Ripening of tomato at different stages of maturity influenced by the post harvest application of ethrel

Transcription

1 Bull. Inst. Trop. Agr., Kyushu Univ. 36: 17-30, Ripening of tomato at different stages of maturity influenced by the post harvest application of ethrel M. Moniruzzaman 1), R. Khatoon 2), M. Moniruzzaman 3), M. F. B. Hossain 2), M. M. Rashid 4) Abstract An experiment was carried out at the laboratory of plant physiology section of HRC during the rabi season of taking tomato (cv. Ratan) fruits of three maturity stages (mature green, breaker and half ripen) and six ethrel levels (control, 125, 250, 500, 1000 and 2000 ppm) to find out the suitable stage of fruit maturity for post harvest application of ethrel and also to determine the optimum dose of ethrel for tomato ripening. The source of ethrel was Prolong (ethrel 40% W/W). The visual color and firmness changes during ripening at 24.5 C ± 1 C and 65-70% relative humidity were evaluated. Different maturity stages, ethrel levels and their combinations showed significant variation in different physical and chemical characteristics of tomato studied. The highest value of rotting was shown by half ripen tomatoes. The 1000 and 2000 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 treated with 250 and 500 ppm was also high level. 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 and breaker stage tomatoes without ethrel and with ppm ethrel treatment. The highest value of vitamin-c, TSS and titrable acidity were shown by half ripen and ph by green mature tomatoes at different day of storage. The ethrel concentration. of ppm gave maximum vitamin-c and TSS at different storage time. Mature green and breaker stage tomatoes treated with ppm ethrel produced maximum TSS at 9 days of storage. Treatment with ppm ethrel hastened the color changes by 3 days when compared with control fruits both in mature green and breaker stage. Keywords: Post harvest application of ethrel, ripening of tomato and stages of maturity Introduction Tomato (Solanum lycopersicon L) is one of the most important and popular vegetables in Bangladesh with a considerable total production of 100 thousand tons produced in an area of hectares (BBS, 2007). This crop is one of the most universally known, widely consumable nutrition and widely 1) Senior Scientific Officer, Plant Physiology Section, Horticulture Research Centre, Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur-1701, Bangladesh 2) Scientific Officer, Plant Physiology Section, Horticulture Research Centre, Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur-1701, Bangladesh 3) Scientific Officer (Horticulture), Plant Physiology Section, Horticulture Research Centre, Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur-1701, Bangladesh 4) Assistant Director (Horticulture), Bangladesh Agricultural Development Corporation (BADC), Kashimpur, Gazipur, Bangladesh *Corresponding author: mzaman.hrcbari@yahoo.com

