Journal of Applied and Industrial Sciences, 2014, 2 (6): 267-272, ISSN: 2328-4595 (PRINT), ISSN: 2328-4609 (ONLINE)

Research Article 267

Effects of Soil Media and Seed Origin on Germination Rate and Seedling Propagation of Acacia polycantha (Wild) subsp. campylacantha (Hochst. ex A.Rich.) Brenan. Hamdon A. Abdelrhman1,2, Heba.A.Noureldeen3,Daldoum Mohammed Ahmed4, Mohd Shahwahid5 & Paridah M.T.1 1

Institute of Tropical Forestry and Forest Products. Universiti Putra Malaysia (UPM), 43400, Serdang, Selangor, Malaysia. 2 Faculty of NATRES, Dept. Of forestry and Range Sciences-University of Kordofan, Elobeid-Sudan. PO-Box160. 3 Gum Arabic Research Centre. University of Kordofan. 4 Faculty of Forestry, University of Khartoum. 5 Faculty of Economics and Management, Universiti Putra Malaysia (UPM), 43400, Serdang, Selangor, Malaysia. (Received November 06, 2014; Accepted December 31, 2014)  Abstract— This study was carried out to evaluate the germination potential and growth performance of Acacia polycantha (Wild) subsp. campylacantha (Hochst. ex A.Rich.) Brenan. The seeds were collected from two locations: South Kordofan and Blue Nile State. Seeds subjected to different treatments conditions. The study consisted of seed dormancy breakage test by several methods (pretreatment with soaking in cold and hot water, corroding by 25 and 50% H2SO4, and itching by electrical needle) and seedling stock rising in the nursery in different soil media (sand, clay and mixture).The study revealed that, seeds were pretreated by electric needle gave the highest germination percentage (60%). Both the electric needle and boiling water were effective treatments for Acacia polycantha seed dormancy breakage; while soaking in cold water and 50% H2SO4 resulted in comparable performance. Seed origin obviously gave little effect on Acacia polycantha seed germination capacity except for the control from Blue Nile which was twice stronger than that of South Kordofan. Index Terms — Acacia polycantha, germination potential, dormancy breakage, Acidic condition electrical needle.

I. INTRODUCTION ustainable management of natural forest reserves and forests outside the reserves, in the Sudan is conceived as a strategic approach to facilitate fulfillment of the national objectives self-sufficiency in forest products beside combating desert encroachment, improving agricultural productivity, reserving the declining trends of the natural systems and contributing to carbon sinks. However, natural forest reserves aren’t well managed other than protection and patrolling exercised by forest guards. Because of the management and the difficulty of protection, natural forests are continuously mined for forest products or for agricultural practices [1]. At present time, vast areas are completely bare of forest cover except for isolated scattered natural forest reserves and the remaining under stocked natural forests outside the reserves. Rural people living around these forests are dependent on them in spite of the preventive measures exercised by the authorities [2].

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*Corresponding author E mail: [email protected]

The recent global Forest Resource Assessment [3] showed that 28.4% (67,546 million ha) of Sudan is forested. The reduction in forest cover between 1990 and 2000 was averaged to 589000 hectares of forest area per year, which amounts to an average annual deforestation rate of 0.77%. Measuring the total rate of habitat conversion (defined as change in forest area plus change in woodland area minus net plantation expansion) for the 1990-2005 intervals, Sudan lost 11.6% of its forest and woodland habitat. According to [4] , there are 112 plant species of which 91 species are endangered and three species almost extinct in the semi-arid area. In addition, the commercial gum producing species in the Sudan are Acacia senegal, A. seyal, A. polycantha, A. raddiana, Baswellia papylifera and Sterculia setigera. A. senegal and A. seyal [5]; they contribute annually about 17100 tons of gum Arabic in Sudan [6]. In spite of its importance and wide spread distribution, A. polycantha has not been profoundly studied and there is lack of information on the tree regeneration both in the nursery and in the field. A. polyacantha is placed in the subspecies campylacantha often grows in the moist, subtropical bush-veld of Africa, usually in alluvial soils near rivers. It is widespread in tropical Africa, occurring from Gambia to Ethiopia and southwards to Kenya and Zimbabwe; [7] . In Sudan, there are several regional varieties which usually occur along rivers and valleys where the water table is fairly high, and the soils are good. Occasionally found on stony slopes and compacted soils, the rainfall between 300-1000 mm, where there is low rainfall plants are found in sites with a high water table; and tolerates cool and hot temperatures, tolerance to frost is unknown [8]. Regeneration and propagation of A. polyacantha are very scanty although the species is very important in terms of presence as part of natural forest in the savanna, and products and services rendered. A. polyacantha tree can be propagated from seeds, which may be immersed in boiling water and soaked overnight to soften the hard outer seed coat. They may then be sown in well-drained, sifted potting soil and placed in a warm place until they germinate. Germination may take between 1 and 4 weeks. The seedlings may be pricked out at the two-leaf stage or left until they are larger and more established, the tree can harbor butterfly larvae, Anthene crawshayi

