Research Findings

Research Findings

(Source: ASEAC 2018 proceedings)

POLY BAG CULTIVATION OF GINGER AND ITS EFFECT ON THE GROWTH AND YIELD OF GINGER (Zingiber officinale Rosc.)

H. D. A. K. Gunaratne, P. R. Idamekorala, T. E. Weerawardena and W. M. S. R. Bandara

Ginger (Zingiber officinale Rosc.) belongs to family Zingiberaceae is well known important spice crop of the world. Ginger production industry in Sri Lanka is facing land limitations for cultivation expanding. Apart from land availability low organic matter content in the existing fields also creating production barriers. The experiment as initiated in 2017 focusing these two issues. The experiment was conducted in Central Research Station, Matale. Two poly bags sizes were used. Two rhizome amounts were selected as planting materials weighing 50g and 100g.  According to the results of the experiment; plant height, number of tillers and yield were higher in the 50kg poly bag unit contained 50 kg mixture of potting mixture formulated using decomposed cow dung, coir dust, top soil and sand in 1:1:1:1 ratio. An also 100g of rhizome amount was given higher growth than 50g as a comparison.

SOIL AND LEAF TISSUE NUTRIENT STATUS OF BLACK PEPPER (Piper nigrum L.) IN SELECTED FARMER’S FIELDS IN RATNAPURA DISTRICT

P.R. IDAMEKORALA, A.P. HEENKENDE, H.D.A.K. GUNARATNEW.M.R.S. BANDAR1

Total extent of black pepper in Sri Lanka is around 39,515 ha. This particular experiment was done in Rathnapura District which as total of 5,337ha of black pepper cultivations. Productivity of black pepper has diminished due to low soil fertility management. Therefore, the requirement on making fertilizer recommendations upon soil fertility levels and leaf nutrient status considered here. During this experiment, leaf tissue nutrient status and soil nutrient status were evaluated in selected pepper growing farm fields in Rathnapura District. Location selection was done considering Agro-Ecological zones. Collected soil samples were analysed for organic carbon content, total nitrogen content, available phosphorous content, pH value and exchangeable Magnesium/Potassium contents. Soil pH ranges from 4.92 to 6.61, Organic carbon content varied from 0.52% to 2.14%. Available phosphorus content was 2.6 – 30.0 ppm. Exchangeable Magnesium and Potassium ranges were 66.00 – 381.00 ppm and 62.90 – 363 ppm respectively.

The findings can be utilized for formulating recommending site specific fertilizer recommendations.

SUSTAINABLE MANAGEMENT OF QUICK WILT DISEASE IN BLACK PEPPER Pipper nigrum L. CAUSED BY Phytophthora capsici

KODITHUWAKKU, R.D., WIJEKOON, W.M.R.W.B., PILLAI, D.S.

Quick wilt or foot rot is a major disease in black pepper (Piper nigrum L.). The known causal organism of the disease is Phytophthora capsici fungus. The specie is a well-known soil borne plant pathogen. Different chemical combinations are recommended for controlling quick wilt in pepper growing areas of Sri Lanka. The common chemical application is Redoxyl (64% Mancozeb and 8% Metalaxyl). Chemical application is effective on controlling the disease. However, repeated application may require with outbreaks. The experiment was done to find a sustainable alternative for managing quick wilt disease. Trichoderma asperellum is well known antagonist fungal specie to soil borne fungal pathogens like P. capsici. In the experiment inoculation of T. asperellum with cattle manure and incorporate the mixture with potting media were done. Then the treated sample compared with different experimental treatment combinations.  According to the observations recorded throughout the two period of experiment timeline, T. asperellum inoculated samples has shown lower occurrence of quick wilt. Re-emergence of disease also suppressed significantly. Therefore, the experiment concluded that use of T. asperellum inoculated cattle manure is a possible sustainable solution for quick wilt.

