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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.
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ThesisItem Open Access Effect of foliar application of selected micronutrients and growth regulators on tuber development , yield and fortification status of sweet potato (Ipomoea batatas L.).(Department of Plant Physiology , College of Agriculture,Vellayani, 2019) Arya, S R; KAU; Viji, M MA field experiment entitled “ Effect of foliar application of selected micro nutrients and growth regulators on tuber development, yield and fortification status of sweet potato (Ipomoea batatas L.)” was conducted at the Instructional farm, College of Agriculture, Vellayani during the period 2017-2019 with an objective to enhance the qualitative and quantitative attributes in sweet potato (Ipomoea batatas L.). Foliar application of selected micronutrients and growth regulators were carried out to study their effect on growth, development and changes in fortification status of sweet potato tubers and leaves. The sweet potato variety used for the experiment was Bhu Krishna. The technical programme consisted of 17 treatments and 3 replications with the design simple RBD. The treatments were C1 : NPK (as per POP) , C2 : NPK (as per POP) with water spray, T1 : C1+ FN (MN mixture( * ) 0.01% each , T2 : C1+ FN (MN mixture( * ) 0.05% each , T3 : C1+ FN (MN mixture( * ) 0.1% each , T4 : T1+ Ethrel 250 ppm , T5 : T1+ Ethrel 500 ppm , T6 : T1+ CCC 250 ppm , T7 : T1+ CCC 500 ppm , T8 : T2+ Ethrel 250 ppm , T9 : T2+ Ethrel 500 ppm , T10: T2+ CCC 250 ppm , T11: T2+ CCC 500 ppm, T12: T3+ Ethrel 250 ppm , T13: T3+ Ethrel 500 ppm , T14: T3+ CCC 250 ppm and T15: T3+ CCC 500 ppm [*MN mixture (Zn+Fe+B+Mn)]. Except C1, for all other treatments foliar sprays were given 3 times ie. at 30 days interval(30 DI). All the biometric and physiological parameters were taken at 25th,50th,75th and 100th days after planting and the quality parameters were taken at harvest. The results revealed that the micronutrients and growth regulators had significant influence on most of the biometric parameters, physiological parameters as well as quality parameters. Tuber characters such as tuber length, tuber diameter, tuber weight and tuber yield were found to be best in plants under the treatment T15 (T3+ CCC 500 ppm at 30DI) and it was on par with T13(T3+Ethrel 500ppm). Branch length (155.50cm), shoot weight (612 g) and specific leaf area (389.44 cm2 g-1) were found to be best in plants under the treatment T3(C1+ FN (MN mixture( * ) 0.1% each at 30DI). Number of leaves also were found to be higher in T3 (91.33) and it was on par with T2, T13 and T15. Cycocel and ethrel are growth retardants and they were found to have dwarfing effect on plants and hence shoot length and shoot weight did not increase in the treatments, T15(T3+ CCC 500at 30DI) and T13(T3+ Ethrel 500 ppm at 30DI) and on the other hand the number of leaves got positively influenced in both these treatments T15 and T13. Except transpiration rate all physiological parameters viz., total chlorophyll content (2.25 mg g-1), caroteinoid content (0.87mg g-1), stomatal conductance (131.33 mmole H2O m-2 s-1), photosynthetic rate (4.49 µmole CO2 m-2 s-1) and water use efficiency (5.35 mmol CO2 mol-1 H2O) were found to be best in plants under the treatment T15 (T3+ CCC 500 ppm) and T13 was on par with T15 in all these physiological parameters studied. Mineral constituents; N (0.614 %), P (0.056%), K (0.489%),Fe (16.30 mg kg-1), Zn (15.07 mg kg-1), Mn (7.37 mg kg-1) and B (1.27 mg kg-1) as well as other quality parameters like total phenol (13.33mg g-1), total sugar (34.48 mg g-1) and protein content (38.40mg g-1) were found to be higher in tubers under the treatment T15 (T3+ CCC 500 ppm) followed by treatment T13 which is considered as the second best treatment with respect to mineral content in tubers. Overall, the combined treatments of micronutrients along with growth regulators were found most effective in influencing quality parameters. Treatment T15 (ie.,NPK as per POP along with foliar nutrition of micronutreint mixture (Fe+Zn+Mn+B @ 0.1% each ) + cycocel (500ppm) at 30 days interval ) was found to be the best in terms of improving both the quantitative and qualitative attributes in sweet potato. Hence it is concluded that the treatment T15 improved the growth and development of plants, physiological parameters of leaves, tuber yield as well as fortification status of sweet potato tubers. Thus this study helped in identifying the best treatment combination of micronutrients and growth regulators for improving growth, development, yield and fortification status in sweet potato.ThesisItem Open Access Developing high temperature tolerance in tomato (Solanum lycopersicum L.) through selective fertilization technique(Department of Plant Physiology, College of Agriculture, Vellayani, 2019) Ammu, Alphonsa John; KAU; Roy StephenThe study entitled “Developing high temperature tolerance in tomato (Solanum lycopersicum L) through selective fertilization technique”, was undertaken with the objectives to identify the critical temperature for pollen germination and to evaluate the selectively fertilized tomato hybrids for high temperature tolerance at the Department of Plant Physiology, College of Agriculture, Vellayani during 2017-2019. The first experiment was designed for the identification of critical temperature for pollen germination using five popular varieties of tomato namely Anagha, Vellayani Vijay, Manuprabha, Manulakshmi and Akshaya. Mature pollen grains from fully opened flowers were collected and incubated at different temperatures (340C to 440C) for two hours in the pollen germination medium. The design followed was CRD with 4 replications. The temperature of 36oC was identified as the critical temperature for pollen germination. Anagha and Manuprabha exhibited the highest (29.69 %) and the least (11.48 %) pollen germination percentage respectively at this critical