Journal of Applied and Industrial Sciences, 2014, 2 (6): 267-272, ISSN: 2328-4595 (PRINT), ISSN: 2328-4609 (ONLINE) crawshayi [9], which is used as food in many parts of Africa. Gum produced from A. polycantha is quantitatively and qualitatively important and has good characteristics and high demand, which will in turn contribute to increase the income of local producers [10]. Its pods and foliage are used as fodder for animals. The tree grows well in a wide range of soil types and terrain like: clay soils in plains; alluvial soils along river banks and detritus rocky areas on hills. Growing media The selection of the growing media is one of the most important decisions in the culture of seedlings. The physical, chemical and biological characteristics of the growing media affect seedlings growth and other aspects of nursery operations as well [11], the purposes of media are to physically support the plant and to supply adequate oxygen, water and nutrient for proper root functions [12]; [13]. The ideal medium should have the following properties: it must be porous, sterile, light weighted, holds sufficient water, consistent in quality and supplies of necessary mineral nutrients, and it should be free of disease organisms, insects, weed seeds and poisonous products [14] and [15]; the most important propagation media are: 1. soils: generally the good soil is the one with particle fractions of 40-50% sand, 20-25% clay and 30-35% silt. Heavy clay soils ought to be mixed with sand before being used. In some cases the soil may need to be sterilized to eliminate diseases and weed seeds; 2. Sand: it is very frequently used as growing media. However seedlings raised in such media need frequent watering for fear of dehydration and also need addition of fertilizers for the media are intrinsically poor in nutrients. In Sudan, the media most commonly used are sand, river alluvium and a mixture of sand and clay (a mixture of 1:1 by volume). Soil mixtures with different organic residues and compost are getting used recently; and some soil (phytolith) from under big trees are used to fill nursery containers in regions where there is no river silt [16]. Seeds Treatments Before sowing the viability of the seed stock must be tested by a chemical or germination test; this procedure economizes the amount of seeds to be used for sowing and save much of the efforts in case there was a germination failure. Hard coated seeds are pretreated to break dormancy. Many methods are used for treating the seeds, they include: soaking in cold or hot water; corroding by acids (H2SO4); scarification by Knifes; itching by electrical burning. Sowing is one of the most important operations carried out in the nursery. Its success or failure may decide whether the nursery will be able to supply the required number of plants and whether the afforestation programs envisaged will be carried out. Therefore, well prepared seed beds are of the utmost importance to the entire work of nursery. Seeds of the same species should not be sown at the same time, but at intervals of about a week, in order to avoid losses from sudden downpours, and in order to ensure a steady supply of seedlings for transplanting [17] and [18]. The aim of the study is to evaluate the germination potential and growth performance Acacia polycantha (Wild) subsp. campylacantha (Hochst. ex A.Rich.) Brenan.

II.

