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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 Etiology and ecofriendly management of fungal diseases of thippali ( piper longum L)(Department of Plant Pathology, College of Agriculture, Vellayani, 2007) Poornima, R; KAU; Santha Kumari, PA survey was carried out at the medicinal garden of College of Agriculture, Vellayani and medicinal garden of Ayurveda Research Institute, Poojappura, Thiruvananthapuram to study the diseases associated with Piper longum L. (Indian long pepper or thippali). The major disease observed was anthracnose caused by Colletotrichum gloeosporioides (Penz.) Penz and Sacc. Pathogenicity test proved that C. gloeosporioides was the pathogen associated with the disease. Cross inoculation studies conducted using C. gloeosporioides isolate of thippali, black pepper and betel vine - the sister plants – showed that the thippali isolate was highly host specific. The colony and conidial morphology of the three isolates also showed considerable difference. C. gloeosporioides of thippali had very small conidia and the culture was also found to be shy sporulating. Studies on the survival of C. gloeosporioides showed that the pathogen survived for 105 days in the infected leaves, under laboratory conditions. In the soil, it survived for 150 days. Of the eleven fungal and four bacterial isolates tested against C. gloeosporioides, T. viride and A.terreus were found to be most effective under in vitro condition. Among the different resistance inducers tested in vitro, SA (1 g/l) was selected for field evaluation, as it had no direct action on the pathogen. Of the two plant based chemicals tested, Ovis reported the highest suppression of the pathogen. These four eco friendly materials selected from the in vitro studies and neem cake were tested in the field to determine their effectiveness in controlling the disease. Their combinations were also studied. Among the different eco friendly materials tested in the field, treatment T12 (T2T5 - A. terreus + neem cake) was found to be best in disease suppression at 45 DAT. Estimation of DRE showed that PO and PPO activity was highest in T3 (Ovis) where as PAL activity was maximum in T1 (T. viride). Combination of treatments revealed that maximum PO activity was in treatment T14 (T3T5 - Ovis + neem cake).The PPO and PAL activity was maximum in T7 (T1T3 - T. viride + Ovis).ThesisItem Open Access Management of phytophthora disease of black pepper (piper nigrum L. walp) using plant growth promoting microbial inoculants(Department of Plant Pathology, College of Agriculture, Mannuthy, 2003) Beena Nair, S; KAU; Anith, K NThe study, "Management of Phytophthora disease of black pepper (Piper nigrum L. Walp) using plant growth promoting microbial inoculants" was conducted at the Department of Plant Pathology, College of Agriculture, Vellayani to investigate the effect of plant growth promoting rhizobacterial strains belonging to fluorescent pseudomonads and Bacillus spp. and the root endophytic fungus, Piriformospora indica on the suppression of nursery wilt of black pepper incited by Phytophthora capsici. Two strains of fluorescent pseudomonads viz., Pseudomonas putida strain 89B61 and P. jluorescens strain RCL3R4, two strains of Bacillus viz., BY -1 and BY -2 and P. indica were included in the study to explore their potential in plant growth promotion and disease suppression. P. capsici inoculated control, uninoculated healthy control, chemical control (0.20 per cent COC drenched at 15 days intervals) and combined application of Trichoderma harzianum and an AMF, Glomus fasciculatum were maintained for comparison. In the dual culture assay, conducted in vitro for preliminary screening, though P. indica exhibited a slight mycelial growth inhibition initially, the pathogen later overgrew the antagonist. Among the bacteria, fluorescent pseudomonad strains exhibited better mycelial growth inhibition 'on both PDA and Carrot Agar. The influence of different biocontrol agents on growth promotion of the black pepper cuttings was not statistically significant. However, the fluorescent pseudomonad, P. putida strain 89B61 exhibited maximum growth promotion. In the experiment conducted to test the potential of vanous plant growth promoting microbial inoculants in suppressing nursery wilt, the plants treated with spore suspension of P. indica exhibited the highest wilt