Winter Tomato Research Articles

Influence of ethephon on ripening and quality of winter tomato fruit harvested at different maturity stages

An experiment taking tomato fruits (cv. BARI Tomato-14) of three maturity stages (mature green stage, breaker stage and half ripen stage) and four ethephon levels [control (distilled water spray), 500, 750 and 1000 ppm] was carried out at the laboratory of plant physiology section of Horticulture research centre, Bangladesh Agricultural Research Institute) during February 14, 2013 to February 27, 2012 to find out the suitable stage of fruit maturity for post harvest application of ethephon (ethrel) for tomato ripening. The source of ethrel was Spectrum (ethephon 39%) manufactured in the United States of America. Treatment with 500 - 1000 ppm ethephon hastened ripening of tomato by 4 days in mature green stage but by 2 and 4 days in breaker stage tomatoes when compared with control fruits. The highest value of rotting was shown by half ripen tomatoes. The 1000 ppm ethrel gave the maximum rotting irrespective of maturity stages. However, the maximum weight loss and shelf life were found in green mature tomatoes. The shelf life of tomato fruits of green mature and breaker stage tomatoes treated with 500 and 750 ppm was also high. The percentage of rotting and weight loss was increased with gradual advancement of time. The highest value of weight loss and shelf life was recorded in green mature tomatoes without ethephon and with 500 and 750 ppm ethephon treatment. The highest value of vitamin-C, TSS and titrable acidity were shown by half ripen and pH by green mature tomatoes at different days of storage. The ethephon concentration of 750 ppm the gave maximum vitamin-C at 6 and 9 days of storage but 1000 ppm gave the maximum TSS% followed by 750 ppm ethephon. The ethephon @ 750 ppm produced the maximum TSS at 9 day of storage in mature green tomatoes but in breaker and half ripen stage tomatoes 750 ppm ethephon gave TSS identical to 1000 ppm at different days of storage. The residue level of ethrel in tomato fruits treated with all ethephon concentrations at 3 and 5 days of storage was below 2 mg/kg which is safe for human health. Therefore, treated tomatoes should be consumed after 3 days of ethephon application.Bangladesh J. Agril. Res. 40(4): 567-580, December 2015

AN ANALYTICAL STUDY OF THE RESPONSE OF SUPPLY FOR WINTER TOMATO CROP DISPLAY IN EGYPT

Tomato crop is considered one of the most important strategic green crops at the national level. It is one of the food and manufacturing crops that some food industry uses it as pasle, it is alse an important source in its contribution to the Egyptian national agricultural income. The research aims at estimating the response supply for winter tomato crop in Egypt to determine the most important variables that can affect the response of the cultivated area of this crop. In addition to estimating the flexibility of the response to these variables, and the amount of the annual response to tomato farmers, and thus reach to the appropriate period necessary to achieve complete response. The response functions show has been estimated in accordance with the model of Marc Nerlov, and the model of Robert Solow. The results of estimating the response supply of the winter tomato crop in Egypt using the model Marc Nerlov for partial adaptation during the period (1995-2013) have shown that the production of the tomato crop per feddan is one of the most variables impact on the farmer's response to the expansion for the cultivation winter tomato., it has Also been clear that there is a response from winter tomato growers to the relative prices between the winter tomatoes and both of the sugar beet and beans. Besides that the results of estimating the response functions show for the winter tomato crop have shown according to the model of Robert Solow that the production of the winter tomato crop per feddan is considered one of the best variables impact on farmer's response to the expansion for the cultivation winter tomato. It has also, been clear that there is a response from the winter tomato growers to the relative prices between the winter tomatoes and both of the sugar beet and beans crops. The research recommends the need to activate the role of agricultural guidance and expansion of the establishment of the indicative fields in order to encourage farmers to use tomato varieties with high productivity. The research, also, recommends the expansion in tomato manufacturing so that it can make a kind of balance between the quantity demanded and the quantity supplied and thus the possibility of maintaining the price stability.