2 18 M.Moniruzzaman et al. grown vegetables in the world. Proper harvesting determines the nutrient contents as well as storage durability of any fruit. In all over the world, tomatoes are harvested at different maturity stages, such as green mature stage, breaker stage, half ripen stage and red ripen stage. Fruits are often harvested at the mature green stage to minimize the damage during post harvest handling. The fruits may later ripen spontaneously or after treatment with ethylene releasing compound (ethrel) before shipment to retailers (Wills et al., 2002). Losses often occurred from excessive deterioration during holding and marketing of tomatoes. This problem is especially acute with tomato harvested when at the breaker or more advanced stages of ripeness. Although ripening makes fruit edible and flavourful, it also initiates the gradual deterioration of fruit quality especially in climacteric fruits such as tomato, in which the onset of ripening is considered to be initiated by endogenous ethylene (Abeles et al., 1992). Tomato fruit firmness and its shelf life decrease during storage. After 3 weeks of storage at C the red ripen stage tomato fruit were found 78.2% rotting but only 47.5% fruit rotting was found in fruits harvested at the mature stagre (Goojing et al., 1999). Mallik et al. (1996) reported that fruit of tomato (cv. Roma VF) showed the lowest physiological weight loss at % after 6 days of storage under ambient condition. Shelf life is the most important aspect in loss reduction biotechnology of fruits and vegetables. There is a natural tendency for the perishable fruits and vegetables to degrade to the simpler compounds (CO 2, H 2 O and NH 3 ) through spontaneous biochemical reaction. This type of reaction reduces the shelf life as well as other qualities of fruits and vegetables. Anju-Kumari et al. (1993) reported that the shelf life for all tomato cultivars were longest with harvesting at the mature green stage ( days). Dennis et al. (1979) stated that it was possible to store green mature fruits for up to 6 to 10 weeks in control atmospheric storage (3% O 2, 5% CO 2, 92% N 2 0 at 13 C and 90-95% RH. The acid content is lower in immature fruit and is highest at the stage when colour starts to appear, with a rapid decrease when the fruit ripens (Boe et al., 1967). During maturation and ripening of fruit, there are changes in total soluble solid (TSS). TSS increases from mature green stage to red ripen stages (Winsor et al., 1962). The palatability of fruits depends on TSS which increases throughout the development of fruit. Colour is an extremely important factor for tomato quality characteristics. For the consumer, colour is an important indicator for eating quality. The fruits which are harvested at mature green or breaker stage are treated with different ethrel containing compounds for the colour development and ripening. Ethrel (ethephon) is a growth regulator that, when applied to tomatoes, results in an increase in ethylene and triggers the ripening of fruit (Anonymous, 2008). Ethylene promotes the ripening process and improves colour development of the fruits. Dhall et al. (2001) reported that ethephon solution (500 ppm) resulted in better ripening of tomato fruits with uniform red colour, desirable firmness and acceptable quality as compared to 1000 ppm. At present ethrel is being utilized for ripening of mature or immature tomato indiscriminately without using optimum doses. Suitable stages of fruit maturity and optimum doses of ethrel for quality and storage of tomato has not yet been developed for developing countries like Bangladesh. Keeping all above facts in mind, this experiment has been undertaken to find out the suitable stage of fruit maturity for post harvest application of ethrel in tomato and to determine the optimum dose (s) of ethrel for tomato ripening

3 Ripening of tomato by the post harvest application of ethrel 19 Materials and Methods The experiment was conducted physiology laboratory, Horticulture Research Centre, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur during February 14, 2012 to February 20, Fruits of different maturity stages were dipped in various concentration of ethrel for five minutes. After dipping, the treated tomato fruits were covered by transparent polyethylene for 6 hours. Freshly harvested tomato fruits of the variety Ratan were collected as per requirement of the study from the vegetable field of HRC, where tomato plants have been grown for this purpose. The experiment consisted of three maturity stages (M 1 = Mature green, M 2 = breaker and M 3 = Half ripen stage) and six levels of ethrel concentrations (T 1 = control, T 2 = 125 ppm, T 3 = 250 ppm, T 4 = 500 ppm, T 5 =1000 ppm and T 6 = 2000 ppm). The experiment was laid out in CRD with three replications. Ten tomato fruits weighing 1000g were placed for each treatment. The source of ethrel was Prolong 40 SL (Ethephon 40% W/W). The temperature and relative humidity was 24.5 C ± 1 C and 65-70%, respectively in the laboratory. The data were analyzed by MSTAT-C computer package and mean separation was done by DMRT at 5% level of probability. Colour development of fruit, firmness of tissue, Vitamin- C in tomato pulp, ph of tomato juice, total titrable acidity content, TSS content of tomato pulp, weight loss (%), rotting (%) and shelf life of tomato. Each data was recorded at 3 days interval upto 12 days but some data were not taken due to 100% rotting of the fruit. Colour development of tomato was determined by visual observation. Firmness of tissue of tomato pulp was determined by finger pressure at 3 days interval. Firmness was classified as hard, slightly hard, medium hard, slightly soft, medium soft and soft. The weight loss of tomato fruit sample was calculated by using the following formula: Initial weight Final weight % Total weight loss of fruit = 100 Initial weight Rotting was determined by visual observation. The shelf life was calculated by counting the days required to attain the last stage of ripening but up to the stage when fruit remained still acceptable for marketing. Vitamin-C in tomato pulp, and total titrable acidity content were taken following standard procedure of Rangana (1986). The ph of tomato juice and TSS were recorded by ph meter and refractometer, respectively. Results and Discussion Colour development of fruit Changes in colour and development of colour on peel of tomato occurred during ripening process of different types of matured fruit have been shown in Table 1. It was found that matured green tomato under all growth regulator treatments required 12 days to develop yellow red. But tomato at breaker stage and half ripen tomato become yellowish red and light red at 6 days, respectively under control. Matured tomatoes subjected to ethrel treatment except 125 ppm attained yellowish red and light red colour at 9 and 12 days respectively. Tomatoes at breaker stage applied with 250, 500, 1000 and

