Blossom End Research Articles

Limitation of mineral supply as tool for the induction of secondary metabolites accumulation in tomato leaves

Agricultural residues are natural sources for secondary metabolites as high value ingredients for industrial uses. The present work aims to exploit the accumulation potential of rutin and solanesol in tomato leaves following nitrogen and general mineral deficiency in a commercial-like greenhouse. Physiological responses of tomato plants were monitored non-destructively with a multiparametric fluorescence sensor, and biochemical parameters were determined by means of HPLC analysis. Nitrogen and general mineral limitation led to an accumulation of rutin in young tomato leaves while solanesol concentration was higher in mature leaves. In young leaves, the fluorescence indices SFR_R and NBI_G showed lower values compared to control plants for both stress treatments. On the contrary, FLAV and ANTH_RG values increased during the experiment, but no differences could be recorded in mature leaves. However, correlation analysis indicates, that the FLAV index is not a reliable tool to estimate the concentration of rutin and solanesol tomato leaves. To monitor fruit yield/quality as primary objective of tomato production, fruits showing symptoms of blossom end rot (BER) were counted before and after stress treatments. BER was determined more frequently for plants grown under a general mineral deficiency, concluding that a practical applicability at the end of fruit production is advisable. Our results indicate that by-products from Solanaceae plants are promising resources for valuable bioactive leaf compounds. To achieve the highest concentrations, the seasonal variation, the optimal environmental conditions, the concentrations in different plant organs and varieties as well as different production systems are of high interest for commercial implementation.

Mechanisms regulating fruit calcium content and susceptibility to bitter pit in cultivars of apple

This work was carried out to investigate the mechanisms regulating fruit calcium (Ca) content and susceptibility to bitter pit (BP) in 'Fuji' and 'Catarina' apples (cultivars with low and high susceptibility to BP, respectively). Fruit of both cultivars were harvested at commercial maturity in an orchard located in southern Brazil, and assessed for xylem functionality and lenticels pore area (mm2 mm-2 of skin) at the distal end. Fruits were also cold stored for four months (0.0±0.5°C/95% RH) and then separated in lots without and with BP. Fruits of both cultivars without and with BP were assessed at the distal (blossom end), middle (equatorial region) and proximal (peduncle end) portions for pectin methylesterase (PME) activity in the skin and flesh tissues, and at distal portion for peroxidase (POD) and ascorbate peroxidase (APX) activities and Ca content in the flesh tissue. At harvest, 'Catarina' apples had lower xylem functionality and lower lenticels pore area at the distal end than 'Fuji' apples. 'Catarina' had higher incidence of BP after cold storage (12.7%) than 'Fuji' (2.3%). In both cultivars, fruit with BP had lower Ca content in the flesh at the distal end. Fruits with BP showed at the distal region higher POD activity in the flesh in 'Fuji' and higher PME activity in the skin in 'Catarina' than fruit without BP. Only in 'Fuji', fruits with BP had higher PME activity in the flesh tissue at the middle and distal portion than fruits without BP. The results show that impairment of xylem functionality, and reduced lenticels pore area and high PME activity in the skin tissue at the distal portion of the fruit might reduce fruit Ca content and increase the incidence of BP, especially in 'Catarina', a cultivar highly susceptible to the disorder.

Influence of preharvest treatment with some organic acids on polyphenol oxidase and peroxidase activities and blossom end browning incidence in ‘Anna’ apples

Influence of preharvest treatment with some organic acids on polyphenol oxidase and peroxidase activities and blossom end browning incidence in ‘Anna’ apples

Applications of calcium and boron increase yields of Italian tomato hybrids (<i>Solanum lycopersicum</i>) in two growing seasons

