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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 Standardisation of nutrient and weed management techniques for organic rice(Department of Agronomy, College of Agriculture, Vellayani, 2013) Murugesh, M S; KAU; Girija Devi, LThe present investigation on “Standardisation of nutrient and weed management techniques for organic rice” was conducted at the Department of Agronomy, College of Agriculture, Vellayani, during 2012-2013. The objectives were to standardise the nutrient schedule, spacing and weed management techniques for organic rice and to assess the economic feasibility of the organic package. The experiment was laid out in the field in split plot design with combination of spacing, S (S1-20 cm x 15 cm and S2-15 cm x 15 cm) and weed management techniques, W (W1-stale seedbed and W2-hand weeding) as main plot treatments and nutrient schedule, N (N1-option-1 of the ad hoc recommendation of KAU: FYM 5 t + 800 kg oil cakes ha-1 (1/2 basal + 1/2 top dressing at active tillering stage), N2-option-2 of the ad hoc recommendation of KAU: FYM 1 t + green leaf manure 1t + dual culture of azolla + 2 kg Azospirillum + 2 kg P solubilizing bacteria + 1kg PGPR (mix 1) ha-1, N3-option-3 of the ad hoc recommendation of KAU: 1/3rd RDN as FYM, 1/3rd as vermicompost and 1/3rd as neem cake + 2 kg Azospirillum + 2 kg P solubilizing bacteria ha-1, N4-soil test based application–half as vermicompost and half as neem cake). The KAU Package of Practices Recommendation (FYM 5 t + 90:45:45 kg NPK ha -1) was taken as control. Closer spacing (S2-15cm x 15 cm), hand weeding (W2) and option-3 of the ad hoc recommendation of KAU (N3) significantly influenced plant height and DMP, while closer spacing (S2-15cm x 15 cm) and option-3 of the ad hoc recommendation of KAU (N3) only had significant influence on tiller production and LAI. Stale seedbed (W1) and closer spacing (S2-15 cm x 15 cm) had significant influence on most of the yield attributing characters, while, among nutrient schedule, N3 (option-3 of the ad hoc recommendation of KAU) attributed the maximum for yield contributing characters, but was on par with N4 (soil test based application) and also with N1 (option-1 of the ad hoc recommendation of KAU) for grain yield. The results on weed control revealed the superiority of closer spacing (S2-15 cm x 15 cm) and stale seedbed technique (W1) over others in controlling the weeds throughout the growth stages. However the weed control efficiency was the lowest in conventional (Control-KAU Package of Practices Recommendation) compared to the organic throughout the growth stages. The nutrient uptake was the highest in N3 (option-3 of the ad hoc recommendation of KAU) and the lowest in N2 (option-2 of the ad hoc recommendation of KAU). However, uptake study had also revealed the superiority of conventional (Control-KAU Package of Practices Recommendation) over organic in the uptake of nutrients. The net returns and B:C ratio were the highest in closely spaced plants (S2-15 cm x 15 cm) and in N3 (option-3 of the ad hoc recommendation of KAU). From the study it can be concluded that for realising higher grain yield in organic rice, a closer spacing of 15 cm x 15 cm (S2) is ideal. Any of the two weed management techniques, i.e., either stale seedbed (W1) or hand weeding (W2) can be practiced for controlling weeds. Option-3 of the ad hoc recommendation of KAU (N3-1/3rd RDN as FYM, 1/3rd as vermicompost and 1/3rd as neem cake + 2 kg Azospirillum + 2 kg P solubilizing bacteria ha-1) is the best nutrient schedule for realizing maximum yield from organic rice. The most economic package for organic rice production is the combination of closer spacing of 15 cm x 15 cm (S2), with stale seedbed technique (W1) of weed control and option-3 of the ad hoc recommendation of KAU (N3-1/3rd RDN as FYM, 1/3rd as vermicompost and1/3rd as neem cake + 2 Kg Azospirillum + 2 Kg P solubilizing bacteria ha-1) as nutrient schedule. The organic package was economically significantly superior to conventional package due to the premium price fetched by organic rice.ThesisItem Open Access Nutrient Management for yield and quality improvement in Kacholam(Department of Agronomy, College of Horticulture, Vellanikkara, 2012) Kavitha, P R; KAU; Meera, Menon VKacholam (Kaempferia galanga