Yield and fruit quality of apple from conventional and organic production systems

The objective of this study was to assess the yield and fruit quality of apple produced with a conventional and an organic production systems in Southern Brazil. The orchards consisted of alternate rows from 10 to 12-year old 'Royal Gala' and 'Fuji' apple trees on M.7 rootstocks, grown as slender spindles, on 4x6 m spacing. Eighteen apple trees of each cultivar and management system were randomly selected and assessed for nutrition, flowering, fruit set, yield, and fruit quality during two growing seasons (2002/2003 and 2003/2004). The organic management system resulted in lower concentrations of K, Mg, and N in leaves and fruits, and in smaller fruits for both cultivars, and lower fruit yield for 'Fuji' than from the conventional production system. For both cultivars, fruits from the organic orchard harvested at commercial maturity had a more yellowish skin background color, higher percentage of blush in the fruit skin, higher soluble solids content, higher density, higher flesh firmness, and higher severity of russet than fruits from the conventional orchard. Fruit from the organic orchard had lower titratable acidity in 'Royal Gala', and higher incidence of moldy core and lower incidence of watercore in 'Fuji', than fruit from the conventional orchard. A non-trained sensory panel detected no significant differences for fruit attributes of taste, flavor and texture between fruit from the production systems for either cultivar.

Postharvest mechanical damage affects fruit quality of 'Montenegrina' and 'Rainha' tangerines

The objective of this work was to evaluate the visual and chemical quality of tangerines after mechanical damage by impacts. The tangerine cultivars Montenegrina and Rainha were submitted to different degrees of impact and evaluated for decay and oleocellosis, loss of fresh weight, total soluble solids, total titratable acidity and ascorbic acid degradation, as well as for epicarp color changes. Experiments with three replicates and experimental units of six fruit for each cultivar were done in a completely randomized design. Impact produced qualitative internal and minor external changes on tangerines. The main modifications produced by impact on the fruit were losses of citric acid and soluble solids, which increased the solid:acid ratio, and losses of ascorbic acid. 'Montenegrina' tangerines are more susceptible to internal quality damage than 'Rainha'.

Effect of preharvest spraying with thidiazuron on fruit quality and maturity of apples

Apple trees, cultivars Gala and Fuji, were sprayed at full bloom with thidiazuron (TDZ) at the doses of 0, 5, 10, or 20 g (a.i.) ha-1 and fruit were assessed for quality and maturity. In both cultivars, the increase of TDZ dose had detrimental effects on fruit quality, causing a reduction of fruit red surface and an increase of percentage of fruit that was asymmetrical and with calyx-end rot. TDZ caused an increment of calyx-end aperture that might have increased calyx-end rot. TDZ increased density and the length : diameter (L : D) ratio of the fruit. The number of viable seeds was not affected by TDZ. TDZ resulted in a substantial delay of fruit maturity in 'Gala' but not in 'Fuji'. TDZ also reduced soluble solids content (SSC) in 'Gala' and reduced titratable acidity in both cultivars.

Pineapple yield and fruit quality effected by NPK fertilization in a tropical soil

There is a lack of information about fertilization of pineapple grown in the State of São Paulo, Brazil. So a field experiment with pineapple 'Smooth Cayenne' was carried out to study the effects of NPK rates on yield and fruit quality. The trial was located on an Alfisol in the central part of the State of São Paulo (Agudos county). The experimental design was an incomplete NPK factorial, with 32 treatments set up in two blocks. The P was applied only at planting, at the rates of 0; 80; 160 and 320 kg/ha of P2 0(5), as superphosphate. The N and K2O rates were 0; 175; 350, and 700 kg/ha, applied as urea and potassium chloride, respectively, divided in four applications during the growth period. Response functions were adjusted to yield or to fruit characteristics in order to estimate the nutrient rates required to reach maximum values. The results showed quadratic effects of N and K on yield and a maximum of 72 t/ha of fresh fruit was attained with rates of 498 and 394 kg/ha, respectively of N and K2O. In order to reach the maximum fruit size, and to improve the percentage of first class fruit (mass greater than 2.6 kg), were necessary rates of N and K respectively 11 and 43 % higher than those for maximum yield. No effect of P rates was observed on pineapple plant growth, despite the low availability of this nutrient in the soil. The effect of N rates was negative on total soluble solids and total acidity while the opposite occurred with K, which increased also the content of vitamin C. High yield and fruit size were closely related to N and K concentrations in the leaves.

