Evaluation of Selected Promising Cherry Tomato Lines (Asian Vegetable Research and Development Center (AVRDC) Kasetsart University Nakhon Pathom, Thailand)

Maji Yaw Htung (2005)

Abstract

          Seven hybrids cherry tomatoes together with an open-pollinated variety CH 154 as check evaluated for yield and yield components, agronomic characters and organoleptic test under Nakhon Pathom, Thailand conditions. TX4003, TX4008 and TX4009 were better than CH145 and other lines in terms of marketable yield, average fruits weight, and number of fruits per plant, percent marketable yield by fruit weight and by fruit number. The acceptability of line 4B4141 in terms of taste was better than CH 154 and also the best among the lines in organoleptic test, brix and fruit firmness.

Introduction

           

Tomato (Lycopersicon esculentum) is native to the Andes mountain of South America, where it was used long before Columbus. It was taken to Europe where it was a popular vegetable by the 1500s. The tomato did not gain wide acceptance in the United States until the mid 1800s. Tomatoes are warm season crop and tomato does not thrive in cold weather and will not set fruit at temperatures below 14.4^oC. Tomato should be grown where they will receive at least 6 hr of direct sunlight and it does not set fruit above 29.4^o C. Most Lycopersicon related species, namely L. hirsutum, L. peruvianum and L. pimpinellifolium
.

          Some other markets trained tomatoes are quoted separately as “trellis” and two plants of training are followed. One calls for  a stake 1.5 m or 2 m long driven into the ground beside each plant and plants are tied to the stake every 30 cm or so. In many regions, little damage is done to tomatoes by insects and diseases at the same time; the total number of enemies encountered in various regions is large. According the diseases fusarium wilt, leaf spots and, the late blight of potatoes, bacterial canker, Verticillium wilt. There are some other diseases these can effect the yield those are bacterial spot, bacterial wilt, early blight leaf mold and powdery mildew (4).

            There are hundreds of tomato cultivars available. Fruits come in a number of shapes, sizes, and colors such as main crop cultivars, orange or yellow fruit cultivars, container cultivars, paste cultivars and cherry tomato or salad tomatoes.

            Cherry tomato (Lycopersicon esculentum var. cerasiforme), so called salad tomato, is the probable ancestor of the cultivated tomato. It varies in size up to 3.5 cm in diameter. The fruit is yellow or red. It has good source of vitamins, minerals and has high sugar content. Cherry tomato became popular because of its good taste and beautiful shape as well as a cash crop. In some Asian countries, cherry tomato is still a new crop which needs to be evaluated for adaptation.

            One of the components of the tomato breeding program of AVRDC is the development of cherry tomato lines for evaluation. One open-pollinated cherry tomato line, CH154, was released as a variety in Thailand. New lines and experimental hybrids have been developed not only by AVRDC but also by tomato breeders in the country. A number of these lines/hybrids are available for evaluation. It is the purpose of this trial to evaluate promising experimental hybrids of cherry tomato under Nakhon Pathom, Thailand conditions to determine if any of these hybrids will be better than the existing varieties grown in Thailand.

Materials and Methods

           

The experiment was conducted at AVRDC-ARC Kasetsart University, Kamphaeng Sean, Nakhon Pathom, Thailand from December 2005 to March 2006. Seven F1 hybrids of cherry tomato lines those are TX1001, TX1002, TX4007, TX4008, TX4009, 4B4141 and one open-pollinated variety CH 145 (check) as check were used to be evaluated.

            Plastic seedling flats were filled with 1:1:1 mixture of coconut husk, compost and rice hall. The seeds were sown on 8 November 2005. Thinning was done one week after sowing by leaving one seedling/pot. The experiment was laid out in RCBD with three replications and 1.6 x 5 m² plot size consisting of 2 rows/plot and 10 plants/row. The plots were mulched with polyethylene sheets before transplanting. The seedlings were transplanted on 7 December 2005. Complete fertilizer (15-15-15) was applied as side dressing at the rate of 187.5 kg/ha 35 days after transplanting. The seedlings were furrowed-irrigated immediately after transplanting and weekly thereafter depending on the soil moisture level. Bamboo sticks were used as trellis two weeks after transplanting. The plots were weeded twice on 5 and 28 January 2006, respectively. To control inset pests and diseases, insecticides and fungicides were sprayed at recommended rate depending on severity of infection/infestation. Harvesting was done twice a week from January to March 2006.

            The data were collected based on plant stand, growth habit, days to first harvest, total yield, marketable yield and fruit number (big and insect-damaged) non-marketable yield and fruit number(crack and small), mean fruit weight, fruits peer cluster, fruit color, firmness, brix, fruit shape, fruit shoulder, and fresh fruit acceptability. The data were analyzed statistically using MASTAT C software.

Result and Discussion

Yield and yield components

           

Result of analysis of variance showed that average fruits per cluster was significant, mean fruit weight, percent marketable yield by weight and by number were highly significant while total yield, marketable yield and number of fruits per plant were not significantly different ( table 1). The average fruits setting of 4B4141 and TX4009 was better than CH 154 and among them 4B4141 was the best fruit-set. Total fruit number of TX4003 and TX4008 was higher than and of the lines and CH 154.

