AP Keerthipala - Academia.edu (original) (raw)
Papers by AP Keerthipala
This paper presents some technical/technological advancements for sustainable development of the ... more This paper presents some technical/technological advancements for sustainable development of the sugarcane industry of Sri Lanka. The research program of the Sugarcane Research Institute, Sri Lanka, has focussed on developing/introducing technical/technological advancements for increasing productivity and profitability of the industry while protecting the sugarcane production environment. The new sugarcane varieties recommended contributes not only to increase yields, but also to protect the industry from severe yield losses during pest and/or disease outbreaks; pyrilla, woolly aphid and white leaf disease. The new propagation methods produce healthy planting material at higher multiplication rate while the new planting methods save requirements of healthy planting material significantly. Application of nutrients according to their availability in the soil and the crop need avoids unnecessary application of fertiliser to minimise costs. Control of pyrilla, woolly aphid, borers, etc. by introducing imported parasites or by augmenting the natural enemies locally available makes possible minimising crop losses by minimising the use of chemicals for their control. Control of diseases, mainly by hot-water treatment of seed cane and production of disease-free planting material by mericloning, minimises the use of chemicals. The small machinery developed by the institute makes possible minimising both chemical use and the cost of weed control. Utilisation of filter-mud and distillery effluent for making compost, and as a carrier medium for phosphatesolubilising bacteria for making bio-fertliser and application of distillery effluent to sugarcane fields helps disposal of sugar factory and distillery wastes without damaging the environment. The method developed for determining the breakeven yield for deciding the number of ratoon crops to be raised, and the formula devised to determine the price to be paid for sugarcane ensuring efficiency and equity requirements and the ex-factory sugar price to ensure mill efficiency and price stability also contributes to green development of the sugarcane industry in Sri Lanka.
RASSA Journal of Science for Society, 2021
This paper presents some technical/technological advancements for sustainable development of the ... more This paper presents some technical/technological advancements for sustainable development of the sugarcane industry of Sri Lanka. The research program of the Sugarcane Research Institute, Sri Lanka, has focussed on developing/introducing technical/technological advancements for increasing productivity and profitability of the industry while protecting the sugarcane production environment. The new sugarcane varieties recommended contributes not only to increase yields, but also to protect the industry from severe yield losses during pest and/or disease outbreaks; pyrilla, woolly aphid and white leaf disease. The new propagation methods produce healthy planting material at higher multiplication rate while the new planting methods save requirements of healthy planting material significantly. Application of nutrients according to their availability in the soil and the crop need avoids unnecessary application of fertiliser to minimise costs. Control of pyrilla, woolly aphid, borers, etc. by introducing imported parasites or by augmenting the natural enemies locally available makes possible minimising crop losses by minimising the use of chemicals for their control. Control of diseases, mainly by hot-water treatment of seed cane and production of disease-free planting material by mericloning, minimises the use of chemicals. The small machinery developed by the institute makes possible minimising both chemical use and the cost of weed control. Utilisation of filter-mud and distillery effluent for making compost, and as a carrier medium for phosphatesolubilising bacteria for making bio-fertliser and application of distillery effluent to sugarcane fields helps disposal of sugar factory and distillery wastes without damaging the environment. The method developed for determining the breakeven yield for deciding the number of ratoon crops to be raised, and the formula devised to determine the price to be paid for sugarcane ensuring efficiency and equity requirements and the ex-factory sugar price to ensure mill efficiency and price stability also contributes to green development of the sugarcane industry in Sri Lanka.