temperature. Pollen viability decreased with increase in temperature in all the five varieties. For the second experiment, the variety Anagha with the highest pollen germination at critical temperature was selected as tolerant (male parent) and the variety Manuprabha with least pollen germination at critical temperature was selected as the susceptible (female parent). Selective fertilization (SF) was done between Anagha and Manuprabha by pollinating the emasculated female parent with 2hr incubated pollen from male parent at critical temperature. Another set of cross was also made with same parental combination without pollen selection. The six crosses were made are Tolerant X Susceptible, Tolerant X Susceptible (SF), Tolerant X Tolerant, Tolerant X Tolerant (SF), Susceptible X Susceptible and Susceptible X Susceptible (SF). The seeds were collected from crosses and sown. The seedings were maintained at ambient temperature for 30 days and then transplanted in pots and exposed to three different temperature conditions ie, at ambient temperature condition, Rainout shelter (ROS) and Open top chamber (OTC) to evaluate the growth performance of the crosses. The observations were taken at 30 and 60 days after transplanting. The experiment was laid out with 18 treatments in CRD with four replications. Plant height and floral characters (number of flower clusters and number of flowers per cluster) were increased significantly with increase in temperature. Among the crosses, T15 recorded taller plants (127.32 cm). Selectively fertilized plants produced significantly more number of flowers per cluster than the normal crosses and T12 recorded maximum (11.00). However, the number of cluster was significantly higher in normal crosses and T15 had maximum number of cluster (45.50). Percentage of flowers with exerted stigma and length of stigma exertion were increased significantly with increase in temperature but the selectively fertilized crosses recorded lower stigma exertion. T15 showed the highest percentage stigma exertion (87.50%) which was at par with T3, T6, T9, T12 and T18. The length of exerted stigma was highest in T15 (2.50mm). Physiological parameters like photosynthetic rate, chlorophyll content, total soluble protein and relative water content decreased significantly with increase in temperature and the selectively fertilized crosses showed higher value than the normal crosses under higher temperature. The photosynthetic rate (17.40 µmol CO2 m-2 s-1) and chlorophyll content (1.91 mg g-1) was recorded higher in T7 which was at par with T1, T4, T10 and T11. In case of total soluble protein there was no significant difference. The relative water content was highest in T4 (74.80%) but at par with T1, T7 and T10. Carbohydrate content decreased with increasing temperature and among the crosses selectively fertilized plants showed significantly higher content. The carbohydrate content was the highest in T8 (79.62 mg g-1) but at par with T5. Temperature tolerance characters like membrane integrity (% leakage), SOD activity and chlorophyll fluorescence were higher in selectively fertilized plants than the normal plants. The percentage leakage increased with increase in temperature and T10 had the least leakage (1.40 %). The SOD activity first decreased and then increased with temperature and T5 exhibited maximum SOD activity (337.50 activity mg-1 min-1) which was at par with T2 and T8. The chlorophyll fluorescence significantly decreased with increase in temperature, the maximum fluorescence recorded in T4 (0.65 fv/fm) which was at par with T1, T7, T10, T16 and T5. Ascorbic acid content of leaves increased significantly with increase in temperature but decreased under OTC. T5 (464.65 µg g-1) and T18 were on par with respect to ascorbic acid. The yield characters like number of fruits, fruit setting %, fruit weight and lycopene content were high in selectively fertilized crosses than the normal crosses. The yield characters decreased significantly with increase in temperature and there was no fruit set at OTC due to very high temperature. T10 recorded highest number of fruits per cluster (6) which was at par with T7 and T1. The fruit setting percentage was the highest in T7 (89.29%) which was at par with all treatments except T2 and T14. The fruit weight increased in ROS condition compared to ambient condition and the highest fruit weight was recorded in T17 (37.77g) which was at par with T16, T5 and T14. Highest lycopene content was recorded in T10 (24.86 µg g-1). The yield was decreased significantly with increase in temperature and the highest yield was obtained in T4 (402.15 g plant-1) which was at par with T4, T7 and T10. Critical temperature for pollen selection and selective fertilization was selected as 360 C. Anagha exhibited higher germination percentage and pollen viability at critical temperature among the five varieties of tomato tested and Manuprabha had the least pollen germination. Selective fertilization technique was found to have an advantageous influence on the physiological and yield attributes as it increased the photosynthetic efficiency and high temperature stress tolerance. Selective fertilization of cross of tolerant and susceptible parent TXS (SF) was found to be the best performing type under high temperature condition.ThesisItem Open Access Impact of foliar application of plant growth regulators and nutrients on high temperature stress mitigation in rice (oryza stavia L)(Department of Plant Physiology, College of Agriculture,Vellanikkara, 2019) Raghunath, M P; KAU; Beena, RThe study entitled “Impact of foliar application of plant growth regulators and nutrients on high temperature stress mitigation in rice (Oryza sativa L.)” was conducted in the Department of Plant Physiology, College of Agriculture, Vellayani during August to December of 2018 with the objectives to study the effect of foliar application of plant growth regulators and nutrients on high temperature mitigation and to advance the flowering time by