Effects of Irrigation Frequency on Yield and Quality Parameters in Apple c.v. ‘Gala,Galaxy’

This study was conducted in 2007 and 2008 in order to determine the effects of irrigation frequency on the yield and quality parameters of dwarf trees of the apple cultivar ‘Gala, Galaxy’ in the first and second year of cultivation. Irrigation water was applied at 3?, 5?, 7?, and 10-day intervals as much as the amount of water consumed from the field capacity. Statistical analysis revealed that the effects of irrigation frequency on yield were significant. Since the trees used in the experiment showed mainly vegetative growth, the effects of irrigation frequency on the fruit quality characteristics varied. Irrigation water amount was applied as 355.7–446.5 mm and 359.2–538.9 mm to the experimental treatments in 2007 and 2008, respectively. The evapotranspiration measured was in the range 400.7–491.5 mm in 2007 but in the range 440.2–600.5 mm in 2008, while the yields in the same years ranged from 1.54 to 2.84 t ha^?1 and from 2.61 to 6.06 t ha^?1. Water use efficiency varied between 2.40 and 4.80 t ha^?1mm^?1 in the first year of the experiment but between 3.45 and 7.08 t ha^?1mm^?1 in the second year. The I₂ treatment, in which the highest yield and water use efficiency were recorded in both years of the experiment under the experimental conditions, was determined as the irrigation scheduling.     

Yield and Quality Response of Young ‘Gala,Galaxy’ Trees under Different Irrigation Regimes

This study was conducted in 2007–2008 to determine the effects of different irrigation regimes on yield, quality and water-yield relationships of young dwarf ‘Gala, Galaxy’ apple trees in Isparta-Turkey. Irrigation water was applied based on a ratio of class A pan evaporation (rates of 0.0 (k_cp0), 0.25 (k_cp1), 0.50 (k_cp2), 0.75 c (k_cp3), 1.00 (k_cp4) and 1.25 (k_cp5)) with 5-day intervals. The effects of irrigation regimes on yield and fruit weight were statistically significant. Seasonal evapotranspiration was measured as 246.5–608.2 mm and 289.3–631.9 mm in 2007 and 2008, respectively. Water use efficiency lead to a yield ranging from 0.0023 to 0.0055 t ha^?1mm^?1 and from 0.0033 to 0.0111 t ha^?1mm^?1 and irrigation water use efficiency varies from 0.0009 to 0.0073 t ha^?1mm^?1 and from 0.0045 to 0.0186 t ha^?1mm^?1 in 2007 and 2008, respectively. The annual average yield response factor, ky, was 1.22. As a result of the research, it was concluded that the irrigation schedule for the 0.75 k_cp3 treatment, applying 0.75 of evaporation from class A pan, could be used in the irrigation of young dwarf apple trees without evident reduction in yield and that high water use efficiencies could be obtained.     

Effects of Fertigation on Pigment Pattern and Fruit Quality of cv. ‘Gala’ Apples

Fruit pigmentation in ripening cv. ‘Gala, Schniga’ apples was monitored under the influence of fertigation weekly during 21 July–31 August 2009, i.e. 34 days before and 7 days after the optimal harvest date in Slovenia. The soil was a heavy loam clay with high humus content (2.8 %) and high acidity (low pH 4.9). The spectral indices NDVI (Normalized Difference Vegetation Index) and NAI (Normalized Anthocyanin Index) were obtained by a PA 1101 on attached fruit on the transition between the ground and blush colour of the fruit surface. NAI increased slowly from 0.25 to 0.6 two weeks prior to optimum maturity. NDVI values fell from 0.9 to 0.2 before and during ripening, with significant changes starting ca. 3 weeks before and during the week after the optimum harvest date. Fertigation delayed fruit ripening viz harvest date by ca. 4 days. Fertigation delayed changes in the intensity of the fruit’s epidermal pigments, expressed as NDVI for 1 week and NAI for 4 weeks, respectively, but had no significant effect on fruit colour or NDVI and NAI values at the optimal harvest date. At this time, those fruits from the fertigated trees were firmer with a lower starch index compared with the un-fertigated control. Statistically, highly significant correlations were found (p?≤?0.01) (r?=?0.35 to r?=?0.91, R²?=?0.11–0.83) between all the studied spectral and standard parameters i.e. fruit fresh firmness, soluble solids content and starch index.     

