Browsing by Author "Jayasinghe, G.G."

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    axonomic Identification of Cinnamon (Cinnamomum zeylanicum Blume) Leaf Miner in Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2021) Samarasinghe, W.D.; Widanapathirana, C.U.; Jayasinghe, G.G.; Samarasingha, K.G.B.A.; Premathilake, U.G.A.T.
    Cinnamon leaf miner is a minor pest in cinnamon cultivations of Sri Lanka, but causes severe losses in cinnamon nurseries resulting considerable expenditure for its management. Present study was undertaken to identify the larval taxonomy and adult morphology of cinnamon leaf miner, as the first comprehensive research in Sri Lanka. The study was conducted at National Cinnamon Research and Training Center of Sri Lanka. Insects reared both under field and laboratory conditions were observed under the microscope. Published taxonomic keys were referred to identify the larva and external morphology of the adult was compared with the previous reports of the experts. The initial instars of the larva were transparent, whitish in colour and it was changed to a glittering red towards the pupation. Larva was characterized by the strong and sclerotized mandibles which enable it to vigorously devour plant tissues. Antennae were short, three segmented and located towards the front of the head. Unequal, five stemmata were located laterally and posteriorly to the antennae. Four segmented strong thoracic legs ended with a claw. Abdomen consisted of 8 segments while pseudo legs were located on the iii, iv, v and x abdominal segments. Equal crochets were in a complete circle. The larva made an irregular shaped tunnel inside the immature leaf of cinnamon and continued to grow up to a length of 5mm inside the mine before pupating in an external cocoon of 6mm. The adult was a greyish moth of 3 to 5mm in length with a wingspan of 7 to 9mm. Wings are entire, scaled, lack stigma on front wing between C and R. Hind wings are fringed. Filiform antenna not knobbed at the tip with more than 41 segments longer than forewings. Proboscis coiled. Tibial spurs are conspicuous. Basal segment of antennae enlarged forming an eye cap. Present study confirmed that the Cinnamon leaf miner belongs to the Acrocercops spp. under Order Lepidoptera, Family Gracillariidae and Subfamily Gracillariinae. This study laid foundation to further studies on biology and management strategies of Cinnamon leaf miner in Sri Lanka. Keywords: Acrocercops spp.; Cinnamon zeylanicum; Gracillariidae; Taxonomy
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    Control Measures for Leaf Fall Disease in Clove (Syzygium aromaticum L.)in Southern Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2012) Senaratne, G.; Jayasinghe, G.G.; Chandrasena, G.
    Among several diseases recorded in Clove plantations, leaf fall disease is severe. Although the disease has been recorded in n\ id country region (Jayasinghe and Liyanage, 1982) in earlier and currently, it is distributed throughout the southern region. Identical purplish brown color spots are noticed when fungus is infected and gradually tune them into brown color. Severely infected leaves are withered, dropped and dried up and cause sudden death of plants finally. There are no proper cultural or agronomic practices to manage the situation. Therefore, this study was carried out to confirm the causal agent of disease and find out most suitable fungicide and application method to manage the disease in field plants.
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    Determination of microbial quality and quantity of stored cinnamon quills
    (Uva Wellassa University of Sri Lanka, 2015) Pathirana, S. M.; Chandrasena, G.; Weerawansha, A. N. R.; Jayasinghe, G.G.