L.) is an important medicinal and aromatic plant of the Zingiberaceae family. In India, kacholam is cultivated throughout the plains for the rhizomes. The economic produce of kacholam is the chopped and dried rhizomes of 6-7 months maturity. Dried rhizomes are used in bulk quantities in ayurvedic medicine and in the cosmetic industry. It is used for curing inflammatory wounds, skin disorders, piles, oedema, fever, epilepsy, splenic disorders and asthma. The constituents of the rhizome oil include para methoxy ethyl cinnamate (60.24 % of the oil), ethyl cinnamate (20.66%), cineol, borneol, 3-carene, camphene, kaempferol, kaempferide and cinnamaldehyde. There is immense scope for cultivation of kacholam in Kerala, as the climatic and soil conditions are optimally suited to its growth and development. Kacholam can be grown as an intercrop in coconut gardens and it has attained the status of a cash crop of homesteads. Though there is an approved ad hoc recommendation of organic manures as well as N, P and K for kacholam, there are reports that the K dose is inadequate. Also, considering the low availability and high cost, the present organic manure recommendation of 20 tonnes ha-1 is rather unaffordable. There are also reports about the inadequacy in the availability of secondary nutrients viz., S, Ca and Mg, which may affect yield and quality of kacholam. A field experiment was conducted during 2011-2012 in the coconut garden of Water Management Research Unit, Vellanikkara to evaluate the effect of varying doses of K and secondary nutrients on yield and quality of kacholam. There were 12 treatments with 3 replications each. Treatments consisted of package of practices (POP) recommendation of 20 tonnes farmyard manure along with 50:50:50 kg N, P and K ha-1 and combinations with S, Ca, Mg and extra dose of K applied as first and second top dressing. Rhizomes were planted at a spacing of 20 x 15 cm and planting was done on 3/ 06/ 2011. Harvesting was done seven months after planting. Observations included biometric observations taken at monthly intervals, nutrient contents at 2 ½ and 5 months after planting, and at harvest. Nutrient uptakes was also worked out. Essential oil and oleoresin in rhizomes were also analysed. The soil pH and chemical parameters were analysed before and after the experiment. There were significant differences among treatments with respect to yield, essential oil, oleoresin, nutrient contents and nutrient uptake. With respect to yield, the treatment receiving S applied either at first top dressing or at second top dressing and that with S, Ca and Mg recorded highest yields as compared to other treatments. Essential oil content also showed the same trend as that of yield. But in case of oleoresin, the content was more only in the treatments receiving S as first and second top dressing. This treatment resulted in highest uptake of all nutrients except Ca at harvest. Application of the secondary nutrients thus had a direct positive effect on yield and quality. Changing the N:K ratio of present NPK recommendation resulted in reduction of yield and other quality parameters. The yield and quality parameters with the reduced organic manure dose were found similar to the present POP. Increased phosphorus content of soil observed after experimentation indicated the possibility of reducing the recommended phosphorus dose. Supplementing S, Ca and Mg with a reduced organic manure dose is also to be tested.ThesisItem Open Access Standardization of organic nutrient schedule for chilli (Capsicum annuam)(Department of Agronomy, College of Agriculture, Vellayani, 2013) Akshay; KAU; Sajitha Rani, TThe research project entitled ‘Standardization of organic nutrient schedule for chilli (Capsicum annuum)’ was conducted at Instructional Farm attached to the College of Agriculture, Vellayani during the kharif season of 2012 to standardize the organic nutrient schedule for chilli and to work out the economics. The investigation was laid out as factorial experiment in Randomized Block Design (RBD) with three replications. The treatments consisted of three levels of FYM - F1 (20 t ha-1), F2 (15 t ha-1) and F3 (10 t ha-1) and three levels of substitution of the recommended dose of nitrogen. The levels of substitution are N1 (100 % recommended dose of N- 75 kg ha-1), N2 (75 % recommended