Long-Term Influence of Irrigation Systems on Postharvest Fruit Quality Attributes in Mature ‘Autumn Rose Fuji’ Apple Trees

ABSTRACT

In a long-term study between 2008 and 2011, effects of various evapotranspiration-based (ETc) irrigation systems on yield and fruit quality attributes of fully matured ‘Autumn Rose Fuji’ apple trees (Malus × domestica Borkh) after 5 months of regular atmosphere storage were examined. Trees with a full sprinkler (FS) system received about 39% more water than those with a full drip (FD) system over the period of 2008–2011. Fruits from trees with FS and FD were larger, while those with 50%FS were smaller than those from all other irrigation treatments. Averaging values over 4 years revealed that applications of any form of deficit irrigation, either by microjet irrigation or by drip, increased fruit-soluble solid concentration and firmness but decreased water core after storage. Trees receiving FS and FD systems (full irrigation systems) had lower fruit firmness reduction after storage than the treatments receiving deficit irrigation systems. Considering yield, and quality attributes in this study, a well-calculated ETc-based FD irrigation system is recommended over any other irrigation regime.     

Effects of Fruit Thinning Severity on Yield and Quality in ‘Sensation’ Mango （Mangifera indica）

Four different fruit thinning severities were tested.The thinning treatments were carried out in October before the occurrence of physiological fruit drop.Different parameters were measured(both qualitative and quantitative) and the results compared among treatments as well as to that of the control.The results showed that wher fruit on ‘Sensation’ mango pani-cles were thinned to two fruit per panicle,a significant difference was obtained for most of the quantitative parameters.The fruits of the treatment where one fruit per panicle was retained and 50% panicles removed,produced the best results for most of the qualitative parameters.     

The Effect of ‘Latent’ Virus Infections on the Yield of Maiden Trees on 20 Apomictic Apple Seedling Rootstocks

Five years’ experiments with apomictic apple seedling rootstock selections budded with apple cultivars have shown that incompatibility in Malus sieboldii, M. sargenti, M. hupehensis and their derivatives is mainly due to high sensitivity of the species rootstocks to viruses latent in commercial apple cultivars. The yields of maiden trees from rootstocks which were budded with material that was virus-free, infected with ‘latent’ viruses and infected with ‘latent’ viruses plus rubbery wood virus were 67%, 28% and 16%, respectively. There were, however, differences in the sensitivity reaction between the rootstocks tested. Fairly good compatibility with scions infected with ‘latent’ viruses was observed in the M. sieboldii root- stock selections 4542, 4556 and 4608 and in M. hupehensis.     

Influence of Melatonin Treatments on Fruit Quality and Storage Life of Sweet Cherry cv. ‘Sweetheart’

The study was carried out to determine the effect of melatonin on quality and postharvest life of sweet cherries (Prunus avium L.) cv. ‘Sweetheart’ during storage. The fruits were dipped at different concentrations of melatonin (0, 250, 500 and 1000?µmol l^?1 for 10?min) and distilled water as control. The changes of sweet cherries were assessed at 7?day intervals by evaluating the following quality parameters: firmness, soluble solids content, titratable acidity, respiration rate, color values (L* and chroma), ascorbic acid content, total anthocyanin content, total phenolic content, and antioxidant activity. The results showed that increasing the dose to 1000?µmol l^?1 melatonin had a remarkable effect on maintaining the quality of sweet cherry. 1000?µmol l^?1 and 500?µmol l^?1 melatonin treatments significantly inhibited the decrease in firmness, ascorbic acid, total phenols, total anthocyanin, antioxidant content and reduced color changes and respiration rate. However, the total soluble solids content and titratable acidity of the fruit were not influenced by melatonin applications. These findings indicate that melatonin treatment may be effective in maintaining quality and bioactive compounds of sweet cherry fruit.

     

Calcium and Potassium Foliar Sprays Affect Fruit Skin Color,Quality Attributes,and Mineral Nutrient Concentrations of ‘Red Delicious’ Apples

This study was conducted to evaluate the influences of foliar spray of potassium (K), calcium (Ca), and their combination on the fruit red skin color and quality attributes of ‘Red Delicious’ apple under conditions of south central Iran with warm and dry summer, where low and high temperature differences are low. The trees were sprayed five times using 5 g L^–1 calcium chloride (CaCl₂) at 3-week intervals starting from 3 weeks after full bloom and three times (at 9, 12, and 15 weeks after full bloom) using 2.5 g L^–1 K sources [potassium chloride (KCl), potassium sulfate (K₂SO₄), and potassium nitrate (KNO₃)] during two growing seasons in 2013 and 2014. Anthocyanin, some physicochemical attributes, and fruit mineral concentrations were measured at harvest. Results showed that spraying with K, CaCl₂, and their combinations significantly increased fruit weight, sugar and anthocyanin concentrations, firmness, and K uptake. A combined foliar application of CaCl₂ and each of the K sources was more effective on the improvement of fruit color, firmness, fruit K and Ca uptake, and K/Ca ratio as compared to the case when either K or Ca was applied alone.     

