Effects of phosphorus fertilizer supplementation on antioxidant enzyme activities in tomato fruits

The effects of soil and foliar phosphorus supplementation on the activities and levels of superoxide dismutase (SOD), guaiacol peroxidase (POX), and ascorbate peroxidase (APX) in tomato fruits were evaluated by determining enzyme activities and isoenzyme analysis. Both protein levels and enzyme activities varied depending on the variety and season. In general, phosphorus supplementation did not alter SOD, POX, and APX activities significantly;however, some treatments showed season- and stage-specific enhancement in activities as noticed with hydrophos and seniphos supplementation. Three different SOD isozymes were observed, and these isozymes showed very similar staining intensities in response to P application and during the three developmental stages studied. Two major isozymes of POX and two different APX isozymes were observed at all the developmental stages. The results suggest that antioxidant enzyme activities may be influenced by the availability of phosphorus, but are subject to considerable variation depending on the developmental stage and the season.     

Nutrient supplementation increased growth and nitrate concentration of lettuce cultivated hydroponically with biogas slurry

Abstract

Recycling of biogas slurry via vegetable production is a multi-benefit and sustainable utilization strategy regarding agriculture and environment. A glasshouse experiment was conducted to investigate the effects of phosphorus (P) and iron (Fe) supplementation on growth and quality of lettuce cultivated hydroponically with diluted biogas slurry. The results showed that direct supplementation of P into diluted biogas slurry together with Fe improved the lettuce growth significantly, and decreased the root to shoot ratio. However, growth responses of lettuce to single addition of P or Fe into diluted biogas slurry were not significant. In addition, supplementation of P and Fe improved leaf chlorophyll content (determined as SPAD value), nitrate concentration significantly or slightly of the lettuces but not vitamin C content. However, addition of P and Fe or microelements through foliar spray is not effective in enhancement of growth and quality except for improving leaf SPAD. In conclusion, as a nutrient solution, the tested biogas slurry needs Fe and P supplementation, and P should be added together with Fe or post Fe supplementation in terms of lettuce yield. Also, direct addition of Fe into diluted biogas slurry was better than foliar spray.     

Rheological characterization of a novel functional food: tomato juice with soy germ

The rheological properties of tomato juice containing 1.5% soy germ were compared to plain tomato juice with and without soy protein isolate. This novel product was developed to provide a delivery system of carotenoids, soy protein, and significant isoflavone content without compromising the perceived juice characteristics of tomato product. Rheological tests depicted physical gel characteristics for all three products. Dynamic tests as a function of temperature showed that the stability and the compatibility between tomato juice and soy germ were higher as compared to soy protein isolate. The hydrophobic and electrostatic interactions between pectin and protein in the tomato soy protein isolate system were weakened as the temperature was increased. In the case of tomato juice with soy germ, the viscosity did not change during heating. The addition of soy germ increased the viscosity of tomato juice reinforcing the entire system without major qualitative effects on the rheological properties of plain tomato juice.     

固体磷肥和液体磷肥对石灰性土壤不同形态无机磷及磷肥肥效影响的研究

土壤磷固定是影响石灰性磷肥肥效的主要原因。本文在田间滴灌条件下采用连续浸提的方法对液体磷肥和固体颗粒磷肥及其不同施用方法对石灰性土壤各形态无机磷含量动态变化的影响进行了研究,并比较了不同处理下加工番茄磷素营养效应。结果表明:各施肥处理0—20 cm土层Ca2-P和Ca8-P含量随施肥时间明显下降,而Ca10-P含量则显著上升,表明磷肥在石灰性土壤中不断向Ca10-P转化并被固定。液体磷肥追肥处理0—20 cm土层Ca2-P含量在各时期均显著高于其他施肥处理(P＜0.05),且液体磷肥追肥可以明显保持土壤0—20 cm土层较高的Ca8-P含量。与其他施肥处理相比,液体磷肥追施可减少石灰性土壤对磷的固定,增加0—20 cm土层Ca2-P和Ca8-P含量(P＜0.05),显著提高土壤磷的有效性。液体磷肥追施处理可显著提高加工番茄叶片含磷量和经济产量(91725 kg/hm2)。与传统过磷酸钙颗粒磷肥作基肥处理（CK1）相比,液体肥料全做追肥可使加工番茄经济产量提高26.7%,并明显提高了磷肥利用率。在滴灌条件下石灰性土壤上液体磷肥分次追施比传统的固体颗粒磷肥基施具有明显的优势,是一种非常具有应用前景的施肥方式。     

