TARI WWW Site

Capacity Building for Development and Implementation of Risk Management Systems on Genetic Resources

Mon, 13 Oct 2008 02:20:00 +1600

Capacity Building for Development and Implementation of Risk Management Systems on Genetic Resources

APEC-ATCWG Workshop on
Capacity Building for Development and Implementation of Risk Management Systems on Genetic Resources
14-17 October, 2008
Taiwan Agricultural Research Institute,
Council of Agriculture, Chinese Taipei

Plant Germplasm Division

Postharvest Handling of Water Bamboo Shoot (Zizania latifia) for Exportation

Thu, 10 Jul 2008 07:40:00 +1600

Postharvest Handling of Water Bamboo Shoot (Zizania latifia) for Exportation

    Water bamboo shoot is one of the major vegetables exported to Japan. It is exported by air transport. High air freight constricts the exportation. Transportation at high temperature may result in off flavor when the transportation time is prolonged.
    The effect of precooling and packaging method on the quality of water bamboo shoot had been investigated. The temperature of water bamboo shoot was lowed to 5℃ within 2 hours when it was precooled with ice water. The temperature of water bamboo shoot in control was 20~24℃ after 4~5 hours precooling with spring water. Water bamboo shoot in both treatments were transferred to 1~2℃ cold room for overnight. Their qualities are the same after simulated air transport.
    The quality of water bamboo shoot maintained good after simulated air transport at room temperature for 24 hours. Off flavor occurred when the time of shipment was prolonged to 48 hours. All the water bamboo shoots tested were packed with thick PE bag and sealed tightly which is the normal method used in commercial operation. The concentration of carbon dioxide was higher than 10% after simulated transportation for 48 hours which may cause off flavor of water bamboo shoot.
    The quality of water bamboo shoot maintained very good after simulated marine shipment at 1 and 2℃ for 14 days. The quality was good with little defect in appearance and on cut surface when the shoot had been kept at 5℃ in simulated shipment. Off flavor didn’t occur in all these treatments. The concentrations of carbon dioxide inside of PE bag were all lower than 5%.
　

Crop Science Division

The new lowland peach cultivar - Tainung No. 2 'Xiami'

Fri, 27 Jun 2008 01:20:00 +1600

The new lowland peach cultivar - Tainung No. 2 'Xiami'

    The “water-honey-peach” (melting) is one of the Taiwan consumer favorite fruits because of its melting, sweet and low acid content. Peach cultivation on the slopes of the mountains is easy to have erosion, chemical residue contamination, and water pollution problems. Consequently, the breeding research emphasized on the development of fruit cultivars adapted to subtropical climate conditions which are at altitudes of less than 600 meters to alleviate contamination problems. The objective of breeding program is to develop low chill (less than 200 CU) peach, flat peach or nectarine cultivars, with a range of fruit development periods (75 to 120 days), which are white, low acid, round, attractive, and firm enough to handle commercially.
    Recently, ‘Xiami’ peach has been released by the Taiwan Agricultural Research Institute, Council of Agriculture. The new cultivar is the second “water-honey-peach” (melting) released for the low elevation growing areas of Taiwan. The sweet, low acid fruit has a desirable texture, a firm but melting texture, and white flesh. The stone is free when fruit is ripe. The attractive fruits are ovate in shape and very large, averaging 204.8g. Fruit ripen about 106 to 139 days from bloom. The fruit development period of the new cultivar can be longer than ‘Premier’ by 2-3 weeks, or ‘SpringHoney’ by 4-5 weeks. It can extend the fruit supply period of peach. The harvest time is before early June and could escape the damage of typhoon. The large fruit size and late ripening is beneficial to the peach grower for extending the fruit supply period.
    ‘Xiami’ trees in the lowland subtropics require 125 chill units (CU) and set a large number of flower buds. It suit to plant in north and central low elevation growing areas of Taiwan. The major production problems are trunk gummosis and oriental fruit fly. The new cultivar increases the multiplicity of cultivar and the potential of extending the fruit supply period and reduces the impact of WTO.