Fruit quality of 'Tahiti' lime (Citrus latifolia Tanak) grafted on twelve different rootstocks

In the present work, the effect of twelve rootstocks on fruit quality of the nucellar clone IAC-5 of 'Tahiti' lime, (Citrus latifolia Tanaka) and the influence of fruit position on tree in fruit quality was evaluated in the Citrus Experimental Station of Bebedouro (EECB), located in the Bebedouro county, state of São Paulo, Brazil. A 8.0 x 5.0m planting frame was utilized. The evaluated rootstocks were: 'Carrizo' citrange (C. sinensis (L.) Osbeck x Poncirus trifoliata (L.) Raf.); the hybrids 'Rangpur' lime x 'Swingle' citrumello (C. limonia Osbeck x P. trifoliata Raf) and 'Changsha' x 'English Small'(C. sunki Hort. ex Tan. x P. trifoliata Raf.); the mandarins 'Sun Chu Sha Kat' (C. reticulata Blanco) and 'Sunki' (C. sunki Hort. ex Tanaka); the 'Rangpur' limes 'Cravo Limeira' and ' Cravo FCAV' (C. limonia Osbeck); the 'Swingle' citrumello (P. trifoliata Raf. x C. paradisi Macf.); the 'Orlando' tangelo (C. reticulata Blanco x C. paradisi Macf.) and the trifoliates cvs. 'Rubidoux', 'FCAV' and 'Flying Dragon' (P. trifoliata Raf.). The experiment was arranged in a randomized block design, with twelve treatments, six replicates and one plant per plot. The rootstocks induced differences in fruit quality; however, all the evaluated quality characteristics were within the values considered as normal and acceptable for the variety, constituting good alternative rootstocks for the 'Rangpur' lime. Additionally, the fruit position in the plant (northeastern or southwestern) had a significant influence on the external fruit color regardless of the rootstock.

Soil nutrient availability and its impact on fruit quality of Tahiti acid lime

The Tahiti acid lime in Brazil is mostly grown in the São Paulo State. The value of this crop production ranks among the ten most important fruits in the country. The Brazilian exports of Tahiti limes have increased in the last years with a corresponding increased demand for superior quality of fresh fruits, which is affected by mineral nutrients. Therefore, this study evaluated nutrient soil availability and its influence on nutritional status of trees based on the determination of leaf and fruit nutrient concentrations, fruit characteristics, and post harvest quality. Eleven commercial groves with trees older than 4-yr and differently managed were studied. Plots with six trees in each grove were sampled for soil (0-20 cm depth layer), leaf and fruit analyses with three replicates. Correlation coefficients were pair wised established for all variables. The results showed that N leaf concentration was well correlated with green color of fruit peel as measured by a color index (r = -0.71**), and which was optimum with Leaf-N around 22 g kg-1. Leaf-Ca was inversely correlated with fruit water loss after 14-day interval from harvest (r = -0.54*) demonstrating that Ca plays an important role in Tahiti fruit shelf-life. Data also suggested that increased fruit K concentration correlated with increased fruit water losses during storage (r >0.58*).

Blueberry pollination in southern Brazil and their influence on fruit quality

Blueberry (Vaccinium ashei) is a relatively new crop in cultivation under Southern Brazil conditions. The first collection introduced in the area was formed by rabbiteye cultivars which need insect pollinators and also pollinizers. The aim of this work was to observe if there were differences between pollinizers on fruit quality of the commercial cultivar and also to observe the most effective and frequent insect pollinators, under natural conditions. It was concluded that pollen source has an effect on quality of blueberry fruits. Bumblebees are the most efficient pollinators; however the species found in southern Brazil are different from the ones mentioned in the U.S. literature.

THE ROLE OF MINERAL NUTRITION ON YIELDS AND FRUIT QUALITY IN GRAPEVINE, PEAR AND APPLE

ABSTRACT Fertilization of temperate fruit trees, such as grapevine ( Vitis spp.), apple ( Malus domestica), and pear ( Pyrus communis) is an important tool to achive maximum yield and fruit quality. Fertilizers are provided when soil fertility does not allow trees to express their genetic potential, and time and rate of application should be scheduled to promote fruit quality. Grapevine berries, must and wine quality are affected principally by N, that regulate the synthesis of some important compounds, such as anthocyanins, which are responsible for coloring of the must and the wine. Fermenation of the must may stop in grapes with low concentration of N because N is requested in high amount by yeasts. An N excess may increase the pulp to peel ratio, diluting the concentration of anthocyanins and promoting the migration of anthocyanins from berries to the growing plant organs; a decrease of grape juice soluble solid concentration is also expected because of an increase in vegetative growth. Potassium is also important for wine quality contributing to adequate berry maturation, concentration of sugars, synthesis of phenols and the regulation of pH and acidity. In apple and pear, Ca and K are important for fruit quality and storage. Potassium is the most important component of fruit, however, any excess should be avoided and an adequate K:Ca balance should be achieved. Adequate concentration of Ca in the fruit prevents pre- and post-harvest fruit disorders and, at the same time, increases tolerance to pathogens. Although N promotes adequate growth soil N availability should be monitored to avoid excessive N uptake that may decrease fruit skin color and storability.