Potato yield response to foliar application of phosphorus as affected by soil moisture and available soil phosphorus

Abstract

Foliar application of phosphorus (P) may be a supplementary treatment to sustain adequate P-status of potato (Solanum tuberosum L.). However, the prediction of the potential benefits of foliar P supply is difficult, since several factors, such as weather conditions and plant P-status influence the effects. We determined the impact of soil moisture and soil P-supply on the responsiveness to foliar P-application under controlled environmental conditions. Plant dry matter yields, P-accumulation and phosphorus use efficiency (PUE) with or without foliar application were determined at five soil P-levels in combination with two soil moisture levels. The results suggest that water status is of importance for the responsiveness to foliar P-application and may be related to diffusion of P through the leaf cells, which require a good water status. The PUE was significantly improved with irrigation while adding P to the soil decreased the PUE.     

Response of Mature Phosphorus-Deficient Apple Trees to Phosphorus Fertilization and Liming

ABSTRACT

The aim of the study was to examine response of mature phosphorus (P) deficient apple (Malus domestica Borkh.) trees to phosphorus fertilization and liming. The experiment was carried out during 2003–2005 in a commercial orchard in Central Poland on ‘Jonagold’ apple trees/M.26 planted in 1996 on a coarse-textured soil with low both pH (4.6) and organic matter (1.2%). Calcium-lactate soluble phosphorus concentration in the soil was within an optimal range despite appearance of leaf phosphorus deficiency symptoms. Soil and foliar applications of phosphorus, and soil liming were applied. Soil phosphorus fertilization was made in the first year of the experimental at a rate of 100 kg P per ha as triple superphosphate. Foliar sprays of a soluble compound containing organic phosphorus were performed 5 times per season at 2-week intervals, starting 4 weeks after full bloom. Soil liming was applied in the fall 2002 at a rate of 1100 kg Ca ha^?1 as hydrated lime. Additional combination as soil phosphorus fertilization plus liming was also applied. Plots unsupplied with phosphorus and lime served as a control. The results showed that liming and liming plus soil P application increased soil pH, and phosphatase activity in the soil, and improved phosphorus nutrition, tree vigor, yield, fruit color, and firmness after storage; effect of these treatments was not found only in the first year of the study. In all years foliar phosphorus sprays improved phosphorus nutrition of apple trees, and fruit color and firmness after storage. In 2 out of 3 years foliar phosphorus application increased yield. The vegetative and reproductive responses of ‘Jonagold’ apple trees did not depend on soil phosphorus fertilization. It was concluded that maintaining an optimal pH of soils for apple trees limits the incidence of orchard phosphorus deficiency and that foliar phosphorus sprays should be applied in phosphorus-deficient apple orchards to improve yield, and fruit appearance and storability.     

The effect of selenium biofortification in alfalfa (Medicago sativa)

Abstract

Biofortification of agricultural productions is important to enhance the quality of the products. The aims of this research were to investigate the possibility of selenium biofortification of alfalfa in the calcareous and non-calcareous soils by applying fertilizers differently (control, soil application, inoculant of seleno-bacteria, foliar application, combined soil, and foliar applications of selenate). Morpho-physiological properties and nutritional responses, such as shoot dry weight, phosphorus, potassium, selenium, zinc, and iron concentration in the plant’s tissue were measured. In all parameters, the use of selenium sources in the calcareous soils had a significant effect compared with the control treatment. Among the methods and sources of selenium, foliar application of sodium selenate gave the best response. By the usage of this treatment, Se concentration was increased up to 112.5% and 182%, respectively, compared with the control treatment in non-calcareous and calcareous soil. According to the results, inoculant of selenium bacteria and sodium selenate are recommended as a natural way to selenium biofortification in alfalfa and to improve the quality of the produced forage. In addition, attention to the biological potential of the soil and the use of native soil bacteria is also recommended.     