dose of N -56.25 kg ha-1) and N3 (50 % recommended dose of N - 37.5 kg ha-1). FYM along with neem cake in 1: 1 ratio is used as organic manure for N substitution. Three controls were also tested in this study. Thèse controls are C1 (KAU POP recommendation -.FYM@ 25 t ha-1 along with75:40:25 kg N:P2O5:K20 ha-1 as inorganic fertilizer), C2 ( KAU Adhoc organic POP recommendation -FYM @25 t ha-1 + Poultry manure at 5 t ha-1 + Pseudomonas + Trichoderma and PGPR mix 1, each @2.5 kg ha-1) and C3 (Farmers practice - Cow dung slurry @ 20 t ha-1) Result of the study revealed that FYM @ 20 t ha-1 recorded significantly higher plant height, no of branches & LAI. The maximum value for all growth parameters were observed at 100% level of N substitution .Combined application of FYM @ 20 t ha-1 along with 100% substitution of recommended dose of N (75 kg ha-1) in organic form registered maximum plant height, branches, LAI, and root spread .This treatment was on par with KAU POP and Adhoc organic POP Maximum yield was recorede at the highest level of FYM (20 t ha-1). Yield contributing characters were also significantly higher at this level. Among the levels of substitution 100% substitution recorded maximum productivity. Application of FYM @ 20 t ha-1 along with 100 % recommended dose of N (75 kg ha-1) as organic form gave maximum productivity which was on par with the yield realized from KAU Adhoc organic POP and KAU POP. Highest level of FYM @ 20 t ha-1 and 100 % substitution of recommended dose of N recorded maximum ascorbic acid, capsaicin content and shelf life. FYM @ 20 t ha-1 along with 100% of substitution of N as organic recorded maximum capsaicin content which was on par with KAU POP recommendation. Ad hoc organic POP recommendation of KAU recorded maximum ascorbic acid content. KAU POP recommendation registered significantly higher N and K uptake than other treatments. Adhoc organic POP recommendations of KAU recorded highest soil pH and organic carbon content. Available nitrogen status of soil was significantly higher in Adhoc organic POP recommendations of KAU but P and K status were on par to KAU POP. Highest B:C ratio and net income were realized in KAU POP. Best nutrient schedules for realising maximum yield from organic chilli is 1) FYM @20 t ha-1 along with 75kg N ha -1 applied through a combination of FYM and neem cake in 1 : 1 ratio + Pseudomonas + Trichoderma and PGPR mix 1, each @2.5 kg ha-1 and 2) Adhoc POP recommendation of KAU -FYM @ 25 t ha-1 along with poultry manure @ 5 t ha-1 + Pseudomonas+Trichoderma and PGPR mix 1, each @2.5 kg ha-1. Economic nutrient schedule for organic chilli is application of FYM @ 25 t ha-1 along with poultry manure @ 5 t ha-1 + Pseudomonas + Trichoderma and PGPR mix 1, each @2.5 kThesisItem Open Access Production potential of cereal fodder crops under various tillage practices in rice fallows.(Department of Agronomy, College of Horticulture, Vellanikkara, 2011) Gintu, George; KAU; Prameela, PIn order to test the feasibility of raising cereal fodders in rice fallows under various tillage systems an experiment entitled “Production potential of cereal fodder crops under various tillage practices in rice fallows” was conducted at the Department of Agronomy, College of Horticulture, Vellanikkara, Thrissur, Kerala. The experiment was laid out in split plot design with four replications during the period from November 2009 to February 2010. The main plots had tillage practices as treatments which included zero tillage with and without herbicide application (M1 and M2), minimum tillage (M3) and normal tillage (M4). The subplots had three treatments, viz., fodder cereals; maize (S1), sorghum (S2) and bajra (S3). Analysis of data on herbage yield of the three fodders under different tillage practices showed that the herbicide based zero tillage, minimum tillage and normal tillage practices resulted in comparable yields (20.72, 18.72 and 18.08 t/ha). Zero tillage without herbicide application resulted in significantly lower yield (11.69 t/ha). Growth parameters like plant height, leaf area index, leaf stem ratio, shoot root ratio etc. recorded at various growth stages also showed the favourable influence of minimum and herbicide based zero tillage on plant growth. Among the cereal fodders, maize recorded significantly higher yield of 20.19 t/ha followed