RESPONSE OF ‘BURLAT’ SWEET CHERRY TREES TO POSTHARVEST SPRAYS OF NITROGEN,BORON AND ZINC

The aim of the study was to examine effects of postharvest sprays of nitrogen (N), boron (B), and zinc (Zn) on reproductive response of sweet cherry (Prunus avium L.) trees, fruit quality and plant nutrition. The experiment was conducted during 2007–2009 in central Poland on mature ‘Burlat’ sweet cherry trees/F12, grown on a coarse-textured soil with low level of organic matter, and optimal soil reaction. Soil status of phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), iron (Fe), manganese (Mn), Zn and copper (Cu) was optimal, whereas B – low. Sweet cherry trees were sprayed with boric acid-B, ethylenediaminetetraacetic acid (EDTA)-Zn, and urea-N at 30–40 d prior to initiation of leaf fall according to following schema: i) spray of N at a rate of 23 kg ha^?1; ii) spray of B and Zn at a dose of 1.1 kg ha^?1 and 0.5 kg ha^?1, respectively; and iii) spray of N, B and Zn at the same rates as in the above spray combinations. The trees sprayed with water served as the control. The results showed that fall spray treatments had no influence on cold damage of flower buds, plant N status and soluble solids concentration in fruit. Postharvest spray of N and combined spray of N, B and Zn injured leaves in the fall but did not cause defoliation. Sprays of B and Zn with or without N increased status of Zn and B in fall leaves, and B in flowers and midsummer leaves. Those sprays also improved fruit set and yield. In one out of two years of the study, fall sprays of N with or without B and Zn decreased mean fruit weight. The above results indicate that only leaf-applied B in the fall improved reproductive response of sweet cherry trees. It is concluded that under conditions of B shortage in a soil and/or plant tissues, postharvest B sprays can be recommended in sweet cherry orchards to improve reproductive growth of the trees.     

RESPONSE OF ORNAMENTAL SUNFLOWER CULTIVARS ‘SUNBEAM’ AND ‘MOONBRIGHT’ TO IRRIGATION WITH SALINE WASTEWATERS

To explore the possibility that saline wastewaters may be used to grow commercially acceptable floriculture crops, a study was initiated to determine the effects of salinity on two pollen-free cultivars of ornamental sunflower (Helianthus annuus L.). ‘Moonbright’ and ‘Sunbeam’ were grown in greenhouse sand cultures irrigated with waters prepared to simulate wastewaters commonly present in two inland valley regions of California: 1) San Joaquin Valley (SJV) where saline-sodic drainage waters are dominated by sodium (Na⁺) and sulfate (SO ^2? ₄ ) and 2) Coachella Valley (CV) where major ions in tailwaters are Na⁺, chloride (Cl^?), SO ^2? ₄ , magnesium (Mg²⁺), calcium (Ca²⁺), predominating in that order. Ten-day-old seedlings were subjected to five salinity treatments of each water composition, each replicated three times. Electrical conductivities (EC) of the irrigation waters were 2.5, 5, 10, 15, and 20 dS·m^?1. Flowering stems were harvested when about 75% of the ray flowers were nearly horizontal. Stem length and fresh weight, flower and stem diameter were measured. Mineral ion concentrations in upper and lower stems, upper and lower leaves were determined. Sodium was excluded from the young tissues in the upper portions of the shoot and retained in the basal stem tissue. Inasmuch as sunflower is also a strong potassium (K)-accumulator, K⁺/Na⁺ selectivity coefficients were unusually high in the younger shoot organs. Despite a five-fold increase in substrate Ca²⁺ in both solutions, shoot-Ca decreased as salinity increased and this cation was retained in the older leaves. A few of the lower leaves of plants irrigated with ICV waters at EC = 10 dS·m^?1 and higher, exhibited necrotic margins which were undoubtedly caused by high concentrations of Cl^? in the tissues. Flowering stems produced in all treatments met florist quality standards in terms of diameters for stems (0.5 to 1.5 cm) and blooms (8 to 15 cm). Across treatments, stem lengths ranged from 60 to 175 cm. Both ornamental sunflower cultivars proved to be good candidates for production of marketable flowering stems using moderately saline wastewaters.     