4 20 M.Moniruzzaman et al. 2000ppm become red and deep red at 9 and 12 days, respectively. But half ripen tomatoes subjected to treat with 250, 500, 1000 and 2000ppm become red at 6 days. In tomatoes of breaker stage light red and red colour was developed at 6 and 9 days, respectively under ethrel treatment except lower dose of ethrel (125 ppm) while tomatoes of control treatment developed yellowish red and light red colour by 6 and 9 days. Similarly, half ripen tomatoes subjected to 250, 500, 1000 and 2000ppm ethrel become red by 6 days whereas half ripen tomatoes of control treatment showed red colour at 9 days. The tomatoes treated with ethrel ripened more quickly than those of control because ethrel hastened ripening. Treatment with ppm ethrel hastened the color changes by about 3 days when compared with control fruits both in mature green and breaker stage, but no difference on color intensity was observed among ppm irrespective of maturity stages after 12 days of storage. Moura et al. (1997) found 1000 mg/l ethephon solution was more efficient in hastening tomato ripening. It was found by Olympio and Norman (2000) that concentrations of 500 and 1000 ppm reduced the ripening time more than all other treatments. The mango cultivars treated with 0.8% (800 ppm) ethrel accelerated ripening (Thanh Hai, et al., 2009). Table 1. Effect of ethrel and maturity stages on the changes in colour development of tomato (cv. Raton) fruits during storage Days after storage Treat. 0D 3D 6D 9D 12D Maturity stages Ethrel conc. T 1 Green Green L. green L. yellow Y. red T 2 Green Green L. green L. yellow Y. red M 1 T 3 Green L. green L. green Yellow Y. red T 4 Green L. green L. green Yellow Y. red T 5 Green L. green L. green Yellow Y. red T 6 Green L. green L. green Yellow Y. red T 1 L. green L. Yellow Y. red L. red Red T 2 L. green L. Yellow Y. red L. red Red M 2 T 3 L. green L. Yellow L. red Red Deep red T 4 L. green L. Yellow L. red Red Deep red T 5 L. green L. Yellow L. red Red Deep red T 6 L. green L. Yellow L. red Red Deep red T 1 L. yellow L. Yellow L. red Red Deep red T 2 L. yellow L. Yellow L. red Red Deep red M 3 T 3 L. yellow Yellow Red Red Deep red T 4 L. yellow Yellow Red Red Deep red T 5 L. yellow Yellow Red Red Deep red T 6 L. yellow Yellow Red Red Deep red L: Light, Y: Yellowish