MATERIALS AND METHODS

268

Materials Seeds of Acacia polycantha were collected from two regions: Southern Kordofan and Blue Nile. Soils as nursery potting fills constituted of a sandy soil brought from a stabilized dune at the experimental farm of the University of Kordofan and a clay soil from Elain Basin. These two fractions were mixed together to make a third growing medium. Containers for nursery stocks raisers consisted of black polythene tubes with dimensions of 20X30 cm, flat, was used for seeds germination and seedling establishment. For seed pretreatment, an analytical grade sulfuric acid with concentrations of 25% and 50% was acquired from the Laboratory of Gum Arabic Research Center; also a device of electrical needle scratcher was used for this purpose. Nursery experiments Seed germination test A polycantha seeds from the two locations were pretreated by various methods: 1) scratching by an electrical needle device for ten minutes; 2) dipping in boiling water for five minutes and drying; 3) soaking in cold water for overnight and drying; 4) soaking in 50% H2SO4 for half an hour and then a thorough washing and drying; 5) soaking in 25% H2SO4 for half an hour and then a thorough washing and drying; 6) untreated seeds were grown as control. The pretreated seeds were sown in Petri-dishes and directly in the growing media (sandy, clay soils and their mixture). Ten seeds from each location and pretreatment were germinated in the Petri-dishes and watered. The number of days of seedling emergence was recorded for one month. Then the germination percentage was calculated using the method followed by [19]. Nursery stock growing and monitoring of A. polycantha seedlings Ten treated and untreated seeds were sown directly in the growing media at a depth of 3 cm and lightly covered by fine sand. The containers of different media were arranged in a way to avoid contamination by irrigation. Watering was applied daily for the first two months by overhead spreading by a container equipped with douche. Nursery operations (weeding, singling, root cutting) were carried out as routinely done. Growth and development of the seedlings were assessed for three months (the reading was recorded every two weeks). The parameters measured were: 1) seedling shoots length (cm); 2) number of leaves and 3) general features of the seedlings growth status, including color, infections and diseases. Data analysis Temporal seeds germination and seedlings growth measurements were presented in table and graphic forms. Final seedlings growth monitoring data were statistically analyzed for analysis of variance (ANOVA) by SAS program (1990) in a PC computer and means were separated by Duncan Multiple Range Test and results were presented in tabulated forms.

Journal of Applied and Industrial Sciences, 2014, 2 (6): 267-272, ISSN: 2328-4595 (PRINT), ISSN: 2328-4609 (ONLINE)

III. RESULTS AND DISCUSSION Nursery stock raising of A. polycantha Table 1 shows the result of the mean separation test for the Germination of A. polycantha seeds when subjected to various pretreatments, seeds of A. polycantha had different germination rates. Seeds treated by electrical needle test gave the highest germination percentage (60%). Treatment with 25 H2SO4 gave the lowest values (20%), even 10% lesser than that of the control (Table 1). Boiling water treatment was almost as effective as electrical needle test in breaking the A. polycantha seed dormancy. Treatments with cold water and 50% H2SO4 gave identical values of seed germination. Generally, location origin had little effect on A. polycantha seeds germination capacity for all the pretreatment tests, except for the control where seed germination rate from Blue Nile was twice stronger than that of South Kordofan area, this attributed to seed quality. It is obvious that, A. polycantha seeds have moderate germination power as their emergence percentage did not

269 exceed 60% with the most effective seed dormancy-breakage methods (electrical needle and boiling water tests). On the other hand, many authors working with acacias and other leguminous seeds [20] and [16] have found that electrical needle and boiling water were among the most efficient tests for breaking the dormancy of these kinds of seeds. Sulfuric acid tests performance was moderate, particularly that of 25H 2SO4, this might be attributed to the short soaking time of seeds by this reagent which was not enough to allow thorough seed-coat corrosion, the study which conducted by [19] revealed that, treating seeds with H2SO4 for an hour and then planting them in soil media is the most perfect pre-sowing management and propagation media A.sieberana seeds. Moreover, [21] stated that, the nicked seed of Acacia polyacantha had a best seed germination and seedling propagation among the other treatments

Table 1.Germination of A. polycantha seeds as affected by pretreatment tests Site

Pretreatment tests and corresponding seed germination (%) E.N B.W C.W H50 H25 CON South Kordofan 60 50 33 44 20 20 Blue Nile 60 60 50 40 20 40 Mean 60 55 41.5 42 20 30 Treatments: E.N: Electric Needle; B.W: Boiling water; C.W: Cold Water; H50: 50% H 2SO4 and H25: 25% H2SO4; CON: untreated control. Temporal growth variation of A. polycantha seedlings as affected by growing media and seed origin Seedlings length of A. polycantha in growing media and seed origins A. polycantha seedlings lengths were monitored after a lapse of four weeks from germination as affected by both the growing media (sand, clay and mixture) and location of seed origin (Blue Nile and South Kordofan). Data shown on Figure 1 reveals that the mixture medium induced the highest seedling length followed by clay and sand. The average weekly increments of the seedlings lengths were 5, 3 and 1.9 cm in the mixture, sand and clay media, respectively. As from the third week on wards, seedlings length growth in the mixture proceeded with the same vigor, while there was a substantial increase in the clay and a moderate increase in the sand, with respective increments of 4, 3.6 and 1.3 cm. In the last week, average seedlings lengths in the mixture and clay were very close, while there was a notable difference with that in the sand medium. From the above mentioned results, it is obvious that A. polycantha seedlings’ length growth is the best in the mixture followed by the clay and then the sand. The performance of seedlings lengths sown in the sand and as affected by the location origin, Blue Nile and South Kordofan, is shown in Figure 2a. During the first week, the Blue Nile seedlings growth was vigorous with an average length of 24.4 cm against only 8.9 cm for South Kordofan. In the second week the Blue Nile seedling length increased twice and continued with the same rate through the third week up to the last week. For South Kordofan, mean seedlings length increment was 2.2 cm, and it continued with a same rate until the last week. The