Crop Science Division

Lychee Tainung No.4

Fri, 06 Jun 2008 01:30:00 +1600

Lychee Tainung No.4

Lychee (Litchi chinensis Sonn) ‘Tainung No.4’ (commercial name: Lucky Lychee) was named in 2008. The female parent of this new cultivar is ‘Chakrapad’ which was introduced from Thailand, Tainung No.4 was selected from a population of ‘Chakrapad’ seedling trees. The original seedling tree of ‘Tainung No.4’ grown at Fengshen Tropical Horticultural Experiment Branch in 1993, before being named, ‘Lychee Tainung No.4’ was known as T2. The juvenility period was ended in 1998, the comparative experiment of vegetative lines of seedling was since 1999, and ended in 2000. The regional test was carried out since 2001, and continued to 2007. The cultivar’s property was ordered in 2008 (No.A00617).
‘Tainung No.4’ has a strong branching habit with wide crotches. The bark is smooth and light grey in color, the leaves are large, shiny and green, with six to eight leaflets. Fruit color is bright red, the fruit shell is covering with flat protuberances. The flower buds usually emerged in early February, and full blooming in mid-March. The matured season is in early June in southern part of Taiwan, and harvest lasts until late July and early August in central Taiwan. The average fruit weight is 41.5±2.2g, the soluble solid content is 17.8±0.4˚Brix, the percentage of edible part (pulp) is 70.2±1.7%. The seeds is normal seed, the average seed weight is 4.7±0.2g. The fruit quality of Tainung No.4 is excellent, and with good flavor.


Fig 1. The cluster of heavy crop		Fig 2. Matured fruit in bright red color

Fengshan Tropical Horticultural Experiment Branch

New detection technique for viruliferous whiteflies

Mon, 21 Jan 2008 01:20:00 +1600

New detection technique for viruliferous whiteflies

    The Silverleaf whitefly (Bemisia argentifolii Bellows & Perring) is responsible for significant damage to various crops, and also can transmit more than 100 virus species. In Taiwan, the tomato yellow leaf curl virus (TYLCV) is the most serious of all disease transmitted by silverleaf whitefly. Pesticides are ineffective against the TYLCV, and therefore the only treatment for an infected plant is eradication of the crop. The most effective method of preventing TYLCV contamination of crops would be by early detection and eradication of the viruliferous whitefly population.
    The purpose of this manuscript is to detail a new methodology for the detection of the whitefly and determination of population virulence. Yellow stick traps, which are more convenient and effective in the field as compared to other methods, is used to attract adult whiteflies. Individual adult flies are then analyzed to confirm the silverleaf whitefly species using the specific PCR primer 772/773. Using these techniques, DNA can be successfully extracted from more than 60% of the flies after being trapped for up to 7 days. Moreover, concomitant use of the GCP1/PA4 primer pair enables detection of the TYLCV in viruliferous whiteflies.
    This technique not only determines whether a whitefly is viruliferous or nonviruluferous, but also estimates the population density of viruliferous whiteflies in the field. Furthermore, similar study in a closed system demonstrates a positive correlation between the number of viruliferous silverleaf whitefly and infected TYLCV tomato. The viruliferous whiteflies would increase change to spread TYLCV and infect tomato if those infected plants would be not rogued. In addition, treatment of tomato plants with pyriproxyfen during the early planting period reduced the population density of silverleaf whitefly , and furthermore decreased the proportion of TYLCV infected tomato plants in the closed system.