percentage of 93.22 per cent which was more than that in the inoculated control (37.48). The plants treated with the fluorescent pseudomonad, P. jluorescens strain RCL3R4 recorded a wilt percentage of 6.70. All other treatments were highly effective and checked the infection completely. The Bacillus strain, BY -2 exhibited better disease suppression in vivo. The fluorescent pseudomonad, P. putida strain 89B61 also showed disease suppression in vivo, which indicated that it has the dual function of plant growth promotion and disease suppression.ThesisItem Open Access Bioherbicidal potential of fungal pathogenes of water hyacinth [Eichhornia crassipes (Mart.) Solms](Department of Plant Pathology, College of Agriculture,Vellayani, 2003) Ancy Salim, M; KAU; Naseema, AThe study entitled "Bioherbicidal potential of fungal pathogens of water hyacinth [Eichhornia crassipes (Mart.) Solrns]", was conducted at College of Agriculture, Vellayani, Thiruvananthapuram during 2001-2003. Fourteen pathogenic fungi of water hyacinth obtained from the survey conducted as a part of the DST project on "Biocontro l of water hyacinth using mycoherbicides" were used for the study. Fungi which were not identified earlier were characterized and identified based on the cultural and morphological characters and was confirmed by sending to Agharkar Research Institute, Pune. These three fungi viz., Bipolaris tetramera, Drechslera sp. and Pestalotiopsis guepinii, were new records on water hyacinth. The fungi varied in the symptom development on water hyacinth with respect to nature of symptoms, parts affected and the time taken for the symptom development. The intensity of infection by the fungi varied from 9.94 to 58.80 per cent. Only five fungi viz., A.eichhorniae, F. moniliforme, F. oxysporum (isolate 2), F. pallidoroseum (isolate 3) and I M. advena gave more than 45 per cent intensity of infection. Cell free metabolites of the various fungi also varied in the symptom development. Intensity of damage varied from 8.03 to 89.00 per cent. Maximum was recorded by M. advena followed by F. pallidoroseum (49.80 per cent), A. eichhorniae (48.80 per cent) and F. oxysporum (47.20 per cent). Host range of A. eichhorniae, F. moniliforme and F. oxysporum was studied in detail. A. eichhorniae infected only three weed plants out of the 37 cultivated and 39 weed plants tested. F. moniliforme infected five 11 cultivated and 11 weed plants. F. oxysporum was found to be pathogenic to seven cultivated and nine weed plants. Combined application of A. eichhorniae and F. p allidorose um recorded higher intensity of infection than when sprayed alone. A. eichhorniae was found to give effective destruction of the weed at 107 spores per ml concentration. A. eichhorniae at 107 spores per ml and F. p all idoroseum at lOll spores per ml together recorded more intensity of infection of 89.84 per cent than when sprayed alone. Talc based combination product of A. eichhorniae and F. pallidoroseum when sprayed at 10.00 per cent concentration recorded an intensity of infection of 93.20 per cent, 10 days after spraying. The formulated product could retain the viability of spores of the pathogens at room temperature for 15 days.ThesisItem Open Access Biocontrol of bacterial wilt in tomato using arbuscular myaorrhizal fungi(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2003) Nandakumar, A; KAU; Surendra Gopal, KThe studies on "Biocontrol of bacterial wilt in tomato using arbuscular mycorrhizal fungi" were carried out at the Oept. of Plant Pathology, College of Horticulture, Vellanikkara during the period 2000 - 2002. The main objectives of the study were to identify suitable native AMF from high and low wilt incidence areas of Thrissur and Palakkad districts, screen them against Ralstonia solanacearum in pot culture under sterile and wilt sick conditions, to determine the optimum inoculation time and inoculum density of :\\1f and to test ~h,- ,,;;;cicncy 0: Aj,\1f in thc wilt sick field. The soil samples collected from Thrissur and Palakkad district were analyzed for their nutrient status, pH, Ralstonia population and total AMF spore count. The Vellanikkara soils were acidic with low ,K, Ca and Mg and high P content when compared to Ozhalapathy and Eruthiampathy soils. The Ralstonia population were generally higher in Vellanikkara soils. On the other hand, Ozhalapathy soils had higher AMF spore count. The Glomus