Browsing by Author "Sunil, K M"

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Climate change adaptation on rice production
(Academy of Climate Change Education and Research Vellanikkara, 2016) Navya, M; Sunil, K M
Crop weather modelling of cocoa production in humid tropics under the purview of climate change
(Academy of Climate Change Education and Research, Vellanikkara, 2018) Vishnu, R P; Sunil, K M
Crops weather relationship in rice
(Department of Agricultural Meteorology, College of Horticulture,Vellanikkara, 2000) Sunil, K M; Kesava Rao, A V R
An experiment was conducted in the Agricultural research Station, Mannuthy during first, second and third crop seasons of 1998-99 to study the crop weather relationship in rice variety 'Kanchana'. The experiment was laid out in randomised block design with three replications. The treatment consisted of three dates of planting in each season i.e., 1 s\ i s" and 30th of June, 1 st 15th and 30th of October and 1 st, 15th and 30th of January. Observations on morphological and yield attributes were recorded during the course of investigation. The daily values of weather elements viz., maximum and minimum surface air temperature, bright sunshine, morning and afternoon relative humidity and wind speed were collected from the Principle Agro Meteorological Station, College of Horticulture, Vellanikkara, to work out the crop weather relationships in rice. . Crops transplanted on 1 st is" and 30tl) of October and 1 st 15th of June were significantly superior in terms of grain yield, panicle number, number of filled grains/panicle, number of leaves, plant biomass, number of tillers and leaf area index. The crop weather relationship studies showed that the wind speed, minimum temperature and mean temperature during flowering to maturity had a significant negative correlation with grain yield. But morning relative humidity and mean relative humidity during transplanting to panicle initiation stage had a significant positive influence on ultimate grain yield. The wind speed, mean temperature, temperature range, RH1-RH2 and solar radiation during vegetative stage were negatively correlated with the straw yield. Maximum temperature during beginning of grain filling to maturity stage also had a negative correlation. But increase in mimmum temperature, mean relative humidity, morning and afternoon relative humidities during transplanting to flowering stage was significantly increase the straw yield as there was a positive correlation. The regression equations developed in the study predicted the grain yield, straw yield, duration of vegetative phase and maximum leaf area index well and a close relation existed between observed and estimated yield. Based on the experimental data, minimum data set for the validation of rice model of the IBSNAT has been generated.
Effect of growing environment and climate change on physiyology of tomato ( Lycopersicon esculentum Mill. )
(Acadamy of Climate Change Education and Research, Vellanikkara, 2015) Rajalakshmi Radhakrishnan; Sunil, K M
The present world production of tomato stands at 100 million tons fresh fruits produced on 3.7 million hectares. Even though productivity levels of tomato have increased, it will not be sufficient enough to the increasing population. Global climate change is any significant long term change in expected patterns of weather over a region which may be naturally induced or anthropogenic. The effect of climate change on crop and terrestrial food production are evident in several regions of the world. Negative impacts of climate trends have been more common than positive ones. Objectives of the study were to study the effect of different growing environment and climate change on the physiological traits of tomato development of crop weather relationships for the selected rice varieties and assessment of possible change in yield due to climate change. The studies were conducted during December 2014- March 15at the Central Nursery, Vellanikkara in the bacterial wilt resistant variety Anagha by providing three different growing environments namely polyhouse, rainshelter and open field conditions with four dates of transplanting. The results showed that the dates of transplanting and growing environment had a significant effect on the physiology of tomato. The crop transplanted inside the polyhouse took the longest duration. Maximum leaf area index (3.8) was observed in in the crop transplanted in open field, polyhouse and rain shelter on different dates on different dates (1 December 2014 and 20 January 2015 respectively). The highest values of leaf relative water content was observed in the first week following transplanting and the lowest values appeared prior to the last harvest regardless of the dates of transplanting and growing environment. The lycopene content was consistently highest in the crops inside the Polyhouse. The highest value for the same was 1.52 mg gm-1 was recorded in crops inside the polyhouse transplanted on 10 January 2015.The fruit ascorbic acid content (2.06 mg gm-1) was highest in the crop inside rain shelter transplanted on 10 December 2014. The highest mean length of style was documented in the flowers of the crop transplanted inside rain shelter (8.08 mm) on 1 December 2014 whereas, the highest mean stamen length was recorded in the flowers of the crop transplanted inside polyhouse (8.28 mm) on 1 December 135 2014). The difference in the length of the style and stamen and its relative position significantly affected the total yield obtained. A difference of more than -0.05 mm considerably reduced the yield. The highest yield (111.5 tons ha-1) was recorded inside the polyhouse in the crops transplanted on 1 December 2014. The net photosynthesis rate was highest in the rain shelter crops regardless of the dates of transplanting. The highest values recorded was 19.7 in the rain shelter and poly house for the crops transplanted on 10 and 20 January 2015. The temperature prevalent was the most crucial factor determining the rate of photosynthesis followed by Carbon dioxide. Under the projected climate change scenarios i.e. RCP 2.6, 4.5, 6.5 and 8.0, the ascorbic acid content increased in the fruit owing to higher temperature and lower soil moisture availability. The lycopene content remained unaffected as the UV radiation concentration is will be changing negligibly for the region where the study is conducted. The duration of the crop will be reduced drastically from 2030 to 2080 under all the scenarios. The results also showed that the effect of minimum temperature would drastically reduce the yield. The increasing atmospheric CO2 concentration is likely to have some positive effect on yield, but the effect is not significant compared to the negative impact of rise in temperature.
Effect of growing environment and microclimate on parthenocarpic cucumber
(Department of Agricultural Meteorology,College of Horticulture, Vellanikkara, 2016) Smitha, K; Sunil, K M
An investigation was carried out in Department of Agricultural Meteorology, College of Horticulture, Vellanikkara during 2015-16 to determine the the effect of growing environments and microclimate on growth and yield of cucumber and crop weather relationships in cucumber under different growing environment.
Effect of weather on leaf blast incidence in rice and predicting potential epidemics under various climate change scenarios
(Academy of Climate Change Education and Research Vellanikkara, 2016) Aswathi, N R; Sunil, K M
Effect of weather on sheath blight incidence in rice and predicting potential epidemics under various climate change scenarios
(Academy of Climate Change Education and Research Vellanikkara, 2016) Devi Krishna, P; Sunil, K M
Impact of climate change on rice production
(Department of Agricultural Meteorology, College of Horticulture, Vellanikkara, 2015) Gangaraju Subramanyam; Sunil, K M
Impact of climate change on water balance of agro ecological units of Kerala
(Academy of Climate Change Education and Research Vellanikkara, 2016) Athul Krishna, K S; Sunil, K M
The research project entitled “Impact of climate change on water balance of agro ecological units (AEUs) of Kerala” was carried out in RARS Pattambi and the daily rainfall data for the period 1991-2014 were collected from 60 stations of Kerala state from the India Meteorological Department, Thiruvananthapurm. Agro Ecological Unit wise information on area and production of various crops were collected fiom Agro Ecology of Kerala, Published by NBSS & LUP and Kerala State Planning Board, 2012. Kerala state, which depends to a great extent on its agriculture for its welfare a detailed knowledge of the Agricultural potential of the region in relation to the climatology of the area is an essential requirement in agricultural planning. In recent decades the increasing population and the resultant higher demands for food have necessitated for optimal exploitation of the available natural resources, in particular, land and water. As the eastern boundary of Kerala is fully bordered by the Western Ghats, the entire state is under the dominant influence of its orography. This results in heavy monsoon rains and large water surplus during a part of the year. This feature combined with the variety of soil types, vegetation classes and geomorphological features result in a diversity of land use patterns. This study assessed the potential impacts of climate change on rainfall and its variations across different agro ecological units as per the projected climate change. To project future climate conditions, the simulation outputs for 2030s, 2050s, and 2080s from seventeen general circulation models (GCMs) were extracted under Intergovernmental Panel on Climate Change (IPCC) greenhouse gases emissions scenario RCP 4.5 to consider the range of uncertainty. Thornthwaite water balance model was estimated to the observed and predicted climate data and this was used to estimate different components of water balance for different agro ecological conditions. This project also studied the impact of climate change on drought, length of growing period and intensity of high rainfall events in the future. The results suggest that future precipitation for the 2030s, 2050s and 2080s are expected to increase based on the multi ensemble GCM outputs. The temporarily and spatial distribution of rainfall like to change significantly throughout Kerala. In nutshell the amount of precipitation during summer and SW monsoon season will expect an increase whereas NE monsoon season and winter season anticipated a decrease in rainfall activity. But the trend is reverse in most of the coastal and high ranges. The total length of growing period is likely to increase in the future due to increased precipitation during summer months. But it can be also noticed that the length of continuous growing period which is a necessity for successful crop production anticipated a decrease. The most interesting observations are the present rain shadow regions of Kerala will going to have a favourable agricultural environment in the future. Studies on impact of climatic change on water balance over the state show that the moisture regime of different AEUs of the state undergo wild fluctuations both in the drier and wetter directions. In general the state is going to witness a hike in evapotranspiration due to increase in temperature as a part of global warming. There is high possibility of flood and drought occurrence in the same calendar year. It can also be inferred that the continuous water surplus period over the state is in a declining trend. It is expected that the results of the present investigation would help in the formulation of climate change adaptive strategies at agro ecological unit level by the judicious management of the available natural resources of land, water and atmosphere. Pointless to say this would enable effective planning for sustainable development of Kerala state.
Impact of projected climate change on cropping pattern of different agro ecological units of Central Kerala
(Academy of Climate Change Education and Research Vellanikkara, 2017) Divya Sunil; Sunil, K M
Agriculture faces hastily growing challenges because it must supply food to an increasing population under shifting climate conditions. To stabilize the negative effects of climate change, researchers have generally emphasized incremental adaptation to existing cropping systems, such as the adjustment of planting window, suitable variety and improved agronomic practices. Characterization of the ecosystems using the AEZ concept is a good decision making approach for variety of farming activities performed by the farmers and is a useful tool for the studying the impact of climate change. The objectives of this study are (1) To study rainfall variability and to determine water availability periods of Agro ecological units of Central Kerala under different climate change scenarios. (2) To study the impact of projected climate change on cropping pattern, crop calendar and the possible changes in the water requirements of major cropping systems prevailed in the various Agro ecological Units of central Kerala. Daily rainfall data for the period 1991-2014 were collected from the India Meteorological Department, Thiruvananthapurm. The weather data from General Circulation Models based on RCP 4.5 and 8.5 were analyzed. Weather cock v.1.5 was used for converting the daily weather data into standard week, month and seasonal formats. The rainfall parameters or indices like seasonal and monthly rainfall, rainy days, high rainfall events, length of growing period were calculated. It is also used to compute PET and Thornthwaite water balances. CROPWAT model was used for the calculations of crop evapotranspiration, crop water requirements and irrigation requirements for the development of irrigation schedules under various management conditions and scheme water supply. A decline in rainfall can be observed during the months January, February, September and December in projected climate as per RCP 4.5 and 8.5 whereas an increased rainfall during the months June, July and August. In nut shell the wet months will be wetter and dry periods will be drier. The south west monsoon and summer season shows an increasing trend in the number of rainy days and amount of rainfall in projected climate. The projected climate indicates that there will be a decreasing trend in the number of rainfall events below 50 mm per day whereas the heavy rainfall events show an increasing trend. Most of the agro ecological units in central Kerala indicate a decreasing pattern in the length of growing period in projected climate as per RCP 4.5 and 8.5. In projected climate the maximum amount of potential evapotranspiration can be observed during the months May, July and September whereas the minimum will be in January, November and December. The number of periods were deficit will happen indicate an increasing trend and also the annual amount of deficit show an increasing pattern in projected climate. A shift in the water surplus periods can be observed during projected climate. Most of the AEUs in central Kerala indicate a reduced number of surplus periods in projected climate. The crop evapotranspiration indicate an increasing trend in the rice based cropping system during the projected climate whereas in perennial crops it shows a decreasing trend. The water requirement indicates an increasing trend in most of the major cropping systems whereas in Rice-Fallow-Fallow cropping the irrigation requirement remains unchanged. As a general trend, the length of growing period in the major rice growing areas of different AEUs are getting shorter with slight differences among various agro-ecological units, implying a higher risk of operating under projected climate as per RCP 4.5. The crop calendar of rice based cropping system indicates a delay in sowing date due to delay in summer showers and the crops will have to suffer water stress during the grain filling stage and will be under heavy rains at the time of harvest in projected climate as per RCP 4.5.
Impact of projected climate change on cropping pattern of different agro ecological units of southern Kerala
(Academy of Climate Change Education and Research Vellanikkara, 2017) Sukanya, K S; Sunil, K M
Climate change poses an emerging threat to sustainability of social and economic development, livelihoods, and environmental management across the globe. Characterization of the ecosystems using the AEZ concept is a good decision making approach for variety of farming activities performed by the farmers and is a useful tool for the studying the impact of climate change. The objectives of this study are (1) to study rainfall variability and to determine water availability periods of Agro ecological units of southern Kerala under different climate change scenarios. (2) To study the impact of projected climate change on cropping pattern, crop calendar and the possible changes in the water requirements of major cropping systems prevailed in the various Agro ecological Units of southern Kerala. Daily rainfall data for the period 1991-2014 were collected from the India Meteorological Department, Thiruvananthapurm. Weather cock v.1.5 was used for converting the daily weather data into standard week, month and seasonal formats. It is also used to compute PET and Thornthwaite water balances. CROPWAT model was used for the calculations of crop evapotranspiration, crop water requirements and irrigation requirements for the development of irrigation schedules under various management conditions and scheme water supply. The annual rainfall availability in most of the AEUs of Thiruvananthapuram, Kollam and Pathanamthitta districts show a decreasing trend in the projected climate and an increasing trend in Idukki, Kottayam and Alappuzha. The number of annual rainy days generally shows a decreasing trend. The seasonal rainfall of southwest and summer monsoon will show an increase from the current situation where as northeast monsoon and winter will have a decreasing trend. In projected climate of both RCP 4.5 and 8.5 there will be high probability of having reduction in the number of months having the surplus and an increase in the number of deficit. The crop evapotranspiration values of rice based cropping system will show a tendency to increase. In perennial cropping systems of coconut based and rubber the projected crop evapotranspiration will have a reduction from the present situation whereas in coffee based cropping system the ETc will have an increasing trend. The irrigation requirement of all the major cropping systems will increase from the present situation except in the case of rice-fallow-fallow. The length of growing period of the cropping season in the major rice growing areas of different AEUs are getting shorter with slight differences among various agro-ecological units, implying a higher risk of operating under projected climate as per RCP 4.5. The sowing date will be delayed up to three to five weeks. It can be also observed that the crops will have to suffer water stress during the grain filling stage and will be under heavy rains at time of harvest in almost all the considered cases.
Modeling the rice production under varied agro ecological situations of Palakkad district and its vulnerability to climate change
(Academy of Climate Change Education and Research Vellanikkara, 2018) Anandu S Hari; Sunil, K M
The research project entitled "Modeling the rice production under varied Agro-Ecological Situations of Palakkad district and its vulnerability to climate change". Was carried out at RARS Pattambi and the daily rainfall data for the period 1991-2014 was collected from the India Meteorological Department, Thiruvananthapuram. The weather data from General Circulation Models based on RCP 4.5 and 8.5 were used for the analysis and projections were made up to 2050. Weather cock v.1.5 was used for converting the daily weather data into standard week, month and seasonal formats. The rainfall parameters or indices like seasonal and monthly rainfall, rainy days and high rainfall events were calculated. It is also used to compute PET and Thornthwaite water balances. The crop simulation model DSSAT-developed by IBSNAT was used for studying the impact of climate change on these ecosystems. The monthly rainfall of various Agro ecological units of Palakkad district indicate an increased rainfall during the months June, July and August in Projected climate as per RCP 4.5 a weakening in rainfall can be noticed during the months January, February, September and December in projected climate, annually, the number of rainy days indicates a declining trend in projected climate. In a nut shell, the wet months will be watter and dry periods will be drier. The south west monsoon and summer season shows an increasing tendency in the number of rainy days and amount of rainfall in projected climate. Most of the agro-ecological units in Palakkad district showed a decreasing pattern in the length of growing period in projected climate as per RCP 4.5 In projected climate, the maximum amount of potential evapotranspiration can be observed during the months May, July and September whereas the minimum will be in January, November and December. The yearly potential evapotranspiration shows an increasing trend in projected climate as per RCP 4.5. The number of periods where deficit will happen indicate a decreasing trend whereas the annual amount of deficit shows an increasing pattern in projected climate. As per the projections maximum amount of water deficit will happen during the month March in most of the agro ecological units of central Kerala. Annually the amount of water surplus indicates an increasing trend in projected climate based on RCP 4.5. In RCP 4.5, which is the most likely scenario for India, the yield reduction will be 10 per cent by 2030s and 2050s respectively. It can be observed from the study that the impact of climate change on rice production varied widely under different agro ecological situations. The major rice growing tracts of Palakkad district except Palakkad eastern plains (AEU 23) showed decline in productivity.