium chloride (CaCl2) with calcium nitrate (Ca (NO3)2) in the Boxus nutrient medium in strawberry provided obtaining optimally developed plants. For blackberries, the best results of proliferation and growth of shoots were obtained on the growing medium of Ly de Fossard, in pear varieties - on the Ly de Fossard medium. For most of the studied apple tree varieties, the most favorable medium was QL, containing 2.0 mg/l of 6-BAP.

Asian citrus psyllid [ACP (Diaphorina citri)] is an important pest of citrus (Citrus sp.) in many citrus-growing regions of the world because of its status as the vector of huanglongbing disease [HLB (citrus greening)]. There are currently no HLB-resistant citrus genotypes and no proven treatments for the disease; thus, vector control through the use of frequent prophylactic pesticide applications is key to managing the spread of this disease. However, this practice is unsustainable and other means of altering ACP biology or reducing populations are needed. To this end, six plant growth regulators (PGRs) were tested to determine their effect on citrus tree vegetative growth and the subsequent impact on the biology of ACP. In greenhouse and growth chamber experiments, ACP reared on trees treated with prohexadione calcium and mefluidide exhibited significant reductions in both fecundity and survivorship, whereas uniconazole affected only fecundity and paclobutrazol affected only survivorship. No significant effects of PGRs on adult ACP weight were observed except on uniconazole-treated trees. No eggs were laid on dikegulac sodium-treated trees; however, this was likely the result of severe phytotoxicity rather than a true PGR effect. Oviposition rate was lower on all the PGR-treated trees, except chlormequat chloride under greenhouse conditions, compared with untreated control trees. In general, oviposition was delayed on PGR-treated trees compared with untreated controls. The observed changes in ACP biology and behavior after PGR treatment were not the result of a reduction in the number of suitable oviposition sites (i.e., growth reduction) or toxicity of the PGRs to ACP, suggesting there were PGR-induced plant biochemical changes that altered host plant quality. Leaf nutrient analyses and photosynthesis indicated that there were no correlative changes in plant nutrient status or carbon assimilation that led to the changes in ACP behavior, although it is possible that phloem-specific nutrient or carbohydrate changes could have occurred that were not detected in our whole-leaf analyses. These results support previous studies in which the fitness of various insect species has been affected by PGR applications, but more research is needed to understand the changes in plant chemistry that are responsible.

The effects of several vitamins and substances known as important agents in regulation of cell metabolism upon secondary xylem differentiation were studied in interaction with auxin (IAA) as applied in lanoline to decapitated stems of 5-year-old <i>Pinus silvestris</i> trees in early and late-summer. Tested substances were: gibberellic acid, kinetin, nicotinic acid, thiamine, pyridoxine, calcium panthotenate, choline chloride, riboflavin, inositol, ascorbic acid, vitamin, A (alcohol), vitamin A (ester), saponin. None of the effects of these substances appeared significant enough to indicate the involvement in the seasonal variation of the response of cambium or differentiating tracheids to auxin. However, several effects, especially those of inositol, vitamin A and pyridoxine upon cambial xylem production and further stages of tracheid differentiation were observed. Auxin (IAA) affected cambial activity and subsequent differentiation of tracheids during the earliest stages of cell ontogenesis. At these stages auxin treatment induced quantitative expression of the developmental processes involving radial growth and secondary wall formation by tracheids. In this respect, auxin did not affect cells advanced in differentiation, however, it proved to be an essential factor in the completion of the full cycle of tracheid ontogenesis.

Abstract. Boron concentrations in rainfall, throughfall and stemflow for Spruce stands, mist, streamwater and groundwater are compared with chloride to assess atmospheric sources and catchment input-output balances for the Plynlimon catchments. In rainfall, boron concentration averages about 4.5 μg-B l-1 and approximately two thirds of this comes from anthropogenic sources. In through-fall and stemflow, boron concentrations are approximately a factor of ten times higher than in rainfall. This increase is associated with enhanced scavenging of mist and dry deposition by the trees. As the sampling sites were close to a forest edge, this degree of scavenging is probably far higher than in the centre of the forest. The throughfall and stemflow concentrations of boron show some evidence of periodic variations with time with peak concentrations occurring during the summer months indicating some vegetational cycling. In mist, boron concentrations are almost twenty times higher than in rainfall and anthropogenic sources account for about 86% of this. Within the Plynlimon streams, boron concentrations are about 1.4 to 1.7 times higher than in rainfall. However, after allowance for mist and dry deposition contributions to atmospheric deposition, it seems that, on average, about 30% of the boron input is retained within the catchment. For the forested catchments, felling results in a disruption of the biological cycle and a small increase in boron leaching from the catchment results in the net retention by the catchment being slightly reduced. Despite the net uptake by the catchment, there is clear evidence of a boron component of weathering from the bedrock. This is shown by an increased boron concentration in a stream influenced by a nearby borehole which increased groundwater inputs. The weathering component for boron is also observed in Plynlimon groundwaters as boron concentrations and boron to chloride ratios are higher than for the streams. For these Goundwaters, increases in boron concentrations are matched linearly by increases in the concentration of the principal ase cation weathering component in the bedrock, calcium. However, the bedrock weathering term is not uniform as the ratio of boron to calcium concentration varies for the different boreholes sampled.

The suitability of soil-test analyses for fertilizer recommendations for hazelnuts was assessed by detailed examinations of correlations with corresponding leaf-tissue concentrations in an orchard survey study. Correlations were examined only where optimum leaf-tissue nutrient concentrations had previously been established (i.e. N, P, K, S, Mg and Ca). Soil nitrate concentrations tended to increase substantially and relatively consistently in orchards where leaf N concentrations were greater than the optimum range, showing that soil and leaf analyses can be used for fertilizer recommendations for conservation and environmental as well as production considerations. Since most of the trees of the orchards in the study had P that was at or above adequate amounts, only limited conclusions could be made for soil P tests. Data from this survey and other literature showed that hazelnut trees can obtain adequate P from soils that have relatively low Bray-1 extractable P. Ammonium acetate extraction provides a reasonably good estimate of the K and Mg that are available to hazelnuts, and, for both nutrients, K and Mg fertilizer should be recommended for hazelnut (compared with many other crops) when soil-test analyses are relatively high. Ammonium acetate extracted considerable Ca from the soil and the amount extracted was not correlated with the concentration of Ca measured in the leaves. Calcium chloride (which extracts only unadsorbed sulphate) was a relatively poor extractant for available S because of the occurrence of sulphate adsorption in these soils. A surface 15-cm soil sample was adequate for most of the nutrients measured, but supplementation with subsurface analyses would improve nitrate, and possibly subsurface S should be included in the development of a soil test for S Soil testing is necessary to determine whether nutrients are building up in the soil. Also, only soil testing can be used for analysis-based recommendations prior to tree planting. Key words: Hazelnuts, Corylus avellana, filbert, nitrogen, phosphorus, potassium

ABSTRACT The interception process is responsible for the spatial and temporal redistribution of the precipitation that reaches the ground. The contact of the precipitation with the canopy influences on the water quality, increasing the concentration of various nutrients in the throughfall (Tf) and stemflow (Sf). The objective of this study was to assess the influence of the interception process on the precipitation quality in a catchment covered by Mixed Ombrophilous Forest. The precipitation (P) monitoring consisted of two rain gauges installed outside the basin. Six gauges were installed within the basin for Tf monitoring. The Sf monitoring was conducted in nine trees. Water sampled at all points was analyzed for color, conductivity, pH, turbidity, and total dissolved solids. The concentrations of Nitrate (NO3-), Chloride (Cl-), Phosphate (PO43-), Sulfate (SO42-), Acetate (CH3CO2-) and Calcium (Ca2+) ions were measured in five points, i.e., one precipitation, two throughfall and two stemflow. Measured precipitation, throughfall and stemflow during the period were 652.1 mm, 584.5 mm (89,6% P) and 2.6 mm (0,4% P), respectively. Total interception loss was 65 mm, corresponding to 10% of the total precipitation. The highest values of the physicochemical parameters were found in the Sf and the Tf. The pH was lower in the Sf, and it decreases with the diameter at breast height. There was no significant relationship between the physicochemical parameters and the canopy cover fraction. The analysis shows the significant difference in the water quality of the precipitation that reaches the ground after being intercepted.