using methyl jasmonate (MeJA) in rice. The investigation comprised two experiments. The extent of variation for various physiological, biochemical, morphological and yield parameters were assessed as an indicator of high temperature stress mitigation by using plant growth regulators and nutrients. The rice variety (Uma) utilized in the experiment was collected from IFSRS, Karamana. Plants were maintained under high temperature condition in a temperature controlled polyhouse from seedling to maturity stage with three replications. Maximum and minimum temperatures were measured daily using a thermo-hygrometer. The first experiment was laid out in CRD with 10 treatments [Brassinosteroid (BR)-50 ppm, Boron (B)-100 ppm, Calcium chloride (CaCl2)-0.6 per cent, Salicylic acid (SA)-50 ppm, Glycine betaine (GB)-20 ppm, Pink- Pigmented Facultative Methylotrophs (PPFM)-1 per cent, 1-methyl cyclopropane (1-MCP)-50 ppm, Gibberllic acid (GA3)-50 ppm, water spray and control (no spray)] were sprayed at panicle initiation, heading and flowering stage. Physiological observations and yield parameters were recorded at 50 per cent flowering and harvesting stage respectively. The study revealed that physiological and biochemical parameters such as cell membrane stability index (%), photosynthetic rate (μmol CO2 m-2 s-1), stomatal conductance (mmol H2O m-2 s-1) and Fv/Fm ratio were found to increase significantly in most of the treatments under high temperature stress condition, whereas leaf temperature(°C) and transpiration rate (mmol H2O m-2 s-1) decreased. Among the treatments, BR spray significantly increased in the cell membrane stability index (141.57%), photosynthetic rate (17.50 μmol CO2 m-2 s-1), stomatal conductance (583.70 mmol H2O m-2 s-1), Fv/Fm ratio (0.74), chlorophyll stability index (109.32%), chlorophyll a/b ratio (1.28) and superoxide dismutase activity (0.33 activity g-1 min-1). Treatments had significant effect on morphological and yield parameters over control plants. Among the treatments, GA3 spray resulted in significant increase in plant height (142.75 cm) and panicle length (21.33 cm). BR spray significantly increased the productive tillers per plant (10.25), pollen viability (80.23%), spikelet fertility percentage (75.4%) and grain yield per plant (15.87 g). The second experiment was laid out in CRD with 10 treatments. Foliar spray of MeJA in varying concentrations was given on spikelet at different time [2mM L-1 MeJA at 7 am, 2mM L-1 MeJA at 8 am, 2mM L-1 MeJA at 9 am, 4mM L-1 MeJA at 7 am, 4mM L-1 MeJA at 8 am, 4mM L-1 MeJA at 9 am, water spray at 7 am, water spray at 8 am, water spray at 9 am and control (no spray)]. Physiological observations were taken at 50% flowering stage and yield parameters were taken at harvesting stage. The study revealed that among the treatments, 4mM L-1 MeJA at 7 am treatment showed early anthesis (08:11 am) and also significant increase in pollen viability (61.93%), spikelet fertility (56.07%), yield per plant (8.55 g) and 1000 grain weight (21.33 g). In the first experiment there was significant variation for physiological, biochemical, morphological and yield components among treatments. BR treatment recorded high pollen viability, spikelet fertility and grain yield per plant by improving the physiological and biochemical traits such as cell membrane stability index, photosynthetic rate, stomatal conductance, Fv/Fm ratio, chlorophyll stability index, chlorophyll a/b ratio and superoxide dismutase activity. Hence, BR treatment can mitigate the ill effects of high temperature stress in rice. In the second experiment there was significant variation for physiological and yield components among treatments. 4mM L-1 MeJA at 7 am showed better performance for all the parameters such as anthesis time, pollen viability, spikelet fertility, yield per plant and 1000 grain weight. Hence, MeJA can advance anthesis time thereby enabling plants to escape from the severe temperature experienced at normal flowering time.ThesisItem Open Access Physiological studies on growth , yield and quality enhancement of chilli (Capsicum annuam L.) under different nutrient management(Department of Plant Physiology, College of Horticulture, Vellanikkara, 2019) Amrutha, E A; KAU; Sudarsana Rao, VChilli is a very important vegetable crop and has a great demand in the processing industry and export market. Chilli crop is more responsive to fertilizer application. Application of fertilizers in excess not only causes environmental problems but also reduces nutrient use efficiency, increases the cost of production and reduces the benefit-cost ratio. Nanotechnology is a newly emerging tool for solving these problems. Nano fertilizer has a particle size less than 100 nm. Due to its small size and water soluble nature it is easily absorbed by plants. The present study was carried out to understand the influence of soil and foliar application of nano NPK fertilizer and to compare with conventional fertilizers on growth, yield and quality attributes of chilli. The investigation on “ Physiological studies on growth, yield and quality enhancement of chilli (Capsicum annum L.) under different nutrient management ” was conducted at Regional Agricultural Research Station, Pillicode from September, 2018 to February, 2019. The experiment consisted of nine treatments with three replications laid out in randomized block design. The treatments were T1 : Control (soil test based nutrient management); T2 : Nano NPK granules (4:4:4); T3 : T1 + Nano NPK foliar @ 0.5 %; T4 : T1 + NPK 19:19:19 foliar @ 0.5 %; T5 : T2 + Nano NPK foliar @ 0.5 %; T6 : T2 + NPK 19:19:19 foliar @ 0.5 %; T7 : Organic POP (KAU, 2009); T8 : Organic POP + Nano NPK foliar @ 0.5 % and T9 : Absolute control. Nano NPK granules were applied as a basal dose and also as top dressing at 30 and 60 days after transplanting @ 0.33 g/plant. Foliar spray of Nano NPK and NPK 19:19:19 were given at 35, 65, 80 and 95 days after transplanting. Morphological observations namely plant