results showed that there was a big difference in seedlings lengths between Blue Nile and South Kordofan origins, where seedlings growth pattern was in parallel lines, and the mean length for Blue Nile origin went in the upper echelon line. For the development of seedlings growth in the clay, in the first reading the Blue Nile seedlings performance was the best; they recorded a mean length of 27 cm but those from South Kordofan origin recorded only 10 cm. The Blue Nile seedlings increment was successive 3.9, 4.2 and 6.2 cm in the second, third and last weeks. But South Kordofan seedlings increment was 1.8, 3.1 and 2.2 cm in the second, third and last weeks, respectively. The South Kordofan seedlings in all the growth terms, did not reach the first length reading of Blue Nile seedlings. The result concluded that the Blue Nile seedlings increment was best when compared with South Kordofan seedlings (Figure 2b). In the mixture medium, the Blue Nile seedlings length growth was the best (31.5 cm) when compared with South Kordofan seedlings length (10.1cm). The average weekly increment of Blue Nile seedlings in the second and third week was 6, 6.9 cm respectively; but the seedlings growth rate in the last week for Blue Nile was moderate only 3.1cm. Seedlings from Blue Nile reached the maximum growth increment in the third week and decreased to more than half in the last week, but those from South Kordofan seedlings grew with the same increment throughout the monitoring period (Figure 2c). Even though, seedlings from the Blue Nile origin had the higher and stronger growth rate than those from South Kordofan origin. For the general comparison of A. polycantha seedlings growth as affected by growing media and seed origin, seedlings from

Journal of Applied and Industrial Sciences, 2014, 2 (6): 267-272, ISSN: 2328-4595 (PRINT), ISSN: 2328-4609 (ONLINE) South Kordofan origin grew at very close rates in all the growing media and all along the monitoring period, and with moderate increments between the measuring intervals. However, seedlings of Blue Nile origin showed a very different growth pattern (Figure 2d). Seedlings from this origin had higher and stronger growth rates from those of South Kordofan in all the media and all along the follow up period.

270 Within the media, seedlings from this origin developed in the following pattern: mixture > clay >sand studied the effect of growing media in the nursery and stated that, the size of the containers and soil media has a crucial effect on seed germination and seedling propagation.

Length (cm)

35 30

Sand Clay

25

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20 15 10 5 0 w1

w2

w3

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Figure1. A. polycantha seedlings length growth in different growing media Blue Nile South Kordofan

40

Length (cm)

35 30 25 20 15 10 5 0 w1

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Figure 2a. A. polycantha seedlings length growth as affected by seed origin in the sand medium 45 40 35 30 25 20 15 10 5 0

Blue Nile South Kordofan

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w2

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Figure 2b. A. polycantha seedlings length growth as affected by seed origin in the clay medium

Journal of Applied and Industrial Sciences, 2014, 2 (6): 267-272, ISSN: 2328-4595 (PRINT), ISSN: 2328-4609 (ONLINE)

Figure 2c.A. polycantha seedlings length growth as affected by seed origin in the mixture medium 50 Blue Nile sand

45

Length (cm)

40 35

South Kordofan sand

30

Blue Nile clay

25 20

South Kordofan clay

15

Blue Nile mixture

10 South Kordofan mixture

5 0 w1

w2

w3

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Figure 2d. Comparison of A. polycantha seedlings length growth performance as affected by growing media and seed origin IV. CONCLUSION This study concluded that: 1)seed coat dormancy breakage and enhancement of germination of A. polycantha can be best obtained by immersing seeds in boiling water, and letting them there till it cools. Other methods (corrosion by conc. H 2SO4, itching by electrical needles) are equally effective, but boiling water has the advantage of being cheaper and safer. 2) Seedling growth performance and nursery stock raising of A. polycantha is best achieved by growing them in sand-clay mixture medium or similar loamy substrate. Clay medium is also similarly effective 3) Seedlings growth performance from Blue Nile origin was superior to that from South Kordofan in all studied growing parameters. ACKNOWLEDGEMENTS The authors would like to thanks the University of Kordofan whom had partially funded this study and they are grateful to Dr. Abd Allah. N. Abd Allah for his valuable comments on the manuscript. REFERENCES [1] Elfadl, M.A. & Luukkanen, O. 2006. Ecological strategies of Prosopis juliflora in the arid environment of the Sudan: 1. Leaf gas exchange approach. Journal of Arid Environment 66: 115.