AN ECONOMIC ANALYSIS FOR THE RE-ALLOCATION OF WINTER TOMATOES PRODUCTION IN EGYPT

land classification according to productivity is important to help decision-makers in determining the zones suitable for cultivating each crop based on its productivity, as well as making the plans for carrying out soil improvement programs. The study results showed an increase of the economic variables for winter tomatoes for both of the first period of (1991-1995) and the second period of (2009-2013). Besides, the index of the net return per feddan at current prices and fixed prices increased to reach about 408.2% and 0.407%, respectively and this increase was due to the increase in productivity and farm-gate prices. The study revealed that the total area of winter tomato after neglecting the districts cultivated during less than three years and dividing the governorates into five productive classes during the period of (2009-2013) reached about 335 thousand feddans, with a total production capacity of about 3.9 million tons. Moreover, the results showed a decrease of the area in the first, second and fifth productive classes at a decreasing change amounted to about 72.9%, 98.7% and 1.3%, respectively whereas, the area increased for both of the third and fourth productivity classes by about 188% and 171.7%, respectively. However, the effects of standard productivity on the cultivated to improve both of the third and fourth productivity classes reached about 36 tons and 21.4 tons, respectively whereas, the effects of standard productivity on the area cultivated to the deterioration of both the first, second and fifth productivity classes amounted to about -4.4, 6.8 and 0.8 tons, respectively. Finally, the study indicated that the re-allocation of resources through the distribution of the districts’ areas with lower productivity among the districts of high productivity will increase the income earned from winter tomatoes to about L.E. 6.5 million, will release an area of about 157.4 thousand feddans, and will save about 308.5 million m3 of water.

The Economic Effect of Using Modern Technology in the Production of the Winter Tomato Crop in Old and Reclaimed Land (A Case Study – Assiut Governorate)

The Economic Effect of Using Modern Technology in the Production of the Winter Tomato Crop in Old and Reclaimed Land (A Case Study – Assiut Governorate)

Effect of Ethephon and Ethylene Gas on Ripening and Quality of Tomato (Solanum Lycopersicum L.) during Cold Storage

The investigation was carried out to obtain information about effect of ethephon and ethylene gas on ripening and quality of winter tomato (cv. Hybrid-1001). The mature green tomatoes were treated with different concentrations of aqueous solution of ethephon (500, 1000 and 1500 ppm) for 5 minutes, thereafter packed in plastic crates and kept in storage room at 20 ± 1°C and 90-95% RH. In another experiment, mature green tomatoes were exposed to ethylene gas (100 ppm) inside the ripening chamber for 24 hours (20 ± 1°C and 90-95% RH) and thereafter kept in the ripening chamber maintained at 20 ± 1°C and 90-95% RH. The physico-chemical parameters of fruits from mature green to senescent stage of maturation were analyzed. The ethylene gas (100 ppm) treatment registered the highest ripening percentage. The ripening and rotting percentage increased with increase in the concentration of ethephon (500-1500 ppm) and with the duration of days for which the fruits were kept for ripening. The titratable acidity of fruits experienced a linear decline but ascorbic acid and lycopene content registered an increase with the advancement of ripening period irrespective of any treatment. The fruits harvested at green mature stage get successfully ripened in 9 days with application of ethephon but the rotting was more than 14% till 9th day which makes fruits unmarketable. Therefore, the application of ethephon for ripening is not a good option. Treatment with ethylene gas (100 ppm) resulted in adequate ripening of fruits after 9 days with uniform red colour, desirable firmness, minimum rotting and acceptable quality and therefore this treatment is better over ethephon. In control fruits similar results of ripening, firmness, rotting and quality were observed as in case of ethylene gas (100 ppm) treatment but the fruits get longer time (11 days) to uniformly ripen.