Grafted eggplant yield, quality and growth in infested soil with Verticillium dahliae and Meloidogyne incognita

The objective of this work was to evaluate the effect of grafting (onto Solanum torvum Sw.) on plant growth, yield and fruit quality of the Pala and Faselis eggplant (Solanum melongena L.) cultivars, grown in a soil infested with Verticillium dahliae Kleb. and Meloidogyne incognita, or in noninfested soil. Soil infestation decreased yield, plant height, final above-ground biomass, and also reduced fruit mean weight and shoot dry weight depending on cultivar or grafting. Grafting decreased fruit oxalic acid and the soluble solid contents, and increased mean fruit weight, depending on cultivar and soil infestation. Grafting also reduced the negative effects of the pathogens on disease index, plant height and shoot dry weight. Cultivar Pala was more vigorous than Faselis, and S. torvum was a vigorous rootstock. The combination of a vigorous rootstock with a weak cultivar (Faselis) is more profitable than that of a vigorous rootstock and a vigorous cultivar (Pala). Using S. torvum as a rootstock for cultivar Faselis, grown in soil infested with the pathogens, is most likely to be useful in conventional and low-input sustainable horticulture, since grafting increases protection against the pathogens, and reduces the losses in quality and yield.

'Royal Gala' apple quality stored under ultralow oxygen concentration and low temperature conditions

The objective of this work was to evaluate the interaction of ultralow oxygen concentrations (ULO) with storage temperatures and carbon dioxide partial pressures and its influence on fruit quality preservation and on the occurrence of physiological disorders in 'Royal Gala' apples. The experiment was carried out in a completely randomized design, with four replicates 25-fruit. ULO conditions (1.0 kPa O2 + 2.0 kPa CO2; 0.8 kPa O2 + 1.5 kPa CO2; 0.8 kPa O2 + 1.0 kPa CO2; 0.6 kPa O2 + 1.5 kPa CO2; and 0.6 kPa O2 + 1.0 kPa CO2) were tested at 0, 0.5 and 1.0°C, in a 5x3 factorial arrangement. Fruit quality and ripening analyses were performed after eight-month storage plus seven days of shelf-life at 20°C. Oxygen partial pressures below 0.8 kPa increased the occurrence of internal breakdown and mealiness. The best ULO condition was 1.0 kPa O2 + plus 2.0 kPa CO2 at 1.0°C. The interaction of ULO conditions and storage temperatures shows the need of increasing O2 partial pressure at higher storage temperatures.

Effect of aminoethoxyvinilglycine (AVG) on preharvest fruit drop and maturity of apples

Apple trees cultivars Gala and Fuji were sprayed four weeks before commercial harvest with aminoethoxyvinilglycine (AVG), at doses of 0, 125, or 250 mg L-1, and assessed for preharvest fruit drop, fruit growth, and maturation on tree. In 'Gala', 64 days after AVG spraying, fruit drop for control treatment was 85%, and AVG (at 125 and 250 mg L-1) reduced it to 10%. In 'Fuji', 64 days after AVG spraying, fruit drop for control was 6%, while treatments with AVG (at 125 and 250 mg L-1) increased fruit drop to 10%. AVG was a powerful retardant of fruit maturation for 'Gala' but not for 'Fuji'. In 'Gala', the most affected attribute was the skin background color, followed, in decreasing order, by soluble solids content, the starch index, skin red color, the flesh firmness, and titratable acidity. In 'Gala', only flesh firmness retention was improved by increasing AVG dose from 125 mg L-1 to 250 mg L-1. The AVG at 250 mg L-1 inhibited "Gala" late fruit growth but not 'Fuji'.

Effects of levels of nitrogen and potassium on yield and fruit maturation of irrigated guava trees in the São Francisco Valley

Yield and physical and chemical characteristics of 'Paluma' guava fruit were evaluated as a function of the harvest at different maturity stages, under influence of nitrogen and potassium fertilization, in Petrolina, State of Pernambuco, Brazil. Fertilizer rates were 67 kg N + 33 kg K2O, 133 kg N + 67 kg K2O, 200 kg N + 100 kg K2O and 267 kg N + 133 kg K2O per hectare. Fruits were evaluated at maturity stages 2, 3, 4 and 5, established according to peel color. Higher doses of N and K induced higher yields. Nevertheless, fertilization with 200 kg of N + 100 kg of K per hectare improved fruit quality, delaying ascorbic acid breakdown and conserving pulp firmness. Main changes took place at maturity stages 4 and 5, when the fruit should present ideal conditions for consumption, namely the increase on soluble solids and soluble sugars content.

