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ThesisItem Open Access Genetic variability, path analysis and stability parameters in sesame(Department of Plant Breeding, College of Agriculture, Vellayani, 1985) Sverup, John; KAU; Gopinathan Nair, VBiometric analysis in a varietal collection of sesame was undertaken to study the genetic variability, correlations, path analysis and stability parameters. One hundred sesame types were evaluated in replicated trials at Vellayani in uplands during rabi and at Kayamkulam in rice fallows during summer. Genetic variability and correlations were estimated and path analysis worked out independently as both the locations. Location trials for estimating stability parameters were conducted at three places viz. in uplands during rabi at Pattambi and Vellayani and in rice fallows during summer at Kayamkulam. Large values for genotypic coefficients of variation were obtained for characters such as number of capsules on branches, number of capsules perplant, number of capsules on main stem and number of branches during rabi as well as summer. The lowest genotypic coefficient of variation was obtained for number of days to maturity during both rabi and summer. High values of heritability were recorded by seed protein content , seed oil content, height upto first capsule and weight of 1000 seeds under both conditions.ThesisItem Open Access Trematodes of Paramphistomatidae Infecting Domestic Ruminants(Department of Parasitology, College of Veterinary and Animal Sciences, 1987) Tarun Shankar, Nath; KAU; George Varghese, CThe thesis embodied the results of an investigation on the prevalence of amphistome infection and their specific identity in different domestic ruminants (cattle, buffaloes, sheep and goats) of Kerala state. A total of 1490 faecal samples from domestic ruminants were collected from different places of Kerala State during a period from April 1985 to March 1986. These samples were examined by sedimentation technique to detect infection with amphistomes and their prevalence. Viscera of 780 slaughtered/ dead ruminants from different parts of Kerala were examined in addition and the available amphistomes were collected for the study and specific identification. The flukes were studied alive, flattened and stained and in certain cases by microtomy sections. Result of the study indicated that the prevalence of infection was far more in cattle and buffaloes than in sheep and goats. The rate of prevalence in cattle, buffaloes and goats was 20.16%, 28.57% and 3.22% respectively. In slaughtered/dead animals the prevalence was 33.09%, 34.67%, 4.17% and 5.81% respectively in cattle, buffaloes, sheep and goats. The highest prevalence was recorded during the rainy season and lowest in dry/summer season. Prevalence during south west monsoon was 38.08% and 20.73% during North East monsoon. The seasonal prevalence hardly varied between cattle and buffaloes but it was consistently low in sheep and goats. Most of the prevalence in all animals were of mixed origin. A total number of 17 species belonging to eight genera of amphistomes were identified. Cevlonocotyle spinicephalus (Tandon, 1955) was recorded from new hosts i.e, cattle and goats, cotylophoron chauhani from goats, in addition to the already reported hosts, buffaloes and sheep respectively. The following conclusions are drawn on the basis of the results of this study: Amphistomes are most prevalent in cattle and buffaloes. Though the infection with amphistomes exists throughout the year, it is definitely more in monsoon seasons. Ceylonocotyle spinicephalus (Tandon, 1955) occurs in cattle and goats and cotylophoron chauhani (Gupta and Gupta, 1972 ) in goats also.ThesisItem Open Access Comparative micromorphologial and physico- chemical study of the upland and midupland laterite soils of Kerala(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1986) Sankarankutty Nair, R; KAU; Aiyer, R SThesisItem Open Access Production potential of two fodder grasses under different management practices(Department of Agronomy, College of Agriculture, Vellayani, 1986) Raghavan Pillai, G; KAU; Madhavan Nair, K PThesisItem Open Access Exchangeable aluminium as an index of liming for the acidic upland soils of Kerala(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1987) Meena, K; KAU; Alice, AbrahamAluminium