by sorghum with 15.91 t/ha and bajra with 15.81 t/ha. Considering tillage practices and crops together, the highest B: C ratio of 3.31 was realized when maize was grown under herbicide based zero tillage closely followed by maize under minimum tillage with a B: C ratio of 3.24. Of the other two crops, bajra was found to be more profitable than sorghum. Like maize, herbicide based zero tillage resulted in a higher B: C ratio (3.0) for bajra than other tillage treatments. The yield reduction in zero tillage without herbicide application was mainly due to weeds. A study of weed spectrum showed that dicots were the major weed flora followed by grasses and sedges. The weed population and weed dry matter production were the highest in zero tillage without herbicide application followed by minimum and herbicide based tillage and the least was in normal tillage. Weed dry matter production in zero tilled without herbicide plot was 1545 kg/ha compared to a much lower dry matter accumulation of 193 kg/ha in normal tillage plot. The silage made from all the three cereal fodders was found to be of good quality with golden yellow colour, pleasant smell and a pH ranging from 3.8 to 4.2. In silage prepared without the addition of molasses, pH was found to be slightly higher (4.2) compared to silage prepared with molasses as additive (3.9). The study revealed that fodder maize under herbicide based zero tillage was the best with regard to yield and B: C ratio. However, for a herbicide free production system, maize grown under minimum tillage is preferred due to its equally good performance.ThesisItem Open Access Relative efficiency of soil and foliar applied nutrients in irrigated rice of Palakkad(Department of Agronomy, College of Horticulture, Vellanikkara, 2013) Nissa, Latheef; KAU; Mercy, GeorgeThe research programme entitled “Relative efficiency of soil and foliar applied nutrients in irrigated rice of Palakkad” was conducted in the farmer’s field, Thathamangalam, Palakkad during Mundakan season October 2011- February 2012 to compare the efficacy of soil and foliar applied nutrients especially magnesium, zinc and boron. The treatments included package of practices recommendation for rice manuring (POP NPK+FYM), NPK alone as in the package of practices recommendation (POP NPK), soil test based nutrient application +FYM, soil application of MgSO4 @ 40 & 80 kg ha-1, ZnSO4 @ 20 & 30 kg ha-1, Borax @ 10 & 20 kg ha-1; foliar spray of MgSO4 @ 0.5 & 1%, ZnSO4 @ 0.5 & 1% and Borax @ 0.25 & 0.5% and an absolute control. Soil application of Mg, Zn and B were done as basal and foliar application were given at 20 and 40 DAT of rice as per the treatments.ThesisItem Open Access Effect of secondary nutrients on yield and quality of turmeric (Curcuma longa L.)(Department of Agronomy, College of Horticulture, Vellanikkara, 2014) Sanghamithre, V K; KAU; Meera, V Menon (Guide)Primary nutrients viz. nitrogen, phosphorus and potassium are generally regarded to be instrumental in maintaining growth, yield and quality of crops. The secondary nutrients, sulphur, calcium and magnesium, though reported to play key roles in the growth and development of crops, seldom get the recognition they deserve. There are no recommendations for these nutrients for most crops. At the same time, there are reports of increasing deficiency of sulphur, calcium and magnesium in the laterite soils of Kerala. Turmeric (Curcuma longa L.) is a vital spice crop of the Zingiberaceae family. The rhizome, which is the economic produce, contains an essential oil, curcumin and related compounds as major constituents. There is immense scope for cultivation of turmeric in Kerala due to favourable climatic and soil condition. Turmeric is a crop requiring heavy fertilization for increasing yield and quality. This research programme was taken up to study the effect of secondary nutrients on the yield and quality of turmeric. The field experiment was conducted during 2013-2014 in the farm of the Department of Agronomy, College of Horticulture, Vellanikkara. There were 10 treatments with 3 replications each. Treatments consisted of package of practices recommendations (POPR) of 40 tonnes farmyard manure along with 30:30:60 kg N, P and K/ha and its combinations with S, Ca and Mg applied one and two months after planting. Rhizomes were planted at a