Silverleaf whitefliey is a vector to transmit more than one hundred species virus		Using yellow stick traps to attract adult whiteflies is more convenient and effective than other methods for seeking and sampling the tiny whiteflies in filed


Symptom of tomato infected TYLCV (left) and health plants (right)

Applied Zoology Division

TNGSW 21 - A new indica type waxy rice variety

Wed, 16 Jan 2008 09:00:00 +1600

TNGSW 21 - A new indica type waxy rice variety

    TNGSW21 (Tai-Nung-Sen-Waxy No. 21) is the first rice variety developed by mutation breeding at Agricultural Research Institute in Taiwan. Mutations were induced by treating the rice seeds of TNG67 variety with sodium azide followed by screening and purification according to the standard pedigree method. SA0419 was then selected after several field trials for 11 years. It has good agronomic traits such as early maturity , easy cultivation, high yield and special waxy grain quality for food processing, and has been named as TNGSW21 variety in November, 2007 by the Rice Breeding Evaluation Committee.
    The seed germination rate and vegetative growth rate of TNGSW21 are higher than those of TNG67 variety. Plant type of TNGSW21 is similar to indica rice, and the phenol reaction of hulls is the same as the indica variety. Therefore, it is classified as an indica variety though it was mutated from japonica type rice. The maturation days of TNGSW21 variety is one week shorter than that of TNG67 and TCSW1 varieties. During grain filling period, the starch and grain dry matter accumulation rates of TNGSW21 are very high and the appearance of its grains is quit uniform. The grain of TNGSW21 is classified as medium-short type with grain weight about 28 g/1000 grains.
    As general indica rice varieties, TNGSW21 is sensitive to low temperature. Therefore, it is suggested that seedlings of this variety are transplanted after late February especially for the central regions of Taiwan. It shows stable yield performance and its grain yield of the second crop season is higher than that of TNG67 variety. The grains of TNG67 and TCSW1 varieties germinate on panicle during rainy season in May, but those of TNGSW21 do not germinate on panicle.
    TNGSW21 shows good grain quality for food processing. For example, the glutinous rice balls are very compact and have good shape after re-boiling; zongzi or glutinous rice wrapped in bamboo leaves is easier to be cooked and the grains still have good shape after long time boiling; mouchi or glutinous cake with paste has good chewing quality and can be stored in the refrigerator without cracking for a long time.
    In order to disseminate the newly released variety, TNGSW21. a seed propagation field has been established in 2008. More researches will be conducted to develop new products or new varieties based on the unique starch character of TNGSW21.


TNGSW21 plants at maturity stage		Rice panicles of TNGSW21 and TCSW1

Rice plants of TNGSW21 and TCSW1		Glutinous rice wrapped in bamboo leaves (zongzi) made from TNGSW21 and other variety rice grains.

Biotechnology Division

The Construction of a Safe Production System for Brazei Mushroom

Mon, 10 Dec 2007 09:00:00 +1600

The Construction of a Safe Production System for Brazei Mushroom

    Taiwan Agricultural Research Institute (TARI) has conducted the research focusing on the problem of Brazei mushroom’s (Agaricus blazei) heavy metal content and discovered through modified sawdust bag, casing soil without heavy metal pollution, and pure water, it is possible to produce safe quality Brazil mushroom.
    It is reported in recent years that Brazil mushroom has β-D-glucan which has efficiency of improving the immune system to become one of consumer’s favorite supplemental mushroom. However, recent random inspections conducted by Department of Health found some Brazil mushroom products sold in the market content excess level (2 ppm) of cadmium, which receives great concerns from the consumer.
     Due to Brazil mushroom’s sensitivity to its cultivation environment, contacts to air, soil, water, media, temperature, and moisture during cultivation stage, the exposure to the cleaning water, and the drying process all determine the quality of dry mushroom. The cultivation of Brazil mushroom in China, Japan and Taiwan is facing a similar problem: productivity, quality inconsistency and high level of heavy metal contain. Early cultivation of Brazil mushroom in Taiwan utilized mainly rice straw with manure and soybean power as compost. Because rice crop is highly susceptible to the influence of cultivation environment, soil, and irrigation water, it is possible to cause slight heavy metal cadmium content problem. The cadmium content level of Brazil mushroom is under the safe standard and has not caused any consuming concern. Although, utilizing rice straw and rice burn as cultivation compost for Brazei mushroom, due to the biological characteristic of this mushroom for accumulating heavy metal cadmium, will cause heavy metal pollution in the fruiting body.
    Monitoring heavy metal contain in Brazil mushroom becomes an important issue in elevating the quality of this mushroom in Taiwan. The experiment discover through utilizing sawdust free of heavy metal contamination, adjuvant (rice bran, wheat middling, lime, calcium superphosphate and urea), clean casing materials (soil or compost), and water, as well as employing environment control and rigorous strain selection, it is possible to drastically reduce the content of heavy metal and increase the quality of domestic Brazil mushroom. Such quality mushroom can not only meet the standard of safe food consumption and provide for the large domestic and international market, but also increase its competitiveness in the world.