An Economic study of winter tomato production in Asyut Governorate

An Economic study of winter tomato production in Asyut Governorate

FUNCTIONAL CHARACTERIZATION OF OLD CULTIVARS OF LONG STORAGE TOMATOES

Nine cultivars of winter tomatoes (known as “storage tomatoes” or “old tomatoes”) were cultivated in southern Italy and analysed for their content in different antioxidant compounds and for their antioxidant activity (AA). The results obtained show a high variability in the lutein, β-carotene and lycopene contents. The β-carotene content was greater than reported in literature for traditional cultivars and in one case, was higher than that of lycopene. In particular, β-carotene amount ranged between 7.51 and 36.58 mg/kg of fresh weight (FW), while lycopene content varied between 8.98 and 106.44 mg/kg FW. To our knowledge, lutein content was determined the first time in this type of tomatoes and its amount ranged between 1.7 and 5.1 mg/kg FW. Caffeic acid was detected only in two cultivars. Rutin amounts varied between 55.6 and 109.15 mg/kg FW. All the extracts (hydrophilic and lipophilic) showed a good AA; moreover, scavenger activity of the hydrophilic fraction, when evaluated by ABTS, was very high reaching 90%.

EFFECT OF ETHEPHON AND ETHYLENE GAS ON RIPENING AND QUALITY OF DETACHED WINTER TOMATO

Fruits of a winter tomato (Lycopersicum esculentum L.) hybrid were harvested at mature green stage and a first lot was exposed to ethylene gas (100 ppm) for 24h in a ripening chamber at 20±1°C and the second lot was treated by immersion in a solution of ethephon {(2-chloroethyl) phosphonic acid} at 2 different concentrations (500 and 1000 ppm) and for two different lengths of times (5 and 10 min). The fruits were air dried and placed in plastic crates followed by storage in a ripening chamber at 20±1°C and 90-95% RH. The colour, texture and flavour parameters of fruits from mature green to senescent stage of maturation were analyzed. The most striking effect of treatment was on colour development of fruits. It was found that treatment with ethylene gas (100 ppm) for 24h inside the ripening chamber or immersion in ethephon solution (500 ppm) resulted in better ripening of tomato fruits with uniform red colour, desirable firmness and acceptable quality as compared to other treatments. The length of time of the ethephon dip treatment did not reveal any significant effect on colour development. The fruits in the control showed very poor ripening and were hard in texture with poor quality attributes.

Evaluation of Newly Developed Parthenocarpic Strains for Production of Winter Tomatoes without Heating

Evaluation of Newly Developed Parthenocarpic Strains for Production of Winter Tomatoes without Heating

Using plant water status to define threshold values for irrigation management of vegetable crops using soil moisture sensors

Thresholds of soil matric potential (SMP) and available soil water content (AWC) required to prevent water limitations between irrigations were determined for bell pepper, melon, and spring and winter tomato grown in Mediterranean-type greenhouses on the south-eastern coast of Spain. Thresholds were identified by measuring the divergence of leaf water potential of un-watered plants from that of well-watered plants. Soil matric potential thresholds were −58 kPa for pepper, −35 kPa for melon, and −38 to −58 kPa for tomato. In general, SMP thresholds were more negative under lower evaporative demand conditions such as during autumn and winter months. Available soil water content thresholds, for a given crop and drying cycle, differed appreciably depending on soil depth and the method used to calculate the values. For the four crops studied, AWC thresholds calculated at 0–40 cm were 13–15% higher than those calculated at 0–20 cm. Each AWC threshold for 0–20 cm depth was 21–29% lower when AWC was based on laboratory rather than field determinations of field capacity and permanent wilting point. For a given method of calculating AWC, AWC threshold values were similar for different crops and drying cycles, suggesting limited sensitivity of the AWC approach. Using the manufacturer's calibration, the capacitance sensor used for SWC measurements overestimated SWC by an average of 36%. An in situ calibration provided generally good agreement with the actual SWC between 0.15 and 0.22 cm 3 cm −3; however, for higher SWC values, the in situ calibration underestimated SWC. The results of this study demonstrated the uncertainty of using recommended fixed AWC threshold values for irrigation management, using SWC sensors, because of issues related to the definition of rooting depth, measurement of FC and PWP, sensor calibration, and sensor accuracy across the relevant range of water contents. These data suggest that SMP thresholds are much more reliable than AWC thresholds for scheduling irrigations in greenhouse-grown vegetable crops. Technical issues regarding on-farm measurement of SMP and SWC are discussed.

