http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/633 2026-04-27T21:24:56Z http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/815 LARGE DIAMETER SHALLOW AGRO-WELLS – A NATIONAL ASSET OR A BURDEN FOR THE NATION? Jayakody, A. N Large diameter open dug Agro-wells have become increasingly popular among farmers in the Dry and Intermediate Zones of Sri Lanka during the decades of 1980 and 1990. The numbers have expanded up to around 50,000 in an unprecedented manner as those were meant to serve as sources of water for irrigation of agricultural crops during the much drier Yala season as well as during the water stress times of the Maha season. However, the haphazard expansion of Agro-wells has created complications after some time of use pertaining to the quantity and quality of available water. As Agrowells were constructed frequently by neglecting the appropriate technical norms, drying up of those have been experienced very often along with a lowering of the groundwater level in the respective areas. Moreover, the water in Agro-wells started to show increasing salt concentrations over the period of usage, which has affected the soils and crops detrimentally. As a result, farmers by now have abandoned a considerable number of Agro-wells, which were constructed by spending a significant amount of money. As such, this paper describes the past and present scenarios of Agro-well farming in Sri Lanka considering the Agro-well net in the country as a national asset and attempts to suggest some possible trustworthy measures to be considered for efficient use and proper re-use of abandoned Agro-wells diverting away from the popularly accepted common paradigm “Agro-wells are only for irrigation of agricultural crops”. 2006-01-01T00:00:00Z http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/813 THE POTENTIAL OF PLANTS AND PLANT PRODUCTS IN STORED INSECT PEST MANAGEMENT Rajapakse, R.H.S In most of the tropical countries including Sri Lanka beetles attack store seeds and is a major cause of serious post harvest losses. In order to protect the stored product from insects not only pesticides but a formulation of plants and their products as powders, volatile oils, non volatile oils and extracts could be effectively used. An overview of available literature on use of plant products against the storage beetles in tropical regions is presented in order to highlight the importance, safe use, and effective control. Seed beetles cause an important part of the total insect damage to seed crops. The potential efficacy of a plant product can depend on the plant species, the plant part, and the time and way of harvesting. The mere fact that the natural products are used, implies that considerable variation is to be expected. Many of the tested plants do show effects against the seed beetles. The most effective plants or methods of application are not known, but results are promising and plant material can be an effective weapon in the battle against the beetles. Plants can be an effective replacement for chemical insecticides to protect stored seeds 2006-01-01T00:00:00Z http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/811 HYBRID NAPIER (Pennisetum perpureum X Pennisetum americarnum) VAR. CO-3: A RESOURCEFUL FODDER GRASS FOR DAIRY DEVELOPMENT IN SRI LANKA Premaratne, S; Premalal, G.G.C Less availability of good quality green forages has led to low productivity from national dairy herd of Sri Lanka. Growing fodder to suit the particular production system is an efficient and economical solution for this problem. Hybrid Napier var. CO-3 is a high yielding perennial fodder grass developed by the Tamil Nadu Agricultural University, Coimbatoor, India in 1997. The Livestock Breeding Project introduced this fodder crop to Sri Lanka in 1999. This grass is placed in a higher category, especially on tillering capacity, green forage yield, regeneration capacity, leaf to stem ratio, crude protein content, in resistance of pest and diseases and in free from adverse factors along with other fodder varieties grown in the country. It recorded an average green fodder of 5 – 8 kg/plant/cut or 250 -350 t/ha/yr under local conditions. Under this situation, nearly a block of 500 grass bushes (approximately 500 m2 or 20 perches land area) is adequate to supply year-round quality fodder without concentrates for two milking cows. This grass is propagated through root-slips or stem-cuttings and could be maintained as a perennial crop up to 4 - 5 years. Endowed with quick regeneration capacity, it can be harvested once in 30 - 45 days. Proper management practice together with correct application of fertilizer, irrigation in drought spells, cutting at the suitable height and interval is essential for maximum profit and persistence of the crop. When harvested at correct stage, CO-3 grass contains 18 -20% dry matter and 15 –16% crude proteins, 9.8 – 12.8% ash, 34 – 37% crude fiber and 74 – 78% neutral detergent fiber on dry matter basis. Surprisingly high crude protein content is one of a distinctive feature of this grass. The Department of Animal Production and Health, Veterinary Research Institute, Gannoruwa and Department of Animal Science, Faculty of Agriculture, University of Peradeniya have launched research and development activities under field situation to investigate the potentials and limitations under on-farm conditions and popularize the grass among small holders. 2006-01-01T00:00:00Z http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/810 ADAPTING CROP VARIETIES TO ENVIRONMENTS AND CLIENTS THROUGH DECENTRALIZED - PARTICIPATORY APPROACH Gunasekare, M.T.K Since 1990s, participatory approaches have became a driving force for agricultural research and rural development. The participatory approach in crop improvement involves the client-farmer in the cultivar selection or breeding and highly appropriate for increasing food security and improving livelihoods of subsistence farmers in developing countries. This has developed over the past decades as an alternative and complementary breeding approach to formal plant breeding to effectively address the needs of the farmers, especially in marginal or resource poor areas. In pursuit of this concept, this paper discusses the trends, advantages and challenges in this approach highlighting the contemporary evidence of success case studies commissioned by various authorities worldwide. While successful experiences are evident, the potential of such applications are still to be explored. Among the key challenges to the approach, this article pays attentions especially to technical, economic and institutional challenges that need to be overcome to integrate end-users based participatory approaches into the formal plant breeding systems. The paper concludes by describing synergies that can potentially be achieved by linking centralized and decentralized plant breeding models over biotechnological methods. 2006-01-01T00:00:00Z