sp. was found to be the most predominant AMF in the soils of high wilt (Vellanikkara, Thrissur district) and low wilt incidence (Ozhalapathy and Eruthiampathy, Palakkad district). The screening of the predominant native AMF cultures against R. solanacearum were carried out individually and in combinations under sterile conditions along with the TNAU commercial culture [or comparison. The treatments with the native AMF combinations 1'i2., GIOIllIlS sp. (OT) + Glomus sp. (ER), Glomus sp. (OT) + Glomus sp. (VM) and Glomus sp (OM) - Glomus sp. (VBT) recorded the least percent wilt incidence with the native A0.1F combination Glomus sp. (OM) + Glomus sp. (VBT) recording the maximum number of days of plant survival (11 days). The dry weight and root length were also higher for these three native AM F combinations. The determination of the optimum inoculation time (at the time of sowing, at 15 days before transplanting and at the time of transplanting) in combination with the inoculum density (@ 25 g kg 1 soil, 50 g kg 1 soil and 75 g kg -I soil) were carried out using different species of AMF in pot culture using wilt sick soil. The inoculation time at 15 days before transplanting 75 g kg -I soil was found to be optimum. This was evaluated further, under pot culture and field experiment studies using the native AMF combinations selected from the screening experiment. The selected native AMF combinations from the screening experiment were tried at 15 days before transplanting @ 75 g kg -I soil in pot culture using wilt sick soil in comparison with the TNAU commercial culture to select the best two combinations for the field experiment. The native AMF combinations recorded the least percent wilt incidence and maximum number of days of plant survival when compared to the TNAU commercial culture. The AMF combinations Glomus sp. (OM) + Glomus sp. (VBT) and Glomus sp. (OT) + Glomus sp. (VM) were found to be the best. A field experiment to test the efficacy of the selected native AMF culture combinations were carried out using the tomato varieties Pusa Ruby (susceptible) and Mukthi (moderately resistant). The native AMF combination Glomus sp. (OT) + Glomus sp. (VM) recorded maximum number of days of plant survival (32 and 50 days respectively) in both the tomato varieties. However, it could not prevent wilt incidence in the case of Pusa Ruby variety, which recorded 100 percent wilt, and Mukthi variety 97 .. 9 % wilt incidence. The same native AMF combinations Glomus sp. (OT) + Glomus sp. (VM) also recorded maximum fruit number in Mukthi whereas Pusa Ruby did not produce fruits as they did not survive even upto flowering. The present study clearly indicated that the native AMF combination Glomus sp. (OT) + Glomus sp. (VM) was the best in pot culture studies using wilt sick soil and could delay the disease incidence in the susceptible Pusa Ruby variety of tomato upto 82 days after transplanting. However, under field conditions it could delay the disease incidence in the susceptible variety Pusa Ruby only upto 32 days and in the moderately resistant variety Mukthi upto 50 days. So more extensive studies are needed to develop a suitable native AMF to control the bacterial wilt in tomato which is effective under field conditions.ThesisItem Open Access Utilization of fungi for composting and mushroom production on coirpith(Department of Plant Pathology, College of Agriculture, Vellayani, 2003) Sherin Salam, A; KAU; Geetha, DThe present study entitled "Utilization of fungi for composting and mushroom production on coirpith" was conducted during 2001 to 2003 at College of Agriculture, Vellayani, Thiruvananthapuram district with the objective to isolate most efficient fungi for degradation of coirpith and standardization of technology for mushroom production on coirpith. Four lignocellulolytic fungi viz., Aspergillus niger, A. ochraceous, Trichoderma harzianum and Rhizopus stolonifer were isolated from retted coirpith. Three mushrooms viz., Pycnoporus sanguine us, Ganoderma applanatum and Pleurotus tuber-regium collected during surveys conducted in different parts of Thiruvananthapuram district, and Lentinus edodes, Pleurotus florida and Calocybe indica were procured from TNAU and College of Agriculture, Vellayani. P. tuber-regium, a mushroom collected during the study is a new report from India. This edible mushroom has a biological efficiency of 46 per cent and is ideally