Addition of nitrogen had no effect on yield and quality of apples in an high density orchard carrying a dwarf rootstock

The effect of N addition on apple yield and quality may vary according to the tree vigor. Apple trees developed over vigorous rootstocks had shown no response to N application in Brazil. In this study it was evaluated the effect of N addition to the soil on yield and quality of ´Royal Gala´ apples grafted on a dwarf rootstock (M.9). The orchard was planted in 1995 (2,857 trees ha-1) on an Oxisol containing 40 g kg-1 of organic matter and pH 6.0. The experiment was carried out from 1998 up to 2005. Treatments consisted of rates of N (0, 50, 100 and 150 kg ha-1 year-1 from 1998 to 2001, and respectively 0, 100, 200 and 300 kg ha-1 afterwards), all broadcasted within the tree row in two equal splits, at bud break and after harvest, as ammonium sulfate. Addition of N to the soil had no effect on fruit yield over the six years regardless of the applied rate. Averaged across treatments and years, fruit yield was 52.3 t ha-1. Nitrogen in the leaves (average of 24 g kg-1) or in the fruits (average of 346 mg kg-1) as well as some attributes related to fruit quality (color, firmness, acidity, soluble solids, physiological disorders) were unaffected by N addition. Some plant parameters related to tree vigor, however, grew higher with the increase on N rate. Thus, it is not necessary to apply N to deep Brazilian soils containing high organic matter in order to assure good fruit quality and yield on high-density orchards carrying dwarf rootstocks probably because the N required for tree growth and fruit production is supplied from soil organic matter decay.

Fruit production in Chile: bright past, uncertain future

In 2007 (the last agricultural census), Chile had 308, 445 ha of fruit orchards: an increase of almost 32% from the previous census (1997). The most important species were table grapes (20%), avocados (13%) and apples (12%). Some 22% of the fruit crops growing area corresponded to juvenile orchards; within the species with higher proportion of juvenile orchards were prunes (42%) and blueberries (56%). Most orchards are located between latitude 27º18` S (Copiapó) and 40º36´S (Puerto Varas). The industry is driven by the export component which accounts for more than 50% of the fruits produced. In the crop season 2009-2010, approximately 254 million boxes (around 2.5 million tons) were exported, representing over US$ 3.5 million. Processed and fresh fruits represented 8.2 and 26.7% of the total forest and agricultural Chilean exports in 2008, respectively. The main markets for this fruits were USA/Canada (42%) and Europe (32%). The fruit grower receives, on average, 12-16% of the total price of the fruit in its final destination. Each year the fruit industry employs 450.000 people directly, of which 1/3 are permanent. Even though the fruit industry employs the highest proportion of the agricultural labor and the growing area has increased in the last 20 years, the proportion of agricultural employment has decreased from 19.5% in 1989 to 10.8% in 2008. It might also be noted that Chile invests only 0.7% of the GDP in research. In the last 40 years, the fruit industry has been a motor for the Chilean economic development, but the lower rates of currency exchange, the rising costs of energy (oil, electricity), and the increasing scarcity of hand labor have drastically reduced the profitability and are putting at risk the viability of a large proportion of the fruit orchards in Chile. It is estimated that this season around 65% of the orchards will have a negative economic balance in their operations. Higher investment in research, improvements in fruit quality and various orchard management practices, as well as higher financial support from the Government are needed for the long term viability of the fruit industry in Chile.

Nitrogen and potassium fertilization affecting the plum postharvest quality

The goal of this research was evaluated the effects of potassium and nitrogen fertilization on the plum (Prunus salicina) fresh fruit quality and after cold storage. The experiment was carried out in a five year-old plum orchard 'Reubennel', located at Araucaria County, Parana State, Southern Brazil, in a Haplumbrept Soil. Potassium fertilizer was applied at 55 and 110 kg/ha/year of K2O, as KCl. Nitrogen fertilizer was applied at 40, 80, 120, 160 and 200 kg/ha/year of N, as urea. It was used a split-plot design in a factorial scheme (2x5). One hundred plum fruits were harvested from each plot, in the same day, when 25 to 50% of the peel presented yellow-reddish color. At harvest and after 17, 27 and 37 days of storage at 0 ± 0.5 ºC, the flesh firmness, the total soluble solids, and the titratable acidity were assessed. Fresh fruit quality was affected by N application, with the best results obtained by applying 40 kg/ha/year of N. The N and K rate of 40 and 110 kg/ha/year, respectively, kept superior fruit quality during the storage. 'Reubennel' cold storage can not exceed 27 days. Fresh and stored 'Reubennel' plum fruit qualities depend on the N and K fertilizer rates.