5 Ripening of tomato by the post harvest application of ethrel 21 Firmness of tissue Firmness is one of the most important aspects of tomato fruit quality. Firmness depends on the stages of tomato fruit maturity, the number of locules per tomato fruit, variety of tomato, manorial and environmental factors. It was found that matured green tomatoes under control required 12 days to become medium soft Table 2. But tomato at breaker stage and half ripen tomato become medium soft at 9 and 6 days respectively under control. Matured tomatoes subjected to ethrel treatment except 125ppm attained medium soft and soft at 9 and 12 days, respectively. Tomatoes at breaker stage treated with 250, 500, 1000 and 2000ppm become medium soft and soft at 6 and 9 days, respectively. But half ripen tomatoes subjected to ethrel 250, 500, 1000 and 2000ppm become soft at 6 days. The mature green tomatoes under 250, 500, 1000 and 2000ppm ethrel become soft at 12 days of storage while mature green tomatoes without ethrel treatment become medium soft at 12 days. In tomatoes of breaker stage, soft tomatoes were developed at 12 days under 250 and 500 ethrel treatment except lower dose of ethrel level (125 ppm) while tomatoes of control treatment become soft by 12 days. Half ripen tomatoes subjected to 250, 500, 1000 and 2000ppm ethrel become soft by 6 days whereas half ripen tomatoes of control treatment becomes soft at 9 days. Ehthrel made the tissue of pulp soft and thus promoted ripening. Firmness decreased with advancement of time. Similar result was found by Kaynas and Surmeli (1995) and Moneruzzaman et al. (2008a). Table 2. Effect of ethrel and maturity stages on the changes in firmness of tomato (cv. Raton) fruits during storage Days after storage Treatment 0D 3D 6D 9D 12D Maturity stages Ethrel conc. T 1 Hard Hard m. hard m. hard m. Soft T 2 Hard Hard m. hard m. hard m. Soft M 1 T 3 Hard m. hard S. soft m. Soft Soft T 4 Hard m. hard S. soft m. Soft Soft T 5 Hard m. hard S. soft m. hard Soft T 6 Hard m. hard S. soft m. Soft Soft T 1 Hard m. hard S. soft m. soft Soft T 2 Hard m. hard S. soft m. soft Soft M 2 T 3 Hard S. soft m. soft Soft Soft T 4 Hard S. soft m. soft Soft Soft T 5 Hard S. soft m. soft Soft Soggy T 6 Hard S. soft m. soft Soft - T 1 m. hard S. Soft m. soft Soft - T 2 m. hard S. soft Soft Soft - M T 3 m. hard S. soft Soft Soft - T 4 m. hard S. soft Soft Soft - T 5 m. hard S. soft Soft Soft - T 6 m. hard S. soft Soft Soft - m: medium, S: slightly

6 22 M.Moniruzzaman et al. Table 3. Main effect of maturity stages and ethrel on vitamin -C and ph content of tomato at different days of storage Days of storage Treatment Vitamin-C (mg/100g) ph 0D 3 D 6 D 9 D 12 D 0D 3 D 6 D 9 D 12 D Maturity stages M c 10.02c 9.029c 6.882c a 4.15a 4.20a 4.23a - M b 14.39b 13.57b 12.34b b 4.12b 4.15b 4.18b - M a 17.94a 16.86a 15.30a c 4.10c 4.09c 4.15c - Ethrel level T e 12.87b 11.24b b T c 13.19a 11.53a b T c 13.21a 11.60a a T a 13.21a 11.56a b T a 13.22a 11.56a c T d 13.25a 11.55a c CV (%) Means within a column having same letters are not significant at 5% level by DMRT Table 4. Effect of ethrel and maturity stages on vitamin-c content of tomato (cv. Raton) fruits during storage Days after storage Treatment 0D 3D 6D 9D 12D Maturity stages Ethrel conc. T hi 9.03d 6.84d 6.30 T hi 9.07d 6.88d 6.33 M 1 T i 9.02d 7.02d 6.46 T h 9.02d 6.87d 6.34 T j 9.05d 6.89d 6.35 T hi 8.96d 6.79d 6.32 T ef 13.54c 12.32c T f 13.53c 12.31c M 2 T ef 13.55c 12.33c T e 13.57c 12.35c T g 13.71c 12.43c - T ef 13.54c 12.32c - T d 16.04b 14.57b - T c 16.97a 15.40a - M 3 T bc 17.00a 15.44a - T b 17.01a 15.45a - T bc 16.99a 15.37a - T a 17.18a 15.55a - CV (%) Means within a column having same letters are not significant at 5% level by DMRT