Abstract. The water quality of the Nant Tanllwyth stream in the Plynlimon region of mid-Wales is related to the key hydrobiogeological controls and the effects of conifer harvesting based on an analysis of rain, cloud, stream and groundwater measurements. The results show the normal patterns of stream water quality response to hydrology. Thus, there is a high damping of atmospheric inputs due to storage in a highly heterogeneous soil and groundwater system. Correspondingly, there is a highly dynamic response for components such as calcium, bicarbonate and aluminium. This response links to the relative inputs of acidic and aluminium-bearing soil waters under high flow conditions and base enriched bicarbonate bearing waters from the groundwater areas under baseflow conditions. The introduction of a deep borehole near the main stem of the river opened up a groundwater flow route to the stream and other parts of the catchment. There were two aspects to this. Firstly, it caused a change to the stream water quality, particularly under baseflow conditions, by increasing the concentrations of calcium and magnesium and by reducing the acidity. The monitoring shows that this change has persisted for over eight years and that there is no sign of reversion to pre-borehole times. Secondly, it caused a change in the groundwater level and chemistry at a borehole on the other side of the river. This feature shows that the fracture system is of hydrogeochemical and hydrogeological complexity. The effects of conifer harvesting are remarkable. At the local scale, felling leads to the expected short term increase in nitrate, ammonium and phosphate from the disturbance of the soil and the reduction in uptake into the vegetation. Correspondingly, there is a reduction in sodium and chloride linked to reduced scavenging of atmospheric inputs from cloud water by the vegetation and also due to increased dilution potential due to reductions in transpiration by the trees. However, within the main stream, virtually no change is observed in stream water quality with felling, except for a decrease rather than an expected increase in nitrate concentration. It seems that the increase in phosphate, for a system that is essentially phosphate limiting, has stimulated biological activity in the stream leading to increased uptake of nitrate and ammonium. However, there is little change in the sodium and chloride in the stream and there are important issues of the representative nature of studying small scale drainage areas. Boreholes, introduced to assess the impacts of the felling programme, show unexpected variations in groundwater chemistry. These variations are associated with the complexity of both flow routing and the chemical reactivity within the groundwater and lower soil zones, rather than changes that can be linked specifically to felling. The implications of the study are discussed in relation to both process understanding and forestry management practices. Keywords: water quality, acidification, conifer, harvesting, pH, nitrate, ammonium, phosphate, nutrients, alkalinity, Plynlimon, Wales, Tanllwyth, streams, groundwater

Fertility of pollen grains is their ability to induce full fertilization. This parameter is one of the most important in the selection of pairs when crossing all fruit crops, including sour cherry. The determination of this parameter in selected and elite forms of sour cherry is an urgent direction in breeding. The purpose of these studies was to determine the fertility of pollen in four selected and elite forms of sour cherry breeding in the Russian Research Institute of Fruit Crops Breeding (RRIFCB). The studies were conducted at the laboratory of cytoembryology over 2 years, from 2019 to 2020, and their results are preliminary. As objects of research, 4 selected and elite forms of sour cherry, with high taste and marketability, were taken. The sour cherry variety Turgenevka, obtained at RRIFCB, was chosen as a control. The collection of pollen from cherry forms to determine fertility was carried out during the period of mass flowering of trees in the first ten days of May. The anthers removed from the flowers were dried at room temperature, opened, and the spilled pollen was poured into parchment paper bags and stored in a desiccator over calcium chloride. Fertility was determined by the method of pollen staining with acetocarmine. According to the research results, it was established that, on average, over 2 years of research, cherry accessions 84847, 84854, 84735 stand out for a high degree of pollen fertility (more than 58.64 % in almost all forms), which makes it possible to recommend them for use in crosses to obtain new hybrids . The highest degree of fertility was observed in pollen of the control variety Turgenevka — it was 76.80 % on average over two years. The lowest fertility was observed in the sour cherry form 84595. In this case, it was only 29.61 %.

Dendroctonus-bark beetles are natural agents contributing to vital processes in coniferous forests, such as regeneration, succession, and material recycling, as they colonize and kill damaged, stressed, or old pine trees. These beetles spend most of their life cycle under stem and roots bark where they breed, develop, and feed on phloem. This tissue is rich in essential nutrients and complex molecules such as starch, cellulose, hemicellulose, and lignin, which apparently are not available for these beetles. We evaluated the digestive capacity of Dendroctonus rhizophagus to hydrolyze starch. Our aim was to identify α-amylases and characterize them both molecularly and biochemically. The findings showed that D. rhizophagus has an α-amylase gene (AmyDr) with a single isoform, and ORF of 1452 bp encoding a 483-amino acid protein (53.15 kDa) with a predicted signal peptide of 16 amino acids. AmyDr has a mutation in the chlorine-binding site, present in other phytophagous insects and in a marine bacterium. Docking analysis showed that AmyDr presents a higher binding affinity to amylopectin compared to amylose, and an affinity binding equally stable to calcium, chlorine, and nitrate ions. AmyDr native protein showed amylolytic activity in the head-pronotum and gut, and its recombinant protein, a polypeptide of ~53 kDa, showed conformational stability, and its activity is maintained both in the presence and absence of chlorine and nitrate ions. The AmyDr gene showed a differential expression significantly higher in the gut than the head-pronotum, indicating that starch hydrolysis occurs mainly in the midgut. An overview of the AmyDr gene expression suggests that the amylolytic activity is regulated through the developmental stages of this bark beetle and associated with starch availability in the host tree.

Effects of incursion of water and nutrients from agricultural land on adjoining native Banksia woodland were examined near Moora, Western Australia, by using a 100-m-wide belt transect from the paddock edge into virgin bush. Transect zones 0–20, 20–50 and 100–300 m inwards were designated as ‘hedge’, ‘transition’ and ‘inner bush’, respectively. Numbers of species of native woody taxa increased from 28 to 42 and plant densities increased from 2200 to 14 900 plants per hectare from hedge through transition to inner bush, while collective total standing biomass (above and below ground) of woody species decreased from 157 to 32 t dry matter per hectare. Data for nutrient contents of this total biomass indicated that total nutrient loads in respect of calcium, potassium, sulfur, phosphorus, magnesium, zinc, copper and sodium were closely related to relative amounts of biomass in the three zones, but hedge vegetation was appreciably enriched in nitrogen but depleted in manganese and chlorine compared to inner bush. Diversity indices indicated differential responses of species to agricultural influence. The dominant tree species, Banksia prionotes, represented 91, 87 and 58% of the total biomass of woody taxa in hedge, transition and inner bush, respectively. Growth ring analyses of basal trunk xylem indicated that this seeder species had recruited after a hot burn in 1963 coincident with land clearing. Since then, annual trunk-area increments in hedge trees have been consistently much greater than in transition and bush. Net annual productivities, dry matter allocation profiles and current leaf areas of B. prionotes showed that the average hedge tree weighed 167 kg total dry matter and was currently increasing at 11.9 kg per year and was in the process of achieving net dry matter gains of 420 g m–2 of leaf surface. Comparable figures for transition trees were 61 kg, 4.7 kg per year and 360 g m–2, for inner bush trees 12.7 kg, 1.1 kg per year and 230 g m–2. Results are related to recent studies on Banksia woodlands and general information on ecotones and their attributes.

The principal objective of this study was to investigate the major organic and trace elemental composition of the stem tissues of three tree species of a mixed forest on Cornwall Island in the St. Lawrence River, Ontario. This forest was exposed to atmospheric hydrogen fluoride (HF) at levels > 71 μg F/m3/24 h from an aluminum smelter (Reynolds Metals Co. Ltd.) for twenty years, followed by fourteen years of reduced emissions (< 40 μg F/m3/24 h), which is still greater than the current Ontario air quality criterion for HF (0.36 μg F/m3/24 h). Increment cores were collected at breast height from white pine, red oak, and American beech from the study woodlot on Cornwall Island and at a control site in Long Sault Provincial Park.Tree-rings were analyzed for eight elements (fluorine, aluminum, manganese, magnesium, calcium, sodium, chlorine and potassium) and some major organic compounds (total extractives, lignin and holocellulose). All three species from the study woodlot showed significant chemical compositional changes during the peak pollution and post-abatement periods. There was a substantial increase of the levels of total extractives (up to 167%), lignin (up to 38%), fluorine, aluminum and manganese and a significant decrease of holocellulose content (up to 17%) in the stem tissues during the period of HF exposure, compared to the pre-pollution period. In contrast, trees from the control site showed no significant change in chemical composition in any of the three periods. Lower cellulose and higher lignin and extractives concentrations potentially makes the wood weaker and less suitable for dimension lumber and pulping. Key words: hydrogen fluoride, extractives, lignin, holocellulose, trace elements

Environments containing significant concentration of NaCl such as salt lakes harbor extremophiles microorganisms which have a great biotechnology interest. To explore the diversity of Bacteria in Chott Tinsilt (Algeria), an isolation program was performed. Water samples were collected from the saltern during the pre-salt harvesting phase. This Chott is high in salt (22.47% (w/v). Seven halophiles Bacteria were selected for further characterization. The isolated strains were able to grow optimally in media with 10–25% (w/v) total salts. Molecular identification of the isolates was performed by sequencing the 16S rRNA gene. It showed that these cultured isolates included members belonging to the Halomonas, Staphylococcus, Salinivibrio, Planococcus and Halobacillus genera with less than 98% of similarity with their closest phylogenetic relative. The halophilic bacterial isolates were also characterized for the production of biosurfactant and industrially important enzymes. Most isolates produced hydrolases and biosurfactants at high salt concentration. In fact, this is the first report on bacterial strains (A4 and B4) which were a good biosurfactant and coagulase producer at 20% and 25% ((w/v)) NaCl. In addition, the biosurfactant produced by the strain B4 at high salinity (25%) was also stable at high temperature (30-100°C) and high alkalinity (pH 11).Key word: Salt Lake, Bacteria, biosurfactant, Chott, halophiles, hydrolases, 16S rRNAINTRODUCTIONSaline lakes cover approximately 10% of the Earth’s surface area. The microbial populations of many hypersaline environments have already been studied in different geographical regions such as Great Salt Lake (USA), Dead Sea (Israel), Wadi Natrun Lake (Egypt), Lake Magadi (Kenya), Soda Lake (Antarctica) and Big Soda Lake and Mono Lake (California). Hypersaline regions differ from each other in terms of geographical location, salt concentration and chemical composition, which determine the nature of inhabitant microorganisms (Gupta et al., 2015). Then low taxonomic diversity is common to all these saline environments (Oren et al., 1993). Halophiles are found in nearly all major microbial clades, including prokaryotic (Bacteria and Archaea) and eukaryotic forms (DasSarma and Arora, 2001). They are classified as slight halophiles when they grow optimally at 0.2–0.85 M (2–5%) NaCl, as moderate halophiles when they grow at 0.85–3.4 M (5–20%) NaCl, and as extreme halophiles when they grow at 3.4–5.1 M (20–30%) NaCl. Hyper saline environments are inhabited by extremely halophilic and halotolerant microorganisms such as Halobacillus sp, Halobacterium sp., Haloarcula sp., Salinibacter ruber , Haloferax sp and Bacillus spp. (Solomon and Viswalingam, 2013). There is a tremendous demand for halophilic bacteria due to their biotechnological importance as sources of halophilic enzymes. Enzymes derived from halophiles are endowed with unique structural features and catalytic power to sustain the metabolic and physiological processes under high salt conditions. Some of these enzymes have been reported to be active and stable under more than one extreme condition (Karan and Khare, 2010). Applications are being considered in a range of industries such as food processing, washing, biosynthetic processes and environmental bioremediation. Halophilic proteases are widely used in the detergent and food industries (DasSarma and Arora, 2001). However, esterases and lipases have also been useful in laundry detergents for the removal of oil stains and are widely used as biocatalysts because of their ability to produce pure compounds. Likewise, amylases are used industrially in the first step of the production of high fructose corn syrup (hydrolysis of corn starch). They are also used in the textile industry in the de-sizing process and added to laundry detergents. Furthermore, for the environmental applications, the use of halophiles for bioremediation and biodegradation of various materials from industrial effluents to soil contaminants and accidental spills are being widely explored. In addition to enzymes, halophilic / halotolerants microorganisms living in saline environments, offer another potential applications in various fields of biotechnology like the production of biosurfactant. Biosurfactants are amphiphilic compounds synthesized from plants and microorganisms. They reduce surface tension and interfacial tension between individual molecules at the surface and interface respectively (Akbari et al., 2018). Comparing to the chemical surfactant, biosurfactant are promising alternative molecules due to their low toxicity, high biodegradability, environmental capability, mild production conditions, lower critical micelle concentration, higher selectivity, availability of resources and ability to function in wide ranges of pH, temperature and salinity (Rocha et al., 1992). They are used in various industries which include pharmaceuticals, petroleum, food, detergents, cosmetics, paints, paper products and water treatment (Akbari et al., 2018). The search for biosurfactants in extremophiles is particularly promising since these biomolecules can adapt and be stable in the harsh environments in which they are to be applied in biotechnology.OBJECTIVESEastern Algeria features numerous ecosystems including hypersaline environments, which are an important source of salt for food. The microbial diversity in Chott Tinsilt, a shallow Salt Lake with more than 200g/L salt concentration and a superficies of 2.154 Ha, has never yet been studied. The purpose of this research was to chemically analyse water samples collected from the Chott, isolate novel extremely or moderate halophilic Bacteria, and examine their phenotypic and phylogenetic characteristics with a view to screening for biosurfactants and enzymes of industrial interest.MATERIALS AND METHODSStudy area: The area is at 5 km of the Commune of Souk-Naâmane and 17 km in the South of the town of Aïn-Melila. This area skirts the trunk road 3 serving Constantine and Batna and the railway Constantine-Biskra. It is part the administrative jurisdiction of the Wilaya of Oum El Bouaghi. The Chott belongs to the wetlands of the High Plains of Constantine with a depth varying rather regularly without never exceeding 0.5 meter. Its length extends on 4 km with a width of 2.5 km (figure 1).Water samples and physico-chemical analysis: In February 2013, water samples were collected from various places at the Chott Tinsilt using Global Positioning System (GPS) coordinates of 35°53’14” N lat. and 06°28’44”E long. Samples were collected randomly in sterile polythene bags and transported immediately to the laboratory for isolation of halophilic microorganisms. All samples were treated within 24 h after collection. Temperature, pH and salinity were measured in situ using a multi-parameter probe (Hanna Instruments, Smithfield, RI, USA). The analytical methods used in this study to measure ions concentration (Ca2+, Mg2+, Fe2+, Na+, K+, Cl−, HCO3−, SO42−) were based on 4500-S-2 F standard methods described elsewhere (Association et al., 1920).Isolation of halophilic bacteria from water sample: The media (M1) used in the present study contain (g/L): 2.0 g of KCl, 100.0/200.0 g of NaCl, 1.0 g of MgSO4.7HO2, 3.0 g of Sodium Citrate, 0.36 g of MnCl2, 10.0 g of yeast extract and 15.0 g agar. The pH was adjusted to 8.0. Different dilutions of water samples were added to the above medium and incubated at 30°C during 2–7 days or more depending on growth. Appearance and growth of halophilic bacteria were monitored regularly. The growth was diluted 10 times and plated on complete medium agar (g/L): glucose 10.0; peptone 5.0; yeast extract 5.0; KH2PO4 5.0; agar 30.0; and NaCl 100.0/200.0. Resultant colonies were purified by repeated streaking on complete media agar. The pure cultures were preserved in 20% glycerol vials and stored at −80°C for long-term preservation.Biochemical characterisation of halophilic bacterial isolates: Bacterial isolates were studied for Gram’s reaction, cell morphology and pigmentation. Enzymatic assays (catalase, oxidase, nitrate reductase and urease), and assays for fermentation of lactose and mannitol were done as described by Smibert (1994).Optimization of growth conditions: Temperature, pH, and salt concentration were optimized for the growth of halophilic bacterial isolates. These growth parameters were studied quantitatively by growing the bacterial isolates in M1 medium with shaking at 200 rpm and measuring the cell density at 600 nm after 8 days of incubation. To study the effect of NaCl on the growth, bacterial isolates were inoculated on M1 medium supplemented with different concentration of NaCl: 1%-35% (w/v). The effect of pH on the growth of halophilic bacterial strains was studied by inoculating isolates on above described growth media containing NaCl and adjusted to acidic pH of 5 and 6 by using 1N HCl and alkaline pH of 8, 9, 10, 11 and 12 using 5N NaOH. The effect of temperature was studied by culturing the bacterial isolates in M1 medium at different temperatures of incubation (4°C–55°C).Screening of halophilic bacteria for hydrolytic enzymes: Hydrolase producing bacteria among the isolates were screened by plate assay on starch, tributyrin, gelatin and DNA agar plates respectively for amylase, lipase, protease and DNAse activities. Amylolytic activity of the cultures was screened on starch nutrient agar plates containing g/L: starch 10.0; peptone 5.0; yeast extract 3.0; agar 30.0; NaCl 100.0/250.0. The pH was 7.0. After incubation at 30 ºC for 7 days, the zone of clearance was determined by flooding the plates with iodine solution. The potential amylase producers were selected based on ratio of zone of clearance diameter to colony diameter. Lipase activity of the cultures was screened on tributyrin nutrient agar plates containing 1% (v/v) of tributyrin. Isolates that showed clear zones of tributyrin hydrolysis were identified as lipase producing bacteria. Proteolytic activity of the isolates was similarly screened on gelatin nutrient agar plates containing 10.0 g/L of gelatin. The isolates showing zones of gelatin clearance upon treatment with acidic mercuric chloride were selected and designated as protease producing bacteria. The presence of DNAse activity on plates was determined on DNAse test agar (BBL) containing 10%-25% (w/v) total salt. After incubation for 7days, the plates were flooded with 1N HCl solution. Clear halos around the colonies indicated DNAse activity (Jeffries et al., 1957).Milk clotting activity (coagulase activity) of the isolates was also determined following the procedure described (Berridge, 1952). Skim milk powder was reconstituted in 10 mM aqueous CaCl2 (pH 6.5) to a final concentration of 0.12 kg/L. Enzyme extracts were added at a rate of 0.1 mL per mL of milk. The coagulation point was determined by manual rotating of the test tube periodically, at short time intervals, and checking for visible clot formation.Screening of halophilic bacteria for biosurfactant production. Oil spread Assay: The Petridis base was filled with 50 mL of distilled water. On the water surface, 20μL of diesel and 10μl of culture were added respectively. The culture was introduced at different spots on the diesel, which is coated on the water surface. The occurrence of a clear zone was an indicator of positive result (Morikawa et al., 2000). The diameter of the oil expelling circles was measured by slide caliber (with a degree of accuracy of 0.02 mm).Surface tension and emulsification index (E24): Isolates were cultivated at 30 °C for 7 days on the enrichment medium containing 10-25% NaCl and diesel oil as the sole carbon source. The medium was centrifuged (7000 rpm for 20 min) and the surface tension of the cell-free culture broth was measured with a TS90000 surface tensiometer (Nima, Coventry, England) as a qualitative indicator of biosurfactant production. The culture broth was collected with a Pasteur pipette to remove the non-emulsified hydrocarbons. The emulsifying capacity was evaluated by an emulsification index (E24). The E24 of culture samples was determined by adding 2 mL of diesel oil to the same amount of culture, mixed for 2 min with a vortex, and allowed to stand for 24 h. E24 index is defined as the percentage of height of emulsified layer (mm) divided by the total height of the liquid column (mm).Biosurfactant stability studies : After growth on diesel oil as sole source of carbone, cultures supernatant obtained after centrifugation at 6,000 rpm for 15 min were considered as the source of crude biosurfactant. Its stability was determined by subjecting the culture supernatant to various temperature ranges (30, 40, 50, 60, 70, 80 and 100 °C) for 30 min then cooled to room temperature. Similarly, the effect of different pH (2–11) on the activity of the biosurfactant was tested. The activity of the biosurfactant was investigated by measuring the emulsification index (El-Sersy, 2012).Molecular identification of potential strains. DNA extraction and PCR amplification of 16S rDNA: Total cellular DNA was extracted from strains and purified as described by Sambrook et al. (1989). DNA was purified using Geneclean® Turbo (Q-BIO gene, Carlsbad, CA, USA) before use as a template in polymerase chain reaction (PCR) amplification. For the 16S rDNA gene sequence, the purified DNA was amplified using a universal primer set, forward primer (27f; 5′-AGA GTT TGA TCM TGG CTC AG) and a reverse primer (1492r; 5′-TAC GGY TAC CTT GTT ACG ACT T) (Lane, 1991). Agarose gel electrophoresis confirmed the amplification product as a 1400-bp DNA fragment.16S rDNA sequencing and Phylogenic analysis: Amplicons generated using primer pair 27f-1492r was sequenced using an automatic sequencer system at Macrogene Company (Seoul, Korea). The sequences were compared with those of the NCBI BLAST GenBank nucleotide sequence databases. Phylogenetic trees were constructed by the neighbor-joining method using MEGA version 5.05 software (Tamura et al., 2011). Bootstrap resembling analysis for 1,000 replicates was performed to estimate the confidence of tree topologies.Nucleotide sequence accession numbers: The nucleotide sequences reported in this work have been deposited in the EMBL Nucleotide Sequence Database. The accession numbers are represented in table 5.Statistics: All experiments were conducted in triplicates. Results were evaluated for statistical significance using ANOVA.RESULTSPhysico-chemical parameters of the collected water samples: The physicochemical properties of the collected water samples are reported in table 1. At the time of sampling, the temperature was 10.6°C and pH 7.89. The salinity of the sample, as determined in situ, was 224.70 g/L (22,47% (w/v)). Chemical analysis of water sample indicated that Na +and Cl- were the most abundant ions (table 1). SO4-2 and Mg+2 was present in much smaller amounts compared to Na +and Cl- concentration. Low levels of calcium, potassium and bicarbonate were also detected, often at less than 1 g/L.Characterization of isolates. Morphological and biochemical characteristic feature of halophilic bacterial isolates: Among 52 strains isolated from water of Chott Tinsilt, seven distinct bacteria (A1, A2, A3, A4, B1, B4 and B5) were chosen for further characterization (table 2). The colour of the isolates varied from beige, pale yellow, yellowish and orange. The bacterial isolates A1, A2, A4, B1 and B5 were rod shaped and gram negative (except B5), whereas A3 and B4 were cocci and gram positive. All strains were oxidase and catalase positive except for B1. Nitrate reductase and urease activities were observed in all the bacterial isolates, except B4. All the bacterial isolates were negative for H2S formation. B5 was the only strain positive for mannitol fermentation (table 2).We isolated halophilic bacteria on growth medium with NaCl supplementation at pH 7 and temperature of 30°C. We studied the effect of NaCl, temperature and pH on the growth of bacterial isolates. All the isolates exhibited growth only in the presence of NaCl indicating that these strains are halophilic. The optimum growth of isolates A3 and B1 was observed in the presence of 10% NaCl, whereas it was 15% NaCl for A1, A2 and B5. A4 and B4 showed optimum growth in the presence of 20% and 25% NaCl respectively. A4, B4 and B5 strains can tolerate up to 35% NaCl.The isolate B1 showed growth in medium supplemented with 10% NaCl and pH range of 7–10. The optimum pH for the growth B1 was 9 and they did not show any detectable growth at or below pH 6 (table 2), which indicates the alkaliphilic nature of B1 isolate. The bacterial isolates A1, A2 and A4 exhibited growth in the range of pH 6–10, while A3 and B4 did not show any growth at pH greater than 8. The optimum pH for growth of all strains (except B1) was pH 7.0 (table 2). These results indicate that A1, A2, A3, A4, B4 and B5 are neutrophilic in nature. All the bacterial isolates exhibited optimal growth at 30°C and no detectable growth at 55°C. Also, detectable growth of isolates A1, A2 and A4 was observed at 4°C. However, none of the bacterial strains could grow below 4°C and above 50°C (table 2).Screening of the halophilic enzymes: To characterize the diversity of halophiles able to produce hydrolytic enzymes among the population of microorganisms inhabiting the hypersaline habitats of East Algeria (Chott Tinsilt), a screening was performed. As described in Materials and Methods, samples were plated on solid media containing 10%-25% (w/v) of total salts and different substrates for the detection of amylase, protease, lipase and DNAse activities. However, coagulase activity was determined in liquid medium using milk as substrate (figure 3). Distributions of hydrolytic activity among the isolates are summarized in table 4.From the seven bacterial isolates, four strains A1, A2, A4 and B5 showed combined hydrolytic activities. They were positive for gelatinase, lipase and coagulase. A3 strain showed gelatinase and lipase activities. DNAse activities were detected with A1, A4, B1 and B5 isolates. B4 presented lipase and coagulase activity. Surprisingly, no amylase activity was detected among all the isolates.Screening for biosurfactant producing isolates: Oil spread assay: The results showed that all the strains could produce notable (>4 cm diameter) oil expelling circles (ranging from 4.11 cm to 4.67 cm). The average diameter for strain B5 was 4.67 cm, significantly (P < 0.05) higher than for the other strains.Surface tension and emulsification index (E24): The assimilation of hydrocarbons as the sole sources of carbon by the isolate strains led to the production of biosurfactants indicated by the emulsification index and the lowering of the surface tension of cell-free supernatant. Based on rapid growth on media containing diesel oil as sole carbon source, the seven isolates were tested for biosurfactant production and emulsification activity. The obtained values of the surface tension measurements as well as the emulsification index (E24) are shown in table 3. The highest reduction of surface tension was achieved with B5 and A3 isolates with values of 25.3 mN m−1 and 28.1 mN m−1 respectively. The emulsifying capacity evaluated by the E24 emulsification index was highest in the culture of isolate B4 (78%), B5 (77%) and A3 (76%) as shown in table 3 and figure 2. These emulsions were stable even after 4 months. The bacteria with emulsification indices higher than 50 % and/or reduction in the surface tension (under 30 mN/m) have been defined as potential biosurfactant producers. Based on surface tension and the E24 index results, isolates B5, B4, A3 and A4 are the best candidates for biosurfactant production. It is important to note that, strains B4 and A4 produce biosurfactant in medium containing respectively 25% and 20% (w/v) NaCl.Stability of biosurfactant activities: The applicability of biosurfactants in several biotechnological fields depends on their stability at different environmental conditions (temperatures, pH and NaCl). For this study, the strain B4 appear very interesting (It can produce biosurfactant at 25 % NaCl) and was choosen for futher analysis for biosurfactant stability. The effects of temperature and pH on the biosurfactant production by the strain B4 are shown in figure 4.biosurfactant in medium containing respectively 25% and 20% (w/v) NaCl.Stability of biosurfactant activities: The applicability of biosurfactants in several biotechnological fields depends on their stability at different environmental conditions (temperatures, pH and NaCl). For this study, the strain B4 appear very interesting (It can produce biosurfactant at 25 % NaCl) and was chosen for further analysis for biosurfactant stability. The effects of temperature and pH on the biosurfactant production by the strain B4 are shown in figure 4. The biosurfactant produced by this strain was shown to be thermostable giving an E-24 Index value greater than 78% (figure 4A). Heating of the biosurfactant to 100 °C caused no significant effect on the biosurfactant performance. Therefore, the surface activity of the crude biosurfactant supernatant remained relatively stable to pH changes between pH 6 and 11. At pH 11, the value of E24 showed almost 76% activity, whereas below pH 6 the activity was decreased up to 40% (figure 4A). The decreases of the emulsification activity by decreasing the pH value from basic to an acidic region; may be due to partial precipitation of the biosurfactant. This result indicated that biosurfactant produced by strain B4 show higher stability at alkaline than in acidic conditions.Molecular identification and phylogenies of potential isolates: To identify halophilic bacterial isolates, the 16S rDNA gene was amplified using gene-specific primers. A PCR product of ≈ 1.3 kb was detected in all the seven isolates. The 16S rDNA amplicons of each bacterial isolate was sequenced on both strands using 27F and 1492R primers. The complete nucleotide sequence of 1336,1374, 1377,1313, 1305,1308 and 1273 bp sequences were obtained from A1, A2, A3, A4, B1, B4 and B5 isolates respectively, and subjected to BLAST analysis. The 16S rDNA sequence analysis showed that the isolated strains belong to the genera Halomonas, Staphylococcus, Salinivibrio, Planococcus and Halobacillus as shown in table 5. The halophilic isolates A2 and A4 showed 97% similarity with the Halomonas variabilis strain GSP3 (accession no. AY505527) and the Halomonas sp. M59 (accession no. AM229319), respectively. As for A1, it showed 96% similarity with the Halomonas venusta strain GSP24 (accession no. AY553074). B1 and B4 showed for their part 96% similarity with the Salinivibrio costicola subsp. alcaliphilus strain 18AG DSM4743 (accession no. NR_042255) and the Planococcus citreus (accession no. JX122551), respectively. The bacterial isolate B5 showed 98% sequence similarity with the Halobacillus trueperi (accession no. HG931926), As for A3, it showed only 95% similarity with the Staphylococcus arlettae (accession no. KR047785). The 16S rDNA nucleotide sequences of all the seven halophilic bacterial strains have been submitted to the NCBI GenBank database under the accession number presented in table 5. The phylogenetic association of the isolates is shown in figure 5.DICUSSIONThe physicochemical properties of the collected water samples indicated that this water was relatively neutral (pH 7.89) similar to the Dead Sea and the Great Salt Lake (USA) and in contrast to the more basic lakes such as Lake Wadi Natrun (Egypt) (pH 11) and El Golea Salt Lake (Algeria) (pH 9). The salinity of the sample was 224.70 g/L (22,47% (w/v). This range of salinity (20-30%) for Chott Tinsilt is comparable to a number of well characterized hypersaline ecosystems including both natural and man-made habitats, such as the Great Salt Lake (USA) and solar salterns of Puerto Rico. Thus, Chott Tinsilt is a hypersaline environment, i.e. environments with salt concentrations well above that of seawater. Chemical analysis of water sample indicated that Na +and Cl- were the most abundant ions, as in most hypersaline ecosystems (with some exceptions such as the Dead Sea). These chemical water characteristics were consistent with the previously reported data in other hypersaline ecosystems (DasSarma and Arora, 2001; Oren, 2002; Hacěne et al., 2004). Among 52 strains isolated from this Chott, seven distinct bacteria (A1, A2, A3, A4, B1, B4 and B5) were chosen for phenotypique, genotypique and phylogenetique characterization.The 16S rDNA sequence analysis showed that the isolated strains belong to the genera Halomonas, Staphylococcus, Salinivibrio, Planococcus and Halobacillus. Genera obtained in the present study are commonly occurring in various saline habitats across the globe. Staphylococci have the ability to grow in a wide range of salt concentrations (Graham and Wilkinson, 1992; Morikawa et al., 2009; Roohi et al., 2014). For example, in Pakistan, Staphylococcus strains were isolated from various salt samples during the study conducted by Roohi et al. (2014) and these results agreed with previous reports. Halomonas, halophilic and/or halotolerant Gram-negative bacteria are typically found in saline environments (Kim et al., 2013). The presence of Planococcus and Halobacillus has been reported in studies about hypersaline lakes; like La Sal del Rey (USA) (Phillips et al., 2012) and Great Salt Lake (Spring et al., 1996), respectively. The Salinivibrio costicola was a representative model for studies on osmoregulatory and other physiological mechanisms of moderately halophilic bacteria (Oren, 2006).However, it is interesting to note that all strains shared less than 98.7% identity (the usual species cut-off proposed by Yarza et al. (2014) with their closest phylogenetic relative, suggesting that they could be considered as new species. Phenotypic, genetic and phylogenetic analyses have been suggested for the complete identification of these strains. Theses bacterial strains were tested for the production of industrially important enzymes (Amylase, protease, lipase, DNAse and coagulase). These isolates are good candidates as sources of novel enzymes with biotechnological potential as they can be used in different industrial processes at high salt concentration (up to 25% NaCl for B4). Prominent amylase, lipase, protease and DNAase activities have been reported from different hypersaline environments across the globe; e.g., Spain (Sánchez‐Porro et al., 2003), Iran (Rohban et al., 2009), Tunisia (Baati et al., 2010) and India (Gupta et al., 2016). However, to the best of our knowledge, the coagulase activity has never been detected in extreme halophilic bacteria. Isolation and characterization of crude enzymes (especially coagulase) to investigate their properties and stability are in progress.The finding of novel enzymes with optimal activities at various ranges of salt concentrations is of great importance. Besides being intrinsically stable and active at high salt concentrations, halophilic and halotolerant enzymes offer great opportunities in biotechnological applications, such as environmental bioremediation (marine, oilfiel) and food processing. The bacterial isolates were also characterized for production of biosurfactants by oil-spread assay, measurement of surface tension and emulsification index (E24). There are few reports on biosurfactant producers in hypersaline environments and in recent years, there has been a greater increase in interest and importance in halophilic bacteria for biomolecules (Donio et al., 2013; Sarafin et al., 2014). Halophiles, which have a unique lipid composition, may have an important role to play as surface-active agents. The archae bacterial ether-linked phytanyl membrane lipid of the extremely halophilic bacteria has been shown to have surfactant properties (Post and Collins, 1982). Yakimov et al. (1995) reported the production of biosurfactant by a halotolerant Bacillus licheniformis strain BAS 50 which was able to produce a lipopeptide surfactant when cultured at salinities up to 13% NaCl. From solar salt, Halomonas sp. BS4 and Kocuria marina BS-15 were found to be able to produce biosurfactant when cultured at salinities of 8% and 10% NaCl respectively (Donio et al., 2013; Sarafin et al., 2014). In the present work, strains B4 and A4 produce biosurfactant in medium containing respectively 25% and 20% NaCl. To our knowledge, this is the first report on biosurfactant production by bacteria under such salt concentration. Biosurfactants have a wide variety of industrial and environmental applications (Akbari et al., 2018) but their applicability depends on their stability at different environmental conditions. The strain B4 which can produce biosurfactant at 25% NaCl showed good stability in alkaline pH and at a temperature range of 30°C-100°C. Due to the enormous utilization of biosurfactant in detergent manufacture the choice of alkaline biosurfactant is researched (Elazzazy et al., 2015). On the other hand, the interesting finding was the thermostability of the produced biosurfactant even after heat treatment (100°C for 30 min) which suggests the use of this biosurfactant in industries where heating is of a paramount importance (Khopade et al., 2012). To date, more attention has been focused on biosurfactant producing bacteria under extreme conditions for industrial and commercial usefulness. In fact, the biosurfactant produce by strain B4 have promising usefulness in pharmaceutical, cosmetics and food industries and for bioremediation in marine environment and Microbial enhanced oil recovery (MEOR) where the salinity, temperature and pH are high.CONCLUSIONThis is the first study on the culturable halophilic bacteria community inhabiting Chott Tinsilt in Eastern Algeria. Different genera of halotolerant bacteria with different phylogeneticaly characteristics have been isolated from this Chott. Culturing of bacteria and their molecular analysis provides an opportunity to have a wide range of cultured microorganisms from extreme habitats like hypersaline environments. Enzymes produced by halophilic bacteria show interesting properties like their ability to remain functional in extreme conditions, such as high temperatures, wide range of pH, and high salt concentrations. These enzymes have great economical potential in industrial, agricultural, chemical, pharmaceutical, and biotechnological applications. Thus, the halophiles isolated from Chott Tinsilt offer an important potential for application in microbial and enzyme biotechnology. In addition, these halo bacterial biosurfactants producers isolated from this Chott will help to develop more valuable eco-friendly products to the pharmacological and food industries and will be usefulness for bioremediation in marine environment and petroleum industry.ACKNOWLEDGMENTSOur thanks to Professor Abdelhamid Zoubir for proofreading the English composition of the present paper.CONFLICT OF INTERESTThe authors declare that they have no conflict of interest.Akbari, S., N. H. Abdurahman, R. M. Yunus, F. Fayaz and O. R. Alara, 2018. Biosurfactants—a new frontier for social and environmental safety: A mini review. Biotechnology research innovation, 2(1): 81-90.Association, A. P. H., A. W. W. Association, W. P. C. Federation and W. E. Federation, 1920. Standard methods for the examination of water and wastewater. American Public Health Association.Baati, H., R. Amdouni, N. Gharsallah, A. Sghir and E. Ammar, 2010. Isolation and characterization of moderately halophilic bacteria from tunisian solar saltern. Current microbiology, 60(3): 157-161.Berridge, N., 1952. Some observations on the determination of the activity of rennet. Analyst, 77(911): 57b-62.DasSarma, S. and P. Arora, 2001. Halophiles. Encyclopedia of life sciences. Nature publishishing group: 1-9.Donio, M. B. S., F. A. Ronica, V. T. Viji, S. Velmurugan, J. S. C. A. Jenifer, M. Michaelbabu, P. Dhar and T. Citarasu, 2013. Halomonas sp. Bs4, a biosurfactant producing halophilic bacterium isolated from solar salt works in India and their biomedical importance. SpringerPlus, 2(1): 149.El-Sersy, N. A., 2012. Plackett-burman design to optimize biosurfactant production by marine Bacillus subtilis n10. Roman biotechnol lett, 17(2): 7049-7064.Elazzazy, A. M., T. Abdelmoneim and O. Almaghrabi, 2015. Isolation and characterization of biosurfactant production under extreme environmental conditions by alkali-halo-thermophilic bacteria from Saudi Arabia. Saudi journal of biological Sciences, 22(4): 466-475.Graham, J. E. and B. Wilkinson, 1992. Staphylococcus aureus osmoregulation: Roles for choline, glycine betaine, proline, and taurine. Journal of bacteriology, 174(8): 2711-2716.Gupta, S., P. Sharma, K. Dev and A. Sourirajan, 2016. Halophilic bacteria of lunsu produce an array of industrially important enzymes with salt tolerant activity. Biochemistry research international, 1: 1-10.Gupta, S., P. Sharma, K. Dev, M. Srivastava and A. Sourirajan, 2015. A diverse group of halophilic bacteria exist in lunsu, a natural salt water body of Himachal Pradesh, India. SpringerPlus 4(1): 274.Hacěne, H., F. Rafa, N. Chebhouni, S. Boutaiba, T. Bhatnagar, J. C. Baratti and B. Ollivier, 2004. Biodiversity of prokaryotic microflora in el golea salt lake, Algerian Sahara. Journal of arid environments, 58(3): 273-284.Jeffries, C. D., D. F. Holtman and D. G. Guse, 1957. Rapid method for determining the activity of microorgan-isms on nucleic acids. Journal of bacteriology, 73(4): 590.Karan, R. and S. Khare, 2010. Purification and characterization of a solvent‐stable protease from Geomicrobium sp. Emb2. Environmental technology, 31(10): 1061-1072.Khopade, A., R. Biao, X. Liu, K. Mahadik, L. Zhang and C. Kokare, 2012. Production and stability studies of the biosurfactant isolated from marine Nocardiopsis sp. B4. Desalination, 3: 198-204.Kim, K. K., J.-S. Lee and D. A. Stevens, 2013. Microbiology and epidemiology of Halomonas species. Future microbiology, 8(12): 1559-1573.Lane, D., 1991. 16s/23s rRNA sequencing in nucleic acid techniques in bacterial systematics. Stackebrandt e., editor;, and goodfellow m., editor. Chichester, UK: John Wiley & Sons.Morikawa, K., R. L. Ohniwa, T. Ohta, Y. Tanaka, K. Takeyasu and T. Msadek, 2009. Adaptation beyond the stress response: Cell structure dynamics and population heterogeneity in Staphylococcus aureus. Microbes environments, 25: 75-82.Morikawa, M., Y. Hirata and T. J. B. e. B. A.-M. Imanaka, 2000. A study on the structure–function relationship of lipopeptide biosurfactants. Biochimica et biophysica acta, 1488(3): 211-218.Oren, A., 2002. Diversity of halophilic microorganisms: Environments, phylogeny, physiology, and applications. Journal of industrial microbiology biotechnology, 28(1): 56-63.Oren, A., 2006. Halophilic microorganisms and their environments. Springer science & business media.Oren, A., R. Vreeland and L. Hochstein, 1993. Ecology of extremely halophilic microorganisms. The biology of halophilic bacteria, 2(1): 1-8.Phillips, K., F. Zaidan, O. R. Elizondo and K. L. Lowe, 2012. Phenotypic characterization and 16s rDNA identification of culturable non-obligate halophilic bacterial communities from a hypersaline lake, la sal del rey, in extreme south texas (USA). Aquatic biosystems, 8(1): 1-5.Post, F. and N. Collins, 1982. A preliminary investigation of the membrane lipid of Halobacterium halobium as a food additive 1. Journal of food biochemistry, 6(1): 25-38.Rocha, C., F. San-Blas, G. San-Blas and L. Vierma, 1992. Biosurfactant production by two isolates of Pseudomonas aeruginosa. World Journal of microbiology biotechnology, 8(2): 125-128.Rohban, R., M. A. Amoozegar and A. Ventosa, 2009. Screening and isolation of halophilic bacteria producing extracellular hydrolyses from howz soltan lake, Iran. Journal of industrial microbiology biotechnology, 36(3): 333-340.Roohi, A., I. Ahmed, N. Khalid, M. Iqbal and M. Jamil, 2014. Isolation and phylogenetic identification of halotolerant/halophilic bacteria from the salt mines of Karak, Pakistan. International journal of agricultural and biology, 16: 564-570.Sambrook, J., E. F. Fritsch and T. Maniatis, 1989. Molecular cloning: A laboratory manual, 2nd edn. Cold spring harbor laboratory, cold spring harbor, New York.Sánchez‐Porro, C., S. Martin, E. Mellado and A. Ventosa, 2003. Diversity of moderately halophilic bacteria producing extracellular hydrolytic enzymes. Journal of applied microbiology, 94(2): 295-300.Sarafin, Y., M. B. S. Donio, S. Velmurugan, M. Michaelbabu and T. Citarasu, 2014. Kocuria marina bs-15 a biosurfactant producing halophilic bacteria isolated from solar salt works in India. Saudi journal of biological sciences, 21(6): 511-519.Smibert, R., 1994. Phenotypic characterization. In methods for general and molecular bacteriology. American society for microbiology: 611-651.Solomon, E. and K. J. I. Viswalingam, 2013. Isolation, characterization of halotolerant bacteria and its biotechnological potentials. International journal scientific research paper publication sites, 4: 1-7.Spring, S., W. Ludwig, M. Marquez, A. Ventosa and K.-H. Schleifer, 1996. Halobacillus gen. Nov., with descriptions of Halobacillus litoralis sp. Nov. and Halobacillus trueperi sp. Nov., and transfer of Sporosarcina halophila to Halobacillus halophilus comb. Nov. International journal of systematic evolutionary microbiology, 46(2): 492-496.Tamura, K., D. Peterson, N. Peterson, G. Stecher, M. Nei and S. Kumar, 2011. Mega5: Molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Molecular biology evolution, 28(10): 2731-2739.Yakimov, M. M., K. N. Timmis, V. Wray and H. L. Fredrickson, 1995. Characterization of a new lipopeptide surfactant produced by thermotolerant and halotolerant subsurface Bacillus licheniformis bas50. Applied and environmental microbiology, 61(5): 1706-1713.Yarza, P., P. Yilmaz, E. Pruesse, F. O. Glöckner, W. Ludwig, K.-H. Schleifer, W. B. Whitman, J. Euzéby, R. Amann and R. Rosselló-Móra, 2014. Uniting the classification of cultured and uncultured bacteria and archaea using 16s rRNA gene sequences. Nature reviews microbiology, 12(9): 635-645

Abstract Background This work was carried out through 2017 and 2018 seasons on Kalmata and Manzanillo olive cultivars. Trees were 15 years old, grown in sandy soil and planted at 5 × 5 m apart irrigated with saline water through drip irrigation system. This investigation aimed to improve flowering, fruit set, yield and fruit quality of the tow olive cultivars. Trees were sprayed with calcium at 0.5% as calcium chloride (21% Ca) and chelated calcium. Results The results revealed that there were significant differences with calcium source treatment regarding number of inflorescences/shoot, no. of total flowers/inflorescences, sex expression, initial fruit set, final fruit set (%) and yield/kg (tree) and decreasing fruit drop (%) of olive oil Kalmata and Manzanillo cultivars compared with unsprayed in both seasons. Conclusions Results proved that olive trees sprayed at the end of December with 0.5% calcium as chelated calcium was the promising treatment for good flowering, fruit set, yield and fruit quality.

This study was conducted in the lath house, Horticultural Department, College of Agriculture – University of Baghdad- Jadriya during the spring and autumn seasons 2015 to investigate the influence of humic acid spray and calcium chloride spray on f “Yanara” gerbera cultivar. This study included two factors; humic acid spray (H) and calcium chloride spray (Ca). The first factor four levels were used, 0, (H0), 5 (H5), 7.5 (H7.5) and 10 (H10) ml.L-1 and four levels of calcium chloride, 0 (Ca0), 50 (Ca50), 100 (Ca100) and 150 (Ca150) mg.L-1. Each treatment replicated three times with a factorial experiment using RCBD. Five plants in experimental unit and the number of plants used was 240 trees. The experimental results showed that humic acid at 10 ml.L-1 and calcium chloride at 150 mg.L-1 (Ca150H0) significantly gave the highest leaves number of 11.20 and 11.47 leaves, the highest leaf area of 195.21 and 210.25 cm2, the highest plant dry weight of 16.92 and 17.95gm, the highest leaf nitrogen content of 2.50 and 2.45 %, highest leaf phosphor content of 0.37 and 0.44% and the highest leaf calcium content of 3.17 and 3.45% for both seasons, respectively. The lowest value of these parameters was found in the control (Ca0H0) treatment. It could be concluded of this experiment that the humic acid at level H10 and calcium chloride at level Ca150 improved vegetative characteristics and leaf mineral content gerbera plant cv. Yanara

In 2015 through 2018, eleven test plots were studied in recreation areas planted with Pinus silvestries pine trees and Picea albea spruce trees. The plots were located in Saint Petersburg and Vyborg (Russia) and Narva-Jõesuu (Estonia). The main factor of decay of both pines and spruces were total toxic salt levels in soil and acidity of soil. Correlated with these factors are the levels of sodium, magnesium, calcium, chloride, bicarbonate, and sulfate ions. The conditions of spruces correlated most significantly with chloride ion levels. The coefficients of regression of the estimates of conditions of pines and spruces on the estimates of soil pollution are not different, in spite of the fact that the arrangements of roots are different in the two tree species. A possible cause of the lack of differences in the coefficients is that toxic salts diffuse into deep soil layers. Factors associated with the presence of humans in the respective recreation areas, as well as pests and climate do not influence the stands. However, upon the highest pollution and the associated attenuation of stands, the activities of pests are highest. Regressions found based on the results obtained during the study may be used for forecasting the conditions of pine and spruce stands at lethal and maximum permissible levels of soil pollution. Differences in the threshold levels of pollution and in the standard errors of regression coefficients between study sites are not high. This makes it possible to use the mean values of these parameters as reference values of maximum permissible and lethal levels of soil pollution and for monitoring and forecasting the conditions of coniferous stands.