El objetivo de este estudio fue evaluar el efecto de tratamientos de boro edáfico y frecuencia del calcio foliar en floración, sobre la producción y ocurrencia de la pudrición apical de híbridos de tomate italiano, cultivados en el sistema convencional en dos temporadas de cultivo. Se realizaron dos experimentos en el área experimental perteneciente a la Universidade Federal de Santa Maria, campus de Frederico Westphalen (Brasil), en los años 2012 y 2013. El diseño experimental fue de bloques al azar con un arreglo factorial 2×2×3×3 cuyo factores fueron dos híbridos (San Vito y Neptuno), en dos épocas de cultivo (primavera-verano y verano-otoño), tres dosis de boro (0; 2,0 y 4,0 g/planta) y tres frecuencias de aplicación de calcio (ausencia de aplicación, aplicación semanal y quincenal) y cuatro repeticiones. El trasplante de plántulas se realizó el día 04 de septiembre de 2012 para la primavera-verano y el 26 de enero para el verano-otoño. El híbrido Neptuno es más productivo en comparación con el híbrido San Vito, pero más susceptible a la pudrición apical. Las dos épocas de cultivo pueden ser recomendadas para el cultivo del tomate italiano en Rio Grande do Sul, aunque el cultivo de primavera-verano presenta mayor productividad cuando se compara al verano-otoño. La frecuencia de aplicación quincenal de CaCl2 al 0,6% se constituye en la mejor opción de manejo de fertilización, en el sentido de obtener mayor productividad y menor número de frutos con incidencia de pudrición apical. El incremento de la dosis de boro condiciona mayor número de frutos por planta y aumento de la productividad.

THE EFFECT OF IRRIGATING BY MAGNETIZED WATER, PROLINE AND YEAST EXTRACT SPRAYING ON QUALITY AND PRODUCTIVITY OF TOMATO CROP UNDER SALT STRESS CONDITIONS

This research aims to rationalize the applications of water and mineral fertilizers for tomato crop, in order to obtain clean organic food, and to maintain the quality and quantity of production. Three biological treatments were applied: first using magnetization technology to improve the drainage water ability to reuse it. Second using proline as an amino acid and third using yeast extraction as an alternative fertilizer. The applied treatments included three levels of magnetized water (1000, 2000 and 3000 gauss); two levels of proline (50 & 100 ppm) and two levels of yeast extract at concentrations of (5& 10%) compared with control treatment. Whereas, five of groups of measurements were carried out to; illustrate the effects of the applied treatment. The measurements were deduced on each of: soil properties, crop growth indicators, flowering time, crop yield and crop quality. The gained results of the present study indicated that applying the magnetized water (3000 G) with proline (100 ppm) at 10 % yeast extract reduces the electrical conductivity (EC) by reduction ratios of (45.09 & 50.19 %), while the soil acidity reduced by (28.93 & 25.08 %) than control through the tested seasons. Also, the mean increment ratios of the plant heights were increased by (25.19 & 25.41%) than control. However, the flowering period was increased up to 88 days. The quality indicators ratios (T.S.S and vit. C) were increased by {(9.39 & 9.0)and (34.2% & 33.50) %} orderly, while tomato acidity and blossom end rote ratios were decreased by {(7.90 & 8.0) and (0.390 & 0.405) %} only than control. As well, the increment ratios in crop yield (y) and the net earn were {(30.10 & 27.87) and (33.19 & 30.24%) orderly than control for (2015 & 2016) seasons.

Yield of determinate tomato cultivars grown in a closed hydroponic system as affected by plant spacing

This study was conducted to determine yield of hydroponically grown determinate tomato cultivars at different plant densities. Four determinate tomato cultivars were subjected to four plant densities during the spring/summer and summer/fall seasons. Results showed no significant differences in marketable yield between the cultivars tested during both seasons. Cultivar Mion showed higher incidence of blossom end rot, while Mariana showed the highest fruit rot during the spring/summer season as compared to the other cultivars. During the spring/summer season, marketable yield increased with increased plant density with the highest yield obtained at 25 plants m -2 followed by 20 plants m -2 . During the summer/fall season, plant density did not show a significant effect in total and marketable yield although a tendency for declined yield with increased density was observed. Number of fruit per plant as well as fruit size decreased with increased plant density during both seasons which did not have an effect on overall yield per plot area. Results demonstrated that increasing the plant density to 25 plants m -2 can improve marketable yield of determinate tomato cultivars during spring/summer season while using a plant density of 10 plants m -2 will be more cost effective during the summer/fall season. Keywords: Gravel film technique, Marketable yield, Unmarketable yield, Soilless cultivation