EFFECTS OF FOLIAR AND SOIL CALCIUM APPLICATION ON YIELD AND QUALITY OF TABLE GRAPE CV. ‘THOMPSON SEEDLESS’

Table grape quality and firmness are key parameters for Chile's export, given distances from the main markets. As a consequence, calcium (Ca) fertilization has become a standard practice in the country, although its effects have not been fully evaluated. The objectives in this study were to investigate the effects of calcium fertilization on table grape nutrition and quality. A two-year field trial was conducted in central Chile, using grapevines (Vitis vinifera) cv. ‘Thompson seedless’, grown on an overhead trellis system. Calcium (CaCl₂) application treatments included foliar, soil, foliar plus soil, and a control without Ca fertilization. Calcium and other nutrients concentration were determined afterwards in soil, leaves, and berries. Also, yield and some fruit quality parameters were evaluated. Calcium application method did not have an effect on soil, leaf or fruit Ca content, neither on yield and berry sugar concentration, with levels being similar to the control treatment. Additionally, in treatments where CaCl₂ was applied to soil, chlorides concentration in soil, leaves, and berries were higher. Also, berries were larger, more turgent, with lower dry matter and larger cells. In the second season, in these same treatments, berry firmness at harvest was higher, but this effect disappeared after the storage simulation period. These results question the validity that Ca applications might improve table grape postharvest quality for growing conditions similar to the ones in this experiment. The temporal changes in berry quality parameters were attributed to higher Cl soil content and the associated plant osmoregulatory mechanisms.     

RESPONSE OF ‘GRANNY SMITH’ APPLE TREES TO FOLIAR TITANIUM SPRAYS UNDER CONDITIONS OF LOW SOIL AVAILABILITY OF IRON,MANGANESE, AND ZINC

The aim of the study was to examine impact of foliar titanium (Ti) sprays on vegetative and reproductive response of apple (Malus domestica Borkh.) trees under conditions of low soil availability of iron (Fe), manganese (Mn), and zinc (Zn). The experiment was conducted during 2005–2006 at a Experimental Station in Isparta region, Turkey, on mature ‘Granny Smith’ apple trees/M.9, planted at a spacing of 3.5 × 1.5 m, on fine-textured soil with neutral reaction, medium status of organic matter, high amounts of available phosphorus (P), potassium (K), and magnesium (Mg), and low availability of Fe, Mn, and Zn. The trees were sprayed with Ti-ascorbate at the green and pink bud stage, petal fall, and 3, 6, and 9 weeks after full bloom, at a rate of 3 g Ti ha^?1 per spray. The efficiency of Ti sprays was compared to combined sprays of Fe, Mn, and Zn [chelated with ethylenediaminetetraacetic acid (EDTA)], applied at the same terms as Ti sprays, at rate of 36 g, 36 g and 24 g per spray, respectively. Trees unsprayed with Ti, Fe, Mn, and Zn served as the control. It was shown that summer leaf Ti concentrations of the trees untreated with Ti were high, varying from 34 to 36 mg kg^?1 dry matter. Foliar Ti sprays increased leaf status of this nutrient but they had no effect on nutrition of essential macro- and microelements, tree vigor, and fruit yield. Mean apple weight, coloring, firmness, soluble solids concentration, and titratable acidity of fruit were not also influenced by Ti sprays. Foliar sprays of Fe, Mn, and Zn improved leaf status of nitrogen (N), Mg, Fe, Mn, and Zn; leaves of the trees sprayed with those micronutrients were also greener, and contained more Fe²⁺ than those of the control plants. Combined sprays of Fe, Mn, and Zn improved tree vigor and fruit yield.     

FOLIAR APPLICATION OF BORON INFLUENCES THE LEAF MINERAL STATUS,VEGETATIVE AND REPRODUCTIVE GROWTH,YIELD AND FRUIT QUALITY OF ‘KINNOW’ MANDARIN (CITRUS RETICULATA BLANCO.)