    Since Cinnamon is one of the major spicecrops in Sri Lanka, maintenance of the quality of the processed cinnamon is very important. Microbial infection of processed cinnamon quills makes lowquality final product leading the product less demandedand high post-harvest losses. The prevailing solution for the microbial infection is fumigation of sulfur and it is not acceptable in many countries due to its harmful effects for consumer health. Therefore identification of common types of microbes on quills and determination offavourable conditions for microbial growth is very important to apply effective control measures. Methodology Experiments were conducted to identify the particular types of fungi that thrive on cinnamon quills and the effect of moisture content, relative humidity, temperature and the storage period to the microbial growth. Cinnamon quills were collected from three different placesjust after processing. The moisture contents of the samples were measured in three days interval using gravimetricmethod. Average relative humidity and ambient temperature were also recorded each period. In quantification process, the number of colony forming units of fungi and bacteria in cinnamon quills were counted separately using colony counter.1g of powdered sample of cinnamon was dissolved in 10ml of distilled sterilized water and 200μl of the solution was poured in to the culture plates. It was allowed to incubate under the room temperature for about three days and colony count of fungi and bacteria were taken.The culture plates with microbial colonies were allowed to incubate further to obtain pure cultures of fungi by frequent sub culturing. Colony characteristics were observed with the time.The pure cultures of fungi were used to prepare slide cultures for microscopic identification highlighting the distinguishing characteristics (Funder, 1953; Cappuccino and Sherman 1996). Results and Discussion According to the morphological and microscopic observations, Rhizopus sp., Penicillium sp., Aspergillus niger, Aspergillus flavus were the most common types of fungi encountered on cinnamon quills. In addition to those types Trichoderma sp. was appeared in the samples taken from one farmer place. It may be happened when peeled cinnamon had been kept in ground for drying and due to bad sanitary conditions in processing place. Rhizopus sp. was rapidly growing white coloured fungus with cottony and fuzzy aerial mycelium. The color of the colony was white initially and turned grey to yellowish brown with time. It was grown as filamentous, branching coenocytichypha without cross-walls. Sporangia were developed on the long stalks raised as groups from nodes directly above the rhizoids. Unicellular ovoid, hyaline and striated sporangiospores were produced by Rhizopus species and they were grown as root like rhizoids initiallyand finally grown as large mycelium. Penicillium colonies were initially appeared in white colourand become blue green, gray green and then gray in colour respectively. It was grown as a thallus with typical characteristic of a highly branched network of multinucleate, septate, and usually colorless.Many-branched conidia sprout on the mycelia, bearing individually constricted conidiospores. Aspergillus flavus colonies were initially appeared in yellowish whitecolour and changed to olive green, dark green and brownish green respectively.Hyphae grew as a thread-like structure and they were septate and hyaline. The asexual spores,conidispores, produced in conidia were rough and dark.Aspergillus niger colonies were initially white and become brownish with white reverse and brownish black colour respectively covering the entire plate.Morphology of Aspergillus niger showed large, globose, dark brown conidial heads, which become radiate. Conidiophores are smooth-walled, hyaline or turning dark towards the vesicle. Conidial heads are biseriatewith the phialides, often septate. Conidia are globose, dark brown and rough-walled.Trichoderma colonies were wooly and the initialcolor is white. As the conidia are formed, yellow-green patches become visible making concentric rings.Conidiosphores were erect, smooth and penicillately branched. Globose conidia were developed on philides produced in the opposite direction in each point. At the beginning the fungal infections of stored cinnamon were very low due to lack of enough inoculums, even though preferable higher moisture contents for fungal growth were retained in stored cinnamon quills. Next 10 days rapid increments of fungal colony forming units were observed because preferable moisture contents were retained further in cinnamon quills. Fungal infection was increased at 10 to 20 days also, but in negative rate due to desirable moisture contents were still remained in the cinnamon quills. Moisture content in the cinnamon quills were below 20 % after 20 to 30 days after processing and in this period fungal contaminations were gradually declined. When the moisture content was reached below 12% in storage cinnamon, fungal infection was at a minimum level. If the moisture level is reduced to below 12% in storage cinnamon as soon as possible, fungal infection can be controlled efficiently. The most interesting phenomenon was the symbiotic relationship between fungal growth and bacterial growth (Figure1).There was very strong significant positive correlation between fungal and bacterial infections (r = 0.912, p = 0.0001). Bacterial contamination never had been occurred without fungal infection. Bacterial colonies were appeared in the culture plates used to have the fungal colonies separately, even though those were treated with antibiotics to retard the bacterial growth.When fungal infection is terminated by managing moisture content, the bacterial infection is automatically reduced
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    Effect of Storage Conditions to Minimize Contaminants before Packaging of Ceylon Cinnamon Quills (Cinnamamum zelanicum Blume)
    (Uva Wellassa University of Sri Lanka, 2018) Chinthaka, N.D.G.A.; Jayasinghe, G.G.; Jayasingha, H.A.S.L.; Abhiram, G.