INFESTATION OFCOFFEE BERRY BORER, Hypothenemus hampei (Ferrari) (ColeopteraScolytidae) ON NEW HYBRID CULTIVAR ‘LAK PARAKUM’ AND SELECTED COFFEE CULTIVARS

MKSRD SAMARASINGHEAND M.A. DISHAN

Damage of Coffee Berry Borer (Hypothenemus hampei Ferrari) is the major pest specie of coffee cultivation all around the globe. The insect belongs to order Coleoptera and family Curculionidae.

The experiment was carried out at Central Research Station on June to October, 2017 and focused on identification of infestation on newly released variety “Lak Parakum”. Then infestation compared with selected cultivars namely Catimor, HDT (Arabica cultivars) and IMY, CCI, BS5 (Robusta cultivars). Normally, Arabica cultivars are more susceptible to the infestation than Robusta cultivars. According to this study, most susceptible cultivar is HDT than Lak Parakum variety.  It is also higher than Robusta cultivars. The mean infestation percentage of HDT is 12.88%. The population of Coffee Berry Borer in Arabica cultivars is higher compared to Robusta cultivars.

IDENTIFICATION OF ALTERNATIVE HOST PLANTS FOR NUTMEG LEAF FALL DISEASE (NLFD)CAUSEDBY Colletotrichum gloeosporioides

WIJEKOON, W. M. R. W. B., RUPASINGHE, P. S. A., DE SILVA, P. D. P. M., KODITHUWAKKU, R.D., PILLAI, D. S and DENIYAPAHALA, D.V. R. I

Nutmeg(Myristica fragrans) is an important Export Agricultural Crop (EAC) grown in Sri Lanka. Nutmeg Leaf Fall Disease (NLFD) is one of the economically important disease reported to the nutmeg cultivations in Sri Lanka. Colletotrichum gloeosporioides and Neofusicoccum spp   were identified as causal organisms of the disease.

Nutmeg has cultivated as a mix crop in Kandyan home gardens in Sri Lanka along with fruit and spice crops. some of these fruit plants are infected with Anthracnose, stem end rot which is caused by same pathogen of NLFD (Colletotrichum gloeosporioides).  Therefore, this study was conducted for assessment of cross infection potential between C. gloeosporioides isolated from nutmeg and selected diseased fruit crops such as avocado, mango, and papaya.

According the results, it is revealed that fungal strains isolated from above fruit crops have cross infection potential and the potential to cause disease to the nutmeg seedlings is more similar and avocado, mango and papaya fruit crops are alternative hosts for the nutmeg leaf fall disease and field sanitation of above fruit plants must be recommended as an additional measure, where nutmeg and these crops are grown together to avoid spreading of NLFD as a long-term disease management strategy.

Identification of regional specific black pepper (Piper nigrum L.)  varieties through Multi locational evaluation of BLACK PEPPER (Piper nigrum L.)

J. M. SENEVIRATNE, I. G. M. RAJAPAKSE, R.A.A.K. RANAWAKE, D. G. H. M. K. DISSANAYAKEAND R. P. S. PRIYANTHA

Sri Lanka has a very diverse gene pool of Black Pepper including wild types. Therefore, Sri Lanka can be considered as a sub centre of origin of Black Pepper and has an enormous potential to improve the crop quality.

The land area available for pepper cultivation in traditional areas is limiting day by day and promoting pepper cultivation in non-traditional areas is inevitable. The non-traditional areas predominantly come from the intermediate mid and low country where the rainfall is the limiting factor.

Therefore, the available pepper germplasm in Sri Lanka need to be characterized properly to identify pepper accessions with good agronomic characteristics such as high yield, tolerance to biotic and abiotic stresses. These accessions can be used to develop commercial varieties with good agronomic traits. Department of Export Agriculture (DEA) has launched many crop developments programmes in the past, including germplasm collection and evaluation. The first germplasm collection and selection programme has identified ten black pepper varieties with high yield and oil content and they were released to the farmers as PNM 1as a composite of GK-49, MB-12, MW-18,MW21, TG-7,IW-5, KW-30, KW-32, KW-33 and MN-1 varieties.