height, leaf area per plant, number of leaves per plant, number of branches per plant, number of fruits per plant and fruit length were recorded to be maximum in the treatment, nano NPK granule with NPK 19:19:19 foliar spray (T6) followed by nano NPK granule with nano NPK foliar spray (T5). Integrated use of nano NPK granules with nano NPK foliar spray application (T5) enhanced the duration of crop and increased the root volume followed by T6 . Higher values of growth indices such as RGR, LAI and total dry matter production was observed in T6 (nano NPK granule and NPK 19:19:19 foliar spray) followed by T5 (nano NPK granules with nano NPK foliar spray). Physiological parameters such as transpiration rate, stomatal conductance, chlorophyll content, leaf relative water content, specific leaf weight, quantum yield (Y(II)), Fv/Fm and electron transport rate (ETR) were statistically on par in all the treatments and was significantly higher than absolute control (T9). Differential application of NPK 19:19:19 foliar spray (T6) and nano NPK foliar spray (T5) along with nano NPK granules increased the fruit yield by 28.07 % and 26.54 % respectively over control (T1). Organic management (T7) alone and organic management with nano NPK foliar spray (T8) recorded 25.54 % and 16.04 % lesser fruit yield than control (T1). However fruit quality parameters like ascorbic acid and oleoresin contents were maximum in the treatment receiving an organic management with a foliar spray of Nano NPK (T8). Maximum benefit cost ratio (1.73) was recorded in treatment T6 (nano granule with 19:19:19 foliar spray) followed by treatment T5 (nano granule with nano NPK foliar spray (1.61) compared to other treatments. The results obtained from the experiments indicated that the application of nano NPK fertilizer both as soil and foliar treatments has a direct positive effect on morphological and yield parameters, which is on par with the treatment involving soil application of nano NPK granules and NPK 19:19:19 foliar spray.ThesisItem Open Access Influence of CO2 enrichment and associated high temperature on reproductive physiology of tomato (Solanum Lycopersicum L)(Department of Plant Physiology, College of Agriculture, Vellayani, 2019) Lakshmi G Ajay; KAU; Manju, R VThe study entitled “Influence of CO2 enrichment and associated high temperature on reproductive physiology of tomato (Solanum lycopersicum L.)”, was undertaken with the objective to study the effect of CO2 enrichment and associated high temperature on flowering and fruiting in tomato and their improvement through growth regulators and nutrient applications and through temperature induction response technique. The experiments were conducted using the Open Top Chamber (OTC) facility at the Department of Plant Physiology, College of Agriculture, Vellayani during 2017-2019. The first part of Experiment I was designed for the standardization of Temperature Induction Response Technique (TIRT) for two popular varieties of tomato namely Vellayani Vijay and Anagha by identifying lethal and induction temperatures. Five day old tomato seedlings grown in petri plates were exposed to different temperatures (35-50 0C) for different durations (1h to 2h). The temperatures of 48oC for 2 h and 38oC (1h)- 43 oC (1h)- 48 oC (2h) proved to be the lethal and induction temperatures respectively for both the varieties based on the recovery responses. In the second part of Experiment I growth performance of temperature induced seedlings of variety Vellayani Vijay was evaluated under elevated CO2 (500 ppm) and ambient conditions. The experiment was laid out in CRD with four replications. Growth parameters like plant height, number of branches and number of leaves were not significantly affected by temperature induction but significantly higher value was recorded in the case of specific leaf area (283.50 cm2 g-1) compared to control (261.83 cm2 g-1). Among the physiological and biochemical parameters, temperature induction resulted in significantly higher values for total chlorophyll content (1.74 mg g-1), total carbohydrate (36.71 mg g-1), photosynthetic rate (22.13 µmol CO2 m-2 sec-1), water use efficiency (4.98 mmol CO2 mol-1 H2O), chlorophyll fluorescence (Fv/Fm) (0.82), relative water content (92.20 %), superoxide dismutase (0.21 activity g-1min-1), chlorophyll stability index (145.97 %) and proline content (1.32 µM g-1 tissue) compared to plants without induction. In the second experiment, flowering and fruiting in tomato under elevated CO2 environment, as influenced by growth regulators and nutrient applications, were evaluated. The experiment was laid out in CRD with eight treatments and three replications. The treatments comprised of 50 ppm NAA (T1), 50 ppm Salicylic acid (T2), 50 ppm Boron (B) (T3), 50 ppm Boron (B) + 50 ppm Zinc (Zn) (T4), as foliar spray (at 40,55 and 75 DAS), nutrient application of POP 125% N: 100% P: 100% K (T5), POP 125% N: 125% P: 125% K (T6), a control (water spray) (T7) and an absolute control (T8). Plant height, number of branches, number of leaves and specific leaf area were found to increase significantly under elevated CO2 condition. Among the treatments, T3 recorded taller plants (85.33 cm). However number of branches (5.50), number of leaves (46.67) were significantly higher in T5. T6 recorded significantly higher value (347.99 cm2 g-1) for specific leaf area. All the physiological and biochemical parameters except transpiration rate and total soluble protein content showed significantly higher values inside OTC. T3 significantly higher values for chlorophyll content (1.55 mg g-1) and chlorophyll stability index (124.88 %) among treatments. T5 recorded highest values for photosynthetic rate (21.62 µmol CO2 m-2 sec-1) and water use efficiency (4.67 mmol CO2 mol-2 H2O). T6 resulted in significantly higher values for chlorophyll fluorescence (0.75), relative water content (96.87 %), superoxide dismutase (0.23 activity g-1 min-1) and peroxidase (44.43 unit min-1 g-1) compared to control. Flowering