spacing of 25 × 25 cm and planting was done on 05 June 2013. Harvesting was done after seven months. Biometric observations were taken at monthly intervals and nutrient contents were analyzed at three and six months after planting and at harvest. Nutrient uptake was also worked out. Curcumin and oleoresin content in rhizomes were also analyzed. The soil pH and chemical parameters were determined before and after the experiment. There were significant differences among the treatments with respect to leaf area index, yield, nutrient content and nutrient uptake. In the case of leaf area index, the treatment receiving Ca as second top dressing (viz. two months after planting) recorded the highest LAI compared to other treatments. Fresh and dry yields of turmeric and benefit: cost ratio was also high in the same treatment. This treatment resulted in the highest uptake of all nutrients except S at harvest. Earlier application of sulphur, calcium and magnesium (viz. one month after planting) also led to higher yield and benefit: cost ratio, confirming the direct positive effect on yield. Absolute control recorded the lowest values for all parameters including yield and quality components. Future research should be focused on altering and testing the dose and schedule of application of S, Ca and Mg, and analysis of their interaction effect to maximize productivity, Application of micronutrients and optimizing their dose and schedule for higher yield and quality should also be attempted.ThesisItem Open Access Production protocol for organic tomato : (lycopersicon esculentum mill.).(Department of Agronomy, College of Agriculture, Vellayani, 2011) Abijith, Kumar V P; KAU; Girija, Devi L (Guide)The research project entitled ‘Production protocol for organic tomato (Lycopersicon esculentum Mill.)’ was conducted at the Instructional Farm attached to the College of Agriculture, Vellayani during the year 2009-2010 to study the effects of organic nutrition and spacing and their interaction upon growth, yield, quality and nutrient uptake of tomato and to assess the residual effect of organic nutrition on the succeeding crop. The experiment was laid out in factorial randomized block design (RBD) with three replications. The treatments consisted of four levels of nutrients, N1 (full nitrogen substitution as organic), N2 (75% nitrogen only and as organic), N3 (50% nitrogen only and as organic) and N4 (Package of Practices Recommendations ‘Crops’: 2007 of Kerala Agricultural University) and three spacing viz., S1 (60 cm x 60 cm), S2 (60 cm x 45 cm) and S3 (60 cm x 30 cm). Before transplanting, the seedlings were given a root dip in Pseudomonas flourescens culture against bacterial wilt disease. The experiment was laid out as 4 x 3 factorial randomized block design (FRBD) with 3 replications. The number of treatments were 12 replication-1. Common treatments such as neem seed oil-garlic emulsion spray, pseudomonas spraying, trichoderma incorporation in the soil and uniform mulching at different intervals were also undertaken. From the results it was found that integrated supply of nutrients through FYM and chemical fertilizers gave the highest fruit yield in tomato. Among the different spacing, the widest spacing of 60 cm x 60 cm recorded the highest fruit yield plant-1. The interaction effects were significant with the highest yield in the combination where the individual effects of nutrient levels as well as spacing were significantly the highest, viz., N4S1. The fruit weight was also the highest in the same treatments and the crop duration the modest. The lowest fruit weight and the shortest duration of crop was observed in N3. The widest spaced plants produced the highest fruit weight and the combination involving POP recommendation and the widest spacing (N4S1) again produced the heaviest fruits. The fruit quality and appearance was also found the best in N1 and N4 when compared to other two levels. Spacing had no effect on the quality characters while the interaction between nutrient levels and spacing had significant effect on lycopene and TSS content with N1S1 giving the highest values for them. The dry weight of plants was found the highest in N1 and in the widest spacing (S1) and among the interaction the same combination produced the highest plant dry weight (N1S1). The nutrient uptake especially