The effects of foliar application of boron (B) in the form of boric acid on vegetative and reproductive growth, yield and fruit quality of ‘Kinnow’ mandarin (Citrus reticulate Blanco.) were investigated. Kinnow mandarin was sprayed with different concentrations of boric acid viz. (0.1%, 0.2%, 0.3% and 0.4%) at fruit set stage. Leaf nitrogen (N), phosphorus (P), potassium (K), B, and zinc (Zn) along with flush length, tree height, tree spread and tree trunk diameter increased, while leaf length and leaf age showed non-significant results after foliar B application. Yield of the ‘Kinnow’ mandarin was significantly affected by foliar application of B and a significant increase in fruit weight at harvest was also observed. Soluble solid concentration (SSC): titratable acidity (TA) ratio, ascorbic acid, total sugars, total phenolic content (TPC) and total antioxidants significantly affected, while pH of juice, SSC, TA, reducing sugars and non-reducing sugars showed non- significant results.     

VEGETATIVE GROWTH,YIELD, FRUIT QUALITY AND FRUIT AND LEAF COMPOSITION OF STRAWBERRY CV. ‘PAJARO’ AS INFLUENCED BY SALICYLIC ACID AND NICKEL SPRAYS

Salicylic acid (SA) occurs naturally in plants at low concentrations. Previous studies reported a vast range of responses after SA application on plants. Nickel (Ni) as an essential element for plant growth and development has been proven to have positive impact on overall plant life cycle. To evaluate influence of these two compounds on strawberry plants cv. ‘Pajero’ this study was carried out as a 3 × 4 factorial in a completely randomized design in greenhouse conditions. Treatments included SA at 0, 1, 2, and 3 mM and nickel sulfate (NiSO₄) at 0, 150 and 300 mg L^?1 concentration. It seems that treatments had promoting effects on measured parameters as 2 mM of SA increased root and shoot fresh and dry weight, concentration of anthocyanins and poliphenolics of fruits significantly, 3 mM of this phytohormone caused augmentation of vitamin C content of fruits. Nitrogen and nickel concentration within leaves and fruits were affected after SA treatments. 150 mg L^?1 of nickel solution promoted total yield, root dry weight and nitrogen concentration of fruits. Worth mentioning, beneficial effects of such treatments were higher when applied together. Further research is needed before recommendation on other cultivars and commercial use.     

EFFECTS OF BAG-CONTROLLED RELEASE FERTILIZER ON NITROGEN UTILIZATION RATE,GROWTH AND FRUITING OF THE ‘FUJI’ APPLE

Bag-controlled release fertilizer is a new type of controlled-release fertilizer designed to meet the needs of the large individual volume characteristic of fruit trees. The effect of bag-controlled release fertilizer on nitrogen (N) utilization, growth-rate, and fruiting was investigated using ‘Fuji’ apple trees (M. domestica Borkh. cv. ‘Fuji’/M.hupehensis Rhed.). The results showed that the available concentration of nutrients in the soil following bag-controlled release fertilizer treatment (BCRT) was more consistent than when application treatments were broadcasted. The BCRT significantly increased N use efficiency, where this was 2.7 or 1.6 times greater than one or four broadcasted treatments, respectively. Trees treated via BCRT were healthier and had more quality spurs due to more constant nutrient concentration in the soil. With the same application amount, the chlorophyll level and Pn content of BCR-treated trees were steadier and higher than those of broadcasted controls; thus, BCRT significantly increased both yield and fruit quality.     

EFFECT OF CITRUS ROOTSTOCKS ON LEAF MINERAL COMPOSITION OF ‘OKITSU’, ‘CLAUSELLINA’, AND ‘SILVERHILL’ MANDARIN CULTIVARS

Citrus performance is strongly related with rootstock. This study was conducted to investigate leaf nutrient contents of ‘Okitsu’, ‘Clausellina’ and ‘Silverhill’ mandarin cultivars budded onto sour orange, ‘Carrizo’ and ‘Troyer’ citrange rootstocks in Dörtyol, Turkey in 2004 and 2005. The maximum nitrogen (N), potassium (K), and copper (Cu) contents were determined for ‘Clausellina’; phosphorus (P) for ‘Okitsu’; and sodium (Na) for ‘Silverhill’. Calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), and zinc (Zn) uptake were similar for the mandarin cultivars. ‘Carrizo’ citrange at N, K, Mg, Mn, and Cu uptake; ‘Troyer’ citrange at N, P, K, and Fe uptake; and common sour orange at Ca, Zn, and Na uptake was superior on the other rootstocks. It was observed that ‘Carrizo’ and ‘Troyer’ citrange rootstocks had advantages over sour orange in nutrient uptake. Thus, growth performance, yield, and quality parameters considered, ‘Carrizo’ and/or ‘Troyer’ citranges could be suggested as rootstocks for the studied mandarin cultivars under similar ecological conditions.     

