Issue 01

MANAGEMENT OF WHITEFLIES (Bemisia tabaci . GENNADIUS) USING Amblyseius swirskii ATHIAS-HENRIOT (SWIRSKI-MITE) IN CHILLI CROP

2023-01-01T00:00:00Z

MANAGEMENT OF WHITEFLIES (Bemisia tabaci . GENNADIUS) USING Amblyseius swirskii ATHIAS-HENRIOT (SWIRSKI-MITE) IN CHILLI CROP Perera, M.T.M.D.R.; Senanayake, N. Whitefly (Bemisia tabaci ) is an important pest of chilli in Sri Lanka. Whiteflies are also vectors of viral diseases in many crops. Indiscriminate use of insecticides leads to resistant development, high residue levels, health hazards and environmental pollution. The laboratory experiment was conducted using the biological agent, Amblyseius swirskii Athias- Henriot, imported from Koppert Biological Systems, Netherlands, for the control of chilli whiteflies. Results indicated A.swirskii reduced the white fly population significantly after two weeks of introduction. The reduction of the population of A.swirskii was statistically significant after the 04th week. The survival of Swirskii mites and whiteflies at the end of the 6th week in the experiment was 25 % and 26.6 % respectively. A.swirskii effectively controlled whiteflies in chilli, though the biological agents did not multiply in the experiment even with the provision of bee's honey as an alternate food source, hence seasonal augmentation releases are necessary.

THE STATUS OF Bactrocera dorsalis AS AN EMERGING PREDOMINANT PEST IN THE COMMERCIAL FRUIT INDUSTRY IN SRI LANKA

2023-01-01T00:00:00Z

THE STATUS OF Bactrocera dorsalis AS AN EMERGING PREDOMINANT PEST IN THE COMMERCIAL FRUIT INDUSTRY IN SRI LANKA Wijekoon, W.M.C.D.; Ganehiarachchi, G.A.S.M.; Wegiriya, H.C.E.; Vidanage, S.P. Fruit flies (Diptera: Tephritidae) are considered the most serious insect pests in the fruit industry worldwide. However, there are no sufficient studies and information on the pest severity and the dominance levels of fruit flies in the fruit industry in Sri Lanka. Hence, the present study aimed to assess the abundance, dominance status, and potential risk of fruit flies in the local fruit market in Sri Lanka. The study was carried out using randomly selected eight (08) fruit stalls (in Galle, Matara, Wellawaya, Monaragala, Ambilipitiya, Kakirawa, Hambanthota, Lunugamwehera) as two stalls in each bio-climatic zone. Adult fruit flies were collected using methyl-eugenol field traps. Trapped flies were identified using standard taxonomic keys. Simpson Population Dominance Index and the Abundance Index for recorded fruit flies were calculated. Four Bactrocera species; B. dorsalis, B. kandiansis, B. correcta and B. latifrons were recorded. Among them, B. dorsalis showed the highest percentage abundance in all selected fruit stalls and in all bio-climatic zones (P<0.05). Out of the four species, B. dorsalis recorded the highest dominance index value (0.61) as the high-dominant fruit fly species. As such, there is an emerging pest risk of B. dorsalis as the predominant fruit fly in the commercial fruit industry in Sri Lanka. These findings will be helpful for fruit exporters, local sellers, cultivators and agriculture authorities in implementing control measures to secure the commercial fruit industry in Sri Lanka.

STEM CUTTINGS AS PROPAGULES FOR VEGETATIVE PROPAGATION OF CASHEW (Anacardium occidentale L.)

2023-01-01T00:00:00Z

STEM CUTTINGS AS PROPAGULES FOR VEGETATIVE PROPAGATION OF CASHEW (Anacardium occidentale L.) Subashini, J.K.W.N.; Perera, P.I.P.; Jayawardana, K.V.G.L.M.C.; Nimantha, S.W.S.L. Due to the existing variability among the populations and the inability of meeting the current demand for planting materials for large-scale cultivation, cashew (Anacardium occidentale L.) requires a promising vegetative propagation method. Stem cutting is the best propagule and needs to induce germination which is restricted in the presence of gum. Wiping of gum secreted onto the cut surface of the stem with three solvents, water, acetone, and kerosene just after and after 5, 10, and 15 min of making the cut was tested to remove the gum. The effect of the presence of apical buds and leaves on the stem cuttings and the application of different types of rooting hormones containing IBA onto the cut surface was tested using three commercial varieties, WUCC-13, WUCC-19, and WUCC-21. Data were analyzed using CATMOD and ANOVA procedures. The results denoted a significant effect of gum solvent for maintaining the cutting viability by giving rise to shoots and callus production (p<0.05). Acetone was the only effective solvent in developing the callus on the cut surface. The application of Indole-3- butyric acid (IBA) indicated a better growth of shoots (p<0.001). Varieties, WUCC-13 and WUCC-21 disclosed better shoot growth. The presence of the apical bud and leaves negatively affected on activation of the axillary buds. Well-developed callus was present on the cut surface indicating the potential of giving rise to adventitious roots.

DEVELOPMENT OF IN-VITRO PROTOCOL TO ENHANCE MASS PRODUCTION OF TURMERIC (Curcuma longa L.)

2023-01-01T00:00:00Z

DEVELOPMENT OF IN-VITRO PROTOCOL TO ENHANCE MASS PRODUCTION OF TURMERIC (Curcuma longa L.) Bandara, M.M.N.T.; Dahanayake, N.; Perera, P.C.D.; Subasinghe, S. Conventionally, turmeric (Curcuma longa L.) is propagated through rhizomes. However, its multiplication rate is very low where a single turmeric rhizome approximately produces 6-8 lateral buds and nearly 20-25% of the harvest should be retained as planting materials for the next season. Therefore, the study focuses on the development of an in vitro regeneration protocol of turmeric for the year-round provision of disease-free planting material. Commercially grown sprouted rhizome buds were surface sterilized with fungicide followed by 70% ethanol, and with different concentrations of Clorox (10, 20, 30 and 40%). Different exposure times (5, 10, 15 and 20 minutes) were tested to develop the best sterilization procedure. MS medium supplemented with different concentrations of hormones BAP (2.0, 3.0, 4.0 and 5.0 mg/l) and NAA (0.25 and 0.5 mg/l) for shoot regeneration, and IBA (1.0, 2.0, 3.0 and 4.0 mg/l) for root regeneration to find the best combination. The results showed that 30% Clorox and 20 minutes exposure time is suitable for surface sterilization of buds about 1.5-2.0 cm long. Shoot regeneration was the highest when the media were treated with 4.0 mg/l of BAP and 0.5 mg/l NAA. The best IBA concentration that gives the highest number of roots in the least number of weeks is 2.0mg/l. Additionally, 58.33% of the plantlets survived after field acclimatization. The study concluded that the protocol can be used for in vitro propagation of turmeric using rhizome buds for large-scale production of plant materials.