MODULATION IN YIELD AND JUICE QUALITY CHARACTERISTICS OF CITRUS FRUIT FROM TREES SUPPLIED WITH ZINC AND POTASSIUM FOLIARLY

Citrus, especially K innow (Citrus deliciosa × Citrus nobilis), fruit yield and quality in Pakistan is not competitive with that of other countries which could be mainly attributed to the lack of good nutrient management for citrus orchards. The yield losses in this fruit crop occur mainly due to heavy fruit dropping. Experiments to overcome these problems were conducted at four different sites one each in Faisalabad, Toba Tek Singh, Jhang and Sargodha districts of Punjab, Pakistan. The soil and leaf chemical analysis showed severe deficiency of Zn and our pervious results have shown that soil amendment with potassium (K) at 75 K₂O kg ha^?1 improved the citrus fruit yield and quality at all selected sites. In the present experiments, effect of foliar application of Zn and K alone or in combination was studied on nutrient uptake, fruit yield, fruit dropping and juice quality. The fruit trees were pretreated with a selected K level of sulfate of potash (SOP) or muriate of potash (MOP), i.e., 75 kg K₂O ha^?1 along with recommended nitrogen (N) and phosphorus (P) doses. Zinc [Zn, 1% zinc sulfate (ZnSO₄) solution], K [1% potassium sulfate (K₂SO₄) solution] and Zn + K (solution containing 0.5% each of ZnSO₄ and K₂SO₄) were sprayed at the onset of spring and flush of leaves or flowers, fruit formation and at color initiation on fruit. Overall, application of Zn, K or Zn + K was effective in improving the nutrient uptake, yield and quality parameters of citrus fruit at all sites. Fruit dropping was also reduced by the foliar spray of Zn, K or Zn + K but the most promising results were recorded with foliar spray containing both Zn and K.     

Effect of fungicide treatment on the quality of wheat flour and breadmaking

Fungicides are applied to crop plants to ensure disease protection and improve growth. To assess the effects of five commercial foliar and spike fungicides in four different combinations on wheat (Triticum aestivum L.), various quality parameters and flour processing properties, including baking quality, were determined. Three commonly used wheat cultivars with different quality classes (E, B, and C) were tested. Falling number, crude protein content, water absorption ability, protease activity, viscosity, and the free amino acid content were mainly lower in the fungicide-treated grains than in the untreated grains. None of the fungicides caused any significant changes in the wet gluten content, dough properties, the mono- and oligosaccharide content, or the breadmaking quality. In general, the commercial fungicide treatments did not cause any statistically significant differences between the treated and the untreated samples with respect to the quality parameters analyzed, although there were indeed significant differences between the three cultivars themselves.     

Potassium and Boron Nutrition Enhance Fruit Quality in Midwest Fresh Market Tomatoes

The tomato fresh fruit market has rigorous quality standards that can be challenging to meet, particularly under highly variable climatic conditions. Information is required about the influence of nutritional regime on tomato fruit and the interaction of potassium (K) and boron (B) in particular. A field experiment was conducted in 2002 and 2003 to evaluate the effects of K and B on yield and quality of fresh market tomatoes cv. ‘Mountain Spring’ at a southwest Michigan site with well‐drained soil (Alfisol Hapludalf, Oakville fine sand). Treatments applied during fruit development included three fertigation regimes (1N:0.8K, 1N:1.7K, and 1N:2.5K) in the presence and absence of a weekly foliar spray of B (300 mg?L^?1 B). Increasing K concentration in the fertilizer increased K content in leaf tissue, but in some cases reduced tissue calcium (Ca) and B. Fruit quality was influenced by nutrition, as the greatest rate of K was associated with increased crack susceptibility as indicated by a fruit bioassay and a 14% increase in incidence of the defect “shoulder check” in field‐grown fruit compared to less rates of K nutrition. Boron foliar spray increased tomato marketable yield and fruit quality, reducing shoulder check incidence by 50% compared to zero‐B‐treated plants in 2003. Because of yield and quality improvements, B was a cost‐effective treatment as shown by partial budget analysis, whereas increasing K nutrition did not provide consistent economic benefits. Moderate K rates were associated with the greatest marketable yield, and the 1N:1.7K plus foliar B nutrient regime produced the greatest quality fruit. Overall data were consistent with the need to carefully evaluate K and B nutrition in tomatoes, in the context of soil type, yield potential, fruit quality, and nutrition regime.     

蚓粪施用方式对不同品种番茄生长和土壤肥力的影响

肥料的施用方式会影响有机肥料的分解和养分释放过程,且不同作物品种在养分需求方面也各有差异。蚓粪是一种能够改善土壤和促进植物生长的新型替代肥料。采用盆栽试验研究了蚓粪施用方式对不同番茄品种生长和土壤肥力的影响,盆栽试验设置为:两个番茄品种:金棚三号和艾瑞尔;4种施肥方式:单施化肥(CF);蚓粪表施(VS),即蚓粪与盆钵上部8 cm厚土壤混施;蚓粪中施(VL),即蚓粪均匀平铺紧邻8 cm处下方;蚓粪全土混施(VM),即蚓粪与所有土壤混合。结果表明:相比全土混施,蚓粪表施和中施更能增加番茄的茎叶生物量并且促进其对氮、钾的吸收;与单施化肥相比,蚓粪的效果更依赖于施用方式,蚓粪表施和全土混施比中施更能提高土壤pH和有机碳含量。在盛花期,无论番茄品种,土壤有效磷、速效钾含量都在蚓粪表施时最高;而在收获期,蚓粪表施和全土混施的有效磷含量高于中施处理。相比蚓粪中施和全土混施,表施降低了艾瑞尔的土壤矿质氮含量。总之,蚓粪的集中施用如表施和中施,能促进番茄生长及养分吸收,并且在不同品种之间效应一致。     

分蘖洋葱伴生对番茄矿质养分吸收及灰霉病发生的影响

【目的】连作栽培已严重影响国内保护地番茄的产量和品质。番茄-分蘖洋葱伴生栽培能缓解番茄连作障碍,保持土壤健康,有效减少番茄生理性卷叶,显著控制土传病害的发生,提高产量5%10%。探索伴生对分蘖洋葱和番茄生长、矿质养分吸收及番茄灰霉病发生的影响有重要意义。【方法】本研究于2012年在温室内采用盆栽的方法,以分蘖洋葱与番茄伴生的栽培模式为研究对象,试验设番茄单作、分蘖洋葱单作、分蘖洋葱与番茄伴生等3个处理,在伴生30 d后测定生长指标(株高,地上干重和地下干重)和根系活力,同时对所有番茄植株进行发病率和病情指数调查。植株称干重并测定N、P、K和Mn含量。用抖根法取番茄和分蘖洋葱根际土,测定其理化性质和土壤脲酶、酸性磷酸酶、脱氢酶和多酚氧化酶活性。【结果】1)与单作相比,伴生条件下番茄株高、地上部干重、地下部干重、根系活力显著升高(P0.05),而伴生条件下分蘖洋葱地上部干重、地下部干重、根系活力显著降低(P0.05);番茄根际土壤脱氢酶与多酚氧化酶活性显著升高(P0.05),而分蘖洋葱根际土壤脱氢酶和多酚氧化酶活性显著降低(P0.05),伴生番茄和分蘖洋葱根际土壤间脲酶和酸性磷酸酶活性差异不显著。2)与单作相比,伴生条件下番茄根际土壤中碱解氮、有效磷、速效钾、有效锰和分蘖洋葱根际的有效磷、有效锰含量显著降低(P0.05),番茄根际土壤中p H、有机质以及分蘖洋葱根际碱解氮、速效钾、p H、有机质无显著变化。3)与单作相比,伴生条件下番茄植株全磷、全锰和分蘖洋葱植株内全氮、全锰均显著升高(P0.05),但番茄植株全氮、全钾含量和分蘖洋葱植株内全磷和全钾含量均无显著变化。4)伴生番茄灰霉病病情指数显著低于单作(P0.05)。番茄灰霉病病情指数与番茄植株全锰含量显著负相关(P0.05),与植株内氮/钾比和氮/锰比极显著正相关(P0.01)。【结论】分蘖洋葱-番茄伴生栽培促进番茄生长但抑制分蘖洋葱生长。与单作相比,伴生的番茄植株内的全磷和全锰含量显著增加(P0.05),且伴生番茄植株内氮/钾和氮/锰比显著降低(P0.01)。分蘖洋葱伴生后显著降低番茄灰霉病的病情指数(P0.05)。综上,分蘖洋葱伴生促进了番茄对磷和锰矿质养分的吸收,提高了番茄抗灰霉病水平并促进了番茄植株的生长。     

Optimizing sampling of tomato fruit for carotenoid content with application to assessing the impact of ripening disorders

Color defines one aspect of quality for tomato and tomato products. Carotenoid pigments are responsible for the red and orange colors of tomato fruit, and thus color is also of dietary interest. The aims of this study were (1) to determine the relative importance of field sampling and analytical replication when measuring lycopene and beta-carotene in tomato fruit and (2) to determine the effect of yellow shoulder disorder (YSD) on the content of lycopene and beta-carotene in tomato juice and tissue. Our results show that increasing biological replications is an efficient strategy for reducing the experimental error associated with measurements of lycopene and beta-carotene. Analytical replications did not contribute significantly to observed variation, and therefore experimental efficiency will be gained by reducing analytical replications while increasing field replication. We found that YSD significantly reduces lycopene in affected tissue and in juice made from affected fruit. In contrast, beta-carotene concentrations were only reduced in affected tissue but were not significantly reduced in juice. With increasing interest in biofortified crops, modulating the carotenoid profile in tomato by minimizing YSD symptoms represents a strategy for improving tomato fruit quality that is currently supported by grower contract structure and processor grades.     

Effect of Fe-Glycine Aminochelate on Pod Quality and Iron Concentrations of Bean (Phaseolus vulgaris L.) Under Lime Soil Conditions

Iron (Fe) has very low solubility and plant availability in calcareous soils, and this generally results in restricted plant production and low quality. During last decades, various commercial chelated fertilizers have been used in agricultural systems to meet iron requirements of crops. However, despite extensive application of these commercial chelate fertilizers, there is real doubt and high concerns regarding many aspects of their action, dynamics, efficiency, and safety in plant-soil–environment systems. In the present study, growth and quality of green bean plants (Phaseolus vulgaris L.) were evaluated under foliar and soil applications of Fe-glycine chelate (iron glycine aminochelate) and commercial Fe-EDDHA chelate in a lime soil. The results showed that morphophysiological parameters were improved by the application of Fe-glycine and Fe-EDDHA treatments. Foliar application of Fe-glycine has significantly improved leaf area and Soil-Plant Analyses Development (SPAD) values compared to control and Fe-EDDHA treatments. Pod yield, shoot (but not root) dry weight, and iron concentrations in leaves and pods (but not in root) were significantly higher when plants were treated by Fe-glycine rather than Fe-EDDHA in both soil and foliar applications. Vitamin C and protein contents were significantly improved and phenolic compounds were reduced by foliar application of Fe-glycine and soil application of Fe-EDDHA. The results indicate that foliar application of Fe-glycine can significantly increase Fe concentrations and quality of beans under lime soils with restricted iron availability.     

Assessment of ZN Interaction with Nutrient Cations in Alkaline Soil and its Effect on Plant Growth

An experiment was conducted to assess the zinc (Zn) availability to wheat in alkaline soils during Rabi 2009–2010. Wheat seedlings in pots having 2 kg alkaline sandy soil per pot were treated with 5, 10 and 15 kg Zn ha^?1 as soil and with 0.5 and 1.0% zinc sulfate (ZnSO₄) as foliar application. Results showed that Zn increasing levels in soil helped in phosphorus uptake up to boot stage but its conversion to grain portion lacked in Zn treated plants. Potassium (K) uptake also increased up to 6.24% in boot stage with treatment of 10 kg Zn ha^?1 + 1.0% ZnSO₄ foliar spray. Zinc (Zn) concentration increased in plant tissues with the increasing level of Zn application but this disturbed the phosphorus (P)-Zn interaction and, thus, both of the nutrients were found in lesser quantities in grains compared to the control. Despite of the apparent sufficient Zn level in soil (1.95 mg kg^?1), improvement in growth and yield parameters with Zn application indicate that the soil was Zn deplete in terms of plant available Zn. The above findings suggest that the figure Zn sufficiency in alkaline soil (1.0 mg kg^?1) should be revised in accordance to the nature and type of soils. Furthermore, foliar application of Zn up to 1.0% progressively increased yield but not significantly; and it was recommended that higher concentrations might be used to confirm foliar application of Zn as a successful strategy for increasing plant zinc levels.     

磷肥对日光温室番茄磷营养和产量及土壤酶活性的影响

采用盆栽方法进行了不同施磷（P2O5）水平下,日光温室番茄产量、不同生育期番茄磷素分配、干物质积累、土壤速效磷含量和酶活性研究,并确定了适宜番茄生长的最佳施磷量与土壤速效磷含量。结果表明,随着磷肥施用量的增加,土壤速效磷含量及番茄各组织含磷量相应增加;当施用P2O5达到0.53 g/kg（处理5）,土壤速效磷含量在60～77 mg/kg时,较适宜番茄生长,番茄产量和单果重达最高,根系和茎叶干物质积累也达到最好水平。当施磷量超过0.53 g/kg时,造成土壤和植株磷累积过高,易引起土壤盐害,降低土壤酶活性,从而降低干物质积累和番茄产量,影响土壤的可持续利用。     

MSW Compost Application on Tomato Crops in Mediterranean Conditions: Effects on Agronomic Performance and Nitrogen Utilization

A two-year field experiment (2001 and 2003) was carried out in a Mediterranean environment to study the effects of municipal solid waste (MSW) compost application compared with mineral nitrogen (N) fertilization on the agronomic performance and N utilization of a tomato crop, in rotation with durum wheat. The research was conducted in the south of Italy where five N treatments and two soil tillage depths (40-45 cm and 10-15 cm) were compared. The N treatments were: MSW compost at 140 kg ha^?1 (Ncom); mineral N fertilizer at 140 kg ha^?1 (Nmin); MSW compost combined with mineral N fertilizer (Nmix) (70 kg ha^?1 as organic N plus 70 kg ha^?1 as mineral N); mineral N fertilizer at 70 kg ha^?1 combined with two applications of foliar fertilizer (Nfito) (3 kg ha^?1 as hydrolyzed proteins), and an untreated control (Contr). During cropping cycles, growth parameters and plant N status (SPAD readings and petiole nitrate content) were determined; at harvest the marketable, overripe, green fruit, total yield, yield components, quality performance, total and fruit N uptake, and N efficiency were recorded. In addition, at the beginning and at the end of the two-year experiment, soil chemical characteristics and mineral N was measured, allowing for the calculation of the mineral N deficit in the soil. The results of this research indicate that the application of MSW compost to tomato plants can serve as a N source in Mediterranean conditions, especially when MSW compost is combined with mineral N fertilizer and deeper soil tillage is applied. In fact, deeper soil tillage increased total yield 7.0 t ha^?1 compared to surface tillage, whereas soil amended with MSW compost increased total yield compared to the untreated control by approximately 6.4% when used alone and 11.1% when combined with mineral N fertilizer. Nitrogen utilization parameters and Harvest Index varied significantly across years and N treatments. Petiole nitrate content and SPAD readings did not vary between Nmin and Nmix treatments, but they were significantly different from the untreated control. This indicates that plant N status was an effective tool to monitor N supply. After the two-year experiment, the Nmix treatment was statistically not significant in total yield (86.1 and 88.2 t ha^?1, respectively), marketable yield (66.9 and 67.7 t ha^?1) and quality compared to the Nmin treatment. Furthermore, the Nmix treatment ensured the least N deficit in the soil, indicating that MSW applications were effectively used as alternative organic supplements. Finally, the results indicated a positive effect of MSW application on organic carbon content in the soil and did not show any significant increase of the heavy metals at the end of the two-year experiment.     