Use of stem diameter variations to detect plant water stress in tomato

The sensitivity of stem diameter variations (SDV) measured with linear variable transducer (LVDT) sensors as indicators of plant water status in tomato was evaluated. Two tomato crops were grown sequentially in a sandy loam soil in an unheated plastic greenhouse. These were an autumn–winter tomato crop (autumn crop) and a spring–summer tomato crop (spring crop). One drying cycle of 61 days was imposed to the autumn crop in winter at 92 days after transplanting (DAT). Two drying cycles, each of 29 days, were applied to the spring crop, to young (58 DAT) and mature plants (121 DAT). For each drying cycle, four replicate plots did not receive irrigation, and four were well watered. During each drying cycle, LVDT sensors continuously measured SDV, and daily measurements were made of leaf (Ψ leaf) and stem water potential (Ψ stem). SDV data was interpreted using the SDV-derived indices, maximum daily shrinkage (MDS) and stem growth rate (SGR). The response of SDV-derived indices to water deficit differed with (1) climatic conditions during stress imposition and (2) crop age. In the winter drying cycle of the autumn crop, the responses of the SDV-derived indices to soil drying were relatively small and slower than Ψ leaf and Ψ stem. Under warmer conditions, the SDV-derived indices were much more responsive to soil drying. In rapidly growing young plants, where SDV was characterized by high SGR and small MDS, SGR was the most sensitive SDV-derived index. In more mature plants with little stem growth, MDS was the most sensitive SDV-derived index. In mature plants grown in warm to hot conditions, MDS (1) responded at a similar time or earlier than Ψ leaf and Ψ stem and (2) had larger “signal” values (ratio of values from unwatered to control plants) than Ψ leaf and Ψ stem. However, there was appreciably more “noise” (coefficient of variation, CV) associated with the SDV-derived indices, giving lower “sensitivity” values, determined from “signal” to “noise” ratios, than for Ψ leaf and Ψ stem. Regression analysis between MDS of well-watered plants and climatic variables gave best results for a linear relationship between MDS and daily maximum vapor pressure deficit. There were strong linear relationships between MDS and Ψ leaf for each drying cycle. The slopes of these relationships differed with crop age indicating that there was no constant relationship between MDS and Ψ leaf for a whole season. Overall these results demonstrated that MDS and SGR can be sensitive indicators of the water status of tomato crops under conditions of moderate to high evaporative demand. However, the variability associated with the SDV-derived indices and the changing MDS–Ψ leaf relationship with crop age represent major issues regarding the development of irrigation scheduling protocols for tomato.

Residues of vinclozolin and procymidone after treatment of greenhouse grown lettuce, tomato and cucumber

Residues of the fungicides vinclozolin and procymidone, used to control the Botrytis cinerea disease, were studied in greenhouse grown lettuce, tomato and cucumber. Residue concentrations differed between the species of treated vegetables, and depended mostly on time of picking (harvest), size of fruits and mode of chemical application. The differences in concentration between one and two applications became smaller with time after application. The greatest differences occurred in lettuce. The residue contents in cucumber fruits assigned both for industrial and home processing (pickling) were higher than the legal limit (3 mg/kg). As a result of washing cucumbers, 22–24% of the residue was eliminated, and by peeling them 79–85% of the vinclozolin and procymidone residues were eliminated. Therefore it is reasonable that one or two applications of these fungicides should be used, with a time lapse of 14 days, but only with cucumbers intended for salad consumption. Vinclozolin residues, when used as vaporisation tablets, were in all cases 35–65% lower compared with the wettable powder (WP) formulation; however, the rate of of residue decrease was much slower. When applied in the form of vaporable tablets, the vinclozolin residue concentration was lower in all the sampled fruits in comparison with the WP formulation. The concentration of fungicide residues detected in winter tomato fruits was higher than that of the spring crop. Irrespective of vegetable the detected levels of fungicide residues were lower in ripe and bigger fruits than in green and smaller ones.