Applied Zoology Division

Doritis, as a potential cut flower in Taiwan

Tue, 07 Aug 2007 02:10:00 +1600

Doritis, as a potential cut flower in Taiwan

    Feasible analysis of the vase life in Doritis for cut flowers was evaluated in Floriculture Research Center, Taiwan Agricultural Research Institute, Council of Agriculture. The results showed that the vase life of Doritis for cut flowers reached up to 16 days would have the potential as an important cut flower in Taiwan.
    Doritis is a typical monopodial orchid but sometimes produces lateral buds from the base of the stem. The leaves are strong and thick with lanceolate shape, which are different from Phalaenopsis and Doritis, are usually categorized as phalaenopsis in commercial and amateur cultivation.
    Doritis is a typical monopodial orchid but sometimes produces lateral buds from the stem base. The leaves are strong and thick with lanceolate shape, which are different from Phalaenopsis spp. The plant size of Doritis is smaller than Phalaenopsis. Most Phalaenopsis varieties bloom in winter and spring but Doritis usually blooms in summer. The inflorescence of Doritis is straight spike. Doritis is known for its various colors of white, white with red lip, white with yellow splashed petals, blue, pink, rose etc. The flower size is about 3 cm and the petals are thick and waxy.
    Most Phalaenopsis varieties having arch-type inflorescence make them difficult for processing in transportation, but Doritis with straight spikes is convenient for packaging and transportation. Once the spike has cut when the first flower bloomed, the other seven to nine flowers will continuously bloom under suitable treatment. Each flower will bloom in 2.5 days and the life of flower is at least for 14 days. Therefore, the vase life of the spike will be longer than 16 days. Doritis is grown easily in Taiwan and has the potential to be a valuable cut flower.

Floriculture Research Center

Ground Covered with Plastic Film in Orchard for Oriental Fruit Fly Management

Mon, 25 Jun 2007 03:30:00 +1600

Ground Covered with Plastic Film in Orchard for Oriental Fruit Fly Management

    The oriental fruit fly larvae when mature will leave host fruits and penetrate into the soil for pupation in the field. Laboratory behavioral observations show that the springing and creeping of the mature larvae on the ground have no specific directionality, and often kept in a fixed range that the larvae even finally return to the place where they take off. As placing the mature larvae on the center of a piece of 2 m x 1.5 m plastic film, it was found that about 90% of the larvae were still on the film 2 hours later, and after 24 hours, 33% of the larvae pupated on the film. Based on the non-directionality of the mature larvae’s moving behavior, ground covered with plastic films and then sprayed with insecticides could be developed as a supplementary control measure for fruit fly management.
    In the laboratory, we sprayed Diazinon on plastic films, and then introduced mature larvae on the films to observe their behavior and test the toxic effects. Results showed that the average time for the larvae to reach death were 10 min, and the larvae before death bounced 20 times. The total bouncing distance in average was 77.7 cm with 3.5 cm for each bounce; however, they died within 33.4 cm in average from their take off points.
    Ground covered with plastic film in combination with insecticide spray could fail the mature larvae in penetrating into the soil for pupation. Besides, the exposure time to the insecticides is increased as the larvae bounce before getting into the soil. The larvae would die from the insecticidal effects even they bounce out of the plastic films. Spray of insecticides on the ground to kill the penetrating mature larvae has been recommended in some countries. However, spray of insecticides on plastic film is more environmentally friendly. In our tests, the toxic effect of diazinon lasted more than half a year in the laboratory, and lasted more than one month at a carambola orchard.
    Besides the insecticidal toxicities, ground covered with plastic film also has the following advantages:
    1. Increase the probabilities of fruit fly mature larvae to be preyed by the predators such as ants, Pheidologeton diversus and Paratrechina longicornis, and birds, or attacked by parasitic wasps.
    2. The increased temperature inside the fallen fruits during the daytime as they exposed to the sun often induces the larvae to leave the fruits; and at the same time the surface temperature of the plastic film can reach over 50℃ (between 10:00-14:00 hours). Such high temperature itself could solely kill the mature larvae on the films.
    3. Ground covered with plastic films in the orchard would hold water when raining, which could drown the mature larvae on the film.
    Infested fallen fruits are hotbeds of fruit flies, and farmers are often short of manpower to remove them immediately. Orchard ground covered with plastic film and sprayed with insecticides during the fruit production season could effectively kill the mature fruit fly larvae, reduce fly densities, decrease the injury, and therefore increase farmer’s profits.
　