Effects of Tea Plant Compost and Mineral Nitrogen Levels on Yield and Quality of Sugar Beet Crop

A field experiment was carried out during two successive seasons of 2009–2010 and 2010–2011 at Sakha Agriculture Reseach Station, Egypt, to study the effects of different applications of compost tea (C) under three mineral nitrogen (N) levels and their interaction effects on sugar yield and juice quality characteristics of sugar beet (Beta vulgaris L.), and soil available nutrients. Results indicated that the sugar yield and juice quality characteristics of sugar beet were significantly increased with compost tea treatments, especially in the plots treated with compost tea foliar application in three batches. A quality percentage of sugar beet was increased about 8.0% in the plots treated with compost tea or interaction between N mineral N and compost tea treatments above the control treatment. The interaction between mineral N and compost tea treatments had a significant effect on sugar yield, sugar percentage, purity, and quality of sugar beet and soil fertility.     

Effect of Recent Genetic Improvement on Some Analytical Parameters of Tomato Fruit Quality

Abstract

Poor flavor in tomato fruit is a serious consumer concern. It could be said that tomato flavor has declined as variety selection and tomato production has placed emphasis on yield, fruit size, firmness, disease resistance, and processing performance and not on aspects of organoleptic fruit quality. Consumers frequently associate recent varieties with a lack of flavor, although such an association has not been proven. We have reviewed the scarce available literature on the influence of recent genetic improvement on quality attributes of tomato. As a case study, we have analyzed several parameters related to fruit quality in some traditional Spanish cultivars and commercial F1 hybrids of tomato. Organic acids and sugars were determined by high performance liquid chromatography (HPLC). Sodium (Na), potassium (P), and phosphorus (K) were analyzed by atomic absorption spectroscopy. Levels of respiration and ethylene production were measured, and fruit firmness was determined using a texture analyzer. All determinations were performed at two maturity stages, representing two frequent consumption stages. Differences between traditional cultivars and hybrids were found for respiration rates, ethylene production, P and K fruit contents. We also found important differences between “old” and “modern” cultivars for their organic acids profile. All cultivars showed similar levels of malic and succinic acids, but the modern hybrids showed a ～75% higher content of citric acid. This could be due to the F1 hybrids carrying chromosomal segments recently introgressed from wild Lycopersicon species. The influence of recent genetic improvement on quality attributes of tomato fruit is discussed.     

木醋液土壤灌溉对土壤养分、番茄产量及品质的影响

采用田间小区试验,研究了木醋液不同灌溉量对土壤养分、盐碱和番茄产量及品质的影响。结果表明,土壤灌溉木醋液可提高土壤碱解氮、速效钾、有效磷含量,且使用量越大,效果越明显,其中有效磷含量增加最为显著,与对照相比可提高9.27%~25.51%;木醋液也可提高土壤有机质及全盐含量,但与对照相比差异不显著;木醋液还可降低土壤p H值,与对照相比可降低0.14~0.27个单位。木醋液低[2.25 t/(次·hm~2)]、中[4.50 t/(次·hm~2)]用量能显著提高番茄株高、增加产量,其中低用量效果最好,与对照相比可提高株高10.53%,增加产量11.52%;高用量[7.50 t/(次·hm~2)]对番茄生长具有一定抑制作用。木醋液可提高番茄可溶性糖含量5.27%~10.28%,提高Vc含量3.46%~17.15%,降低硝酸盐含量4.25%~15.33%,对有机酸含量影响不明显。综上所述,建议设施土壤番茄季木醋液灌溉量为2.25~4.50 t/(次·hm~2)为宜。