Effects of 22S, 23S-Homobrassinolide and Gibberellic Acid on Occurrence of Physiological Disorders and Fruit Quality of ‘Summit’ and ‘Regina’ Sweet Cherries

Plant growth regulators play a vital role in fruit growth and development. However, effects of compounds belonging to the group of brassinosteroids have not been fully investigated in sweet cherries. One relatively new and one commonly applied growth regulator, 22S, 23S-Homobrassinolide and GA₃, respectively, were tested on ‘Summit’ and ‘Regina’ sweet cherries to determine the effects on fruit quality and physiological disorders. The substances were applied with a handgun sprayer at full bloom and at the beginning of fruit development (shuck split) for a 2-year period. GA₃ was applied at the concentrations of 25, 50, 100 mgL^?1 and 22S, 23S-Homobrassinolide at 0.05, 0.1, 0.5 mgL^?1. A combined application of 100 mgL^?1 GA₃ + 0.1 mgL^?1 22S, 23S-Homobrassinolide was also applied. Effects of GA₃ and 22S, 23S-Homobrassinolide on fruit weight and size were evident for the concentrations applied and between the seasons for both of the cultivars. Combination of the both growth regulators and 100 mgL^?1 GA₃ alone produced longer fruits compared to the control trees in ‘Regina’. The 22S, 23S-Homobrassinolide applications increased the firmness of the flesh slightly, but not to a great degree, compared to the GA₃ applications alone. The brightness of the red color was better with GA₃ applications in ‘Summit’ and ‘Regina’. Brassinosteroid caused the fruits to have comparably dull red color. Total soluble solid contents of the cultivars were influenced by the substances and the year of the application. Stem resistance to separation from the fruit was under the influence of both treatments and seasons. In general, 22S, 23S-Homobrassinolide provided better stem resistance than the GA₃ applications. There were no effects of the substances on the development of physiological disorders.     

Individual and combined effects of shading and thinning chemicals on abscission and dry-matter accumulation of ‘Royal Gala’ apple fruit

Summary

Shade and chemical thinning treatments were applied to mature ‘Royal Gala’/M.26 apple trees either alone or in combination to study their effects on the pattern of abscission and growth of spur fruit. Natural fruit drop occurred in two distinct waves in both years; the first wave peaked 20 d after bloom (DAB) at a weekly abscission rate of c 15% in both years. The second wave of fruit drop in 2001 occurred earlier and was more intense than in the previous season. Application of NAA as a bloom thinner increased the maximum weekly abscission rate during the first wave of fruit drop in both years. Chemical fruit thinning treatments (Carbaryl in 2000, BA or delayed lime sulphur in 2001) had no effect on abscission or growth of spur fruit. Covering trees with 80% shade cloth for 3 d (2000) or 5 d (2001) stimulated a wave of fruit abscission that peaked c 10–15 d after removal of the cloth. Shade during the period from 20–25 DAB stimulated more fruit drop than earlier shade treatments, resulting in weekly abscission rates as high as 70%.There were no additive effects of combining thinning chemicals and shade treatments on abscission of fruit from spurs. However, additive effects of shade and thinning treatments were observed when measured as whole-tree crop density values, indicating that abscission of fruit from one-year wood was stimulated when low light conditions preceded application of (fruit) thinning chemicals. Shading trees from 34–39 DAB in 2000 resulted in a transient reduction and subsequent increase in the rate of dry-matter accumulation in fruit that were retained. Considerable challenges lie ahead in developing models of fruit growth that can account for the inter-dependent effects of light and crop load on fruit abscission and development that exist within an orchard environment.     

Foliar Spray with Different Agrochemicals on Fruit Quality and Exportability of ‘Washington’ Navel Orange Fruit (Citrus sinensis L.)

The present study was carried out to improve fruit set, yield, quality, marketability, and exportability of ‘Washington’ Navel orange. Pre-harvest foliar sprays of GA₃, K, and Ca, either alone or combined, were applied at full bloom. The following treatments were applied: {control (T₁), 25 mg/L GA₃ (T₂), 2% K₂SO₄ (T₃), 25 mg/L GA₃ + 2% K₂SO₄ (T₄), 25 mg/L GA₃ + 2% Ca Cl₂ (T₅), 2% K₂SO₄ + 2% Ca Cl₂ (T₆), and 25 mg/L GA₃ + 2% K₂SO₄ + 2% Ca Cl₂ (T₇). All treatments improved fruit set, yield, physical and chemical characteristics, mineral content of leaves and fruit rind, and the percentage of exportable fruit in comparison to the control. Fruit set, fruit detachment force, peel firmness, and the mineral content of leaves and fruit rind were enhanced significantly with the combination of GA₃ + K₂SO₄ + Ca Cl₂ (T₇) in comparison to all other treatments and the control. Results indicated that all foliar combination treatments improved fruit quality and marketability, and increased the percentage of exportable fruit and reduced the defects of non-exportable fruit.     

