Thumbnail Image

Kerala Agricultural University, Thrissur

The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively. Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively. On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs. In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc. During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU). Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.

Browse

2012 - 201924
Reset filters
Subject: Agricultural Meteorology × End date: 2019 × Start date: 2010 × Type: Thesis × Thesis Type: M.Sc ×
Reset filters

Search Results

Now showing 1 - 9 of 24
  • Thumbnail Image
    ThesisItemOpen Access
    Carbon sequestration potential of selected seaweeds of Thikkodi, Kerala
    (Academy of Climate Change Education and Research, Vellanikkara, 2019) Saranya, M S; KAU; Vinod, K
    The coastal blue carbon is the carbon sequestered by mangrove, tidal marshes, seagrasses and macroalgae which account for less than 0.5% of the seabed. Unlike, other blue carbon sectors (mangroves, tidal marshes and seagrasses), the macroalgae do not have sedimentary substratum. The macroalgae are commonly known as seaweeds. The ‘seaweeds’ as the name suggest is not an unwanted plant or weed. It has an important role in the marine ecosystem by acting as a sink for carbon emissions. The present study is based on the carbon sequestration potential of selected seaweeds of Thikkodi coast, Kerala. The state of Kerala has a long coastline of about 580 km, ranking only third among all the maritime states of the country. Some of these coastline stretches are pegged with areas of seaweed resources. The Thikkodi coast (11º28’30.8” N, 75º37’04.5”E) in the Kozhikode district of Kerala is well known for its rocky intertidal coast with a luxuriant growth of seaweeds of diverse species. An extensive study of seaweeds and their species diversity was carried out for a period of one year from September 2018 to August 2019 along the Thikkodi coast of Kerala. A total of 40 species of seaweeds were recorded which belonged to 23 genera, 18 families and 14 orders. A total of 19 species belonged to Chlorophyta, while 12 species belonged to Rhodophyta and 9 species belonged to Phaeophyta. The distribution and seasonal abundance of different species along the Thikkodi coast was also studied. The biodiversity indices were studied using PRIMER (Plymouth Routines in Multivariate Ecological Research). The biodiversity indices such as Shannon-Wiener diversity (H’), Pielou’s evenness (J’), Margalef species richness (d) were calculated. The seaweeds collected from Thikkodi coast were used to carry out the carbon sequestration potential studies. While comparing the three zones, the highest value of species richness (S) was obtained in zone 1 (S=14.00), followed by zone 2 (S=8.75) and zone 3 (S=7.08). The Margalef’s index (d) which incorporates the number of individuals (N) and species (S) was the highest in zone 1 (2.10), while it was minimum in zone 3 (1.08). The equitability or individuals among the different species showed much variation between the zones and the values ranged from 0.67 (zone 2) to 0.77 (zone 1). In the present study, the Shannon Wiener Index (H’) showed wide variation between the zones ranging from the lowest value of 1.33 (zone 3) to the highest value of 1.99 (zone 1). The Simpson Index (1-Lambda’) showed variations in values ranging from 0.66 (zone 3) to 0.82 (zone 1). The experiments were conducted on selected seaweeds particularly Gracilaria corticata, Caulerpa scalpelliformis and Caulerpa peltata. Carbon dioxide was dissolved in seawater at different concentrations using a soda maker by adjusting the fizz. After determining the initial CO2, the seaweeds were incubated in 125ml light bottles under a water column of 50-60cm for 2 hours. The initial CO2 concentration (mg/l) and the CO2 utilization were examined by titrating the seawater against 0.5N Sodium hydroxide solution using Phenolphthalein indicator. The Gross Primary Production (GPP) and Net Primary Production (NPP) were also estimated. For Gracilaria corticata, the utilization efficiency increased from 33.33% to 83.33% in lower CO2 concentration of 26.4mg/l and 79.2mg/l respectively. For Caulerpa scalpelliformis, the utilization efficiency increased from 25% to 42.86% in a lower CO2 concentration of 17.6mg/l and 30.8mg/l respectively. For Caulerpa peltata, the utilization efficiency increased from 66.67% to 75% in a lower CO2 concentration of 13.2mg/l and 35.2 mg/l respectively. When the concentration of CO2was increased beyond a threshold level, the CO2 utilization efficiency decreases and cease down to zero .Same is the case for productivity. Therefore the study implies that the carbon sequestration potential of different species of seaweeds varies. The macroalgae have a greater potential to act as carbon sink and based on the sequestration potential of seaweeds, selection of different species of seaweeds can be made possible for developing Seaweed Aquaculture Beds (SABs). The SABs provide important structure in coastal ecosystem and play an incredible role in climate change mitigation aspects.
  • Thumbnail Image
    ThesisItemOpen Access
    Study the impact of abiotic stress on photosynthetic potential of tropical tuber crops under elevated CO2
    (Academy of Climate Change Education and Research, Vellanikkara, 2019) Ancy, P; KAU; Nameer, P O