This experiment was carried out with specific objectives to evaluate the performance of the identified black pepper varieties at different agro-climatic regions.

This study has shown that Panniyur-1 and UD-21 performed well in all locations showing horizontal adaptability. They were also better in field establishment. The yield data revealed that four varieties under evaluation in Middeniya experiment: KWW-12, UD-21, MB-12 and Wasanagama were performing better, yielding 4796.7, 4460.0, 3622.0 and 3363.3 grams of black pepper per vine respectively. The yield data from Matale experiment revealed that, UD-21, Panniyur-1 and KWW-10 varieties were the best cultivars in that side giving more than two kilos of dry pepper per vine per year. In Nillambe experiment they were the Panniyur-1, DM-7, Wasanagama and KWW-12 varieties that yielded 1937.3, 1887.1, 1752.0,1477.9 grams of black pepper per vine per year respectively. The varieties; UD-21, MB-12 was performing well in both Middeniya and Matale. KWW-12 was performing extremely well in Middeniya experimental plot. Hence KWW-12, UD-21 and MB -12 varieties can be highly suitable variety to Middeniya area.

EFFECT OF BIOFILMS and potting media ON GROWTH OF PEPPER (Piper nigrum L) AT NURSERY STAGE

P.G.A.L. KUMARA, C.I.M. ATTANAYAKE, P.R. IDAMEKORALA, E. RANDENIYA, H.A. SUMANASENA, Y.M.S. BANDARA, G. SENEVIRATHNE AND I. KUMARASINGHE

Nursery management practices are one of the important agronomic practices as poor field establishment is highly associated with the vigour of the initial planting material consequently the yield. Application of biofilm technology has a potential to improve the initial vigour of pepper rooted cuttings.

Therefore, in this study, a locally available biofilm forming product in combination with different potting mixtures were tested to find out the effectiveness at nursery stage of pepper rooted cuttings. Three mixtures of potting media namely;1:1:1:1 (standard), 1:2:1:1 and 1:3:1:1 of each component representing river sand: top soil: cattle manure and coir dust respectively were tested in combination with two biofilm solution levels, i.e. 40 ml of 0.25 ml / L concentrated biofilm liquid were used for one nursery pepper plant in once a month and twice a month respectively and each experiment treatment combinations with three replicates.

As per the results alternative potting media containing more top soil appeared to be suitable and effectiveness of biofilm application on growth performances of pepper rooted cutting during nursery stage was also appeared. However, the associated combine effect with biofilm could not be isolated due to the nature of experimental design in this study. Therefore, it is recommended to repeat the experiment with biofilm for black pepper rooted cutting in factorial experimental design.

SEPARATION AND QUANTIFICATION OF LIGHT BERRY COMPONENT OF MATURE HARVEST OF BLACK PEPPER (Piper nigrum L.) 

THUSHARI LIYANAGE, P.D.A.M DALUKWETIYA, E.D.K. EDIRISINGHE, A.I. KARUNARATHNE

In Sri Lanka immature harvesting of black pepper is commonly practiced. Immature berries are the best starting material for oil and oleoresin extraction. Immature pepper harvesting has a huge negative impact on mature pepper industry. In the event of fully matured pepper berry harvesting also a light berry component (< 450 g/L) is recorded during processing which can be identified through gravity separation. This low bulk density pepper berries can be used for extraction of oil and oleoresin.

The study was focused to quantification the heavy berries and light berries yield component at the time of mature pepper harvest in farmer level and determination of oil, oleoresin and piperin content of different grades of three pepper varieties. The Pepper samples were collected from Central Research Station – Matale and Sub Research Station Nillamba. Compared Black pepper varieties/cultivars are Paniyur – 1, TG 7 and UD21. The highest light berry percentage (52%) was observed in Paniyur – 1 (TG7, 22% and UD21, 6%).  The highest value of bulk density was shown in grade 1 in all three selections. Grade 1 is more suitable for the black pepper production. It is nearly 50 % of the harvest. Rest of the production in harvest is low bulk density pepper corn component (Grade 2, Grade 3 and Grade 4). The oil, oleoresin and piperin percentages were comparatively higher in grade 2 (< 450 g/L) in all varieties at the time of mature pepper harvest in farmer level. This low bulk density pepper corn can be used for extraction of oil and oleoresin. Furthermore, Variety pannuyr-1 is more suitable for oleoresin extraction and variety TG 7 is suitable for piperin extraction. According to this result can be recommended to industry; gravity separation is essential processing step to do to get low bulk density yield component for extraction as well as to reduce immature pepper harvesting.