suited for cultivation in Kerala. T. harzianum was the fastest colonizer on retted coirpith followed by G. applanatum and L. edodes. The maximum reduction of organic carbon, C:N ratio, cellulose and lignin and the maximum increase of nitrogen content in retted coirpith was recorded when it was degraded by T. harzianum, Among the different substrates used for mushroom production, the maximum yield of P. florida was realized in a substrate containing 1: 1 combination of retted coirpith and spent mushroom substrate while the maximum yield of C. indica was observed in a substrate containing 1:3 combination of non-retted coirpith and paddy straw. , Composted coirpith was found to be unsuitable as a substrate for large scale cultivation of oyster and milky mushrooms.ThesisItem Open Access Biological management of phytophthora pod rot of cocoa(Department of Plant Pathology, College of Horticulture, Vellanikkara, 2004) Bhavani, R; KAU; Koshi, AbrahamPhytophthora pod rot (PPR) is one of the serious diseases of cocoa in Kerala. Fifteen isolates of the pathogen were isolated from different locations of Thrissur district and their pathogenicity established. The cultural and morphological characters of 15 isolates of the pathogen like growth on Carrot Agar, mycelial width, length of sporangiophore, sporangial ontogeny, length and breadth of sporangia, L/B ratio, and pedicel length were studied. Based on these characters, the different isolates were identified as Phytophthora palmivora (Butler) Butler. To find out the variations among the isolates of P. palmivora the morphological, virulence and protein profile characteristics of 15 isolates were studied in addition to their sensitivity towards fungicides and antibiotics. Analysis of data on protein profiles and sensitivity towards fungicides did not show much variation among the isolates. But the isolates showed some variations with regard to their morphology, virulence and sensitivity to antibiotics. Among 225 cocoa types screened for host resistance, eight cocoa types viz., G VI 14, G VI 73, G VI 77, G VI 124, G VI 138, G VI 154, G VI 279, G VI 284 showed moderately resistant reaction. Sixty three types were moderately susceptible and rest highly susceptible. Quantitative estimation of epiphytic microflora from cocoa pods yielded more bacteria than fungi and actinomycetes. The epiphytic fungi and bacteria showed antagonistic activity against P. palmivora. Actinomycetes were not antagonistic to the pathogen. Eight fungal and seven bacterial antagonists including standard cultures of T. harzianum and P. fluorescens [Pf (K) and Pf (T)] exhibited maximum inhibition on the pathogen. Studies on the detached pods revealed the efficacy of epiphytic fungal isolate 20F and two bacterial isolates 23B and 24B against the pathogen. The efficient fungal isolate 20F was identified as T. viride Pers. ex. S.F. Gray and the bacterial isolates 23B and 24B as P. fluorescens Pelleroni. The mechanism of antagonism of epiphytic T. viride and standard T. harzianum was studied. The antagonists overgrew the pathogen and showed interactions like coiling, penetration, hyphal malformations and disintegration of host hyphae. Three P. fluorescens isolates including Pf (K) produced HCN and siderophores. T. viride (20F) and T. harzianum were compatible with Akomin 40 and Indofil M45. They were incompatible with Bordeaux mixture, Bavistin and Kocide. Fytolan was partially compatible. The two fungal antagonists were compatible with insecticide phorate, while Sevin was partially compatible. Ekalux, Nuvacron and Endosulfan were incompatible. Ammonium chloride, Rajphos and MOP were compatible with two Trichoderma spp. while ammonium sulphate was incompatible. Two native P. fluorescens (23B and 24B) and standard Pf (K) were compatible with Akomin 40, Indofil M45 and Bavistin and incompatible with Bordeaux mixture, Kocide and Fytolan. With regard to insecticides, the lower two concentrations of Sevin, Ekalux, Endosulfan and Nuvacron were compatible with the bacterial antagonists, while higher concentration was incompatible. Phorate was partially compatible. Fertilizers like Rajphos and MOP were compatible with antagonists. Urea was incompatible. Ammonium sulphate and ammonium chloride were partially compatible. Among different fungicides screened, Bordeaux mixture, Fytolan and Kocide completely inhibited P. palmivora. The lower two concentrations of Akomin 