Sugar Tech, 2002
An analysis was carried out to study the effect of changes in domestic prices of sugar, sugar imp... more An analysis was carried out to study the effect of changes in domestic prices of sugar, sugar import, tariff rates, interest rates and exchange rates together with mill capacities, per capita incomes and world sugar prices during the post-liberalisation period on the sugar sector of Sri Lanka to suggest policy guidelines for its development. The analysis was based on a simulation model which consisted of relationships of sugarcane area, cane and sugar production and imports, consumption and price of sugar determined using data from 1978 to 1999. The results indicated that domestic price of sugar was the most important economic variable in determining sugarcane area and hence cane and sugar production, and sugar consumption. Price of sugar had a positive relationship with cane area and an inverse relationship with sugar consumption. The domestic price was mainly determined by the world price which was highly volatile. Thus need for a rational pricing policy on sugar to benefit both sugar companies and consumers was emphasized. A sugar pricing policy based on an efficiency price and a mechanism to insulate the effects of fluctuations of world price on the local price to offer a stable price to both sugar companies and consumers together with offering an incentive for improving sugarcane processing efficiencies and a component for ensuring a revenue for government was suggested.
G. CHANDRASENA, A.P. KEERTHIPALA, V.P. JAYAWARDENA, W.A.M.J.S.B. ABEYSINGHE and A. NIMAL PERERA S... more G. CHANDRASENA, A.P. KEERTHIPALA, V.P. JAYAWARDENA, W.A.M.J.S.B. ABEYSINGHE and A. NIMAL PERERA Sugarcane Research Institute, Uda Walawe, Sri Lanka. Department of Animal Science, Faculty of Agriculture, University of Peradeniya, Sri Lanka. sri@bellmail.lk
Journal of The Institute of Brewing, 2006
Use of inferior yeast cultures represents one of the reasons for low fermentation efficiencies in... more Use of inferior yeast cultures represents one of the reasons for low fermentation efficiencies in Sri Lankan alcohol distilleries that use sugarcane molasses. The present study isolated and characterised yeast strains found in natural environments in Sri Lanka and evaluated their performance under laboratory conditions in an effort to select superior strains for industrial fermentations. Yeasts were characterised based on morphological and physiological features such as sugar fermentation and nitrate assimilation. Ethanol production, alcohol tolerance and growth rate of the most promising strains were monitored following laboratory fermentations of molasses. Over a thousand yeast cultures were collected and screened for fermentative activity and a total of 83 yeast isolates were characterised as higher ethanol producers. Most of these belonged to the genus Saccharomyces. Certain strains produced over 10% (v/v) alcohol in molasses media during 72 h laboratory fermentations. Only two ...
An alternative approach for determining optimal replanting cycles of sugarcane is suggested based... more An alternative approach for determining optimal replanting cycles of sugarcane is suggested based on cane yield decline and corresponding break-even yield beyond which the cumulative return on investment tends to decline. Ratios of cumulative net returns to cumulative costs and yield declines in relation to reference yields are calculated to determine their functional relationship. The yield decline corresponding to the maximum cumulative return on investment is found using this relationship. The corresponding break-even yield is obtained by deducting this yield decline from the reference yield. The crop should be replanted when cane yields drop below the break-even yield. This method was applied to farm-level data collected from 1990-91 to 1994-95 in Sri Lanka. The results showed that rain-fed settler farms at Sevanagala and Pelwatte should be replanted after the eighth ratoon or when cane yields fall below 32 tlha. In the out-grower situations at Pelwatte, crops should be replante...
Soil moisture deficit during dry spells has been a major cause for low productivity in rain-fed s... more Soil moisture deficit during dry spells has been a major cause for low productivity in rain-fed sugarcane in the Sevanagala sugar project of Sri Lanka. This has reduced average annual cane production in the rain-fed sector by about 21%. This study was conducted in 2009 and 2010 to investigate the possibility of run-off water harvesting and use of agro-wells for supplementary irrigation to mitigate this drought effect in rain-fed sugarcane. Irrigation water was collected in to earthen runoff water harvesters constructed using sand bags. Depth to ground water table was recorded weekly in the wells constructed in close proximity to sugarcane fields. The recharge capacities of these agro-wells were recorded after each pumping operation. The results revealed that there was a potential to harvest about 125 to 150 m3 of run-off water during the rainy period in the rain-fed sector of Sevanagala. The groundwater table in the low-lying areas of the sugarcane fields fluctuated between 50 - 35...