7 Ripening of tomato by the post harvest application of ethrel 23 Vitamin-C content of tomato pulp Vitamin-C content of tomato pulp varied significantly in fruits of different maturity (Table 3). Results showed that vitamin-c content was decreased with the advancement of time. Half ripen tomato contained the highest quantity of vitamin-c (20.02mg/100g) while the mature green tomato contained the lowest quantity of vitamin-c (11.41mg/100g) at harvest. This is perfect agreement with Moneruzzaman et al. (2008). In entire period of storage ethrel treatment with all concentrations maintained a lead over control in respect of vitamin-c content. This in agreement with Thanh Hai, et al. (2009) who got the vitamin-c content in mango compared to control using 0.8% (800 ppm) ethrel. Maturity stages, ethrel and their combinations were found to have significant effect (Table 4). The maximum vitamin-c content at 3, 6 and 9 days of storage was recorded in half ripen tomato coupled with 2000ppm ethrel which was at par with 125, 250, 500, 1000 and 2000 ppm ethrel coupled with the same maturity except 3 days of storage. However, there was no significant difference among all concentrations of ethrel irrespective of matured green and breaker stage in vitamin-c content. ph of tomato juice The ph content of tomato juice varied significantly in fruits of different maturity (Table 3). It was found that ph increased with the advancement of ripening of fruit. During entire period of storage, the highest ph value was observed in mature green tomatoes followed by breaker stage and half ripen fruit, respectively. This result corroborates the results of Moneruzzaman et al. (2008b). The effects of ethrel on ph of tomato were found significant at 3 day of storage. However, the highest ph value was noticed in 250 ppm ethrel in entire period of storage. The interaction effect on ph was insignificant. Table 5. Main effect of maturity stages and ethrel on TSS and titrable acidity content of tomato at different days of storage Days of storage Treatment TSS Titrable acidity 0D 3 D 6 D 9 D 12 D 0D 3 D 6 D 9 D 12 D Maturity stages M c 4.21c 4.25c 4.54b c 0.41b - M b 4.30b 4.45b 4.66a b 0.45a - M a 4.49a 4.60a 4.68a a 0.46a - Ethrel Conc. T b 4.3b 4.57c T b 4.38b 4.60b T a 4.41b 4.64a T a 4.46a 4.65a T a 4.48a 4.65a T a 4.49a 4.64a CV (%) Means within a column having same letters are not significant at 5% level by DMRT TSS: Total Soluble Solid,

8 24 M.Moniruzzaman et al. TSS content of tomato pulp TSS content of tomato pulp varied significantly in fruits of different maturity (Table 5). Half ripen tomato contained the highest quantity of TSS (4.35%) while it was the lowest (3.85%) in mature green tomatoes at harvest. For all maturity stages, TSS increased gradually with the advancement of ripening process. This is in consonance with the results of Moneruzzaman et al. (2008b) and Winsor et al. (1962). Ethrel levels were also found to have significant effects on change in TSS content of tomato juice at 3, 6 and 9 days of storage. The maximum TSS content was observed in 500 ppm ethrel at 9 days of storage. The TSS content was also found to be significantly influenced by the combined effect of maturity stages and ethrel levels at 0, 3, 6 and 9 days of storage (Table 6). At 3, 6 and 9 days of storage 500, 1000 and 2000 ppm ethrel gave the highest TSS compared to control. In breaker stage 250, 500, 1000 and 2000 ppm ethrel maintained a lead over control in respect of TSS content at 3, 6 and 9 days of storage. Again in full ripen stage,250, 500, 1000 and 2000 ppm ethrel produced more TSS than that of control treatment. Table 6. Effect of ethrel and maturity stages on TSS content of tomato (cv. Raton) fruits during storage Days after storage Treatment 0D 3D 6D 9D 12D Maturity stages Ethrel conc. T e 4.20i 4.49d 4.60 T f 4.21i 4.51d 4.57 M 1 T d 4.25ghi 4.54d 4.62 T bc 4.23hi 4.54cd 4.63 T b 4.30fgh 4.60bc 4.61 T b 4.32fg 4.55cd 4.61 T cd 4.40e 4.61b 4.62 T d 4.35f 4.62b 4.65 M 2 T b 4.41e 4.68a 4.73 T bc 4.50d 4.68a 4.66 T b 4.52cd 4.68a - T b 4.52cd 4.68a - T a 4.57bc 4.60bc - T a 4.51d 4.69a - M 3 T a 4.59ab 4.72a - T a 4.62a 4.73a - T a 4.63a 4.67a - T a 4.64a 4.71a - CV (%) Means within a column having same letters are not significant at 5% level by DMRT