Impact of Leaf Removal on Yield Components and Monoterpene Composition during Maturation of Vitis vinifera L. CV ‘Italia’ Cultivated in Tunisia

ABSTRACT

The effect of leaf removal on the yield components, the fruit composition and the free and bound monoterpenol concentrations during maturation of Vitis vinifera L. ‘Italia’ berries were studied over two years (2002 and 2003). Results suggest that leaf removal treatments had no impact on berry and cluster weights, whereas it induced a significant modification in chemical composition of the fruit expressed by Brix degree, titratable acidity, and monoterpenol concentrations.     

Potassium Mineral Nutrition Combined with Sustained Deficit Irrigation to Improve Yield and Quality of a Late Season Peach Cultivar (Prunus persica L. cv ‘Chatos’)

ABSTRACT

Fruit quality traits are directly related to agronomic practices such as irrigation and fertilization, especially potassium supply since its effects on quality and water drought resistance. The objective of this study was to evaluate the effect of different combinations of potassium rate and application mode (in soil: 200S and 100S, foliar spray: 100F) with two irrigation regimes (FI: irrigation with 100%ETc and DI: irrigation with 66%ETc) on peach yield and quality parameters. The experiment was performed during two consecutive years. At harvest, only in the second year significant differences between treatments were observed in yield. In fact, potassium foliar spray, even in DI regime, improved yield. The fruit diameter was slightly affected by treatments in the first year. However, in the following season foliar potassium spray even in DI water regime increased fruit size. Concerning the firmness, no significant differences were observed in the first year except for the second year it decreased with DI strategy independently of potassium treatment. The soluble solids content was strongly affected by the treatments. The highest values were observed in 100F+DI treatment with no significant effect on acidity. Vegetative growth was affected only by water regime which DI reduced shoot length.     

Investigations on Chlorosis of Fruit Trees.: II.—The Composition of Leaves,Bark and Wood of Current Season’s Shoots in Cases of Lime-Induced Chlorosis.

Summary

Radish (Raphanus sativus) is an important crucifer vegetative crop in Japan. We studied the morphological and anatomical characteristics of radish roots over a 6-week period using three radish cultivars with three different root shapes: long-type (Lt), round-type (Rt), and thin-type (Tt). We found that significant differences in the thickness of the roots first appeared 4 weeks after sowing. In Lt and Rt plants, the roots thickened rapidly, especially in the middle section that is composed of the lower part of the hypocotyl and the upper part of the taproot. The taproot increased in length in Lt plants, but failed to elongate in Rt plants. In Tt plants, the roots showed much smaller increases in mean diameter and length. Transverse sections through the taproots showed significant differences, both in cell number and in cell size 4 weeks after sowing. Lt and Rt plants contained more cells in the secondary xylem and phloem than Tt plants, and cell expansion was also greater in the storage roots of the Lt and Rt cultivars. These results will contribute to a better understanding of the development of radish roots of different shape.     

Rootstock Induced Seasonal Changes of N,P and K Nutrient Levels in Satsuma Mandarin cvs. ‘Okitsu’, ‘Clausellina’ and ‘Silverhill’

Rootstocks-scion relations have critical consequences about nutritional status, tree vigour, resistance to pest and pathogens, yield and yield quality. In this study, we therefore investigated seasonal variations of leaf mineral nutrient concentrations in Satsuma mandarin’s cvs. ‘Okitsu’, ‘Clausellina’ and ‘Silverhill’ budded on different citrus rootstocks under Dörtyol-Hatay, Turkey ecological conditions. Nitrogen (N), phosphorus (P) and K (potassium) concentrations of the leaves showed slightly similar trend each other, in general these nutrients reduced from January to March–April, and increased during the growing season until mid- and late summer, then decreased until December. Despite rootstocks did not significantly affect the leaf N, P and K concentrations rootstock-scion relation was pre-eminent and nutrient dependent. Most conspicuous scion dependent changes were recorded for K concentration whereas P concentration was little influenced. In terms of scion-rootstock combination, the range of N and K concentrations were 2.11% (‘Okitsu’/sour orange) to 2.34% (Silverhill/sour orange), and 1.09% (‘Okitsu’/Carrizo citrange) to 1.39% (‘Clausellina’/Carrizo citrange), respectively; but P concentrations were highly similar %0.13 (‘Okitsu’/sour orange) – %0.16 (‘Clausellina’/Carrizo citrange), in the entire growing season. It can be concluded that there are considerable differences in nutrient uptake ability of scion-rootstock combination.     