    Climate change and agriculture are interconnected processes, both of which take place on a universal scale. Global warming is expected to have significant impacts on agriculture. Most of the studies reported a positive impact in photosynthetic rate of C3 plants due to eCO2. However other players of climate change such as drought and rising temperature can harmfully affect crops. Cassava and sweet potato are two major tropical root crops grown in India. The main objective of the present study was to figure out the impact of adverse conditions of climate change such as water deficit stress and high temperature stress on photosynthetic potential of tropical tuber crops under elevated CO2 and there by identify crop/varieties suitable for changing climate conditions. The study was conducted during the period of October 2018 to July 2019 on four contrasting cassava and four contrasting sweet potato varieties. Observations on photosynthetic parameters viz., the net photosynthetic rate (Pn), stomatal conductance (gs) transpiration and sub-stomatal/intercellular CO2 concentration (Ci) were recorded using a LI6400 portable photosynthesis system, LI-COR Inc, Lincoln, USA. Elevated CO2 have positive effects on photosynthetic parameters under WDS free as well as WDS conditions in cassava as well as sweet potato. Even though WDS reduces photosynthetic rate, eCO2 could sustain greater Pn rate than ambient CO2 under WDS. Under eCO2 rising temperature can benefit cassava and sweet potato only under WDS free conditions. For cassava Pn was not significantly affected by temperatures. For sweet potato Pn significantly increased with rise in temperature. It indicates that increasing temperature is not a limiting factor for cassava and sweet potato, but beneficial for them under WDS free conditions. Responses of cassava and sweet potato to WDS and rising temperature are also influenced by the variety. Cassava variety Sree Athulya responses well to eCO2 as well as to rising temperature under WDS free conditions. Cassava variety Sree Vijaya can perform well under WDS compared to other varieties. Sweet potato variety Sree Arun exhibits higher Pn under WDS free conditions. Bhu Krishna and Kanhangad had high Pn under WDS as well as at higher temperature. From this study it can be concluded that tropical root and tuber crops especially cassava and sweet potato have a great potential for better adaptation at elevated CO2 environment under adverse climate conditions such as water deficit stress and increasing temperature. They can become crops providing food security for future environment under climate change.
  • Thumbnail Image
    ThesisItemOpen Access
    Crop weather relationship studies in finger millet (Eleusine coracana (L.) Gaertn) in central zone of Kerala
    (Department of Agriculture Meteorology, College of Horticulture, Vellanikkara, 2019) Anunayana John, T; KAU; Ajithkumar, B
    Finger millet (Eleusine coracana (L.) Gaertn) is an important food crop next to rice, wheat and maize. The crop is native to Africa. Finger-millet is capable to withstand three stresses such as warming stress, water stress and nutrition stress, so it is called as Climate Change Compliant Crop (CCCC). These attributes combine to make finger millet a suitable crop for ensuring food security in drought prone areas of the countries. The present study was done to estimate the crop weather relationship in finger millet (var : GPU-28) in central zone of Kerala and to identify the ideal date of planting and best crop establishment method during 2018. The field experiment was conducted at experimental field of Instructional Farm, College of Horticulture during the kharif season of 2018. Split plot design was adopted with five dates of planting viz., May 15th, June 1st, June 15th, July 1st and July 15th as the main plot treatments and three planting methods viz., broadcasting, dibbling and transplanting as the sub plot treatments with number of replications as three. Considering the weather observations, the daily observations of weather recorded during the crop period like maximum, minimum and mean temperature, rainfall and relative humidity showed considerable variations especially during the mid-growth period. Heat units like Growing Degree Days (GDD), Heliothermal Units HTU) and Photothermal Units (PTU) were also calculated for the crop growth period. Growth and yield attributes like plant height, dry matter accumulation, number of ear heads, finger number per ear head, finger length, thousand grain weight, grain yield, straw yield, harvest index and the duration of different phenophases were also noted. Growth indices such as crop growth rate and relative growth rate were worked out to analyze the growth and development of the crop. Micrometeorological and weeds observations were also made. Correlation analysis was carried out using the weather parameters, yield and phenological data to estimate the crop weather relationship in finger millet. The results shows that maximum temperature was showing a negative correlation, while relative humidity, vapour pressure deficit and rainfall was showing positive correlation in most of the yield and yield contributing factors. Considering the micro meteorological observations, June 1st planting showed the highest values for both forenoon and afternoon soil temperature. Highest soil moisture was observed in broadcasting method of planting at 15cm depth and it did not show any considerable variations with respect to date of planting. Weed intensity and dry weight was shown higher during the dibbling method of planting. ABSTRACT Plant height was found to be higher for dibbling method of planting at 60 days after sowing and May 15th planting showed the higher values which was on par with June 15th planting. Dates of planting had significant effect on the dry matter accumulation which showed higher values for June 15th planting which was on par with June 1st planting at harvest in broadcasting method. Crop growth rate showed an increasing trend during the vegetative phases and there after followed a decreasing trend up to harvest, while relative growth rate showed a gradual decreasing