9 Ripening of tomato by the post harvest application of ethrel 25 Titrable acidity content of tomato pulp The total titrable acidity in tomato pulp varied significantly in fruits of different maturity (Table 5). The half ripen tomato pulp contained the highest quantity of titrable acidity (0.46%) at 6 and 9 day of storage. However, there was no significant difference between breaker stage and half ripen stage in respect of titrable acidity at 9 day of storage. The ethrel effect on titrable acidity was insignificant. The interaction effect between ethrel and titrable acidity was also insignificant. Weight loss (%) Maturity stages, ethrel levels and their combination were found to have significant effect on total loss in weight of fruit (Table 7). Total weight loss in mature green tomatoes was always higher during the entire period of storage. At the 3 days of storage, it was 2.66% that rose to 6.65% at 9 days In half ripen tomatoes; weight loss was the lowest, being 1.99% at 3 days and 5.99% at 9 days of storage. Weight loss in mature green tomatoes was higher because higher rate of dehydration were generally happened in tender tissue. This is in line with the result of Moneruzzaman et al. (2008a). Ethrel conc also had significant effect on weight loss of tomato (Table 6). The ethrel concentration of 250, 500, 1000 and 2000 ppm gave higher weight loss than control at 3, 6 and 9 days of storage. The interaction effect was significant at 3 and 9 days of storage with regard to total weight loss in fruit (Table 8). Here the weight loss gradually increased with the advancement of storage period. Ethrel at 500ppm at the 3 days of storage and 250 ppm at 9 days of storage gave maximum weight loss in green mature tomatoes. However, there was no significant difference between 250, 500, 1000 and 2000 ppm ethrel when they interacted with mature green tomatoes at 3days of storage. At 9 days, the effect of 250, 500 and 2000 ppm ethrel coupled with mature green tomatoes were similar on weight loss. Table 7. Main effect of maturity stages and ethrel on weight loss and rotting of tomato at different days of storage Days of storage Treatment Weight loss (%) Rotting (%) 0D 3 D 6 D 9 D 12 D 0D 3 D 6 D 9 D 12 D Stage of maturity M a 5.14a 6.65a b 27.78c 76.11c M b 4.60b 6.23b b 30.56b 87.22b M c 4.47b 5.99c a 44.44a 100.0a Ethrel Conc. T b 4.47b 6.01c b 26.67c 85.55b T b 4.23b 5.97c b 28.89c 85.55b T a 5.00a 6.50a b 28.88c 81.11b T a 5.91a 6.41b b 18.89c 85.55b T a 4.87a 6.39b a 40.00b 93.33a T a 4.94a 6.47a a 52.00a 95.66a CV (%) Means within a column having same letters are not significant at 5% level by DMRT

10 26 M.Moniruzzaman et al. Table 8. Effect of ethrel and maturity stages on weight loss of tomato (cv. Raton) fruit during storage Days after storage Treatment 0D 3D 6D 9D 12D Maturity stages Ethrel conc. T bc de 7.20 T b f 7.02 M 1 T a a 7.10 T a ab 7.37 T a b 7.62 T a a 7.51 T de j 6.75 T cd i 6.86 M 2 T b c 6.92 T b de 7.18 T bc e - T bc cd - T e k - T e k - M 3 T e fg - T de hi - T de gh - T de fg - CV (%) Means within a column having same letters are not significant at 5% level by DMRT Table 9. Effect of ethrel and maturity stages on rotting of tomato (cv. Raton) fruits during storage Days after storage Treatment 0D 3D 6D 9D 12D Maturity stages Ethrel conc. T c 20.00d 73.33ef T c 23.33cd 76.67def M 1 T c 23.33cd 63.33g T c 20.00d 70.00f T a 30.00c 86.67bc T a 50.00ab 86.67bc T c 20.00d 83.33cd T c 23.33cd 80.00cde M 2 T c 23.33cd 80.00cde T c 26.67cd 86.67bc T a 40.00b 93.33ab T a 50.00ab 100.0a T b 40.00b 100.0a T b 40.33b 100.0a M 3 T b 40.33b 100.0a T b 40.33b 100.0a T a 50.00ab 100.0a T a 56.67a 100.0a CV (%) Means within a column having same letters are not significant at 5% level by DMRT