[2] Forest National Corporation 1995. Annual Report. Forest National Corporation, Department of Management. Khartoum, Sudan. [3] Forest Resources Assessment 2005. Global Forest Resources Assessment. Country Report 212: Sudan, Forestry Department, FAO, Rome. [4] Sudan, SCSB 2001. National Biodiversity Strategy and Action Plan. Sudan Country Study on Biodiversity. Khartoum, Sudan. [5] Mohammed, M. H. (2011). Management of Natural Stands of Acacia seyal Del. variety seyal (Brenan) for Production of Gum Talha, South Kordofan, Sudan(Doctoral dissertation, University of Khartoum, Sudan). [6] FAO (1995). Serveying of world forest cover area. Forestry paper No. 112. Food and Agriculture organization of the United Nation, Rome, 59p. [7] Mhlonishwa D. 2005. Dlamini Walter Sisulu National Botanical Garden: Making the most of indigenous trees. Briza Publications, Pretoria, South Africa. [8] Vogt K. 1995. A field guide to the identification, propagation and uses of common trees and shrubs of dry land Sudan. SOS Sahel International. UK. [9] Smit, N. 1999. Guide to the acacias of South Africa. Briza Publications, Pretoria, South Africa. [10] Adam. I. M. and K. E. Fadl (2011). "Effect of tapping tools and date of tapping on Acacia polyacantha gum yield in South

Journal of Applied and Industrial Sciences, 2014, 2 (6): 267-272, ISSN: 2328-4595 (PRINT), ISSN: 2328-4609 (ONLINE) Kordofan State, Sudan." Journal of Forestry Research 22(1): 117-122. [11] Landis, T.D. 1990. Cotainer and growing media, vol. 2: The Container Tree Nursery Manual. Agric. Handbook, 674. Department of Agriculture, Forest Service. Washington, DC. pp41-85. [12] Ingram, D.L, Henly, R.W. and Yeager, T.H. 2003 Growth media for container grown ornamental plants. Environmental horticulture. Access,2008. Department of Florida Cooperative Extension Service, Institute of food and Agriculture Sciences, University of Florida. [13] Pasian, C.C. (2001). Physical characteristic of growing mixes. Ohio State University. Horticulture and crop sciences. http://www.horticulture.com/bulletin/97-04/dirt.htmi [14] Ingram, D.L. 2004. Landscape plant propagation. Work Bank: Unit 11, Propagation of Cuttings. Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural, Sciences University of Florida. Web Site: http://edis.ifas.ufl.edu. [15] Hince, B. 1999. Tree nursery practices. Practical guidelines for research nurseries. International Centre for Research in Agroforestry. http://edis.ifas.ufl.edu.

272 [16] Hammad, G.H. 2007. The Effects of Polythene Bag-Size and Soil Types on Seedlings of three Tree Species. MSc. Thesis, University of Khartoum, Faculty of Forestry. 157pp. [17] Evans, J. 1982. Plantation forests in the tropics. Oxford University press, 472p. [18] El Amin, H. M. 1990. Tree and Shrubs of Sudan ISBN. 1Thanca Press England. 484P. [19] Innocent Pahla, Tavagwisa Muziri, Tiniel Chinyise, Simbarashe Muzemu , James Chitamba. 2014 Effects of Soil Type and Different Pre-sowing Treatments on Seedling Emergence and Vigour of Acacia sieberan. International Journal of Plant Research, ISSN: 2163-2596 e-ISSN: 2163-260X, 4(2): 51-55. [20] Ama, H.A. (2002). Effects of Compost on growth and development of Seedlings of Acacia nilotica, A. seyal, A. senegal and A. tortilis. MSc. Thesis, University of Khartoum, Faculty of Forestry. 66pp. [21] BALI. R. S., CHAUHAN. D. S. and N. P. TODARIA 2013 Effect of growing media, nursery beds and containers on seed germination and seedling establishment of Terminalia bellirica (Gaertn.) Roxb., a multipurpose tree. International Society for Tropical Ecology, ISSN 0564-3295, 54(1): 59-66