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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.

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.

Can nutritional status of apple trees be determined by leaf analysis in early vegetation

ABSTRACT In this study, whether the nutritional status of apple trees can be predicted in the early stages of vegetation was determined by leaf analysis. For this purpose, from different districts of Isparta province in Turkey where apples are cultivated extensively, 150 apple orchards were assessed according to the production potential of districts. The leaf samples were collected at six different stages of vegetation from these orchards, and nitrogen, phosphorus, potassium calcium, magnesium, iron, copper, zinc, manganese, and boron (N, P, K, Ca, Mg, Fe, Cu, Zn, Mn and B) amounts were determined. Correlations were examined between the sixth period and the previous periods. The presence of significant correlations was interpreted, as leaf analysis can be used to determine the nutritional status of apples in the early growth period. Consequently, it was determined that leaf analysis can be carried out at any time from the beginning of vegetation for all elements except Fe and Cu.

Nitrogen fertilization affected the pollen production and quality in apple cultivars “Jerseymac” and “Golden Delicious”

Abstract Pollen quality is very important for apple production because of its gametophytic self-incompatibility. This study was conducted to determine the effects of different nitrogen fertilization doses on pollen production and quality in apple cultivars “Jerseymac” and “Golden Delicious” in Egirdir province of Turkey. Apple trees were fertilized with 0, 30, 60, and 90 g nitrogen per tree in each year during five consecutive years between 2001 and 2005. Nitrogen fertilization significantly affected pollen production and quality in both apple cultivars. The highest pollen number (55,087) as well as the highest percentage of viable (45.6%) and germinated pollens (62.1%) were determined from 60 g nitrogen fertilization dose in apple cultivar “Jerseymac.” However, differences between 30, 60, and 90 g per tree nitrogen doses were not significant. Likewise, 60 g nitrogen fertilization per tree also resulted in the highest number of pollens (84,395) and the percentage of viable pollens (52.1%) in apple cultivar “Golden Delicious.” The highest percentages of germinated pollens were obtained from the 30 (54.8%) and 60 g nitrogen fertilization (59.6%) doses in apple cultivar “Golden Delicious.” The number of anthers per flower and morphological homogeneity were not affected by nitrogen fertilization treatments in both apple cultivars.

Effects of transition from flood irrigation to drip irrigation on leaf nutrient concentrations of apple cv. Starkrimson Delicious

Abstract In Turkey, fruit growers have started to shift from flood irrigation to drip irrigation in apple orchards in the recent years. It was thought that such a transition might have adverse effects on nutrition of the plants throughout the transition period. In this study, effects of transition from flood irrigation to drip irrigation on nutrient uptake of the plants were investigated through leaf analyses for two years. Experiment was conducted in randomized blocks design with three replications and four trees in each replication. Flood irrigation (control) and drip irrigation with two different irrigation intervals (4 and 7 days) were compared. Leaf samples were collected in the middle of the growth period and their nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and boron (B) contents were determined. Present findings revealed that transition from flood irrigation to drip irrigation did not result in any nutritional problems. On the other hand, significant increases were observed in contrary, the uptake of P, Fe, Mn, Zn, and B uptake of the plants.

Interpretation of Leaf Analysis Performed in Early Vegetation in Apple Orchards

ABSTRACT Mid-summer leaf analyses are commonly used as the standard method worldwide to assess the nutritional status of fruit trees. It may be too late to correct nutritional disorders by mid-summer. In this study, reference values that will be used to evaluate the nutritional status of apple trees early in the growing season were derived. To determine the reference values for all sampling periods, the regression curves were created by using the reference values of each period. Correlations were examined between the sixth period and earlier sampling times. The presence of statistically significant correlation coefficients was interpreted as leaf analysis can be used to determine the nutritional status of apples in the early season. It was concluded that leaf analysis can be carried out anytime from commencing two weeks after full loom to lasting 98 days after full bloom for all elements except Iron and Cupper.

Farklı Potasyum Dozlarının Jerseymac ve Golden Delicious Elma Çeşitlerinde Çiçek Tozu Kalitesi ve Üretim Miktarlarına Etkisi

B u calisma Egirdir (Isparta)’ de M9 anaci uzerine asili 4 yasindaki Jerseymac ve Golden Delicious elma cesitlerinde yapilmistir. 4 yil sure ile azot ve fosfor dozlari sabit olmak uzere farkli potasyum dozlari (0,50,100 ve 150 g/agac) uygulanmis agaclardan cicekler acmadan once (balon asamasinda) alinan orneklerde, in vitro kosullarda cicek tozu canlilik ve cimlenme yetenekleri, cicek tozu sayisi, anter sayisi ve morfolojik homojenik durumlari incelenmistir. Elde edilen sonuclara gore potasyum uygulamalari cicek tozu canliligi, cicek tozu sayisi ve cimlenme oranini artirmis olup en yuksek degerler 50 g ve 100 g K2O/agac uygulamalarindan elde edilmistir