Fig. 1. Mature oriental fruit fly larvae jumping out from fallen fruits and penetrating into the soil.		Fig. 2. Mature oriental fruit fly larvae died on the plastic film sprayed with insecticide.


Fig. 3. Pheidologeton diversus moving mature oriental fruit fly larvae on the plastic film.		Fig. 4. Mature oriental fruit fly larvae drowned in rainy water accumulated on the plastic film.

Applied Zoology Division

ARI successfully releases a good and efficient helper, an once-over sweet potato harvester, for harvesting sweet potatoes for energy purpose

Wed, 02 May 2007 01:20:00 +1600

ARI successfully releases a good and efficient helper, an once-over sweet potato harvester, for harvesting sweet potatoes for energy purpose

    Agricultural Research Institute (ARI) successfully demonstrated and released a self-propelled harvester to local farmers on May 3, 2007 at Tainan county. The efficient helper can reduce the need of manpower and increase the harvesting efficiency of sweet potatoes, which are purposely cultivated in large-scale for energy use.
    Sweet potatoes are rich in vitamin A, B2, C and minerals. Except the use as raw material for starch making, most of them are used for fresh eating. The total harvested area and the total yield of sweet potatoes in Taiwan were 10,230 hectares and 213,991 tons, respectively, in 2005. Recently, the government had launched into a positive policy on bio-energy. The sweet potato is one of candidate bio-energy crops for producing alcohol. The cultivation area for experiment reached 30 hectares in 2005.
    In Taiwan, the current harvesting operation of sweet potatoes involves three processes. They are vine-cutting, digging and hand-collecting. Even though the tractor and relevant tools are partly used for the former two processes, it still takes lots of manpower to work smoothly. The self-propelled, once-over harvester of sweet potato can fulfill the functions of vine-cutting, digging, separating, conveying and temporary storage simultaneously, thus improving the harvest efficiency, saving more times, and reducing the cost of labors.
    The dimensions of the prototype harvester with a 4-cylinder diesel engine of 50 horsepower are 570 cm in length, 190 cm in width, and 185 cm in height. The width and tread of the harvester’s tracks are 40 cm and 103 cm, respectively. The engine not only supplies the HST system with power for propelling the harvester, but also drives other harvest machanisms by hydraulic systems. It is assessed that the harvesting operation of sweet potatoes per hectare using the developed harvester reduces one machine operator (2,000 NTD/person) and seven field labors (900 NTD/person), which amount to 16,600 NTD for wages or about 60 % of the manpower cost. Furthermore, the harvesting capability is enhanced from 0.5 up to 0.6~0.7 hectare per day. Being expected to satisfactorily meet with the need of large-scale cultivation of sweet potato for energy use, the machine has been included as one demonstration model of the newly-developed machines in 2007. The achievement of this research was also issued a Taiwan utility model patent (M324961), entitled as “Self-propelled tuberous root harvester”, in January, 2008.


The self-propelled sweet potato harvester is in operation.		The harvested sweet potatoes are collected in plastic bag.

Agricultural Engineering Division