Morphological Evaluation of Tomato (Solanum lycopersicum Linn.) Cultivars

Tomato ( Solanum lycopersicum Linn.) is widely cultivated and is economically beneficial. Tomato cultivars were obtained from traditional agriculture systems, and their morphological characters were evaluated. The cultivars included Pepper tomato [ ED/CH/01] , Edo local [ ED/CH/02] , Golden tomato [ ED/CH/03] and Derica tomato [ ED/CH/04] . Results of the principal component analyses of 27 morphological characters indicated that two characters accounted for 94.65 % of the observed variations. Scatter plots suggested good tendency of grouping for the four accessions. In the dendrogram, two clusters were formed with ED/CH/01, ED/CH/02 and ED/CH/03 grouped together whereas ED/CH/04 clustered separately. The clustering pattern implicated a common origin and/or gene pool for the cultivars. Cultivars ED/CH/01, ED/CH/03 and ED/CH/04 showed determinate growth type, while ED/CH/02 showed a semi-determinate growth pattern. Further, in terms of plant size, ED/CH/01 and ED/CH/02 were intermediate, while ED/CH/0 3 and ED/CH/0 4 were large. The characteristics of the flower and fruits exhibited diversity in terms of the corolla color, style, shape, fruit size at maturity, exterior color of the mature fruit, fruit shoulder, fruit cross-sectional shape, and fruit blossom end shape. These cultivars collectively possess characteristics that can be used by plant breeders. We recommend that further characterization using molecular techniques as well as conservation attention for these local germplasms should be conducted

Morphological markers for identification of hybrids and their parental lines in tomato (Solanum lycopersicum)en

Four hybrids, viz, PH-1, 2, 4 and 8 and their parental lines were studied for developing identification keys using morphological characters. Out of 39 characters studied, fourteen qualitative and six quantitative characters werepolymorphic for identifying the parents from the hybrids and also among themselves. Characters like stem anthocyanin pigmentation on upper one-third portion, fruit green shoulder, leaflet petiole attitude with respect to main axis, leaf serration, stem pubescence, fruit shape at blossom end, fruit shape in longitudinal section and stigma lobes were important for development of identification keys. These characters were stable during two growing seasons (rabi 2014-15 and rabi 2015-16) and no variation was observed for any character in any genotype. A combination of these morphological markers could effectively utilized for distinguishing all the hybrids and their parental lines under study.

The use of foliar applications of abscisic acid to reduce blossom end rot in processing tomatoes

Blossom end rot (BER) in susceptible varieties of processing tomatoes can cause significant losses in marketable production. When using black biodegradable mulch, varieties of processing tomatoes susceptible to BER suffer an increase in the proportion of fruit affected compared with bare soil conditions. Elongated Italian pear-type cultivars of processing tomatoes used for premium whole peeled canned tomatoes are more susceptible to BER than blocky varieties. The percentage of fruit affected by BER increased fivefold (2.7 vs. 14.5%) between a susceptible cultivar without and with biodegradable mulch. Exogenous foliar applications of abscisic acid (ABA) at concentrations of 500 mg L-1 in greenhouse tomatoes have been found to reduce the incidence of BER significantly. The objective of this study was to determine whether exogenous applications of ABA can reduce the incidence of BER in a susceptible cultivar and, if so, to determine the economic viability of its use in field-grown processing tomatoes. A trial was conducted at La Consulta, INTA Experimental Station in Mendoza, Argentina, during the seasons 2014-15 and 2015-16. Black biodegradable mulch, 22 microns thick, was used. Daily water replenishment was done by a single surface tape according to evapotranspiration tank type “A”, adjusted by local KC. A variety susceptible to BER was used, 'HM 3861' (HM CLAUSE). The experimental unit was a 5-m length of bed with five replicates in a completely randomized design. During the main fruit setting period of the crop, four night-time foliar applications of ABA were used at 5-day intervals. Four different concentrations of ABA were used: 0 (control), 100, 300 and 500 mg L-1 in the 2014-15 season and 0 (control), 500, 1000 and 2000 mg L-1 in the 2015-16 season. General production parameters including BER index were measured at harvest. Stomatal conductance was measured during the application period. These parameters were evaluated by regression tests among treatments at α=0.05. The results obtained in the field showed no statistical differences in BER or any of the variables measured between treatments in the first year. In the second year, stomatal conductance was lower with higher doses of ABA, and the effects lasted about 3 days, indicating that application intervals should not exceed 4-5 days.