An Assessment of the Effects of ENSO Events on Fresh Vegetable and Melon Supplies

The historical effects of El Niño/La Niña events on supplies of selected fresh vegetables and melons (Cucumis melo L.) were evaluated by estimating single-equation supply relationships. Economic variables in the estimated equations were, generally, of the correct sign and significant at usual levels. El Niño events had a negative and statistically significant effect on the Texas muskmelon, Florida fall squash [Praecitrullus fistulosus Stocks) Pang.] and the California fall lettuce (Lactuca sativa L.) supply with expected production declines of 15%, 21%, and 5% relative to historical mean production. In contrast, the expected supplies of United States summer onions (Allium cepa L.) and Florida fall and winter tomatoes (Lycopersicon esculentum Mill.) increased about 7%, 10%, and 25% during El Niño events. La Niña events had a negative and significant effect on Texas muskmelon, honeydew, and watermelon, with supplies expected to decline 20%, 29%, and 13% with the occurrence of this event.

Viruses infecting winter tomato crops in the North West Frontier Province of Pakistan

Malakand Agency is a unique production area in the North West Frontier Province (NWFP) of Pakistan that is frost-free and in which tomato is grown as a winter crop. Tomato production in this area has been affected by virus-like diseases for the last 10 years. Tomato nurseries and fields at 11 locations in Malakand Agency were surveyed for tomato viruses during 1994–95. A total of 1071 samples from nurseries and 5083 samples from 142 fields were tested by indirect enzyme-linked immunosorbent assay (ELISA). In nurseries, 3 viruses, Potato virus X (PVX), Potato virus Y (PVY), and Tomato mosaic virus (ToMV), were detected with an incidence range of 9.8–22.3, 0–36.6, and 16.5–51.3%, respectively. In the field, 5 viruses [Cucumber mosaic virus (CMV), PVX, PVY, ToMV, and Tomato yellow top virus (TYTV)] were frequently found with an incidence range of 0–13.3%, 2.6–16.7%, 0.4–13.8%, 26.1–41.3%, and 1.7–11.3%, respectively. All 5 viruses except TYTV were also detected from weed species in tomato fields or in the nearby vicinity. Of 12 commercial tomato varieties screened against CMV, PVX, PVY, and ToMV, 2 varieties (Florist and Forset) were resistant to 4 of the viruses including ToMV, for which the highest incidence was recorded in nurseries and field. These 2 varieties represent a previously undescribed and potentially useful source of resistance to the 4 inoculated viruses.

Stomatal limitation of photosynthesis in winter production of greenhouse tomato plants

In May, greenhouse tomato (Lycopersicon esculentum Mill.) plants near the end of their winter production cycle were shown to exhibit a diurnal photosynthetic decrease. In order to identify the physiological causes of this decline, we compared in May the photosynthetic characteristics of the fifth youngest leaves from tomato plants of different ages corresponding to a winter production (11-month-old plants) and to a spring production (5-month-old plants). Although the leaves were developed simultaneously under the same environmental conditions, only the ones from the winter production showed a diurnal decline of the in situ CO 2 assimilation rate (A CO2 ). This was accompanied by a decline of internal CO 2 and stomatal conductance and by large accumulations of hexoses. When stomatal closure was relieved under saturated CO 2 concentration (5%) using a leaf-disc electrode system, the fifth leaves of both tomato cultures had similar maximum quantum efficiency of O 2 evolution (Φ max ), light-saturated rate of O 2 evolution (P max ) and quantum efficiency of photosystem H (PSII) photochemistry (ΔF/F m , q,. and q N ), We concluded that the diurnal decline of A CO2 observed in winter tomato production during May originates from a stomatal limitation that is not dependent on environmental conditions but rather related to the developmental stage of the plants.

Stomatal limitation of photosynthesis in winter production of greenhouse tomato plants

In May, greenhouse tomato (Lycopersicon esculentum Mill.) plants near the end of their winter production cycle were shown to exhibit a diurnal photosynthetic decrease. In order to identify the physiological causes of this decline, we compared in May the photosynthetic characteristics of the fifth youngest leaves from tomato plants of different ages corresponding to a winter production (11-month-old plants) and to a spring production (5-month-old plants). Although the leaves were developed simultaneously under the same environmental conditions, only the ones from the winter production showed a diurnal decline of the in situ CO2 assimilation rate (ACO2). This was accompanied by a decline of internal CO2 and stomatal conductance and by large accumulations of hexoses. When stomatal closure was relieved under saturated CO2 concentration (5%) using a leaf-disc electrode system, the fifth leaves of both tomato cultures had similar maximum quantum efficiency of O2 evolution (Φmax), light-saturated rate of O2 evolution (Pmax) and quantum efficiency of photosystem II (PSII) photochemistry (ΔF/F′m, qP and qN). We concluded that the diurnal decline of ACO2 observed in winter tomato production during May originates from a stomatal limitation that is not dependent on environmental conditions but rather related to the developmental stage of the plants.