toxicity is the major factor limiting crop production in the acidic soils and the usual practice of alleviating aluminium toxicity is liming* / The present investigation was carried out to find out the distribution of water s dluhle and exchangeable aluminium in the acidic upland soils of Kerala and to test the suitability of exchangeable aluminium as an index for liming them* It was further programmed to find out the growth, yield and nutrient uptake pattern of two acid sensitive crops namely cowpea and fodder maize in soils under different levels of exchangeable aluminium brought out by the use of different levels of lime* Chemical analysis of eighty soil samples representing the five major upland soil types of Kerala viz* laterlte, alluvial, red loam, sandy and forest a oil have indicated the highest amount of exchangeable aluminium and percentage aluminium saturation in the laterite soils* The soil with 3 high level of exchangeable aluminium and percentage aluminium saturation was selected for conducting a pot culture experiment to test the suitability of using exchangeable aluminium as an index of liming* The exchangeable aluminium content of this soil was maintained at different levels by applying different levels of lime and the performance of these crops in this soil was compared by making biometric observations and by chemically analysing plant and soil samples* From the results of the study it was seen that higher levels of exchangeable aluminium adversely affected the growth, yield and nutrient uptake In cowpea and fodder maize* Maintenance of exchangeable aluminium at 1*26 me/100 g with a corresponding percentage aluminium saturation valua of around 30, by the use of 500 kg lime/ha appeared to be the optimum for maximising the yield of cowpea* But in fodder maize this level of lime was found to be insufficient and complete elimination of aluminium toxicity appeared to be essential for maximising production* Since the critical levels of exchangeable aiuainiua appears to be different for different crop3, it is desirable that lias levels to reduce exchangeable aluminium to such a critical level alono be applied. The results of the present study thus point to the advantage in adopting the exchangeable aluminium level of soil as a better index of liming for various crops grown in the upland acidic soils of Kerala.ThesisItem Open Access Study of bacterial leaf spot of betel vine- biochemical changes and control(Department of Plant Pathology, College of Agriculture, Vellayani, 1986) Koshi, Abraham; KAU; James, MathewThe bacterial leaf spot is one of the most serious diseases of betel vine in Kerala. The bacterium is one of the most serious disease of betal vine. Confidering the seriouness of the disease , studies were undertaken on the different aspects of the disease and to find out a suitable control /management practice.ThesisItem Open Access Cytogenetic studies on intervarietal hybrids of sesamum (Sesamum indicum L.)(Department of Agricultural Botany, College of Agriculture Vellayani, Trivandrum., 1984) Chandramony, D; KAU; Krishnan Nair, NThesisItem Open Access Forecasting models for crop yield in cashew (anacahdium occident ale l.)(Department of Statistics, College of Veterinary and Animal Sciences, Mannuthy, 1987) Usha, Menon R; KAU; George, K CThesisItem Open Access Factors governing response of rice to liming in Kerala soils(Department of soil science and Agricultural chemistry, College of Agriculture Vallayani , Trivandrum, 1986) Mary Kutty, K C; KAU; Subramania Aiyer, RA study has been conducted on the factors governing response of rice to liming in Kerala soils with a view to evolve suitable coliorative measures. A five pronged approach to the studies made are highlighted to enable a clear understanding of achievements as against the objectives and approaches made. A laboratory study with one hundred soil samples to assess the nature of acidity of four major rlce growing tracts of Kerala State viz.,Kuttanad, pokali, kole and latoritic alluvium has been carried out. The kuttanad soil lncludes karl, karapadon and kayal lands. Path coefficient anaysis of important fifteen acidity contributing factors against seven parameters for measurement of soil acidity and the inter-relation ships of 22 soil characters show that aluminium saturation of effective CEC is the best parameter