was delayed under elevated CO2 condition. There was an increase in total number of flower clusters inside OTC. However a significant reduction in pollen viability (82.35 %) was noticed under elevated CO2 conditions. T3 resulted in a higher pollen viability (30.28 %) and fruit setting percentage (38.52 %) compared to control under elevated CO2 condition. Days to fruiting was found to be delayed inside OTC. T7 and T4 significantly increased the fruit weight. T5 resulted in less fruit drop leading to increased number of fruits. Yield per plant was significantly higher for T5 (190.85 g plant-1), T6 (155.21 g plant-1) and T3 (148.29 g plant-1) compared to control (61.83 g plant-1). Under elevated CO2 condition, T5, T4and T3 were found to increase the yield per plant. T3, T1 and T6 resulted in an increase in the lycopene content, thus improving quality of the fruit. In the present study, CO2 enrichment was found to have a deleterious influence on flowering and fruiting in tomato mainly due to reduced pollen viability and floral deformities. TIRT was proved to improve photosynthetic efficiency and stress tolerance mechanism. Foliar spray with 50 ppm B + 50 ppm Zn at 40, 55 and 75 DAS and addition of 25% extra nitrogen than recommended dose in equal splits were found to improve yield and quality to a great extent. This was achieved through improvement in pollen viability, fruit set and individual fruit weight and also through a reduction in fruit drop. These treatments can be exploited further, individually or in combination, in any crop management programme for tomato under increasing CO2 and associated high temperature conditions. The study also highlights a need for reassessment of critical nutrient requirements for individual crops in the changing global climatic scenario.ThesisItem Open Access Physiological approaches for enhancing the ex vitro establishment of tissue cultured orchid (Phalaenopsis sp.)(Department of Plant Physiology, College of Agriculture, Vellayani, 2019) Sayooj, S; KAU; Viji, M MThe study entitled “Physiological approaches for enhancing the ex vitro establishment of tissue cultured orchid (Phalaenopsis sp.)” was undertaken during 2017-2019, at College of Agriculture, Vellayani, Thiruvananthapuram, with the objective to study the physiological changes that occur during ex vitro establishment of orchid Phalaenopsis sp. and to find out measures to overcome the field mortality rate and improve propagation efficiency. The experiment was laid out in completely randomized block design with three replications of ten treatments as well as a control. In vitro derived plantlets of Phalaenopsis sp. obtained from Biotechnology and Model Floriculture Centre, Kazhakuttam were used for the study. Ten treatments were T1 and T2 (plantlet dip with triazole @ 5ppm and 10 ppm respectively), T3 and T4 (plantlet dip with triazole @ 5 ppm + foliar application of triazole @ 5ppm after 15 days of planting and plantlet dip with triazole @ 10 ppm + foliar application of triazole @ 5ppm after 15 days of planting respectively) , T5 and T6 (plantlets providing with 40-50% light intensity & 60-70% humidity and 40-50% light intensity & 80-90% humidity respectively) T7 and T8 (plantlets providing with 70-80% light intensity & 60-70% humidity and plantlets providing with 70-80% light intensity and 80-90% humidity respectively) , T9 (plantlet dip of PGPR mix І -5%) , T10 (root zone application of arbuscular mycorrhizal fungi -5g/plantlet) and a control (C). The crop was maintained in the hardening chamber for 70 days and observations were taken at 15, 30,45 and 60 days of ex vitro transfer. Results revealed that growth regulators, growth stimulants, light and humidity had significant effect on physiological, morphological, biochemical, biometric and anatomical characters during the ex vitro establishment of tissue cultured orchid Phalaenopsis sp. During their ex vitro establishment, physiological parameters like specific leaf area and photosynthetic rate showed significantly higher response at all the four stages of observation, in the treatment provided with 40-50% light intensity and 80-90% humidity (T6) whereas transpiration rate was the lowest in T3 (plantlet dip with triazole @ 5 ppm + foliar application of triazole @ 5ppm after 15 days of planting and plantlet dip with triazole @ 10 ppm). Among the stomatal characters, stomatal index was not significantly affected by growth regulators, light intensity, humidity and growth stimulants. However, highest stomatal frequency was recorded in T3 (plantlet dip with triazole @ 5 ppm + foliar application of triazole @ 5ppm, after 15 days of planting). Plantlets treated with arbuscular mycorrhizal fungi (T10) recorded the highest plant height during 15 and 30 DAP. However at 45 and 60 DAP, plantlets which were provided with 40-50% light intensity and 80-90% humidity (T6) recorded the highest plant height. Number of leaves per plantlet and survival percentage were also found highest in T6. But in the treatment, T3 (plantlet dip with triazole @ 5 ppm + foliar application of triazole @ 5ppm) maximum number of roots was observed at all the four stages of observation. The results also showed that chlorophyll a and total chlorophyll content of the leaves were maximum in T3 whereas in T6, the highest chlorophyll b and carotenoid content were found at all the four stages of observation. Also T3 (plantlet dip with triazole @ 5 ppm + foliar application of triazole @ 5ppm) recorded the highest protein content and carbohydrate content. Leaf area and root length were also found to be significantly higher in T6 (plantlets provided with 40-50% light intensity and 80-90% humidity). Root shoot ratio was the highest in T9 at 15 and 30 DAP and T3 recorded the highest root shoot ratio at 45 and 60 DAP. Fresh weight and dry weight of the plantlets were recorded maximum in T10 (plantlets treated with arbuscular mycorrhizal fungi). There was no significant difference in the number of mesophyll layers of orchid leaves during