11 Ripening of tomato by the post harvest application of ethrel 27 Rotting (%) Stages of maturity, ethrel levels, and their combinations were found to have significant effect on rotting (%) of tomatoes Table 7 and 9. Rotting in half ripen tomatoes was found always higher during the entire period of storage. There were no rotten tomatoes found at 3 days. At the 6 days of storage, total rotting percent was 13.89% that rose to 100% on 12 days of storage in half ripen tomatoes. On the other hand, rotting percent in mature green tomatoes being 6.67% at 6 days and was 76.11% at 12 day of storage. In breaker stage, the rotting rotting (%) was 6.67% at 6 days, 44.44% at 9 days that rose to 87.22% at 12 days of storage. The rotting (%)is higher in half ripen tomatoes because of higher rate of transpiration, more skin permeability for water loss and high susceptibility to decay organism of this climacteric type of fruit. This corroborates the report of Moneruzzaman et al. (2008a). The highest rotting of 20% was recorded in 1000 and 2000 ppm ethrel at 6 day of storage. But at 9 days of storage the maximum rotting % was noticed in 2000 ppm folloed by 1000 ppm ethrel. Again at 12 days of storage rotting % was found highest in 2000 ppm ethrel. The ethrel levels of 1000 and 2000ppm gave the highest rotting percent irrespective of maturity at 6 days of storage. At 9 days of storage,the ethrel level of 2000 ppm produced the maximum rotting (%) irrespective of maturity stages. The breaker stage coupled with 2000 ppm and half ripen stage irrespective of ethrel levels gave 100% rotten tomatoes. Shelf life of tomato Mature green tomato had a higher storability than the breaker stage followed by half ripen tomatoes. Maximum shelf life was days in mature green tomatoes followed by breaker stage (9.11 days) and minimum was 7.88 days for half ripen tomatoes (Fig. 1). It was found by Moneruzzaman et al. (2008a) that mature green tomatoes of cv. Roma VF had the highest shelf life (13 days) followed by half ripen tomato (12 days). Ethrel levels had also significant effect on shelf life of tomatoes (Fig. 2). Control was recorded to give the longest life (10.11 days), closely followed by 500, 125 and 250 ppm level. The lowest life was recorded by 2000 ppm ethrel (6.56 days). Fig. 1. Effect of maturity stages level on the shelf life of tomato (cv. Ratan). Bar indicatas LSD 0.05.

12 28 M.Moniruzzaman et al. Fig. 2. Effect of ethrel levels on the shelf life of tomato (cv. Ratan). Bar indicates LSD Fig. 3. Interaction effet of maturity stages and ethrel levels on shelf life of tomato (cv. Ratan). Bar indicates LSD 0.05.

