EFFECTS OF DIFFERENT CUTTING METHODS AND TIMES OF CUTTING ON GROWTH PERFORMANCE AND GUM RESIN PRODUCTION OF FERULA ASSA-FOETIDA

Ferula assa-foetida L. is an important industrial and medicinal plant of Iran which is mainly distributed in arid and semi-arid areas of Khorasan province in north east of the country. Gum of this plant is widely used in pharmacological industry. This plant is endangered because of more harvesting and unsustainable harvesting methods. The objective of this study was to evaluate the effects of different cutting methods (conventional, cut of crown part, concave and surface) and times of cutting (5, 10 and 13 times) on gum yield of this species in its wild habitat in Mazar region in Bajistan. The treatments were studied under a factorial experiment which was arranged in a completely randomized design with three replications. Results showed significant differences among cutting methods and times of harvesting. Yield of gum was affected by times of harvesting and the highest yield was obtained in 10 cutting times. The highest and lowest gum yields were obtained in concave method with 10 cutting times (25.24 g/plant) and superficial method with 5 cutting times (2.02 g/plant), respectively. Results showed that conventional cutting method destroys crown buds, which causes death of the plant. The highest gum yields and the best plant regeneration rates were obtained by using of concave method with 10 cutting times.


Introduction
Asafetida (Ferula assa-foetida L.) is the plant used for production of dried latex (gum oleoresin) exuded from the rhizome or tap root, a perennial fleshy tap root.It grows 1 to 1.5 m tall, has deeply dissected leaves, and inconspicuous yellow flowers borne in compound umbels.The bark is wrinkled and black and contains large amounts of thick alliaceous juice (Behpour et al., 2011;Golmohammadi, 2013).
As its name suggests, asafetida has a fetid smell but in cooked dishes it delivers a smooth flavor, reminiscent of leeks.The genus Ferula (Apiaceae) consists of about 170 species worldwide, with thirty species found in Iran, of which fifteen are endemic (Mozaffarian, 1996).Its root is erect, succulent, and nearly thick.Its leaves are gray with short hairs.It is a monocarp plant with schizocarp fruits, and it grows up to 1,000 m above sea level (Krebs, 1989).Phytochemical analyses of Ferula spp.confirmed the presence of 62% of resin, 25% of gum, 3-7% of essential oils, 1.28% of free acid sulfuric, and a little of vanilla.Also, some novel compounds such as sesquiterpene coumarin derivatives and sesquiterpene chromone derivatives have been isolated from the roots of Ferula assa-foetida.Their structures were established by comprehensive spectroscopic analysis (Bahrami et al., 2013;Meng et al., 2013).
The exudates from this plant are locally known as 'anghuzeh', 'heng' and 'buganeh', and have been traditionally used for treatment of a vast range of diseases: urinary, gastrointestinal, respiratory infections and epilepsy, as well as an aphrodisiac and as emmenagogues.It is used to treat snake and insect bites as well as worm infections (Hadidi et al., 2003;Shweta et al., 2011).
Ferula assa-foetida is one of the most important plants in arid regions of South Khorassan province.Local beneficiaries of the South Khorassan believe that they have a profit of 1,300 to 1,500 USD annually from gum harvesting for each family in habitats.South Khorassan province ranks third in gum production, in Iran (Golmohammadi, 2013).Unfortunately, habitats of asafetida decrease yearly, because of the conventional and non-scientific harvesting methods.Conventional harvesting of gum has some steps as identification regions, marking, twist, cutting and gum collection (Shinwari and Gilani, 2003;Golmohammadi, 2013).
A study of the effect of different methods of cutting on gum yield and Ferula assa-foetida survival showed that sap rate was changed from 19.6 to 62.9 g per plant by different cutting methods and times of cutting.Two-way cutting of the crown was recommended as the best cutting method (Omidbeygi and Pirmoradei, 2006).Shad (1995) reported that four cuts at harvesting period and a 6-day interval between cutting and collection is the best collection method with 5.28 g/plant gum yield.Salar et al. (2006) reported that the best harvesting age for this plant is when the plant is 5 years old or older.Askarzadeh (1999) observed a non-significant difference between different cutting methods in gum yield.
The aim of this study was to investigate the effect of cutting methods and times of cutting on yield and regeneration of this plant in wild habitat of Mazar in South Khorasan province in Iran.

Material and Methods
The main habitats of asafetida were identified according to the latest researches and field works in Razavi Khorasan province.The sample plants were selected and marked in Mazar village in Bajestan for the field studies (Figure 1).Plants were randomly selected and marked in the habitat.Treatments consisted of 4 harvesting methods: conventional cutting, cutting a part of crown, concave cutting, and superficial cutting and 3 different times of harvest including 5 times, 10 times and 13 times (Figure 2a-f).
The gum resin was harvested 5 days after cutting.Regeneration of the plants was checked and recorded in the following year.A factorial experiment based on a completely randomized design was used for the data analysis.

Results and Discussion
Results (Table 1) showed that both harvesting methods and cutting times have a significant effect (p≤0.01) on gum yield.The highest and the lowest yields of gum were observed in concave method and superficial method, respectively.Thirteen cutting times resulted to the highest yield of 20.93 g/plant (Figure 3).The lowest resin yield was found in the superficial cutting method (Figure 4).interaction between harvesting methods and times of cutting was also significant.The highest gum yield was obtained by using concave harvesting method with 10 cutting times.The lowest yield was achieved by using superficial method with 5 cutting times (Figure 5).Furthermore, 25.2 g of gum per plant was collected when using the concave method with 10 cutting times, which is a considerable amount.The highest regeneration percentage (90 100%) of plant in the second year was observed in the superficial method with 5 cutting times, but in conventional cutting method with 13 cutting times, only 10% of the plants survived (Figure 6).The lowest regeneration (0 10%) was observed in conventional cutting method with 13 times of cutting (Figure 6, Table 2).
The results showed that, although conventional method mostly applied by local people provide high gum yield, this method destroys the crown buds of the plant and plant cannot survive in the next year.The best harvesting method which provides a considerable yield and also gives a chance to plants for regeneration and surviving is concave harvesting method with 10 cutting times.
The results of the study are confirmed in other studies.Shad (1995) reported that four cutting times at harvesting period with a 6-day interval between cutting and harvesting was the best collection method.He indicated that the new method of cutting increased the gum yield per plant from 2.150 g/plant in conventional  Gums and resins form an important group of forest products.The industrial applications of gum and resin have expanded tremendously in recent years.Millions of people worldwide, especially in developing countries, depend on collection of gums, resins and latex as a means for their livelihood.Commercial tapping of gum and resin is done by making deep cuts on the crown which may disable plant regeneration.Based on the absence of cultivation of these plants, there is a grave concern about the loss of the wild germplasm.Simple and effective tapping techniques which ensure optimum yield and regeneration of tapped trees have been developed for gum, which ensures sustainable production of these materials (Balakrisnan, 2000).
Figure 2. Different cutting methods for harvesting the gum resin of asafetida.

Figure 3 .
Figure 3. Gum resin yield at different times of cutting of asafetida.

Figure 4 .
Figure 4. Gum resin yield of asafetida using different cutting methods.

Figure 5 .
Figure 5. Interaction between cutting methods and cutting times on gum resin yield.Vertical bars indicate the standard errors.
Figure 6.Regeneration of the asafetida plants in the second year.

Table 1 .
Analysis of variance for the gum resin yields of asafetida in different harvesting methods and cut-off frequency.and ** : significant at p<5% and p<1% respectively; ns : non-significant. *

Table 2 .
Regeneration of asafetida plants after different cut-off frequency and cutting methods.