the ex vitro establishment. However, cuticle thickness was found highest in T3 (plantlet dip with triazole @ 5 ppm + foliar application of triazole @ 5ppm, after 15 days). Survival percentage is considered to be the most important factor during the ex vitro establishment of tissue cultured orchids. Among the different treatments, T6 (plantlets provided with 40-50% light intensity and 80-90% humidity) recorded the highest survival percentage at all the four stages of observation (80, 76, 72, 66 percentage respectively) compared to control. Considering the physiological, morphological, biochemical, biometric and anatomical characters, treatment T6 (plantlets provided with 40-50% light intensity and 80-90% humidity) is adjudged as the best physiological approach to overcome field mortality and improve propagation efficiency of tissue cultured orchid Phalaenopsis sp. during ex vitro establishment.ThesisItem Open Access Physiological evaluation of herbicidal effects on rice, broadleaved weeds and sedges(Department of Plant Physiology, College of Horticulture, Vellanikkara, 2019) Linu, C; KAU; Girija, TThe study on “Physiological evaluation of herbicidal effects on rice, broadleaved weeds and sedges” was conducted during the period from July 2018 to November 2018 at Agricultural Research Station, Mannuthy, Thrissur. The objectives of the study were identification of broadleaved weeds and sedges that are selectively controlled by Almix®, penoxsulam and 2,4-D and also to evaluate the effect of these herbicides on the growth, physiology and yield of rice. The experiment was laid out in RBD with three replications and six herbicidal treatments. The rice variety selected for the study was Jyothi. Treatments included normal and twice the normal doses of 2,4-D, Almix® and penoxsulam and two controls (hand weeded and unweeded). The herbicides were sprayed 20 DAS. Morphological parameters were observed at 20 days interval. Biochemical parameters were estimated before herbicidal application, one week after herbicidal application and at the time of flowering. Yield attributes and yield were recorded during the harvest of the crop. Twice the normal doses of herbicides resulted in 10-12% reduction in plant height of rice while normal doses of herbicides resulted in 3-6% reduction in plant height at the time of harvest. Tiller number of rice crop was found to be affected by herbicide application.At the time of harvest, tiller number of 2,4-D (normal dose) applied plot was on par with hand weeded plot while in case of Almix® and penoxsulam the reduction was 4 and 5 % respectively. Twice the normal doses of herbicides adversely affected tiller number in all three herbicide treatments and it was significantly lower than unweeded control. Number of days taken for flowering was found to be affected by herbicide application compared to hand weeded control. Effect of herbicides on growth indices viz., crop growth rate (CGR) and net assimilation rate (NAR) indicated that only after critical period of growth, there was a significant variation among the treatments. In case of relative growth rate (RGR) and leaf area index (LAI) there was a significant reduction in herbicide applied plots compared to hand weeded control throughout the growth stages. Twice the normal doses of herbicides showed greater reduction in the growth attributes. Biochemical parameters such as soluble protein, total amino acid and nitrate reductase enzyme activity showed a decline in herbicide treatments compared to hand weeded control. Proline content and catalase enzyme activity showed an increase with herbicide application while physiological parameters such as IAA content, cholorophyll content, stomatal conductance and net photosynthesis showed a decline. Twice the normal doses of herbicides significantly affected these parameters compared to the recommended doses of these chemicals. Weed count, dry weight, weed control efficiency and weed persistence index were taken one week after herbicide application and at 60 DAS. Lower weed count, dry weight, weed persistence index and higher weed control efficiency were recorded in twice the normal doses of herbicides as compared to the normal doses. In the present study, grain yield was highest in handweeded plot which was on par with normal doses of 2,4-D and Almix®. Since disease infestation was higher in penoxsulam treatment the yield was also affected. Twice the normal doses of herbicides contributed to 22-33% reduction in grain and 19-23% reduction in straw yield respectively. Among the herbicides 2,4-D (synthetic auxin type) showed a better performance compared to Almix® and penoxsulam (ALS inhibiting type). A net house experiment was conducted to understand the bioefficacy of the herbicides on broadleaved weeds and sedges, viz. Marsilea quadrifoliata, Ludwigia parviflora, Cyperus iria, Fimbristylis miliacea and Sphenoclea zeylanica. The study revealed that Marsilea quadrifoliata was not controlled by both the doses of 2,4-D and penoxsulam while both the doses of Almix® could effectively control the weed. Ludwigia parviflora was controlled by both the doses of 2,4-D while only twice the normal dose of Almix® could control the weed. Penoxsulam did not have any effect on the weed. Fimbristylis miliacea was controlled by penoxsulam and 2,4-D but Almix® was not effective for this weed. Cyperus iria could be controlled only by 2,4-D while Sphenoclea zeylanica was effectively controlled by all the three herbicide formulations. The dosage of chemical influenced the time taken for complete drying of the plant. Though catalase and superoxide dismutase enzyme activity showed increase in the resistant weeds, further studies are required to elucidate the resistance mechanism.ThesisItem Open Access Evaluation of CO 2 enrichment effects on resource utilization in cowpea and amaranathus(Department of Plant Physiology, College of Agriculture, Vellayani, 2019) Srikanth, G A; KAU; Manju, R VThe current experiment entitled "Evaluation of CO2 enrichment