Yield of determinate tomato cultivars grown in a closed hydroponic system as affected by plant spacing

ABSTRACT In South Africa there are no established spacing recommendations for determinate tomato cultivar production under closed hydroponic systems. This study was conducted to determine yield and quality of hydroponically grown determinate tomato cultivars at different plant densities. Four determinate tomato cultivars (Dynimo, Mariana, Mion and Sama) were subjected to four plant densities (10, 16, 20 and 25 plants/m2) during the spring/summer and summer/fall seasons. Experimental layout was a randomized complete block design in a factorial scheme of four plant spacing x four cultivars with three replicates. There were no significant differences in marketable yield between the cultivars tested during the spring/summer and summer/fall seasons. Cultivar Mion showed higher incidence of blossom end rot, while Mariana showed the highest fruit rot during the spring/summer season as compared to the other cultivars. During the spring/summer season, marketable yield increased with increased plant density with the highest yield obtained at 25 plants/m2 followed by 20 plants/m2. During the summer/fall season, plant density did not show a significant effect on total and marketable yield although a tendency for declined yield with increased density was observed. Number of fruit per plant as well as fruit size decreased with increased plant density during both seasons which did not have an effect on overall yield per plot area. Increasing the plant density to 25 plants/m2 can improve marketable yield of determinate tomato cultivars during spring/summer season while using a plant density of 10 plants/m2 will be more cost effective during the summer/fall season. This information will enable farmers to optimise yield and quality of determinate tomato cultivars under closed hydroponic systems.

Screening for bacterial wilt resistance of bell pepper under sick field conditions and morphological characterization

The present investigation was carried out on 46 genotypes of bell pepper to study bacterial wilt resistant genotypes and their morphological characterization under natural sick field conditions at Palampur aiming at the development of high-yielding, bacterial wilt (Ralstonia solanacearum) resistant lines of bell pepper. Based upon the mean performance, genotypes DPCBWR-14-39, DPCBWR-14-36, DPCBWR-14-31, DPCBWR-14-35, DPCBWR-14-11, DPCBWR-14-7 and DPCBWR-14-29 were found to be top yielders and resistant to bacterial wilt disease. All the genotypes taken for study were found to be resistant and moderately resistant to bacterial wilt disease except DPCBWR-14-22, DPCBWR-14-23, DPCBWR-14-34, DPCBWR-14-37 and DPCBWR14–43. Bell pepper germplasm contained sufficient genetic variability and can be used for crop improvement. Coincidently, among the top five high yielding progenies most showed green group (GG), blocky fruit shape, pendent fruit position, cordate fruit shape at pedicel end and sunken fruit shape at blossom end. Thus, these genotypes can be further used for breeding programmes and can be directly used after multi-location testing as these possess inherent ability to high yielding alongwith bacterial wilt resistance.

Bio-controlling Effect of Leaf Extract of Tagetes patula L. (Marigold) on Growth Parameters and Diseases of Tomato.

The genus Tagetes (Asteraceae) is native to Americas but some of its members (in particular T. erecta and T. patula) commonly known as marigolds were naturalized in the old world (India, North Africa and Europe) as early as in 16th century. The flowers of French marigold (Tagetes patula L.) are widely used in folk medicine, in particular for treating inflammation-related disorders. This study investigated the potential use of marigold (Tagetes patula L.) flower aqueous flower extract by spaying method on tomato plants on a weekly basis and the data of growth, yield and disease of tomato pants were observed from 10th day onwards under field condition. The marigold flower extract showed significant increase in shoot height, number of branches, number of leaves, number of buds, number of flowers and number of fruits of tomato plant, while significant reduction in various diseases of tomato plants over control at probability level ***p<0.001. The percentage of reduction of disease was calculated after the spray of marigold flower aqueous extract on plants. The marigold flower extract was found effectively in controlling canker (62.82%), early blight (61.53%), wilt (18.42%), fruit spot (27.41%), blossom end rot (50.43%) and sun scald (26.44%) in comparison to controls under field condition. The findings are in line with the bio-controlling properties of marigold preparations as bio-pesticide confirmed in growth and yield of tomato plants. Thus, marigold can contribute in reducing use of chemical pesticides and act as a good alternative to synthetic pesticides.