N and P was found the highest in N4 and K in N1. In closer planting the nutrient uptake was the highest consequent to the increase in population. The organic carbon and available nutrient status after the experiment was the highest in N1. The effect of nutrient levels and spacing were significant in benefit-cost ratio at the normal market price as well as the premium prices of the produce. The POP recommendation (N4) with an integrated nutrient approach with organic and inorganic sources fetched the highest B:C ratio. Similarly for planting distances, it was found that tomato cultivation become remunerative in terms of B:C ratio only when the plants were spaced at a closer distance than wider spacing. Inorder to study the residual effect of organic nutrition, a crop of amaranthus (Amaranthus tricolor) was raised after tomato and the biometric characters of the residual crop studied were influenced by nutrient levels with the highest values in N4 (control) and the lowest in N3. The marketable yield of amaranthus was also found the highest in N4 (control). Similarly the economics of amaranthus cultivation revealed the significance of N4 and S3 in producing the highest B:C ratio. The combination of N4 and S3 also recorded the highest B:C ratio in amaranthus. The uptake of nutrients especially N and K was found the highest in N4 and N1. Though spacing had no significant role in the uptake of nutrients, the combination of nutrient levels and spacing had significant influence and the highest uptake was observed in N4S3. The combined B:C ratio of tomato-amaranthus sequence was determined at the premium price of tomato plus the market price of amaranthus by assuming a 20 % hike for the organic produce in the market. The effect of nutrient levels and spacing were significant with N4 giving the highest B:C ratio and N3 the lowest. The closely spaced plants (S3) recorded the highest B:C ratio and the widest spaced plants (S1), the lowest. The interaction effect was significant with the highest B:C ratio in N4S3 and the lowest in N3S1. Among the organic treatments N1 was found the best with a combined B:C ratio of 1.38 followed by N2 (1.00) and the lowest in N3 (0.78). Among the organic combination with spacing it was in N1S3 the highest B:C ratio found (1.42) followed by N1S2 (1.36) and N1S1 (1.35).ThesisItem Open Access Production technology for organic sweet potato(Department of Agronomy, College of Agriculture, Vellayani, 2011) Dhanya, T; KAU; Pushpakumari, RKerala the ‘Land of coconut’ occupies first position in area and production of coconut in India but the productivity is below the national average. This is because of unproductive and senile palms, lack of adaptation of recommended cultivation practises and serious incidence of pests and diseases. The root (wilt), an endemic disease of Kerala causes an annual loss of 968 million nuts. Recently another type of yellowing characterised by mid whorl yellowing shedding of immature nuts and drying of inflorescence without showing characteristic ribbing symptom is rapidly spreading in many parts of Kerala. There is no research report available in this emerging problem in the coconut growing tracts of Kerala. Since there is rampant spreading of yellowing to other coconut cultivated areas causing a serious reduction in nut yield, this problem demands immediate attention. Hence an experiment was conducted in the Department of Plant Physiology, College of Agriculture, Vellyani to generate the basic information on the causative agents and on the changes of physiological, molecular and anatomical realms of coconut affected by mid whorl yellowing A wide variation was observed in the physiological parameters like total pigments, relative water content, carbohydrate fractions, proteins, phenols and antioxidants betweenpalms with yellowing and control palms. The palms with yellowing showed a significant reduction in the total chlorophyll, chlorophyll a, chlorophyll b and carotenoid content when compared to the healthy palm. Relative water content was lower for all the palms with yellowing compared to the control palm and the healthy palms were maintaining a better water status and membrane integrity. All the selected palms with yellowing recorded an accumulation of reducing sugars compared to the healthy palms. The trend was similar for starch