for measurement of soil acidity. karapadon and hoyol land3. Path coefficient analysis of Important flftaon acidity contributing factors against seven parameters for racasurcsnont of soil acidity and tho intor-rclationahlpo of 22 soil characters show that aluminium saturation of effective CEG Is tho boot parameter for measurement of soil acidity. '*’*** fifteen factors ldontlflod as proton sources .ooount tor 95.9 por oont of th. mo.ourom.nt. vaulting th. 00. hundnd «il “ "P1” « • 9rOUp*S * pPln0lp*1 . —a erne seven clusters ire formed. This goipaMnt H ^ appliaatlan of prinoip.1 l» a probably th. ur district could however bo grouped together In a cluster with a range of aluminium saturation of effective CBC 70# 1 to 75,0 per cent. The fourth and fifth clusters °f soils studied except the kari soil and having tioir aluminium saturation of effective CCC in tho range of 40.1 to 70.0 por cent. Tho kayal soils of Kuttanad, poWcali and lstsritlc alluvium find a placo in tho sixth cluster with an aluminium saturation of effective CCC in tho range of 30.1 to 40.0 ~jCr cent. The seventh cluster nalnly of lateritic alluvium and a few loss acidic pokkali soils has aluminium saturation of effective CtC below 30.0 per cent. A pot cult ire experiment has been conductod in a highly acid soil hnri s o il o f Kuttanad having tho pH values 3.5 with 39 rico variotioo In or.lor to ocroon out a variety tolorant to acidity. Tho varlotlon hovo boon acroonod £or toloranco to acidltyunlng th. method of D2-0tatloticn. nolocting tho impor- , „h,.a throo cluotoro ora formed. Thoy hova tant character, ano . . flB toiorwit. tedium tolorant boon oharactori«od a and l.aat tolaa th. tolarant varlotl.. Jyothi variety acidity. ****** ^ .jvoc.cy of a p M of ia ranWd t *• • r method, of managmant ..... oowblnlng v.ri.ty 1 including lining and v»»vn>«ing for obtaining better productivity m hl3hly ^ soils of k« . u . liming la a hydro-an\eliorativo process, a pot culeKperlnon,. has been carried out to otudy the effect of 3 -eto^iaia coupled with washing with different levels of water and periods between washing in two highly acid soils. The fact that washing the ooil two or throe tinvas at an interval of 2 days maintaining 10 can water from tlio ooil surface after the application oa lino lu noro efficient often yielding better rerulta with a lower Lining done will certainly make the use of l-inin'1 materials in the management of acid soiis An economic promoaition. This further orroloins the preference for low rates L i •- *- of llmln already acca. tod try farm ra in Kuttanad in spite of oonorve 1 Lae"", of rosoon.sG to li.nin , in resGoj-cn st itions, where tho s o ils ire r.uc.i lesn acid than those confronted in cultivator’s f i e ld a. *, o t cult iroa»no?l.jant hao ixi'.n conducted to otudy tho ff o ' graded lovolo of lining (on dry and wot noli baoio) isingj tiio non'. tr- ,*l-rant vori ty in lour major ncld rlao noil ypon suc„h a-nn Lat-rltic alluvium, Uolo, i»kl;ali and tori soils (,.o f i r s t crop and tho subsequent thrco crons roo:>octivoly. Ml the ros >onso functions fittod hava l>oan in quadratic rxxlol .jcoopt those Involving lo t o r lt ic alluvium. in tolo soil. ti.o residual a££oct o£ limine, io much in , , in tho nocond succeeding avidence only m ^ crop.aCtor which a drastic decrease In ,y#i4enlldd has boon obtained. In th« case of __ r•siflual offoot, however, has been pronounce poWcali no . ^ crop8. In kari soil, th. maximum yl.ld In the second ^ ^ fcha ,uphoat rats of liming nor as could not be obta^ ^ for r.^du.1 effsct.. Th. r.al- • o o n s s ' j u e n o . , r a p i d l y b y t h . .M o n d o r o p dual »PP“ In the case of laterltic alluvium9 application of lime maximum ever* the yield decreases significantly and rapidly. Response functions for the first and second crops could not be worked out. This indicates that tho maximum yiold might have been attained at a lovol of liming bo low 1/4 La doso. However* for the third and fourth crops, at tho rate of liming tried, a quadratic residual response function could bo fitted. Tho results on residual effect of lime hnvo alco shown that higher rates of lirr.e application introduces problems of roacidification at a faster rate. Tho depressive effects of line at higher rate are again a pointer to the need to ac opt low lining rates ;?ut ’./ith frequent applications