Integrating Physiology and Architecture in Models of Fruit Expansion.

Architectural properties of a fruit, such as its shape, vascular patterns, and skin morphology, play a significant role in determining the distributions of water, carbohydrates, and nutrients inside the fruit. Understanding the impact of these properties on fruit quality is difficult because they develop over time and are highly dependent on both genetic and environmental controls. We present a 3D functional-structural fruit model that can be used to investigate effects of the principle architectural properties on fruit quality. We use a three step modeling pipeline in the OpenAlea platform: (1) creating a 3D volumetric mesh representation of the internal and external fruit structure, (2) generating a complex network of vasculature that is embedded within this mesh, and (3) integrating aspects of the fruit's function, such as water and dry matter transport, with the fruit's structure. We restrict our approach to the phase where fruit growth is mostly due to cell expansion and the fruit has already differentiated into different tissue types. We show how fruit shape affects vascular patterns and, as a consequence, the distribution of sugar/water in tomato fruit. Furthermore, we show that strong interaction between tomato fruit shape and vessel density induces, independently of size, an important and contrasted gradient of water supply from the pedicel to the blossom end of the fruit. We also demonstrate how skin morphology related to microcracking distribution affects the distribution of water and sugars inside nectarine fruit. Our results show that such a generic model permits detailed studies of various, unexplored architectural features affecting fruit quality development.

Agromorphological genetic diversity of Spanish traditional melons

The variability of 62 Spanish landraces (and two hybrids used as reference) was described by analysing 39 morphological traits and eight SSR makers. Results showed that 81% of the examined genetic pool belonged to the inodorus type. Spanish traditional melons presented fruits from flattened and globular shapes to elliptical. Rind colour varied from pale green, almost white and yellow to dark green and almost black. Rind texture varied from smooth to intensely wrinkled. Spanish landraces also had larger fruits (average fruit weight ~2.6 kg) and longer vegetative cycles (117 days to maturity) compared to landraces from other geographical origins. Farmers seem to have focused on selection towards large fruits, which usually requires the longest production cycles. Fruit colour, size and shape seemed to have been determinant in varietal selection. Hierarchical clustering resulted in two main groups (climacteric and non-climacteric). The largest group was composed of 60 accessions of non-climacteric types, which includes the most demanded by national markets, ‘Piel de Sapo’, which fruits were characterized by an ovate or elliptical shape, a green rind, big spots and stains distributed over the whole fruit, a rounded blossom end shape and a very pointed stem end shape. The study demonstrates that the Spanish genetic pool is much more diverse. Wide variability was found in a geographical area with vast historical importance in melon farming. These evaluations has allowed the identification of several uniform groups of non-climacteric cultivars (‘Piel de Sapo’, ‘Mochuelo’, ‘Tendral’, Yellow/White, Winter and Black groups) and a set of highly variable climacteric ones. However, many accessions with singular properties remain unclassified, demonstrating the morphological variability of the studied collection. Melons in Spain have wide variability together with a vast historical importance on farms. Some fruit types, or at least some morphological characters reflected by painters during centuries, have reached the present. The present study confirmed the need to preserve these irreplaceable genetic resources and continue their study and evaluation for valuable traits which could enhance farmer’s opportunities for entering new markets.

Tomato growth responses to foliar application of ammonium sulfate in hydroponic culture

ABSTRACTThis study was done to evaluate the growth responses of tomato plants (Lycopersicon esculentum Mill.) to foliar application of ammonium sulfate in different concentrations of 0, 50, 100, or 200 mM once per week, as well as 50 mM in every other day under greenhouse and hydroponic culture system. The results showed that foliar application of ammonium restricted the plant height, yield, and vitamin C content of fruits, but it increased the chlorophyll content in treated plants. The highest and the lowest yield were obtained from zero (control) and 200 mM treated plants, respectively. Fruit hardness was not affected by treatments, while blossom end rot disorder was increased by higher concentrations of ammonium sulfate. In general, the result indicated that tomato plant is rather sensitive to foliar application of ammonium sulfate particularly to higher concentrations and application numbers.