content except for palms with general yellowing. The control palms recorded maximum protein content compared to other palms with yellowing. A significant increase in the phenolic compounds was observed in palms with yellowing compared to the healthy palms. This results point to an activated defense system. The 14th leaf starting from the first fully opened one is the most widely used leaf for nutrient analysis as recommended by the IRHO. (Fremond et al., 1966).The 14th leaf data from the control palms and palms with different types of yellowing were analysed. The data showed that there were significant reductions in the levels of major nutrient nitrogen, phosphorus and also in the levels of magnesium and the micronutrient manganese in case of palms showing mid whorl yellowing compared to the control palm. But significantly higher levels of accumulation were found in case of potassium, calcium, iron and copper. These variations in the nutrient levels can have an influence on symptom development in coconut palms. The maximum yield was recorded for the control palm. Chlorophyll degradation and loss of structural integrity were evident from the anatomical studies of leaf tissues in case of palms with yellowing. Vascular browning which extended to the cortex and the vascular disintegration in the roots of affected palms were seen on anatomical analyses. A pure quality DNA was obtained by modified CTAB DNA isolation protocol. Molecular analyses using nested PCR showed that with the phytoplasma specific universal primers P1/P7-R16F2n/R16R2 provided an amplicon ) in the positive control and palms with inner and middle whorl yellowing and the primers R16mF2 /R16mR1 -R16F2n/ R16R2 provided an amplicon for the positive control and palms with inner, middle and general yellowing. The root (wilt) phytoplasma specific semi- nested primers IF7/7R3- IF7/7R2 provided an amplicon of 493 bp only for the positive control and no amplification was seen in any of the selected palms. The control palm and the palms affected with outer whorl yellowing provided no amplification at all for any of the primers tested. Amplification of phytoplasma specific universal primers in palms with mid whorl yellowing indicates that phytoplasma has got a role in development of the specific symptom. This demands immediate attention and extensive studies on the etiology, changes in biochemical profile, anatomy etc. Salient Findings Amplification of phytoplasma specific universal primers in palms with mid whorl yellowing indicates that phytoplasma has got a role in development of the mid whorl yellowing symptom. But in case of the root (wilt) phytoplasma specific primers, there was no amplification in palms with mid whorl yellowing. This suggests that the mid whorl yellowing of coconut palm which is an emerging problem in Kerala may not be associated with the root (wilt) disease. The results of biochemical and physiological analyses of the selected palms clearly indicate an altered primary metabolism, source-sink relation and a complexity in the nutriophysiology. These altered conditions can act as predisposing factors for the development of specific symptoms. The anatomical analyses showed damages of roots in the palms with mid whorl yellowing. They will have internal browning of vascular elements, extending into the cortex and also disintegration of vascular elements. Future line of work Detailed analysis of nutriophysiology, source-sink relation and hormonal profile. Studies on soil factors like nutrient level and water status. Extension of anatomical studies to different type of tissues. Extension of molecular studies into identification of specific phytoplasmal strains associated with mid whorl yellowing of coconut palms. Development of management strategy for the improvement of the field performance and productivity of coconut palms with mid whorl yellowing.ThesisItem Open Access Integrated weed management under system of rice intensification (SRI)(Department of Agronomy, College of Horticulture, Vellanikkara, 2011) Musthafa, Kunnathadi; KAU; Abraham, C TAn experiment was conducted to assess the performance of system of rice intensification (SRI) vis-à-vis conventional system with special emphasis on weed problems under SRI and to develop an economic weed management strategy. Aiming at reducing drudgery while using manual