trend from mid-growth period. Duration of phenophases was similar for both broadcasting and dibbling method, while transplanting took comparatively more days to attain each stages. Duration also showed a decreasing trend with delay in date of planting. Heat indices like GDD and PTU followed a decreasing trend with delay in date of planting which indicates their positive impact on the growth and yield performance of finger millet. Considering the yield attributes like number of ear heads m-2, it showed higher values for transplanting method in May 15th planting. Finger number per ear head was higher for June 1st planting which was on par with both May 15th and June 15th planting. Highest finger number per ear head was attained for transplanting method which was on par with dibbling method of planting. Finger length showed the highest value in May 15th planting which was on par with June 1st planting. Date of planting showed significant effect on the straw yield as it was higher in May 15th planting and was lower in July 1st planting which was on par with July 15th planting. Harvest index attained higher values for July 1st planting which was on par with July 15th and June 1st planting. Interaction effect of the treatment combination of May 15th planting with transplanting method attained the highest grain yield (2833.3 kg ha-1) compared to other methods. Assessment of cost of cultivation revealed dibbling method showed highest value while it was lowest in broadcasting method. But the B:C ratio was highest in transplanting and the lowest was observed in dibbling method of planting. This revealed that transplanting method not only encourages yield production, but also economically feasible compared to broadcasting and dibbling methods. So the present investigation on the crop weather relationship in finger millet suggested that the positive contribution of various weather and micrometeorological parameters like relative humidity, vapour pressure deficit, rainfall, forenoon and afternoon soil temperature etc. and the reduced maximum temperature and temperature range which increased the production of number of ear heads, finger number per ear head, increased finger length, straw yield etc. This ultimately leads to increased grain yield in May 15th and June 1st date of planting. In case of the three planting methods, studies suggested that transplanting can be considered as best establishment method for finger millet cultivation in central zone of Kerala.
  • Thumbnail Image
    ThesisItemOpen 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.
  • Thumbnail Image
    ThesisItemOpen 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.
  • Thumbnail Image
    ThesisItemOpen 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.
  • Thumbnail Image
    ThesisItemOpen 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.
  • Thumbnail Image
    ThesisItemOpen Access
    Climate change impact on crop water requirement of rice in Thrissur district
    (Academy of Climate Change Education and Research, Vellanikkara, 2016) Basil, Abraham; KAU; Kurien, E K
    Rice crop occupies a major position in the agricultural production in Kerala State. Under the present climate change scenarios the climatic parameters are subject to variations and that in turn will affect the water requirement of the crop. A great stress on the irrigation reservoirs and projects for additional water to be released will be effected. It was attempted to generate the climate data for 2030, 2050, 2080 under IPCC emission scenarios RCP.45.The crop water requirement for rice was calculated under the predicted climate for Thrissur district using CROPWAT model. The minimum temperature in the district were found to increase during the future years. The maximum temperature also showed an increasing trend through the future years. The summer months January – March were found to remain as the hot months during the predicted years. The solar radiation was also found to increase. The average annual rain fall for Thrissur district was found to vary as 3139.1, 3089.8 and 3307.6 mm for the future years of 2030, 2050, 2080. The onset of south west monsoon may become early. The summer rains will continue to give a good amount of rain fall through the future years. There will be a reduction in the post monsoon rain fall and a poor distribution of rain fall over the district. The crop evapotranspiration in all the three rice growing seasons of virippu, mundakan and punja was found to increase under the predicted scenario. Crop evapotranspiration was found to increase from 49.99 mm during 2015 to 61.27 mm during 2080 in the first crop season (virippu). During the second and third crop season (mundakan and punja) crop evapotranspiration varied from 56.53 mm to 82.17 mm and 77.06 mm to 83.17 mm respectively. When compared to the year 2050 the irrigation water demand was found to decrease during the year 2080. During the first crop season the irrigation water demand will increase to 319.6 mm in the year 2050 and later during 2080 it was found to decrease to 265.6 mm. There will be a considerable increase in the water requirement during the second crop season during 2050’s and 2080’s when compared with the present day demand. It was also indicated that under RCP 4.5 scenario the water demand to the rice crop during second crop season will be more by 100 mm of water.The crop water use efficiency was found to decrease during future years. An additional amount of 200 billion litres of water will be required for meeting increased water requirement during the second crop season for irrigating rice. The requirement for the third crop season will be high as 750 billion litres.
  • Thumbnail Image
    ThesisItemOpen 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.