Standardization of production technology for hybrid coloured capsicum (Capsicum annuum var grossum) based on yield and economic benefit under different protected structures in plains of India

The present experiment was conducted to evaluate the yield and economic gain in cultivation of coloured capsicum (Capsicum annuum var grossum (L.) Sendt) hybrids in different protected structures. Six hybrids of coloured capsicum, i.e. Indra, Natasha, Bomby in red coloured group and Orobelle, Swarna, Kanchan in yellow coloured group were tried in 3 different types of protected structures compared to open field (OF) conditions. It was found that protected technology significantly enhanced crop duration (300) days in fan-pad cum force ventilated polyhouse (FFVP), 265 days in naturally ventilated polyhouse (NVP),250 days in insect proof net house (IPNH) as compared to 200 days in open fields. FFVP technology registered maximum fruit weight and yield (1.98 kg/plant, 11.83 kg/m2) followed by NVP(1.75 kg/plant, 10.42 kg/m2), IPNH(1.11kg/plant, 6.68 kg/m2) and OF (0.33 kg/plant, 1.98 kg/m2), respectively. Economic analysis of different protected structures exhibited considerably higher net returns of Rupees 247.33/m2 in FFVP, Rupees 309.67/m2 in NVP, Rupees 86.43/m2 in IPNH and Rupees 14.75/m2 in OF condition. The benefit cost ratio was calculated as 1.73in FFVP, 2.47 in NVP, 1.48 in IPNH while the lowest value of 1.32 in OF condition. Disease incidence cum mortality of plant (2.43%) was minimum in all capsicum varieties grown under FFVP, while it was higher in NVP (6.52%) followed by IPNH (9.75%) with maximum in OF (43.65%). Whereas blossom end rot of fruits was minimum in FFVP (2.98%) followed by OF (3.28%). It is evident from the results that protected structures enhanced the production of coloured capsicum as compared to open field condition particularly during off-season in plains. Further, among different hybrid varieties evaluated, Indra in red group and Orobelle in yellow group are found more suitable for growing in these conditions while Bomby and Swarna were also performed at par under protected structure.

Influence of Temperature Differential between Tomatoes and Postharvest Water on Salmonella Internalization

Salmonella bacteria may internalize into tomato pulp when warm tomatoes from the field are submerged into colder water. Several washing steps may follow the initial washing and packing of tomatoes at the packinghouses; the potential for internalization into tomatoes in subsequent washing steps when tomatoes have a cooler pulp temperature is unknown. Our objective was to evaluate Salmonella internalization into mature green and red tomatoes with ambient (21°C) and refrigeration (4°C) pulp temperatures when they were submerged into water at various temperature differentials, simulating repacking and fresh-cut operations. Red (4°C and 21°C) and mature green (21°C) tomatoes were submerged (6 cm) into a six-strain Salmonella cocktail (6 log CFU/ml) and maintained at ±5 and 0°C temperature differentials for varying time intervals, ranging from 30 s to 5 min. Following submersion, tomatoes were surface sterilized using 70% ethanol, the stem abscission zone and blossom end epidermis were removed, and cores were recovered, separated into three segments, and analyzed. Salmonella populations in the segments were enumerated by most probable number (MPN). The effects of temperature differential and maturity on Salmonella populations were analyzed; results were considered significant at a P value of ≥0.5. Internalized populations were not significantly different (P ≥0.5) across temperature differentials. Salmonella internalization was seen in tomatoes under all treatment conditions and was highest in the segment immediately below the stem abscission zone. However, populations were low (typically >1 log MPN per segment) and varied greatly across temperature differentials. This suggests that the temperature differential between tomatoes and water beyond the initial packinghouse may be less important than submersion time in Salmonella internalization.