effects on resource utilization in cowpea (Vigna unguiculata L.) and amaranthus (Amaranthus tricolor L.)" was undertaken with the objective to study the impact of CO2 enrichment on cowpea and amaranthus imder varying moisture, temperature and nutrient regimes. Four sets of pot culture experiments were conducted during 2015 to 2018 with two varieties of cowpea, Lola and Vellayani Jyothika and Arun variety of amaranthus. The technology used for CO2 enrichment was Open Top Chamber (OTC) system established under Department of Plant Physiology, College of Agriculture, Vellayani. Carbon dioxide was released from CO2 cylinders to one of the two OTC's bringing the CO2 level to 600 ppm and the second OTC worked as control at ambient CO2 for chamber effect. The experiments were laid out in CRD factorial. First experiment was conducted to study the varietal variation in cowpea in response to CO2 enrichment through OTC. Experimental plants were maintained in OTC from sowing to harvest. Observations were taken at biweekly intervals till 3 months. In this study highest values were recorded in variety Lola for number of leaves per plant (79.5), specific leaf area (208.78 cm^g"'), root weight (14.91 g), shoot weight (65.05 g), root shoot ratio (0.229), total dry matter production (79.98g), single pod weight (12.88 g), number of seeds per pod (12.34) and early flowering was also observed under elevated CO2 condition. In Vellayani Jyothika, highest values were recorded for number of pods per plant (11.75), total yield (102.59 g/plant) and total chlorophyll content (0.897 mg g"^), stomatal frequency (2203.84 cm'\ starch (14.26 mg g"') and reducing sugar (15.97 mg g"'), and fibre content (1.34 mg g"') under elevated CO2 condition. Parameters like total soluble protein recorded lower values (8.75) under CO2 enrichment. Quality parameters were modified with a reduction in total protein content (15.76, 14.75 mg g"') and increase in fibre content (1.34, 1.23 mg g '). Among the two varieties of cowpea, Vellayani Jyothika was found to be the best responding variety to elevated CO2 in terms of yield parameters and so was selected for further experiments. In the second experiment evaluation of plant response to elevated CO2 under different soil moisture regimes were evaluated. Two weeks old potted plants were shifted to OTCs. All the three sets of plants were maintained at field capacity (FC) initially. Soil moisture levels were brought down to 80% and 70%, in the second and third sets 30 days after planting and were maintained for a period of 30 days at these soil moisture regimes in OTCs. The result indicated an improvement in growth performances of cowpea and amaranthus under mild and severe moisture stress conditions (80% and 70% FC) in terms of increased number of leaves (46.82, 43.22), specific leaf area (360.43, 261.58 cm^ g-') root weight (9.02, 8.51 g), shoot weight (30.56, 22.16 g), root shoot ratio (0.327, 0.216) and dry matter production (38.98, 29.67g) respectively. The same trend was found in the case of amaranthus for number of leaves per plant (41.00, 37.66), specific leaf area (171.25, 157.59 cm^ g'), plant height (79.66, 72.32 cm), root weight (0.840, 0.416 g), shoot weight (4.740, 3.031 g), root shoot ratio (0.197, 0.130) and dry matter production (4.82, 4.71 g). In the case of cowpea CO2 enrichment induced early flowering in all the three soil moisture conditions. Significant increase in yield was also obtained under stress condition (78.51 and 77.08 g/plant) due to increase in number of pods per pod (8.67, 7.32), single pod weight (11.63, 10.36 g), number of seeds per pod (9.33, 8.75) both under 80% and 70% PCs. In cowpea, total chlorophyll content (1.671, 1.238 mg g"'), RWC (85.24, 77.97 %), stomatal frequency (2144.00, 1964.53 no cm"^), starch (6.12, 5.69 mg g"'), reducing sugar (12.48, 12.09 mg/g), phenol content (0.943, 0.801 mg g') free amino acid content (5.960, 4.823 mg/g), SOD activity (3.466, 4.230 g-Wnute-'), ascorbic acid content (6.87, 5.84 mg/lOOg). Reduction of transpiration rate (0.547, 0.335 mmol water m-^ s"') total soluble protein (6.02, 5.13 mg g'^), membrane integrity (% leakage) (37.80, 34.61%) under CO2 enrichment after stress. The same trend was found in the case of amaranthus total chlorophyll content (1.245, 1.206 mg g"'), RWC (84.98, 79.37%), stomatal frequency (691.16, 573.78 no cm'^), reducing sugar (17.61, 13.56 mg g"'), starch (2.66, 2.53 mg g"'), phenol content (6.20, 3.53 mg g"') free amino acid content (1.071, 1.036 mg g'), SOD activity (1.842, 1.526 g-'minute-'), ascorbic acid content (36.93, 28.40 mg/lOOg), reduction of transpiration rate (2.093, 1.410 mmol water m- s ) total soluble protein (15.42, 15.06 mg g '), membrane integrity (3.480, 3.017%) under elevated CO2. Evaluation of plant responses to elevated CO2 under different soil nutrient regimes was earned out in the third experiment. Potted plants of cowpea and amaranthus (Variety Arun) were used for conducting the experiment. Plants were maintained at FC at four nutrient levels throughout the crop period. The best performance given by plants receiving nutrients as per POP recommendation along with 25% extra nitrogen In cowpea, the values were recorded as follows, number of leaves (76.00), specific leaf area (468.95 cm^ g"^), dry root weight (42.0%), dry shoot weight (0.5%), root shoot ratio (4.9%). total dry matter production (117.58 g), number of pods per plant (16.66), single pod weight (15.83 g), number of seeds per pod (13.33) and total yield (169.53 g/plant). In the case of physiological and biological parameters also this level of nutrient application recorded maximum values for total chlorophyll content (1.528 mg stomatal frequency (2782.01 no cm"^), total soluble protein (20.25 mg g'), starch (13.88 mg g"'), reducing sugar (14.65 mg/g), total protein (15.25 mg g ) and fibre content (1.18 mg g"') and The highest number of root nodules per plant (45.26) and highest nutrient use efficiencies for N, P and K (1.013, 2.675, 0.293 g) were