This paper presents some technical/technological advancements for sustainable development of the ... more This paper presents some technical/technological advancements for sustainable development of the sugarcane industry of Sri Lanka. The research program of the Sugarcane Research Institute, Sri Lanka, has focussed on developing/introducing technical/technological advancements for increasing productivity and profitability of the industry while protecting the sugarcane production environment. The new sugarcane varieties recommended contributes not only to increase yields, but also to protect the industry from severe yield losses during pest and/or disease outbreaks; pyrilla, woolly aphid and white leaf disease. The new propagation methods produce healthy planting material at higher multiplication rate while the new planting methods save requirements of healthy planting material significantly. Application of nutrients according to their availability in the soil and the crop need avoids unnecessary application of fertiliser to minimise costs. Control of pyrilla, woolly aphid, borers, etc. by introducing imported parasites or by augmenting the natural enemies locally available makes possible minimising crop losses by minimising the use of chemicals for their control. Control of diseases, mainly by hot-water treatment of seed cane and production of disease-free planting material by mericloning, minimises the use of chemicals. The small machinery developed by the institute makes possible minimising both chemical use and the cost of weed control. Utilisation of filter-mud and distillery effluent for making compost, and as a carrier medium for phosphatesolubilising bacteria for making bio-fertliser and application of distillery effluent to sugarcane fields helps disposal of sugar factory and distillery wastes without damaging the environment. The method developed for determining the breakeven yield for deciding the number of ratoon crops to be raised, and the formula devised to determine the price to be paid for sugarcane ensuring efficiency and equity requirements and the ex-factory sugar price to ensure mill efficiency and price stability also contributes to green development of the sugarcane industry in Sri Lanka.
RASSA Journal of Science for Society, 2021
This paper presents some technical/technological advancements for sustainable development of the ... more This paper presents some technical/technological advancements for sustainable development of the sugarcane industry of Sri Lanka. The research program of the Sugarcane Research Institute, Sri Lanka, has focussed on developing/introducing technical/technological advancements for increasing productivity and profitability of the industry while protecting the sugarcane production environment. The new sugarcane varieties recommended contributes not only to increase yields, but also to protect the industry from severe yield losses during pest and/or disease outbreaks; pyrilla, woolly aphid and white leaf disease. The new propagation methods produce healthy planting material at higher multiplication rate while the new planting methods save requirements of healthy planting material significantly. Application of nutrients according to their availability in the soil and the crop need avoids unnecessary application of fertiliser to minimise costs. Control of pyrilla, woolly aphid, borers, etc. by introducing imported parasites or by augmenting the natural enemies locally available makes possible minimising crop losses by minimising the use of chemicals for their control. Control of diseases, mainly by hot-water treatment of seed cane and production of disease-free planting material by mericloning, minimises the use of chemicals. The small machinery developed by the institute makes possible minimising both chemical use and the cost of weed control. Utilisation of filter-mud and distillery effluent for making compost, and as a carrier medium for phosphatesolubilising bacteria for making bio-fertliser and application of distillery effluent to sugarcane fields helps disposal of sugar factory and distillery wastes without damaging the environment. The method developed for determining the breakeven yield for deciding the number of ratoon crops to be raised, and the formula devised to determine the price to be paid for sugarcane ensuring efficiency and equity requirements and the ex-factory sugar price to ensure mill efficiency and price stability also contributes to green development of the sugarcane industry in Sri Lanka.