Tomato Fruit Marketability, Blossom-End Rot Incidence and Quality as Affected by Different Calcium Sources and Time of Application Under Calcareous Soil

Two field experiments were carried out during the winter seasons of 2011/2012 and 2012/ 2013 at The Experimental Farm of The Faculty of Environmental Agricultural Sciences, El-Arish, Suez Canal University, North Sinai Governorate, Egypt. The experiment aimed to study the effect of spraying tomato plants (Solanum lycopersicum) GS 12 cv. with different calcium sources (calcium chloride, calcium carbonate and calcium chelate as well as without calcium) at different times of application, viz, T1: spraying one time at full blooming, T2: spraying one time after 15 days from T1, and T3: spraying two times at T1 + T2 on marketable yield, unmarketable yield (expressed as fruits infected by blossom end rot (BER)), and quality of fruits after 10 days of beginning the storage period. Plants were grown under low tunnels. Spraying tomato plants with Ca+ as CaCl2 or CaCO3 and other Ca sources increased the marketable yield/ fed. , and also increased fruit shelf life period expressed as decreasing in fruit weight loss and increasing fruit firmness. Foliar application of CaCl2 recorded the lowest values of lycopene contents in both seasons. Time of calcium application did not reflect any significant effect on both marketable and nonmarketable yield as well as marketability (%) and BER incidence (%), and almost pH and TSS values. Application of T3 increased the fruit contents of vitamin C (V.C), while using T2 decreased the content of lycopene. All interaction treatments with control (without application of calcium) decreased marketable yield, marketability (%), but it increased unmarketable yield, BER incidence (%), fruit weight loss and TSS in the 2nd season. Therfore, spraying tomato plants grown under low tunnels in calcareous soil with Ca in different sources had positive effects on both marketable yield and blossom-end rot incidence, total yield, marketability%, BER% and on fruit quality after 10 days of storage period compared to control.

Qualitative Inheritance of External Fruit Traits in Watermelon

Genes for watermelon [Citrullus lanatus (Thunb.) Matsumura &amp; Nakai] fruit traits have been identified since the 1930s. We conducted a study of fruit traits including fruit stripe width, stripe color, rind color, fruit shape, and blossom end shape (concave vs. convex). Ten watermelon cultivars (inbred lines) were used as parents. Several new genes or alleles were discovered. A series of alleles at the g locus is proposed to explain the inheritance of fruit rind pattern: G (medium or dark solid green), gW (wide stripe), gM (medium stripe), gN (narrow stripe), and g (solid light green or gray). The dominance series is G &gt; gW &gt; gM &gt; gN &gt; g. Another series of alleles at the ob locus is proposed for the fruit shape: allele ObE for elongate fruit, which is the most dominant; allele ObR (not the same as the o gene for round) for the round fruit; and allele ob for oblong fruit, which is the most recessive. Gene csm is proposed for the clear stripe margin in the cultivar Red-N-Sweet and is recessive to the blurred stripe margin (Csm) in ‘Crimson Sweet’, ‘Allsweet’, and ‘Tendersweet Orange Flesh’.

Fruit Calcium: Transport and Physiology.

Calcium has well-documented roles in plant signaling, water relations and cell wall interactions. Significant research into how calcium impacts these individual processes in various tissues has been carried out; however, the influence of calcium on fruit ripening has not been thoroughly explored. Here, we review the current state of knowledge on how calcium may impact the development, physical traits and disease susceptibility of fruit through facilitating developmental and stress response signaling, stabilizing membranes, influencing water relations and modifying cell wall properties through cross-linking of de-esterified pectins. We explore the involvement of calcium in hormone signaling integral to the physiological mechanisms behind common disorders that have been associated with fruit calcium deficiency (e.g., blossom end rot in tomatoes or bitter pit in apples). This review works toward an improved understanding of how the many roles of calcium interact to influence fruit ripening, and proposes future research directions to fill knowledge gaps. Specifically, we focus mostly on grapes and present a model that integrates existing knowledge around these various functions of calcium in fruit, which provides a basis for understanding the physiological impacts of sub-optimal calcium nutrition in grapes. Calcium accumulation and distribution in fruit is shown to be highly dependent on water delivery and cell wall interactions in the apoplasm. Localized calcium deficiencies observed in particular species or varieties can result from differences in xylem morphology, fruit water relations and pectin composition, and can cause leaky membranes, irregular cell wall softening, impaired hormonal signaling and aberrant fruit development. We propose that the role of apoplasmic calcium-pectin crosslinking, particularly in the xylem, is an understudied area that may have a key influence on fruit water relations. Furthermore, we believe that improved knowledge of the calcium-regulated signaling pathways that control ripening would assist in addressing calcium deficiency disorders and improving fruit pathogen resistance.