cono weeder, it was also envisaged to develop the prototype of a self propelled cono weeder. The field studies laid out in randomized block design with 16 treatments in three replications were conducted at RARS, Pattambi in Palakkad district and in farmers’ fields at Alappad Kole in Thrissur district, during the Mundakan seasons of 2007 and 2008. The soil at Pattambi was lateritic sandy clay loam with pH 4.96 and medium fertility, and that at Alappad Kole was clayey in texture with pH 5.0 and of high fertility. At both locations, the density and dry weight of weeds at 45 and 60 days after transplanting (DAT) were higher in all the SRI treatments especially when weed control was done through repeated cono weeding. At Pattambi, weed density and weed dry weight were the lowest in conventional system with post emergence herbicides, which recorded lower nutrient removal by the weeds and the lowest weed index and also higher gross return, net return and B:C ratio. The weed density and dry weight in the SRI fields were the lowest with pre emergence herbicide followed by hand weeding at 30 DAT, but the use of post emergence herbicides showed higher B:C ratio. At Alappad Kole, the weed density and dry weight, both at 45 and 60 DAT, were the lowest in conventional system with cono weeding at 10 DAT followed by post emergence herbicides. Cono weeding followed by hand weeding, pre emergence herbicides followed by hand weeding as well as the use of post emergence herbicides were also equally effective in controlling the weeds 233 in the conventional system, and were on par in the B:C ratios. In the SRI plots cono weeding at 10 DAT followed by post emergence herbicides recorded the lowest weed density and dry weight, however, use of post emergence herbicides recorded the highest net return and B:C ratio among the SRI treatments. Thus, considering the acute shortage and high wages for the labourers in Kerala, weed management through post emergence herbicides will be the preferable option for the farmers in both conventional and SRI systems of rice cultivation. Comparison between the two systems of rice cultivation at two different rice growing ecosystems showed that SRI improved the performance of individual hills through higher number of tillers hill-1, root length and root dry weight hill-1. On the other hand, the tiller number, dry matter production, root dry weight and productive tillers per unit area were higher in the conventional treatments. Owing to higher number of productive tillers per unit area the grain yield of conventional treatments was significantly higher than that of the typical SRI. At Pattambi, conventional system with post emergence herbicides recorded higher number of productive tillers m-2, panicle length, number of filled grains panicle-1, 1000 grain weight and grain yield (2877 kg ha-1), which was 33 per cent higher than the grain yield in the typical SRI. This treatment also recorded significantly higher B:C ratio (1.27) compared to that (0.91) of the typical SRI. However, the highest straw yield (2510 kg ha-1) at Pattambi was observed in ‘SRI with cono weeding at 10 DAT followed by post emergence herbicides’, which was on par with the typical SRI treatment. At Alappad Kole, higher number of productive tillers m-2, more filled grain percentage, highest 1000 grain weight, highest grain yield (6073 kg ha-1) and highest straw yield (5109 kg ha-1) were recorded by conventional system with cono weeding followed by hand weeding, which showed an increase of 93 per 234 cent in grain yield, with an additional yield of 2934 kg ha-1, and 109 per cent in straw yield over the typical SRI and recorded the highest gross return, net return and B:C ratio (2.46). Thus, the study showed the superiority of conventional system of rice cultivation at a spacing of 20 cm x 10 cm over the SRI system at a spacing of 30 cm x 30 cm at both the two different rice growing ecosystems studied viz., the sandy loam soils at Pattambi and the clayey soils at Alappad Kole. Prototype of the self propelled cono weeder was developed and field tested. It works satisfactorily in a single forward pass, and covers an area of 0.1 ha h-1. The field study showed that the self propelled cono weeder is effective for inter row weeding in rice, however, further refinement is needed to improve its weeding efficiency.