13 Ripening of tomato by the post harvest application of ethrel 29 The maximum shelf life (11.33 days) was recorded in case of mature green tomatoes without ethrel application (Fig. 3). The lowest shelf life was found from 2000 ppm ethrel applied in half ripen tomatoes (6 days) closely followed by 1000 ppm ethrel applied in half ripen tomatoes and 2000 ppm ethrel in breaker stage. The ethrel level of 250 and 500 ppm coupled with either mature green tomatoes and breaker stage tomatoes gave shelf life identical to green tomatoes treated with fresh water (control). Conclusion It was observed that ppm ethrel developed colour and made tissue softness more quickly than other treatments and hastened the color changes compared to control. Vitamin-C content and TSS were higher in breaker and half ripen tomatoes than green mature tomatoes during storage time. The ethrel concentration of ppm gave maximum vitamin-c and TSS from 3 to 9 days. But 1000 and 2000 ppm ethrel failed to produce the highest TSS compared to 250 and 500 ppm ethrel at 12 days. The highest shelf life was recorded in mature green and breaker stage tomato and lowest in half ripen tomatoes. Although minimum rotting (%) and maximum shelf life were noticed in control and 125 to 500 ppm ethrel, 1000 and 2000 ppm showed maximum rotting (%) and minimum shelf life. Therefore it might be concluded that tomato fruits should be harvested at mature green and breaker stage for ethrel application at 250 to 500 ppm for tomato ripening. References Abeles, F.B., P.W. Morgan and M. Saltveit. (1992). Ethylene in Plant Biology. 2 nd Ed., Academic Press New York. P Anju-kumari, M.l., S.P.S., Bhardwaj and A. Kumari. (1993). Influence of stage of harvest on shelf life and quality of tomato. Hort. J. 6: Anonymous. (2008) Retrived on BBS (Bangladesh Bureau of Statistics). (2007). Statistical pocket book of Bangladesh, Bangladesh Bureau of Statistics, Bangladesh. P Boe, A.A.J.Y. Do and D.K. Salunkhe. (1967). Tomato ripening: Effects of life frequency, magnetic field and chemical treatments. Econ. Bot. 24:124. Dhall, R.K., B.V.C. Mahajan and A.S. Dhatt. (2001). Effect of ethephone and ethylene gas on ripening and quality of detached winter tomato. /actahort/books /877/877_138.htm. Goojing, L., X.U. Zhaihao, W. Shov, G.J. Li, Z.H. Xu, D. Dhai, and W.I. Shou. (1999). The effects of cultivars electrical conductivity and harvest date on the storability of cherry tomato grown in soil less culture.acta agric. Zhejiangansis. 11: Kaynas, K. and N. Surmeli. (1995). Characteristics changes at various ripening stages of tomato fruits stored at different temperatures. Turk. J. Agric. For. 19: Mallik, S.E., B.Bhattacharia and B. Bhattacharia. (1996). Effect of stage of harvest on storage life and quality of tomato. Eviro. Ecol., 14: Moneruzzaman, K.M., A.B.M.S. Hossain, W. Sani and M. Safiuddin. (2008a). Effect of stages of maturity and ripening conditions on the physical characteristics of tomato. Ame. J. Bioch. and Biotech. 4(4): Moneruzzaman, K.M., A.B.M.S. Hossain, W. Sani and M. Safiuddin. (2008b). Effect of stages of maturity and ripening conditions on the biochemical characteristics of tomato. Ame. J. Bioch. and Biotech. 4(4): Moura, M.A., S.R. Zanin and F.L. Finger. (1997). Influence of ethephon and a surfactant on ripening of harvested tomato fruit. HortScience. 32 :3478. Ranganna, S. (1986). Handbook of Analysis and Quality control for Fruit and Vegetable products. Tata McGraw Hill Pub. Co. Ltd., New Delhi, India. pp

14 30 M.Moniruzzaman et al. Thanh Hai, V.U., P.T. Huong, P. Sruamsiri, M. Hegele and J. N. Winsche. (2009). Effect of ethrel postharvest application on ripening of Tron and Hoi mangoes (Mangifera indica L.). Conf. on Int. Res. on Food Security, Natural Resource management and Rural Development, Univ. Of humburg, Oct. 6-8, p V.M. Olympio, J.C. Norman. (2000). Influence of pre-post harvest application of ethephone (2 chloroethyl phosphonic acid) on tomatoes. hortsci.ashspublications.org/ content/ 32/3/ abstract. Wills, R.B.H. and V.V.V. Ku. (2002). Use of 1-MCP to extend the tomato ripen of green tomatoes and post harvest life of ripe tomatoes. Postharv. Biol. Technol. 26: Winsor, G.W., J.N. Davies and D.M. Massey. (1962). Composition of tomato fruit juices from whole fruit and locules at different stages of ripens. J. Sci. Agric. 13: