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Open Access
Impact of heat and nutritional stress on the growth and reproductive performance of bucks
(Academy of Climate Change Education and Research, Vellanikkara, 2015) Abdul Niyas, P A; KAU; Girish Varma, G
A study was conducted to assess the combined effect of heat stress and nutritional restriction on growth and reproductive performances in Osmanabadi Bucks. Twenty four adult Osmanabadi bucks (average body weight (BW) 16.0 kg) were used in the present study. The bucks were divided into four groups viz., C (n=6; control), HS (n=6; heat stress), NS (n=6; nutritional stress) and CS (n=6; combined stress). The study was conducted for a period of 45 days. C and HS bucks had ad libitum access to their feed while NS and CS bucks were under restricted feed (30% intake of C bucks) to induce nutritional stress. The HS and CS bucks were exposed to solar radiation for six hours a day between 10:00 h to 16:00 h to induce heat stress. The data was analyzed using repeated measures analysis of variance. Both C and HS groups showed significantly higher (P<0.01) body weight and body condition scoring (BCS) as compared to restricted feeding groups (NS and CS). The allometric measurements also were significantly (P < 0.01) lower in restricted fed groups (NS and CS) as compared to ad libitum fed groups in CS bucks as compared to other groups (C and HS). Among the scrotal measurements, Scrotal circumference afternoon (SCA) and scrotal length afternoon (SLA) differed significantly (P<0.05) between the groups. The highest semen volume (P<0.01) was recorded in C group bucks as compared to other groups. The significantly (P<0.05) higher mass motility and progressive motility was recorded in C group bucks. However, both mass motility and progressive motility did not differ between the stress groups (HS, NS and CS). The highest plasma GH (P<0.01) was recorded in CS group and the lowest in rest all the groups (C, HS and NS). The highest plasma testosterone level was recorded in C group and the lowest in rest all groups (HS, NS and CS). The interaction between treatment and experimental days significantly (P<0.01) influenced body weight, BCS, allometric measurements, scrotal circumference, left testicular length and width, right testicular width, semen volume and growth hormone concentration. The higher expression of testicular Heat Shock Protein 70 (HSP70) Messenger Ribonucleic Acid(mRNA) was reported in HS goats. Testicular section showed significant changes for different stresses. The highest loss of spermatid density indicating decreased spermatogenesis was recorded in CS followed by HS and NS 109groups compared to C group. It can be concluded from this study that when nutrition is not compromised Osmanabadi bucks were able to withstand heat stress. This is evident from the non-significant difference on various growth and reproductive parameters studied between C and HS groups. Further, the study also revealed that Osmanabadi bucks possessed superior adaptive capability to combined stresses simultaneously. This is evident from the significant interaction of treatment and experimental days on majority of the parameters studied.
Open Access
Phenology of medicinal snake gourd (Trichosanthes cucumerina L.) under different seasons
(Academy of Climate Change Education and Research, Vellanikkara, 2015) Harsha Satheesh; KAU; Kanakamany, M T
The present study entitled “Phenology of medicinal snake gourd (Trichosanthes cucumerina L.) under different seasons” was carried out at Academy of Climate Change Education and Research (ACCER), Vellanikkara during the period 2014-2015. Field experiments were conducted at All India Coordinated Research Project on Medicinal, Aromatic Plants and Betel Vine (AICRP on MAP & B), College of Horticulture, Vellanikkara. The objective of the study was to assess the influence of weather parameters on yield and yield attributing characters of medicinal snake gourd (Trichosanthes cucumerina L.) under open and rain shelter during winter, summer and rainy seasons. The experiment was laid out in a randomized block design with six treatments and four replications each in open and rain shelter during winter, summer and rainy seasons. Observations on meteorological, growth characters, floral biology, yield and quality parameters were recorded under open and rain shelter in all the three seasons. Significant difference was observed in number of flowers, number of fruits produced, pollen fertility, fruit yield per plant, herbage yield per plant, total yield per plant and per plant cucurbitacin content for plants grown under rain shelter as well as in open condition during the three seasons. During winter, summer and rainy seasons crops grown under rain shelter recorded highest vine length, number of branches, maximum leaf area and number of male and female flowers produced, herbage yield per plant and dry yield per plant than open condition. Whereas pollen fertility, pollen viability and fruit weight were found to be highest in open condition than in rain shelter during summer season and found more in rain shelter during winter and rainy seasons. Earlier anthesis of both male and female flower was recorded during summer season under open condition. Highest herbage yield per plant, fruit yield per plant and total yield per plant were recorded under open condition during summer season. But during rainy season it is higher under rain shelter when compared to open field.Per plant cucurbitacin content was highest for the plants that grown under open environment than in rain shelter. It was found to be maximum during summer season followed by winter and rainy season. Weather parameters such as canopy air temperature, daily minimum and maximum temperature were high under rain shelter during the three cropping seasons. Relative humidity and soil moisture were high under rain shelter during winter and summer and low during rainy season. Correlation analysis with the weather parameters and crop was studied. Relative humidity and soil moisture had a significant negative correlation with the number of male flowers produced, pollen fertility, herbage yield per plant, total yield per plant and per plant cucurbitacin content. Canopy air temperature, minimum and maximum temperature showed positive correlation with the number of male flowers, produced pollen fertility, number of fruits, fruit yield per plant, herbage yield per plant, total yield per plant and per plant cucurbitacin content whereas rainfall had a negative correlation.
Open Access
Modeling the impact of climate change on growth and yield of tomato
(Academy of Climate Change Education and Research, Vellanikkara, 2015) Safia, M; KAU; Sunil, K M
Tomato is the world’s largest vegetable crop. It is one of the most important vegetable crops cultivated for its fleshy fruits and it is considered as important commercial and dietary vegetable crop. The average productivity of tomato in our country is nearly 158q per hectare. Its successful production in the tropics is, however, constrained by environmental variations especially under open field conditions. The rising temperatures and carbon dioxide concentration and uncertainty in rainfall associated with climate change may have serious direct and indirect consequences on crop production and hence food security. Objective of the study were Modeling of growth and yield of tomato and the impact of climate change based on projected climate change scenarios using DSSAT 4.5 model and the impact of climate change will be studied based on projected climatic scenarios (RCP.2.6, 4.5, 6.0 and 8.5). The field was designed as spilt plot under 3 growing situations (S1-poly house, S2-rain shelter, S3-Open condition) at Central Nursery, Vellanikkara. The date of planting was on 2014 December 1st, 10th, 2015 January 10th and 20th. The variety chosen was Anagha. The date of transplanting and growing environment had a significant effect on the various morphological, Phenological and yield parameters. Then greatest height was obtained by polyhouse (251.7cm) on 01 December 2014.The greatest biomass accumulation (2.23 t ha-1) inside the polyhouse on 10 December 2014 and 10 January 2015. The crop transplanted in polyhouse on 01 December 2014 had the longest duration of 114 days. Maximum LAI was recorded in the crop transplanted inside the polyhouse, rain shelter (20 January 2015) and open field (10 December 2014). Highest yield 111.5 t ha-1 in the crop transplant inside polyhouse on 01 December 2014. DSSAT model was validated and gave good RMSE values. 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. The yield of tomato (Anagha) will be reduced considerably due to climate change.
Open Access
Tree growth climate relationship in plantation teak (Tectona grandis L.f.) grown in Thrissur district, Kerala
(Academy of Climate Change Education and Research, Vellanikkara, 2015) Gayathri, Asok; KAU; Anoop, E V
The present study ―Tree growth climate relationship in plantation teak (Tectona grandis L. f.) grown in Thrissur District, Kerala‖ was conducted to develop tree-ring chronologies from plantation teak (Tectona grandis ) at the site Vazhani in Thrissur forest division, Kerala, to understand the relationship between climate and tree growth. The work was carried out at the Department of Wood Science, College of forestry, KAU, Vellanikkara, Thrissur. The study samples were selected from the sample collection in the Department of Wood Science, College of Forestry. The collected samples are thinned and sanded with different grades of sand papers to expose the growth rings. Statistical parameters like SNR (Signal to Noise Ratio) and EPS (Expressed Population Signal) showed a good dendroclimatic potential. Weather parameters such as rainfall, temperature and moisture index showed significant positive and negative correlation with Ring Width Index. Summer temperature, showed significant positive correlation and annual temperature showed negative correlation. South West monsoon rainfall showed significant positive correlation. Correlation between Ring Width Index and Moisture Index showed positive correlation during previous year North East monsoon.
Open Access
Crop weather relationship in cauliflower (Brassica oleracea var.botrytis L.)
(Department of Agricultural Meteorology, College of Horticulture, Vellanikkara, 2012) Karthika, V P; KAU; Prasada Rao, G S L H V
A field experiment was conducted during 2010-11 and 2011-12 at the Department of Agricultural Meteorology, College of Horticulture, Vellanikkara with the objectives to study the effect of weather on growth and yield of cauliflower and to assess the suitability of cauliflower under various crop growing environments. The study included five planting times at an interval of 15 days (1st November, 15th November, 1st December, 15th December and1st January) and two tropical hybrid varieties (Basant and Pusa Kartik Sankar). The different growth and yield characters like plant height, number of leaves, plant biomass, duration of different growth stages and curd weight were recorded along with monitoring of the incidence of various pests, diseases and physiological disorders. The daily weather parameters like maximum and minimum temperatures, forenoon and afternoon relative humidity, forenoon and afternoon vapour pressure, bright sunshine hours, wind speed, rainfall and rainy days were collected and used in this study. Based on these weather parameters, other important weather variables like mean temperature, diurnal temperature range, forenoon and afternoon vapour pressure deficits and solar radiation were determined. Various heat units like growing degree days, heliothermal units and photothermal units were also worked out. The maximum and mean temperature, diurnal temperature range, forenoon and afternoon relative humidity, forenoon and afternoon vapour pressure deficits, bright sunshine hours and solar radiation were found to be higher in 2010-11 as compared to 2011-12. Plant height, number of leaves and the duration of different growth stages were found to be highly variable among the different planting times in both the years, but when pooled over years, these characters became non-significant (except the duration from curd initiation to harvest) with respect to the planting time as a result of the higher variability between the two years for the different weather parameters. The curd weight and the plant fresh and weights exhibited high significant difference for the different planting times. Duration from transplanting to curd initiation was found to be more critical for the curd yield. To determine the critical weather elements affecting the crop growth, correlation analysis was done and it was observed that the crop duration would increase with increase in the maximum temperature, bright sunshine hours, solar radiation and afternoon vapour pressure deficit whereas, the afternoon relative humidity showed a negative influence on crop duration. The curd yield and plant weight were found to be decreasing with increase in the maximum temperature and sunshine hours. The various heat units exhibited positive correlation with the duration of different growth stages. Based on the weather parameters experienced by the crop during the transplanting to curd initiation period, a regression equation with an R2 value of 0.95 was developed to predict the curd weight. The present study revealed that first fortnight of November is the optimum planting time for tropical cauliflower in Thrissur District, since the maximum curd size was obtained when planted on 1st November in 2011-12. The optimum weather for the planting of tropical cauliflower was observed to be less than 31.2°C of maximum temperature, less than 26.8°C of mean temperature, less than 8.8°C of diurnal temperature range, less than 6.0 hrs of bright sunshine hours and less than 22.3 MJ m-2 of solar radiation, with 22.5°C of minimum temperature. Intermittent rainfall and higher relative humidity observed during the earlier planting times were found to be conducive for the incidence of pests and diseases and the bacterial disease black rot was observed as a serious threat to cauliflower cultivation in this region.
Open Access
Validation of ceres model to calibrate the genetic coefficients of rice (Oryza sativa L.)
(Department of Agricultural Meteorology, College of Horticulture, Vellanikkara, 2015) Arjun, Vysakh; KAU; Ajithkumar, B
Rice (Oryza saiva L.) is vulnerable to unfavourable weather events and climate conditions. Despite technological advances such as improved crop varieties and irrigation systems, weather and climate are important factors which play a significant role in rice production. The present investigation “Validation of CERES model to calibrate the genetic coefficients of rice (Oryza sativa L.)” was carried out in the Department of Agricultural Meteorology, College of Horticulture, Vellanikkara during 2013-15, to determine the crop weather relationship, to validate the CERES (Crop Environment Resource Synthesis) -Rice model and to calibrate the genetic coefficients for rice. The field experiment was conducted at Agricultural Research Station, Mannuthy during the kharif season of 2014. Split plot design was adopted with five dates of planting viz., 5th June, 20th June, 5th July, 20th July and 5th August as the main plot treatments and two varieties viz., Jyothi and Kanchana as the sub plot treatments. The number of replications for the experiment was four. Different growth and yield characters viz., plant height, dry matter accumulation, number of panicles, spikelets, filled grains, 1000 grain weight, grain yield, straw yield and duration of different crop growth phases were recorded. The daily weather parameters like maximum and minimum temperatures, forenoon and afternoon relative humidity, forenoon and afternoon vapour pressure deficits, bright sunshine hours, pan evaporation, wind speed, rainfall and rainy days were recorded during the entire crop growing period, to determine the crop weather relationship. The maximum temperature showed an increasing trend towards the late plantings. The minimum temperature, afternoon and forenoon relative humidity, rainfall and rainy days were found to be higher in early planting dates compared to late plantings. Plant height, dry matter accumulation, yield and yield attributes were highly variable among the different planting dates. Yield and yield attributes were influenced by various weather parameters experienced by the crop during different dates of planting. Days taken to complete maturity got reduced with delay in planting dates in both the varieties. Jyothi variety took more days to complete different phenophases, compared to Kanchana. The highest yield in Jyothi was recorded for June 5th planting, whereas June 20th planted crop recorded highest yield in Kanchana. The various growth indices such as leaf area index, leaf area ratio, leaf area duration, absolute growth rate, crop growth rate, net assimilation rate and relative growth rate were worked out to study the crop growth and development. During the early growth stages, these growth indices showed an increasing trend and decreasing trend was noticed in the later stages. To determine the critical weather elements affecting the crop growth, correlation analysis was performed. It was observed that crop duration decreased with increase in temperature and bright sunshine hours, whereas, the forenoon and afternoon relative humidity, rainfall and rainy days showed positive influence on crop duration. Multiple linear regression equations were fitted, to predict the grain yield based on weather variables. A crop model can simulate the actual system of field in the lab. CERES-Rice model has been widely used to understand the relationship between rice and its environment. Crop performance in terms of genetic coefficients used in the model can be used as a tool for strategic decision making. The crop genetic coefficients that influence the occurrence of developmental stages in the CERES-Rice models were derived and validated, to achieve the best possible agreement between the simulated and observed values. Calibration was done with independent data sets of two rice varieties viz., Jyothi and Kanchana for different genetic coefficients, which characterize the performance of the crop. The results of simulation studies in respect of phenophases and yield of rice were compared with the observed values. Root Mean Square Error (RMSE), Mean Absolute Percentage Error (MAPE) and D-stat (index of agreement) were used as model accuracy measures. Predicted yield and phenology of both rice varieties, Jyothi and Kanchana under different planting dates were reasonably close to the observed values, as indicated by the RMSE, MAPE and D-stat values.
Open Access
Impact of climate change on rice production
(Department of Agricultural Meteorology, College of Horticulture, Vellanikkara, 2015) Gangaraju, Subramanyam; KAU; Sunil, K M
The impacts of climate change on agriculture are global concerns and for that matter India, where agriculture sector alone represents 23 per cent of India’s Gross National Product (GNP) and the livelihood of nearly 70% of the population is exposed to a great danger, as the country is one of the most vulnerable countries to climate change. Climatic changes are already exerting a considerable drag on yield growth (Lobell et al., 2011). Future impacts of climate change on rice yield in India would likely be larger than the historical ones (Auffhammer et al., 2012). Objectives of the study were 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 2014-15 at RARS, Pattambi in two varieties (Aathira and Vaisakh) with nine dates of planting. The results of the study showed the effect of weather parameters on biometric characters varied significantly with variety and time of planting. Both the varieties recorded the maximum plant height (Aathira is 133 cm and Vaisakh is 145.33 cm) when planted on June 1st and maximum LAI during June 15th. The highest grain yield of variety Vaisakh was recorded by the crop planted on January 1st (6.30 t ha-1). Whereas in Aathira crop planted on Oct 30th (5.86 t ha-1) recorded the highest yield. In both the varieties minimum temperature above 24.0°C in the panicle initiation to flowering stage has reduced the yields. Maximum temperature above 32.0°C during tillering stage will negatively influence the biomass accumulation. Multiple Regression equations were developed for predicting grain yield, leaf area index and duration. DSSAT model was validated and it was given good RMSE values for both the varieties (Aathira 515.6 kg ha-1, Vaisakh 377.75 kg ha-1). The simulation analysis as per the projected climatic scenarios for the periods 2030s, 2050s and 2080s indicate that among the two varieties, variety Aathira will perform better in the first crop season. Vaisakh, an upland variety, tolerant to temperature and drought, the performance is better under third crop season. The most alarming finding of the study is the huge reduction in yield during the second crop season, which is considered as the major rice growing season of Kerala. In RCP 4.5, which is the most likely scenario for India, the yield reduction will be 35 per cent, 38 per cent and 43 per cent during 2030s, 2050s and 2080s respectively in case of variety Aathira, the yield reduction will be 21 per cent, 40 per cent and 47 per cent during 2030s, 2050s and 2080s respectively for Vaisakh, during the second crop season.