40 and Indofil M45 at all concentrations permitted slight growth. Bavistin was not inhibitory to the fungus. Nuvacron at all concentrations, the highest concentration of Ekalux and two higher concentrations of Endosulfan were inhibitory to the pathogen. Sevin and phorate exerted varying levels of inhibition. Urea and MOP were not much inhibitory to the pathogen. Ammonium chloride, ammonium sulphate and Rajphos showed partial inhibition. Field evaluation of isolates of P. fluorescens [23B, 24B, Pf (K)] and two Trichoderma spp. revealed the efficacy of fluorescent pseudomonads in reducing the incidence of PPR of cocoa. The efficacy was comparable with the recommended fungicides.ThesisItem Unknown Characterisation of a tospovirus causing necrosis disease of cowpea (vigna unguiculata (L.) walp.)(Department of Plant Pathology, College of Agriculture, Vellayani, 2005) Ayisha, R; KAU; Umamaheswaran, KStudies were conducted on the tospo virus causing necrosis disease of cowpea [Vigna unguiculata (L.) Walp.] in Kerala. This investigation was conducted to characterize the virus. The characteristic symptoms appeared as chlorotic spots, veinal and bud necrosis, distortion and reduction in leaf size. Host range studies were done and the virus was found to have its host range in the members of the families Chenopodiaceae, Solanaceae, Leguminosae, Amaranthaceae and Malvaceae. The virus was mechanically transmitted through sap extracted in 0.01M phosphate buffer (pH 7.2) containing 2mercapto ethanol. The virus could be efficiently transmitted by the aphid vector, Aphis craccivora and Thrips palmi. The virus could be transmitted through graft but not through seeds. Thermal inactivation point was 50-55oC, dilution end point, 10-2-10-3 and longevity in vitro for 4 h at room temperature (28±2oC) and 8 h under refrigerated conditions (8oC). The virus causing necrosis was identified as tospo virus by ELISA and DIBA. Virus was related to WSMV, a tospo isolate. Biochemical changes indicated a decrease in chlorophyll content in virus inoculated leaves compared to healthy control. There was no significant difference observed in carbohydrates. Increase in protein content was observed in inoculated cowpea plants. The phenol content was found more in inoculated leaves compared to healthy control. The level decreased during later stages. Peroxidase, polyphenol oxidase and phenyl alanine ammonialyase showed a decreasing trend with age in both inoculated and healthy plants. But it was comparatively high in inoculated plants. Native polyacrylamide gel electrophoresis performed for PPO and peroxidase revealed that there was four isoforms of PPO for both inoulated and uninoculated control. Only quantitative change in one of the isoform was observed in PPO. One isoform in peroxidase was observed in inoculated plant but no isoform was observed in healthy. PAGE analysis of proteins with samples extracted from diseased and healthy plants showed the presence of three novel proteins in diseased sample. One of the proteins molecular weight, 28 kDa co-relates with the N-Protein of TSWV reported earlier.ThesisItem Unknown Management Of Bacterial wilt Of Solanaceous Vegetabbles Using Microbial Antagonists(Department of Plant Pathology, College of Horticulture,Vellanikkara, 2003) Manimala, R; KAU; Sally Mathew, KStudies on 'Management of bacterial wilt of solanaceous vegetables using microbial antagonists' was conducted at the College of Horticulture, Vellanikkara during 2000- 2002. The major objective was to find out effective microbial antagonists against bacterial wilt ofbrinjal, chilli and tomato. Estimation of population of R. solanacearum showed the maximum in Vellanikkara than Ozhalapathy. The total rnicroflora was higher in Ozhalapathy than Vellanikkara and resistant varieties of the three crops recorded better association of microflora than susceptible ones. In in vitro evaluation , rhizosphere organisms isolated from the low wilt incidence area (Ozhalapathy) exhibited better antagonism against R. solanacearttm than those isolated from Vellanikkara. Among them, fungi were more effective than bacterial and actinomycete antagonists. The major fungal antagonists belonged to Trichoderma spp. and Aspergillus spp. T. viride (Ozhalapathy), T. pseudokoningii (forest soil) and Aspergillus niger (Eruthyampathy) were the most effective ones against R. solanacearum. Among the bacterial antagonists, P. aeruginosa