Performance of ‘Discovery’ apple on M.9, M.26 and MM.106 rootstocks at two densities

Summary

The apple rootstocks M.9, M.26, and MM.106 were evaluated for their efficiency in bringing ‘Discovery’ apple trees into production. The experiment, carried out over a ten- year period compared two planting densities at 1666 and 3333 trees per ha. Tree vigour differences between rootstocks were measured in term of trunk growth, tree volume, weight of branches pruned off and final weight of the above-ground parts of the trees. Fruit production is presented both as total yield and as the weight of first class fruit. Fruit colour development is also shown. Cropping efficiency is calculated and presented in relation to the different vigour measurements. The results confirm that ‘Discovery’ is slow to come into production. M.9 was the most productive rootstock, but due to vigour differences MM.106 gave the same yields per tree, although the latter had the lower yield efficiency. M.26 performed poorly; its vigour was similar to M.9 but it produced the lowest yields.     

Effects of Plant Growth Promoting Rhizobacteria (PGPR) on Growth,Yield and Fruit Quality of Sour Cherry (Prunus cerasus L.)

The sour cherry cv. ‘Kütahya’ is one of the most produced cultivars in Turkey. This study was conducted with cultivar ‘Kütahya’ cultivated on Prunus mahalep both 2010 and 2011 years. In this study, the effects of Bacillus mycoides T8 and Bacillus subtilis OSU-142 bacteria strains on yield, fruit properties and plant growth was aimed to investigate. Floral and foliar applications of T8, OSU-142 and T8+OSU-142 on sour cherry significantly increased the yield per tree, shoot length and leaf area, compared with the control. The highest shoot length was found in the T8+OSU-142 (51.74 cm) application while the least value was found in the control (46.71 cm). The yield increased from 8.229?kgtree^?1 (in control) to 13.663 (T8 application) and to 11.660?kgtree^?1 (T8+OSU-142 application) in average of two years. The results of the present study suggested that Bacillus T8 and Bacillus OSU-142, alone or in combination, have a great potential for the enhancement of yield and plant growth of sour cherry and therefore they have been suggested in growth promotion in sour cherry cultivation.     

Evidence of Clonal Variation and Latent Virus Effect on the Vigour of Cox’s Orange Pippin Apple Trees on M.9 Rootstocks

Apple trees on M.9 EMLA rootstocks free from known virus are at least 50% larger than those on M.9a containing latent virus. Evidence is presented that about half of this difference can be attributed to clonal variation and the rest to virus effects.     

Effect of agar,galactomannan and indole-butyric acid on in vitro rooting of the pear cultivar ‘Durondeau’ and apple rootstock cultivar ‘Marubakaido’

Summary

The influence of partial substitution of agar by galactomannans in culture media supplemented with different concentrations of indole-3-butyric acid (IBA) was studied on in vitro rooting of pear (Pyrus communis L.) cultivar ‘Durondeau’ and apple rootstock (Malus prunifolia Borkh.) cultivar ‘Marubakaido’. The galactomannans applied were obtained from Cassia fastuosa (cassia) and Cyamopsis tetragonolobus (guar gum) seeds. The results obtained with mixtures of agar and galactomannan (3 g l^–1 each) were compared with those from media solidified with a standard concentration of agar (6 g l^–1). The rooting of pear shoots was enhanced significantly in the presence of a mixture of agar plus cassia galactomannan compared to medium solidified with agar only. The modified media promoted a higher number of roots than the control, and increased the percentage of rooted shoots. A maximum of 84.8% rooting was obtained on half-strength MS medium (¹?2MS) supplemented with 0.49 µM IBA and solidified with a blend of agar plus cassia galactomannan. For the apple rootstock, only the number of roots per shoot was influenced significantly by the addition of galactomannan to the rooting medium. The highest number of roots per shoot was 16.67 on ¹?2MS medium gelled with a mixture of agar plus guar galactomannan supplemented with 4.90 µM IBA. The behaviour of the agar-galactomannan gel and the possibility of reduced costs when compared with systems containing only agar, suggest new biological and commercial applications for galactomannans.