recorded under this treatment. In amaranthus, higher values were recorded in for number of leaves per plant (52.11), specific leaf area (316.20 cm^ g"'), dry root weight (2.13 g), dry shoot weight (4.34 g), root shoot ratio (0.64 g) and total dry matter production (10.47 g). Total chlorophyll content (1.542 mg g"'), stomatal frequency (705.64 no cm"^), total soluble protein (20.25 mg g"'), starch (3.29 mg g"'), reducing sugar (23.14 mg g"'). Calcium content (23.69 mg g'), Fe content (6.71 mg g"') and ascorbic acid content (43.51 mg/lOOg), under elevated CO2 condition. Though a C4 plant like amaranthus also responded to CO2 enrichment, extend of increase in growth and dry matter production was less compared to cowpea, which can be due to the mnate CO2 enrichment mechanism present in C4 systems. The fourth experiment was conducted to study the temperature and humidity interaction with CO2 enrichment. Potted plants of cowpea and amaranthus (variety Arun) were used for conducting the experiment. Plants were maintained at EC throughout the crop period as per POP recommendations of KAU. One set of plants were exposed to mist and the second set was maintained without exposure to mist. In cowpea, highest values were recorded by plants exposed to mist for number of leaves per plant (76.14), specific leaf area (471.07 cm^ g"'), dry root weight (21.74 g), dry shoot weight (72.46 g), root shoot ratio (0.302), dry matter production (104.2 g), single pod weight (15.93 g), number of pods per plant (18.75), number of seeds per pod (14.00), total yield (175.36 g/plant), RWC (96.48%), total chlorophyll content (1.651 mg g'^), stomatal frequency (2724.83 no cm"^), starch (13.29 mg g'^), reducing sugar (15.71 mg g"'), phenol (1.128 mg g"'). Free amino acid (6.398 mg g"'), SOD activity (3.56 g-Wnute-') and ascorbic acid content (9.36 mg/lOOg), Early flowering was induced in this set of plants. Parameters like transpiration rate (1.394 mmol water m-^ s"') total soluble protein (8.82 mg g"'), membrane integrity (43.92% leakage) recorded lower values under CO2 enriched treatments. In amaranthus, higher values were recorded under mist condition for number of leaves (48.51), specific leaf area (327.68 cm^ g"') dry root weight (2.160 g), dry shoot weight (6.74 g), root shoot ratio (0.517), dry matter production (8.90 g). RWC (95.38 %), Total chlorophyll content (1.382 mg g"'), stomatal frequency (694.02 no cm"^), starch (4.19 mg g'), reducing sugar (23.02 mg g"'), phenol (7.92 mg g"'), Free amino acid (1.536 mg g"'), SOD activity (2.44 g-'minute-') and ascorbic acid content (42.75mg/100g). Parameters like transpiration rate (12.36mmol water m-^ s ), total soluble protein (19.05 mg g') (25.40 %) and membrane integrity (% leakage) (6.47 % leakage) recorded lower values. Significant improvement in plant performance and increase in yield are seen under CO2 enrichment with mist exposure in the cases of cowpea and amaranthus The present study shows the existence of varietal variation in the crop responses under CO2 enrichment gives option for selection of varieties with better yield and quality under the changing climatic condition. Elevated CO2 concentration is found to be improve stress tolerance through better photosynthetic rate and activation of defence mechanism. Improved production technologies can be developed especially with mist facility with minimizing irrigation requirement. This can also be utilized for enhancement of antioxidant production which are economically valuable secondary metabolites. Exploitation of soils lacking sufficient nutrient and water can be done through the introduction of low cost CO2 enrichment methods. Since soil moisture and temperature are the primary determinants of nutrient availability and acquisition plant nutrition can strongly be influenced by global climate change. This necessitates site specific CO2 enrichment studies. The present study showed the existence of varietal variation in the crop responses under CO2 enrichment which gives option for selection of varieties with better yield and quality under the changing climatic scenario. Elevated CO2 concentration is found to improve the performance of plants grown under low soil moisture levels by improving the performance of photosynthetic machinery and by activating defence mechanisms. Based on this, improved high-tech agriculture production technologies with mist facility can be developed with minimum irrigation requirement which will ensure maximum water use efficiency. This also gives a possibility of utilizing the interactive effects of different cultivars, CO2 enrichment, and other abiotic factors for enhancing the production of antioxidants, many of which are economically valuable secondary metabolites. The present programme also opens up possibilities of quality improvement of agricultural products based on the interaction of elevated CO2 with factors like cultivars, growth stages, light, nutrient and abiotic stress factors. Intensification of cultivation and quality improvement are equally important to address the new challenges of global health because many of the economically important crops, when grown under field conditions at the elevated atmospheric C02were reported to have deleterious impacts on quality. The present study indicated the improved performance of cowpea under CO2 enrichment with additional nitrogen input. This points towards the changing nutrient requirement of crop plants under the current scenario of increasing CO2 concentration and suggests for bringing out modifications in the nutrient recommendations with additional nutrients, especially nitrogen. Exploitation of soils lacking sufficient nutrient and water also can be done through the introduction of low cost CO2 enrichment methods. Since soil moisture and temperature are the primary determinants of nutrient availability and acquisition, plant nutrition can strongly be influenced by global climate change. So this study also points to the requirement of site specific CO2 enrichment studies.