            According to the table, total yield was not significant but the total yield of TX4002, TX4003 and TX4009 were differently higher than among the lines. The percent marketable yield by weight of TX4003, TX4008, and TX4009 were significantly higher than among the lines and CH154. The fruits number of percent marketable yield of TX4003, TX4007, TX4008, TX4009 were high significantly different from other lines and Ch 154.

            TX4003, TX4008 and TX4009 were highly significantly different from CH154 in average fruits per cluster, fruits number of plant, total marketable yield, and percent marketable yield by weight and percent marketable yield by number.

Table 1.Yield and yield component of 8 cherry tomato lines in areplicated yield trial.
	AVRDC-ARC, Kasetsart University, Nakhon Pathon, Thailand,
	November 2005 to March 2006
	Total	Total	Average	No.of	Mean	Percent	Percent
Variety	Mark.	Yield	Fruits	Fruits	Fruit	Mark.	Mark
	Yield	(t/ha)	per	per	Weight	yield	yield
	(t/ha)		Cluster	plant	(g)	By Wt.	By No.
TX4009	47.2	49.6	8.09ab	178.7	8.51c	93.7a	88.4a
TX4003	43.3	46.2	7.63abc	183.6	10.1b	93.6a	89.1a
TX4002	37.5	46.5	7.25bc	156	11.9a	80.7b	78.6bc
TX4007	35.4	40.4	7.05c	146.3	7.09c	87.4ab	84.7ab
TX4008	34.8	37.6	7.92abc	211.7	8.04c	92.7a	90.7a
CH154(check)	30.9	36.1	7.88abc	180.7	8.2c	85.6ab	78.4bc
TX4001	29.9	34.5	7.29bc	169.3	7.89c	86.6ab	76.9bc
4B4141	27.1	33.8	8.29a	170.7	9.08	97.8b	71.2c
Mean	35.8	40.6	7.6	174.6	**	87.5	82.25
F-test	ns	ns	*	ns	7.23	**	**
C.V	26.07	24.27	5.86	15.17		3.45	3.98
Mean followed by the same letter(s) in a colum are not significantly at 5% level by
DMRT. ns=non significant, * = significant at 5% level and ** = highly significant
at 1% level.

Agronomic character

           

The normal plant growth habit of cherry tomato is indeterminate except for TX4002 and TX4007 which are semi-determinate. TX4001, TX4002, TX4003 and TX4007 were the earliest to reach 50% flowering at about 25 days from transplanting. The earliest of lines to be harvested are TX4001, TX4002, TX4003 and TX4007 as 56 days for each.

            The fruits shape of TX4002, TX4008 and TX4009 are globe shape and others are oblong shape including CH154, and then all the lines and CH 154 fruits shoulder are green. From the Royal Horticulture Society color chart TX4001, 4B4141 and Ch 154 are orange-red and TX4002, TX4003, TX4007, and TX4009 are red.

Organoleptic test, Brix and Fruit Firmness

            The acceptability of tastes is color, appearance, taste and sweetness. The most acceptance line is 4B4141. But the acceptability of TX4003, TX4008 and TX4009 were available. The highest brix level was observed in 4B4141 and TX4001 which were better than of CH154, however, the brix values were not significantly different. 4B4141 has the most firm skin, was higher than other lines and CH 154.

Conclusion

All of hybrid cherry tomato lines and check cherry tomato variety showed promising result under Kamphaeng Sean condition. Among the hybrid lines TX4003, TX4008 and TX4009 were better than CH154 and other lines and check in terms of average fruits of cluster, fruits number, total marketable yield, percent marketable yield by weight and percent marketable yield by number. Particularly the acceptability taste of 4B4141 line was better than CH154 and also the best among the lines in organoleptic test, brix and fruit firmness.

Acknowledgements

            I am extremely thankful to the organization of American (101) Veterans, Inc. Project Old Soldier, Mr. Peter Lutken (Head of 101 Project Old Soldier) and Dr. Ed Runge (Technical Advisor of 101 Project Old Soldier) for the providing of sponsorship. Moreover, I would like to mention to Mrs. Nang Ja (Superintendent of Project Old Soldier in Myanmar) for her decision to send me to be able to attend this training. Sincerely thanks go to Mr. Efren C. Altoveros (Training Officer) who was undertaking patiently for this guidance and supervision during the training course. I also appreciate and thank to Ms. Somchit Preongwitayakun, Mr. Worawit Sorajjapinun, Ms. Chanida Ammaranan, all AVRDC and TRC staffs and farm staff for their kind help and work hard during the training course and throughout the experiments period.

References

1.                  AVRDC. 1989. Tomato and pepper production in the tropics. In: Proceedings of International Symposium on Integrated Management Practices. 21-26 March 1988. Asian Vegetable Research and Development Center, Tainan, Taiwan. Pp. 2, 14, 70.

2.                  Splittstoesser, W.E. 1984. Vegetable Growing Handbook, The AVI Publishing Company, Inc. Westport, Connecticut. Pp. 272-275.

3.                  Work, P. and J. Carew. 1995. Vegetable Production and Marketing, Wiley Eastern Private Limited: New Delhi. Pp. 325-335.

4.                  AVRDC.1990. Vegetable production training manual. Asian Vegetable Research and Development Center. Shanhua, Tainan. Pp. 277-280.

Vong Hiep Long. 1998. Cherry tomato varietal trial. In: ARC Training Report. AVRDC-ARC. Kasetsart University, Nakhon Pathom, Thaila