FOLIAR APPLICATION OF ZINC INFLUENCES THE LEAF MINERAL STATUS,VEGETATIVE AND REPRODUCTIVE GROWTH,YIELD AND FRUIT QUALITY OF ‘KINNOW’ MANDARIN

Deficiency of zinc (Zn) is widespread in many citrus orchards of Pakistan, consequently hampering fruit yield. Effects of foliar applications of zinc sulfate on tree nutrition, growth, productivity and fruit quality were studied on ‘Kinnow’ mandarin. Leaf nitrogen (N), calcium (Ca), and manganese (Mn) were highest for trees sprayed with 0.2% zinc sulfate, while phosphorus (P) and iron (Fe) were highest with 0.6% zinc sulfate and potassium (K) and Zn were highest with 0.8% Zn sulfate applications. Trees sprayed with 0.6% zinc sulfate exhibited highest increase in height, crown width and stem girth, fruit diameter, fruit weight, ascorbic acid contents, and total phenolics compared to all other treatments. Pre-harvest fruit drop was lowest and total number and weight of fruit per tree was highest at harvest with 0.4% zinc sulfate application. In conclusion, foliar application of zinc sulfate up to 0.6% improved tree mineral nutrients, growth, and productivity with better fruit quality in ‘Kinnow’ mandarin.     

LEAF MINERAL COMPOSITION OF ‘NOVA’, ‘ROBINSON’ AND ‘FREMONT’ MANDARIN CULTIVARS ON DIFFERENT ROOTSTOCKS

Rootstock selection has a critical importance for mineral nutrition of budded cultivars. This study was conducted at the experimental farm of Mustafa Kemal University, Dörtyol, Turkey. The aim of this study was to investigate the effect of sour orange, Troyer and Carrizo citrange rootstocks on the leaf nutrient contents of ‘Nova’, ‘Robinson’, and ‘Fremont’ mandarin cultivars in the 2004 and 2005 growing seasons. Carrizo citrange was examined for nitrogen (N), potassium (K), magnesium (Mg), sodium (Na), and manganese (Mn); Troyer citrange for iron (Fe); and sour orange for calcium (Ca) and zinc (Zn) were superior on the others. Nitrogen, phosphorus (P) and Mg levels of mandarin leaf budded on sour orange were under or just above the deficiency threshold. Potassium, Mn, and Zn content of ‘Robinson’; P, Ca and Fe content of ‘Fremont’; and Cu content of ‘Nova’ were statistically higher. Therefore, it can be concluded that Carrizo rootstock may be suggested for the region and regions with similar ecological conditions.     

EFFECT OF VARIOUS FOLIAR SPRAYS ON SOME FRUIT QUALITY ATTRIBUTES AND LEAF NUTRITIONAL STATUS OF THE PEACH CULTIVAR ‘ANDROSS’

The effect of various products applied as foliar sprays on some fruit quality attributes and leaf nutritional status of the peach cultivar ‘Andross’ for a three year period is reported. Foliar application of all calcium (Ca) products plus boron (B), did not affect mean fruit weight compared to the control. Application of profical plus calcium phosphite plus power 7-B resulted in an increase of flesh firmness. Low flesh firmness was measured at the potassium nitrate (KNO₃) and Chelan-K treatments. Foliar application of all Ca and K products did not alter significantly total soluble solids, total titratable acidity, and length and width of pits in comparison to the control. The highest amount of compact pits (without visual split) for the three year period was measured after foliar application of silene-K. Profical plus calcium phosphite plus power 7-B, and calcium chloride (CaCl₂) plus power 7-B gave also good results for the three years. Foliar application of agriphos, chelan-K, silene-K, and KNO₃ resulted in an increase of K concentration of leaves compared to the control. Foliar application of CaCl₂, bcazin, power-Ca, profical and calcium phosphite plus profical resulted in an increase of Ca concentration of leaves compared to the control for all the years. The efficacy of the foliar sprays varied from year to year indicating the influence of the climatic conditions on tree nutrition.     

EFFECT OF PREHARVEST SPRAYS OF CALCIUM CHLORIDE AND SUCROSE ON CRACKING AND QUALITY OF ‘BURLAT’ SWEET CHERRY FRUIT

The aim of the study was to examine impact of preharvest sprays of calcium (Ca) and sucrose on splitting and quality of ‘Burlat’ sweet cherry fruit. The study was carried out during 2009–2010 in Poland and Turkey, on mature trees planted at a moderate density on coarse- and medium-textured soils. Sweet cherries were sprayed with calcium chloride (CaCl₂) and/or sucrose at a rate of 5 kg of each material per ha, using ca. 1000 L of water. In Poland, sprays of CaCl₂ and/or sucrose were applied 8–14 h before each rain, starting 21 d before harvest, whereas in Turkey the spray treatments were made schematically: 7, 14 and 21 d before harvest. Sprays of water were treated as the control. The results showed that preharvest sprays of CaCl₂ and/or sucrose did not affect yield, mean fruit weight, and fruit acidity. Sprays of CaCl₂ increased fruit Ca status, and simultaneously reduced fruit cracking in an orchard or laboratory test. In the trial performed in Turkey, part of fruit sprayed with CaCl₂ (<5%) had spray deposit on the peel. Sucrose sprays did not affect fruit cracking. In one year of the study in Turkey, sucrose sprays increased soluble solids concentration of fruit; however, part of fruit treated with sucrose (<2%) had spray deposit on the skin.     

EFFECTS OF SINGLE,DUAL AND TRIPLE INOCULATIONS WITH BACILLUS SUBTILIS,BACILLUS MEGATERIUM AND RHIZOBIUM LEGUMINOSARUM BV. PHASEOLI ON NODULATION,NUTRIENT UPTAKE,YIELD AND YIELD PARAMETERS OF COMMON BEAN (PHASEOLUS VULGARIS L. CV. ‘ELKOCA-05’)

This study was conducted in order to investigate the effects of single, dual, and triple inoculations with Rhizobium, N₂-fixing Bacillus subtilis (OSU-142), and P-solubilizing Bacillus megaterium (M-3) on nodulation, plant growth, nutrient uptake and seed yield of common bean (Phaseolus vulgaris L. cv. ‘Elkoca-05’) in comparison to control and mineral fertilizer application under field conditions in 2006 and 2007 in the cold highland in Erzurum plateau (29° 55′ N and 41° 16′ E with an altitude of 1850 m), Turkey. Bacterial inoculations significantly increased all the parameters investigated compared with the control treatment, equal to or higher than nitrogen (N), phosphorus (P), and NP treatments. The lowest shoot dry weight and chlorophyll content values were recorded in the control treatment and the bacterial inoculations increased shoot dry weight by 19.7–54.3% and chlorophyll content by 34.1–59.3% over control. Nodule dry weight significantly increased in Rhizobium alone treatment. Additionally, nodulation by native soil Rhizobium population was increased in single inoculations of OSU-142 and M-3. Significant increases of the seed yield under different inoculation treatments ranged between by 6.6% (Rhizobium + OSU-142 + M-3) and 12.2% (OSU-142 alone) over the control whereas N, P and NP applications corresponded to increases of 5.6%, 4.0% and 7.4%, respectively. All bacterial inoculations, especially triple inoculation, significantly increased uptake of macronutrients and micronutrients by common bean. In conclusion, seed inoculation with Rhizobium, OSU-142 and M-3, especially OSU-142 alone, may substitute partially costly NP fertilizers in common bean production even in cold highland areas such as in Erzurum.     

PLANT NUTRITION IN RESPONSE TO DRIP VERSUS BASIN IRRIGATION IN YOUNG ‘NAGPUR’ MANDARIN ON INCEPTISOL

Evaluation of drip irrigation treatments scheduled at 40, 60, 80, and 100% of alternate day cumulative pan evaporation (Ecp) against basin irrigation method was undertaken in 1-year-old ‘Nagpur’ mandarin (Citrus reticulata Blanco) trees budded on rough lemon [Citrus jambhiri (L)] rootstock on an alkaline Inceptisol soil type for three seasons during 2003–2005. Growth responses showed significantly (P ≤ 0.05) higher annual increase in tree height (0.44–0.50 m), scion girth (37–45 mm), and canopy volume (0.508–0.986 m³) under drip-irrigation except irrigation at 40% Ecp, compared to tree height (0.40 m), scion girth (36 mm), and canopy volume (0.463 m³) under basin irrigation. The highest magnitude of increase in different growth parameters was observed with drip irrigation at 80% Ecp, which produced the net water saving of 32% over basin irrigation method. Response on leaf nutrient composition under drip irrigation at 80% Ecp likewise produced the similar response, [2.27% nitrogen (N), 1.98% potassium (K), and 121.8 ppm iron (Fe)], significantly (P ≤ 0.05) higher than under basin irrigation (1.12% N, 1.04% K, and 98.3 ppm Fe), with other nutrients, e.g., phosphorus (P), manganese (Mn), copper (Cu), and zinc (Zn) remained unaffected.     

CORRELATION BETWEEN YIELD,MUST ATTRIBUTES AND NUTRITIONAL STATUS OF THE GREEK RED WINE GRAPE VARIETY ‘AGIORGITIKO’

The appropriate tissue and sampling time for the Greek wine-grape variety ‘Agiorgitiko’ nutritional diagnosis was to be evaluated by relating leaf tissue nutrient contents with the yield and must potassium (K), pH, total soluble solids (TSS), and titratable acidity (TA). At bloom, véraison and harvest, leaves opposite the basal cluster (LOBC) and youngest mature leaves (YML) were harvested, and soil and berry samples were collected from six vineyards in Nemea, Greece. Petiole K concentration of the LOBC was found to be better correlated with the yield, TSS, TA and must K than the blade or whole leaf K content; the contrary was observed in nitrogen (N), phosphorus (P), calcium (Ca), and magnesium (Mg) concentrations. The LOBC reflected better the nutritional status of the variety compared to the YML. Regarding the sampling time, petiole K presented stronger correlations with yield and must K, TSS, TA at harvest whereas N and P at bloom and véraison.     

INFLUENCE OF PREHARVEST SPRAYS OF A MIXTURE OF CALCIUM FORMATE,CALCIUM ACETATE,CALCIUM CHLORIDE AND CALCIUM NITRATE ON QUALITY AND ‘JONAGOLD’ APPLE STORABILITY

The aim of the study was to examine effect of preharvest sprays of a mixture of calcium (Ca) formate, Ca-acetate, Ca-chloride (CaCl₂) and Ca-nitrate [Ca(NO₃)₂] on quality and apple storability. The experiment was conducted during 2008–2009 at the Experimental Station of the Research Institute of Horticulture in Skierniewice, Poland, on mature ‘Jonagold’ apple trees/M.26, planted at a moderate density on a coarse-textured soil with low status of organic matter and abundant in exchangeable Ca. Apple trees were sprayed with Ca, 7 times per season, at 2-week intervals, starting 3 weeks after blooming. In the spray treatments a mixture of Ca-formate, Ca-acetate, CaCl₂ and Ca(NO₃)₂ (as Insol Wap fertilizer), CaCl₂ or Ca(NO₃)₂ were used at rates of 7.3 kg Ca, 11.8 kg Ca, and 9.9 kg Ca ha^?1 per season, respectively. The trees sprayed with water were treated as the control. The results showed that Ca sprays caused no leaf and fruit injury. Calcium spray measures did not affect yield, mean fruit weight, and soluble solids concentration (SSC), titratable acidity and starch index of fruit at harvest. However, at harvest apples sprayed with Ca contained more this nutrient and were firmer than those of the control plots. After storage apples sprayed with Ca had more acids, and were firmer and less liable to bitter pit than the control fruit. Calcium sprays did not affect SSC of fruit after storage but reduced postharvest decay of fruit caused by Peziculla spp. and Penicillium expansum fungi. Apples sprayed with Insol Wap material were the least affected by the above pathogens. It is concluded that in apple orchards preharvest sprays of a mixture of Ca-formate, Ca-acetate, CaCl₂ and Ca(NO₃)₂, containing 10% Ca (w/w) with ca. 50% in an organic form, can be the alternative to sprays of CaCl₂ or Ca(NO₃)₂.     

EFFECT OF AUTUMN CALCIUM SPRAY AT A HIGH RATE ON ‘GRANNY SMITH’ APPLE QUALITY AND STORABILITY

The aim of the study was to examine effect of autumn calcium (Ca) spray at a high rate on apple quality and storability. The investigation was carried out during 2005–2006 in Isparta district, Turkey, under semi-arid conditions, on mature ‘Granny Smith’ apple trees/M.9 EMLA, planted at a spacing of 3.5 × 1.5 m on fine-textured soil rich in Ca. The trees were sprayed with Ca in summer and/or in autumn, using organically complexed Ca to avoid possible leaf and fruit injuries. In autumn (10 days before harvest), the trees were sprayed with Ca at a rate of 8 kg ha^?1. In summer, the another trees were sprayed with Ca six times at a rate of 1.5 kg ha^?1 in each measure; the first spray treatment was performed 6 weeks after full bloom, and the others at 7–9 day intervals. The third part of the trees was sprayed with Ca in summer as well as in autumn, at the same terms and rates as given above. Trees unsprayed with Ca served as the control. It was found that Ca sprays in autumn or in summer plus in autumn damaged leaves; however those treatments did not caused defoliation. Calcium sprays had no effect on apple yield, mean fruit weight, fruit skin russeting, and firmness, soluble solids concentration and titratable acidity of fruit at harvest. Fruit flesh Ca concentrations of the control trees were high. However, the highest fruit Ca concentration was recorded on the trees sprayed with Ca in summer plus in autumn. Calcium sprays in summer or in autumn increased fruit Ca concentrations but their effects were weaker than summer plus autumn Ca applications. After 100 days of refrigerated air storage, soluble solids concentration of fruit did not differ between the studied combinations. Only apples sprayed with Ca in summer plus in autumn were firmer and contained more organic acids than the control fruit. During storage, there were neither pathogenic diseases nor physiological disorders. Based on the obtained results we conclude that Ca sprays in summer plus in autumn at high rate can prolong ‘Granny Smith’ apple storage even thought initial fruit Ca concentration is as high as 502–504 mg Ca kg^?1 DW or 84.1–84.8 mg Ca kg^?1 FW.     

BIOREGULATORS INFLUENCE CALCIUM CONCENTRATION AND COLD HARDINESS OF YOUNG ‘DELICIOUS’ (MALUS DOMESTICA,BORKH) APPLE TREES

Calcium concentration and cold hardiness in woody shoots of young ‘Delicious’ apple trees increased during the first half of the dormant season by early-fall whole-tree application of bioregulators and/or plant protectant. Compared with untreated controls, the plant protectant, α-[(1,3-dioxolan-2-ylmethoxy) imino] benzene acetonitcile [Hytech Polymer, (formerly ProTec^TM), Agro-K, Corp., Minneapolis, MN, USA] applied in September at 5 or 10% induced more cold hardiness in late October and November, whereas treating at 0.05% with the bioregulator, 2-chloroethyl-methyl-bis(phenylmethoxy)silane [CGA-15281, Novartis International AG, (formerly Ciba-Geigy Limited) Basel, Switzerland], induced greater cold hardiness and higher woody tissue calcium concentration in November and December. Applied in October, CGA-15281 resulted in woody tissue with the highest cold hardiness rating from November through March. From October 28 through 8 December, tissue from control trees had the lowest calcium concentration and frequently the least amount of cold hardiness. In woody stems of young apple trees, cold hardiness was more closely related to calcium concentration than that of the other eleven measured mineral elements; this was especially apparent from November to March (r = ?0.856).