Open Access
Simulation of environmental and varietal effects in rice using ceres model
(Department of Agricultural Meteorology, College of Horticulture, Vellanikkara, 2014) Naziya; KAU; Ajithkumar, B
The present investigation on “Simulation of environmental and varietal effects in rice using CERES model” were carried out in Department of Agricultural Meteorology, College of Horticulture, Vellanikkara during 2012-13 to determine the crop weather relationship, to calibrate the genetic coefficient and simulation of phenology, growth and yield of Jyothi and Kanchana varieties of rice. The experiment was laid out in split plot design with four replications at Agricultural Research Station, Mannuthy during the Kharif season of 2013. Five dates of planting was assigned as a main plot treatment viz., 5th June, 20th June, 5th July, 20th July and 5th August with two varieties (Jyothi and Kanchana) as sub plot treatment. The different growth and yield characters like plant height, leaf area index, dry matter accumulation,1000 grain weight, grain yield, straw yield, number of panicles, spikelets, filled grains and duration of different growth phases were recorded along with monitoring the incidence of various pest and diseases. The daily weather parameters like maximum and minimum temperatures, forenoon and afternoon relative humidity, forenoon and afternoon vapour pressure deficits, bright sunshine hours, evaporation, wind speed, rainfall and rainy days were determined. The minimum temperature, afternoon and forenoon relative humidity, rainfall, rainy days, bright sunshine hours and evaporation were found to be higher in early planting dates compared to late plantings. Plant height, leaf area index, dry matter accumulation, yield and yield attributes were highly variable among the different planting dates. Yield and yield attributes were influenced by various weather parameters experienced by the crop during different dates of planting. Days taken to complete maturity were reduced with each successive delay in planting dates in both the varieties. Genotypic variations are found between the varieties but days taken for each phenophases were found to be similar. June 5th and July 20th planting recorded the highest yield in Jyothi whereas June 20th and July 5th planting gave highest yield in Kanchana. Jyothi was found to be superior to Kanchana during the crop season. To determine the critical weather elements affecting the crop growth, correlation analysis was done and it was observed that crop duration would decrease with increase in temperature and bright sunshine hours whereas, the forenoon and afternoon relative humidity, rainfall and rainy days showed a positive influence on crop duration. Multiple linear regression models were fitted, to predict the grain yield based on weather variables. The crop genetic coefficients that influence the occurrence of developmental stages in the CERES-rice models were derived, to achieve the best possible agreement between the simulated and observed values. Calibration was done with the independent data sets of two rice varieties viz. Jyothi and Kanchana for different genetic coefficients, which characterize the performance of the crop. The performance of the CERES-rice simulation model was tested and evaluated using the calibrated genetic coefficients for both the varieties with their respective planting dates. The results of simulation studies in respect of phenophases and yield of rice were compared with the observed values from the field experiment. Root Mean Square Error (RMSE) and D- stat (index of agreement) were used to evaluate the model performance and found that predicted yield of both rice varieties Jyothi and Kanchana under different planting dates were reasonably close to the observed values.

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