Sugar Tech, 2002
An analysis was carried out to study the effect of changes in domestic prices of sugar, sugar imp... more An analysis was carried out to study the effect of changes in domestic prices of sugar, sugar import, tariff rates, interest rates and exchange rates together with mill capacities, per capita incomes and world sugar prices during the post-liberalisation period on the sugar sector of Sri Lanka to suggest policy guidelines for its development. The analysis was based on a simulation model which consisted of relationships of sugarcane area, cane and sugar production and imports, consumption and price of sugar determined using data from 1978 to 1999. The results indicated that domestic price of sugar was the most important economic variable in determining sugarcane area and hence cane and sugar production, and sugar consumption. Price of sugar had a positive relationship with cane area and an inverse relationship with sugar consumption. The domestic price was mainly determined by the world price which was highly volatile. Thus need for a rational pricing policy on sugar to benefit both sugar companies and consumers was emphasized. A sugar pricing policy based on an efficiency price and a mechanism to insulate the effects of fluctuations of world price on the local price to offer a stable price to both sugar companies and consumers together with offering an incentive for improving sugarcane processing efficiencies and a component for ensuring a revenue for government was suggested.
G. CHANDRASENA, A.P. KEERTHIPALA, V.P. JAYAWARDENA, W.A.M.J.S.B. ABEYSINGHE and A. NIMAL PERERA S... more G. CHANDRASENA, A.P. KEERTHIPALA, V.P. JAYAWARDENA, W.A.M.J.S.B. ABEYSINGHE and A. NIMAL PERERA Sugarcane Research Institute, Uda Walawe, Sri Lanka. Department of Animal Science, Faculty of Agriculture, University of Peradeniya, Sri Lanka. sri@bellmail.lk
Journal of The Institute of Brewing, 2006
Use of inferior yeast cultures represents one of the reasons for low fermentation efficiencies in... more Use of inferior yeast cultures represents one of the reasons for low fermentation efficiencies in Sri Lankan alcohol distilleries that use sugarcane molasses. The present study isolated and characterised yeast strains found in natural environments in Sri Lanka and evaluated their performance under laboratory conditions in an effort to select superior strains for industrial fermentations. Yeasts were characterised based on morphological and physiological features such as sugar fermentation and nitrate assimilation. Ethanol production, alcohol tolerance and growth rate of the most promising strains were monitored following laboratory fermentations of molasses. Over a thousand yeast cultures were collected and screened for fermentative activity and a total of 83 yeast isolates were characterised as higher ethanol producers. Most of these belonged to the genus Saccharomyces. Certain strains produced over 10% (v/v) alcohol in molasses media during 72 h laboratory fermentations. Only two ...
An alternative approach for determining optimal replanting cycles of sugarcane is suggested based... more An alternative approach for determining optimal replanting cycles of sugarcane is suggested based on cane yield decline and corresponding break-even yield beyond which the cumulative return on investment tends to decline. Ratios of cumulative net returns to cumulative costs and yield declines in relation to reference yields are calculated to determine their functional relationship. The yield decline corresponding to the maximum cumulative return on investment is found using this relationship. The corresponding break-even yield is obtained by deducting this yield decline from the reference yield. The crop should be replanted when cane yields drop below the break-even yield. This method was applied to farm-level data collected from 1990-91 to 1994-95 in Sri Lanka. The results showed that rain-fed settler farms at Sevanagala and Pelwatte should be replanted after the eighth ratoon or when cane yields fall below 32 tlha. In the out-grower situations at Pelwatte, crops should be replante...
Soil moisture deficit during dry spells has been a major cause for low productivity in rain-fed s... more Soil moisture deficit during dry spells has been a major cause for low productivity in rain-fed sugarcane in the Sevanagala sugar project of Sri Lanka. This has reduced average annual cane production in the rain-fed sector by about 21%. This study was conducted in 2009 and 2010 to investigate the possibility of run-off water harvesting and use of agro-wells for supplementary irrigation to mitigate this drought effect in rain-fed sugarcane. Irrigation water was collected in to earthen runoff water harvesters constructed using sand bags. Depth to ground water table was recorded weekly in the wells constructed in close proximity to sugarcane fields. The recharge capacities of these agro-wells were recorded after each pumping operation. The results revealed that there was a potential to harvest about 125 to 150 m3 of run-off water during the rainy period in the rain-fed sector of Sevanagala. The groundwater table in the low-lying areas of the sugarcane fields fluctuated between 50 - 35...