Competition for assimilates and fruit position affect fruit set in indeterminate greenhouse tomato

Localization and characterization of fruit set in winter tomato crops was investigated to determine the main internal and external controlling factors and to establish a quantitative relationship between fruit set and competition for assimilates. Individual fruit growth and development was assessed on a beef tomato cultivar during the reproductive period (first nine inflorescences). A non-destructive photograph technique was used to measure fruit growth from very early stages of their development and then calliper measurements were made on big fruits. From these measurements we determined the precise developmental stage at which fruit growth stopped. Fruit potential growth, which is defined as the growth achieved in non-limiting conditions for assimilate supply, was also assessed by this method on plants thinned to one flower per inflorescence. The latter was used to calculate the ratio between actual and potential growth, which was found to be a good index of the competition for assimilates. Time lags of fruit set were observed mainly on distal organs. When more than three flowers were left on each inflorescence, distal organs developed at the same time as proximal organs of the following inflorescence. Consequently they were submitted to a double competition within one inflorescence and among inflorescences. It was shown that, what is commonly named 'fruit set failure', is not an irreversible death of the organ and that a small fruit could resume growth after a delay of several weeks as soon as the first fruits ripened and thus ceased to compete for assimilates. In that case proximal fruits resumed growth before distal ones. The delayed fruits contained only few seeds but a germination test confirmed that fertilization took place before fruit set failed. Competition for assimilates was calculated during plant development by the ratio between actual and potential fruit growth. Potential growth of proximal fruits was strongly dependent on the position of the inflorescence on the stem, whereas potential growth of distal fruits was lower than or equal to that of proximal fruits of the same inflorescence and it was independent on the inflorescence position. We took into account both inflorescence and fruit positions to establish a quantitative relationship between fruit set of individual inflorescences and the ratio between actual and potential fruit growth.

U.S.‐Mexican Trade in Winter Vegetables and Illegal Immigration

AbstractThis paper presents an integrated approach to U.S.‐Mexican trade in a labor‐intensive commodity (fresh winter tomatoes) and illegal immigration of agricultural labor. A seven‐equation econometric model is developed that includes excess demand (U.S. import) and supply (Mexican export) equations for fresh winter tomatoes, U.S. demand and Mexican supply equations for apprehensible individuals, intercountry price and wage relationship equations, and a U.S. Border Patrol apprehension effort equation. The empirical results indicate that both U.S. and Mexico economic conditions affect the number of apprehended illegal Mexican aliens. The results also indicate that immigration and trade policies affect apprehensions.

Imports and the Supply of Winter Tomatoes: An Application of Rational Expectations

AbstractA model of the Florida tomato industry is formulated under the hypothesis that growers make production decisions as rational economic agents. This assumption implies that anticipated Mexican tomato imports as well as other economic variables are taken into account when the planting decision is made. Maximum likelihood estimation methods are used to solve the simultaneous equations model, and the implications of the model's reduced form are analyzed. The empirical findings are consistent with the rational expectations hypothesis that producers respond to market information in its entirety when making acreage decisions.

Resistance of tomato cultivars and progenies to fruit hollowness

In field experiments with fall and winter tomatoes, the incidence of fruit hollowness was found to range from 0 to more than 80%, depending both on the cultivar and the environment. The most resistant cultivars were Bonner Beste and Potentate; the most susceptible were Exhibiton, Moneymaker, E.S. 1, Berco, Cromco and Ailsa Craig. The rate of hollowness of F1 and F2 generations of crosses between resistant and susceptible parents suggests that resistance behaves as a partially dominant character governed by a small number of genes. Thus, commercial F1 hybrids resistant to the disorder are easy to produce. The heritability of the resistance character was found to be rather high.