COMPARISON OF CHEMICAL QUALITIES OF IMPORTED INDIAN AND LOCAL TURMERIC SAMPLES

I.V.A.D.C.S. INDURUWA, K. RAJKUMARand V.P.N. PRASADI

Annual turmeric requirement of Sri Lanka is around 6,800 MT. Sri Lanka imported 4,958 MT of turmeric in 2017 and domestic turmeric production is 1866 MT in the same year. Sri Lanka is one of the major turmeric import country in Asia and mainly imported from India.

Sri Lankan consumers prefer Indian Turmeric than locally grown turmeric due to its attractive light-yellow colour. Therefore, this research was conducted to compare chemical characteristics of local and imported Indian turmeric samples. Six Indian turmeric samples collected from whole sale market, Colombo and six local turmeric samples collected from Matale were analysed. Curcumin content, volatile oil content, oleoresin content, total ash content and acid insoluble ash content were determined according to AOAC (Association of Official Analytical Chemists) Standard methods. Significantly higher curcumin content was found in Sri Lankan turmeric samples (4.48%) whereas the Indian samples were contained low curcumin values (2.42%). Total ash content of Sri Lankan turmeric samples (8.27%) is significantly higher than Indian samples (7.9%). There is no significant difference in oil, oleoresin and acid insoluble ash content between Sri Lankan and Indian turmeric samples. Sri Lankan turmeric may provide more health benefits compared to Indian turmeric since it contains higher curcumin content.

Source: ASEAC 2017 proceedings

VARIATION IN GROWTH AND YIELD CHARACTERISTICS OF GINGER (Zingiber officinale Rosc.) UNDER DIFFERENT IRRIGATION INTERVALS


H.M.P.A. SUBASINGHE and S.G.M.D.L. SENEVIRATHNE

Ginger (Zingiber officinale Rosc.) is a perennial plant but, grown as a short duration crop for
approximately 8 months. The average yield of the crop has varied widely among farmers due to
different management practices. Farmers are mostly not well-aware on the importance of timely irrigation and continuous moisture retention in ginger cultivation. Therefore, this study was carried out to analyse the impact of soil moisture on different growth and yield parameters of ginger under supplementary irrigation. The local ginger variety was used and different irrigation treatments i.e. 5, 10, 15 and 20 days irrigation intervals (DII) and control (no irrigation) were imposed while conducting other recommended agronomic practices. The meteorological, micro-meteorological and different biometric data were recorded accordingly. The highest level of moisture and the lowest canopy temperature were observed with 5 DII and a gradual soil moisture reduction was observed with the increasing irrigation interval. Soil moisture in control plots showed a high fluctuation with late inter-monsoon and early southwest monsoon rains and exceeded that of the 5 DII plots in some weeks. The lowest mean number of days for germination and the highest germination percentage were reported with 5 DII. However, the number of roots, total root length and fresh and dry weight of normal roots varied among different treatments while water storing roots showed better performances in 5 DII. Fresh and dry weights of above and below ground parts reached the highest in 5 DII after 5 months of sowing (MOS). After 6 MOS, ginger with 5 DII showed better results for all attributes of plant height, number of pseudo-stems, number of leaves, leaf area and rhizome weight. The final rhizome yield was also the highest in 5DII. Hence, soil moisture is a vital factor for almost all growth parameters of ginger and ultimately its rhizome yield. Source: ASEAC 2017 proceedings.