and B. subtilis (Vellanikkara) were promising one. All commercial antagonists viz. T. viride, A. niger (Varanasi), A. niger (AN 27) T. harziamtm, B. subtilis and P. fluorescens were also effective against R. solanaeearum. Of the culture filtrates tested, T. virens and.E. subtilis (commercial) showed the maximum inhibition of the pathogen. The antagonists which were found most effective in laboratory condition performed well in pot culture studies also. Among the different methods of application of antagonists adopted, either seed treatment + soil drenching or root dipping were effective in reducing the wilt incidence and in delaying the wilt appearance. Use of antagonists in highly susceptible varieties did not give a promising control of bacterial wilt under field condition. In field trial, using a moderately resistant variety Mukthi, antagonists showed some effect in controlling bacterial wilt indicating that, an integrated effect by combined use of host resistance and microbial antagonists can provide a better control of bacterial wilt pathogen in the field.ThesisItem Unknown Effect of nitrogen, phosphorus and potassium nutrition on incidence and intensity of grey blight of coconut(Department of Plant Pathology, College of Agriculture, Vellayani, 2003) Subramanyan, K; KAU; AdvisorSantha Kumari, PThe investigation on the "Effect of nitrogen, phosphorus and potassium on incidence and intensity of grey blight of coconut" was conducted during 2001-2002 at the Coconut Research Station, Balararnapuram, Thiruvananthapurarn, Kerala. The coconut palms cultivated in the Permanent Manurial Trial experimental plot of the station was used for the studies. The pathogen was isolated from the infected leaf tissue by the standard tissue isolation technique. Cultural and morphological studies confirmed the identify of the pathogen as Pestalotiopsis palmarum (Cooke) Stey. Among the different artificial media tried potato dextrose and sucrose were the best for growth and sporulation of the pathogen. Conidial morphology of fungus was studied on six media. The fungus produced largest conidia and appendages on PDA and PSA, while those produced on PDA had the maximum breadth. The maximum incidence and intensity of grey blight was observed in the month of August. During the subsequent months it declined and the least was observed in February . . The incidence and intensity of the disease was correlated with different levels of NPK fertilizer application and nutrition status of palms. Higher rate of nitrogen, phosphorus and potash application in soil resulted in higher rate of these nutrients in the leaf samples and higher rate of the disease. The disease intensity was maximum In palms supplied with the treatment combination N )P2K2 and minimum in N2P2Ko. The highest disease incidence and intensity were observed when the relative humidity was above 83 per cent. The maximum temperature at this period was 29.7oC and the minimum temperature 20.7()C. The rainfall during this period was 243.3 mm. These weather parameters were observed during the month of August. The lowest disease incidence and intensity was observed when the relative humidity was 77.2 per cent. The maximum temperature was 31.4°C and minimum temperature 22.3°C. Rainfall during this period was 15 mm. These weather parameters were recorded during the month of February. There was a positive correlation on the incidence and intensity of grey blight with rainfall, relative humidity and wind speed where as a negative correlation was observed with temperature. Nutrient composition of the healthy leaf tissue indicated that with an increase in the nitrogen level, there was a corresponding increase in the nutrient status of major, secondary and micronutrients. A similar trend was noticed with phosphorus and potassium also. However, with increase in potassium level there was a corresponding decrease in the magnesium content. Similarly with an increase in phosphorus a decrease in zinc and boron content was observed both in healthy and diseased leaf tissues. Both in two way and three way interactions, involving NP, NK, PK and NPK the composition of nutrients of healthy as well as in diseased leaves increased with increase in the levels of nitrogen, phosphorus and potassium. Chlorophyll, total sugar, amino acid and phenol contents in healthy tissues were found to be high with higher levels of fertilizer application.