    Cinnamon is one of the major spice crops in Sri Lanka. Maintenance of the quality of the processed cinnamon is very important in exportation to get a good market value. Microbial and store pest contaminations of processed cinnamon quills make the final product less demanded with high post-harvest losses. This study was conducted to identify the most suitable storage conditions to maintain the export quality of the cinnamon quills without using synthetic chemicals. Collected cinnamon quill samples from the processing center of National Cinnamon Research and Training institute at Palolpitiya were stored at different time durations (0,3,7,14 days) with different combinations of temperature and relative humidity (RH) levels [(15 °C, 45%), (15 °C, 60%), (30 °C, 30%) and (30 °C, 60%)] in a growth chamber. The experiment was conducted as triplicate using 16 treatments. Moisture content (%), store pests per 100g, fungal and bacterial colony per 100g and color of the cinnamon quill samples were measured before applying the treatments and after 3 days, 7 days and 14 days from the treatment. Results revealed that 9.6% of mean moisture level was gained after14 days, under 30°C temperature and 60% RH and it has taken 3 days to decrease moisture level up to 12% under the treatment of (15 °C, 45%), (30 °C, 30%) and (30 °C, 60%) (P<0.05). Under the 30 °C temperature and 30% RH store pests were decreased up to 1 within 3 days while 7 days spent to kill all the store pests. All the store pests were killed after 14 days under the treatment of (30 °C, 30%) (30 °C, 60%) and (15 °C, 60%) (P<0.05). Significantly lower fungal and bacterial colonies were observed after 14 days under 15 °C temperature and 60% RH (P<0.05). Quill samples under the 15°C temperature and 60% RH showed the best color in colorimeter than the quills of other storage conditions as per the ISO standards. Thus, the expected quality of the cinnamon quills can be gained within 14 days under the 15°C temperature and 60% RH.
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    Effect of Weed Control Methods on Soil Invertebrate Community in Cinnamon (Cinnamomum zealanicum Blum) Ecosystem
    (Uva Wellassa University of Sri Lanka, 2013) Buddhika, I.D.M.; Herath, H.M.S.K.; Jayasinghe, G.G.
    Cinnamon is an important perennial spice crop, which is grown commercially mostly along the coastal belt from Negambo to Matara, and in areas such as Kalutara and Ratnapura. Various agronomic practices are associated with the cinnamon cultivation and weed control is one of those. Methods such as chemical weeding (Glyphosate), mammoty weeding and slash weeding are the popular weed control practices. Soil invertebrates are defined as the organisms without backbone. Soil invertebrates can have different impacts on land productivity. Their community can be altered with different agronomic practices especially weed control. Therefore, this research was conducted to examine the effect of different weed control methods on soil invertebrate community in cinnamon cultivation. Methodology The study was conducted at Cinnamon Research Station, Palolpitiya, Matara (6˚ 01' 38" N, 80˚ 33' 36" E, 47 m)as three experiments during the period of June – August, 2013. The first experiment was conducted to identify the soil invertebrates which are found in cultivated cinnamon lands for many years. Five trials were undertaken using five soil samples taken from different places in the cultivated cinnamon land. The soil invertebrates were extracted to a reagent bottle with 70% ethyl alcohol using modified Berlese funnel extractors. Extracted soil invertebrates were observed under the stereo microscope and identified using a dichotomous key. The second experiment was conducted to determine the effect of three different weed control methods (mammoty weeding, chemical weeding and slash weeding) with a control (no weed control) on soil invertebrate community in cinnamon cultivation. Three plots, in which three different weed control methods practiced were selected and tested consecutively for three months as the main treatments. Three different levels of soil depths (1-10, 11-20 and 21-30 cm) with litter layer as the sub treatments with three replicates were assigned in split-plot design. Soil invertebrates were extracted from 412cm soil sample using modified Berlese funnel extractors, observed through stereo microscope, identified using a dichotomous key and counted the number of individual in each soil invertebrate orders. Data were subjected to ANOVA using SAS package. The third experiment was carried to ascertain the relationship between soil invertebrates with selected soil properties and rainfall. Selected soil properties were tested according to the standard methods. Soil bulk density was tested using core sampler method on dry basis and soil moisture content was determined using gravimetric method. Soil organic matter content was tested according to Walkey and Black method and soil pH was determined using pH meters. Monthly rain fall data were recorded in a rain gauge fixed in Cinnamon Research Station. The relationships were tested by correlation analysis using SAS package.