http://ir.lib.ruh.ac.lk/handle/iruor/15415 2026-04-26T19:01:37Z http://ir.lib.ruh.ac.lk/handle/iruor/16215 WEEDY RICE: AN INSIGHT INTO GENETIC DIVERSITY AND POPULATION STRUCTURE FOR EFFECTIVE WEED MANAGEMENT Tennakoon, A.; Sandamal, S.; Ge, S.; Marambe, B.; Ratnasekera, D. Weedy rice (Oryza sativa f. spontanea) is a conspecific weed that has invaded cultivated rice fields, effectively adapted to modern management practices, leading to substantial yield losses and reduced harvest quality. The understanding of weedy rice genetic diversity and population structure is critical in developing effective control measures. Twenty weedy rice populations were collected around the island and evaluated using 33 SSR markers. Our findings indicated that the genetic diversity (He) in a population of weedy rice was reasonably high (0.305 - 0.560). A high level of within-population (79%) and a low level of among-population (21%) genetic variation were found by analysis of molecular variance (AMOVA). There is no significant correlation across genetic and geographical distances (P>0.05). The unweighted pair group method with arithmetic mean (UPGMA) demonstrated that 20 populations were structured into two well-separated groups. Remarkably, many admixed individuals were evident according to the STRUCTURE. Weedy rice management strategies should focus on micromorphological monitoring to detect, group, and eliminate weedy rice in paddy fields, restricting the exchange of saved paddy seeds among geographical regions, increasing the production and distribution of certified seeds, the varietal recommendation for rice-growing regions to minimize mixing of varieties with different age classes, raising awareness are the recommendations to reduce the emergence of future weeds 2023-01-01T00:00:00Z http://ir.lib.ruh.ac.lk/handle/iruor/16212 WATER FOOTPRINT OF PADDY CULTIVATION UNDER CONTROLLED RUNOFF CONDITIONS: A CASE STUDY IN KURUNAGALA DISTRICT, SRI LANKA Palliyaguru, M.P.G.N.M.; Navaratne, C.M.; Wickramasinghe, D.D.; Nanayakkara, C.M. Paddy cultivation is the largest global consumer of water, and it also significantly contributes to water pollution. Investigating the water footprint of paddy agriculture can provide insights into how pollutants affect the ecosystem. This study aimed to quantify the total water footprint for paddy grown in Sri Lanka's Low Country Intermediate Zone under supplementary irrigation. A lysimeter study was carried out to determine the amount of leached nutrients below the root zone. The experimental design was a Complete Randomized Block Design (CRBD) with two factors (cropping season and gradient) and two levels (Yala and Maha; upper and lower). The green and blue water footprints for both sites were estimated using the CROPWAT 8.0 model by crop water requirement option. The results revealed that the loss of NO3-N through leaching accounted for 8.61 ± 1.84 kg/ha (8%), and the leaching losses of PO4 3- - P were 0.49 ± 0.1 kg/ha (2%) under controlled runoff conditions during the experimental period. The nitrogen fertilizer-induced grey water footprint (WFgrey) for one tonne of rice produced was 193 ± 27 m3 /t, and the phosphorous fertilizer-induced WFgrey was 61 ± 7 m3 /t. The study identified nitrate as the critical element for water pollution. The estimated total water footprint (WFtotal), which was the sum of green, blue, and grey water footprint, was 1409 ± 95 m3 /t under controlled runoff conditions, while the global average value is 1325 m 3 /t. The estimated value is about 6% higher than the global average value. Therefore, these findings demonstrate the need for further research 2023-01-01T00:00:00Z http://ir.lib.ruh.ac.lk/handle/iruor/16208 QUADRATIC ALMOST IDEAL DEMAND SYSTEM ANALYSIS OF DEMAND FOR SELECTED VEGETABLES AND FRUITS IN NIGERIA Obisesan, A.A. This study analyzed the demand for selected vegetables and fruits in Nigeria. It determined price effects on demand for fruits and vegetables, examined the demographic variables influencing demand and revealed the expenditure elasticity across income quartiles and sectors. Data from the three waves of Living Standard Measurement Survey-Integrated Survey on Agriculture namely 2010/11, 2012/13 and 2015/16, were employed in the analysis. The demand for bananas, citrus, pineapples, fresh okra, onions pepper and tomatoes was examined using the Quadratic Almost Ideal Demand System. Households in Nigeria consumed more vegetables than fruits. The results revealed that the staple vegetables in Nigerian diets are tomatoes, onions and pepper. It was observed that movement in relative prices elicited high quantity response. All the fruits and vegetables included in the model were normal goods. Vegetables and fruits responded similarly to expenditure increases in urban and rural Nigeria. The own-price elasticities, both uncompensated and compensated agree with the demand theory. More consideration should be given to the intensifying production of fruits and vegetables in technology development and investment to make them available and affordable 2023-01-01T00:00:00Z http://ir.lib.ruh.ac.lk/handle/iruor/16205 PRODUCTION OF PLANT-BASED MILK FROM LOCAL ALMOND NUTS (Terminalia catappa L.) AND EVALUATION OF ITS SENSORY AND NUTRITIONAL PROPERTIES Samarasinghe, S.P.A.K.; Chandimala, U.R.; Gunathilake, D.M.C.C. An experiment was conducted to investigate the possibility of making plant-based milk using Local Almond (Terminalia catappa L.) nuts. Harvested nuts were cleaned, shelled and, separated into two sets based on their maturity stage: well-ripened and mature-green. Local Almond nuts at both maturity stages were blanched and blended with water at a ratio of 1:2 (w/w), and two different plant-based milk samples were prepared as T1, from well-ripened and T2, from mature-green fruit kernels. The sensory evaluation of prepared kernel-based milk samples was conducted, occupying a panel of 30 semi-trained members using a five-point hedonic scale. The product’s appearance, odour, flavour, mouthfeel, and overall acceptability were tested and analyzed using the Friedman test. The proximate composition of the prepared plant-based milk samples was determined in triplicates, and the energy content of the milk samples was estimated based on their nutritional values and was compared with those of Cow’s milk. Data were analyzed using ANOVA procedures at a 5% significance level. Obtained sensory data revealed that among two milk samples, milk prepared from well-ripened Local Almond kernel (T1) was recorded as the best sample except for aroma for all organoleptic attributes. The proximate analysis found that the crude protein, crude fat and crude fiber content of both T1 and T2 Local Almond milk samples were higher than those of Cow’s milk. Among the samples, the T1 showed the highest crude fat content (13.30 ± 0.01%), whereas T2 showed the highest crude protein content (7.40 ± 0.00%). Carbohydrate content of both T1 (2.09± 0.00%) and T2 (1.20± 0.00%) was less than that of cow’s milk (4.80 ± 0.01%). The study suggests mixing milk extracted from mature green fruits and well-ripened fruit kernels to improve the final nutritional quality of Local Almond milk. This study reveals the requirement for further studies related to Local Almond kernel-based milk as a good source of plant-based milk and a potential substitute for Cow’s milk 2023-01-01T00:00:00Z