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ThesisItem 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 applicationsThesisItem Open Access Physiological investigations in relation to flowering, fruit set and capsule developmentj of cardamom (elettaria cardamomum maton)(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1986) Vasantha Kumar, K; KAU; Mohanakumaran, NInvestigations were carried out at the Cardamom Research Station, Pampadumpara and at the College of Horticulture, Vellanikkara during 1982 – ’84 to gather information on the physiological factors governing flowering, fruit set and capsule development of the three popular cardamom cultivars, Malabar, Mysore and Vazhukka. Emphasis had been given to unravel the causes of fruit (Capsule) shedding so as to evolve methods of control. Studies on growth and development in a broad sense depicted that an individual tiller of cardamom had a biennial growth habit. The different aspects of flowering and fruit set studied. Indicated that the variability was high in the Vazhukka cultivar and low in the Mysore cultivar. An early crop bearing habit was exhibited by Malabar, whereas Mysore possessed a late bearing habit and Vazhukka exhibited varying trends. The percentage of fruit set was high in Vazhukka, followed by Malabar and Mysore. Influence of climatic components on the physiology of flowering showed that a distinct dry spell triggered the panicle initiation process. The onset of rain coupled with high temperature was congenial for flower opening. A high soil moisture status combined with a high status of relative humidity (which resulted from a well distributed rainfall) enhanced the setting of capsules. Histological studies conducted in the genotype PV-1 (Malabar) showed that differentiation of panicle primordial was more during November to March. A prominent vascular zonation was observed in the rhizome nodes prior to the initiation of panicle promordia. Histology of the seeds revealed the development of starch grains at the greenish- yellow seed stage. Biological assays for endogenous auxins, inhibitors and cytokinins in the developing capsules indicated a spurt in auxin and cytokinin activity preparatory to fruit set. The level of inhibitory substances rose after the fruit set stage, while that of auxins fell which favoured the formation of an abscission zone causing shedding of immature capsules. Exogenous application of NAA (40 ppm) and 2, 4-D (4 ppm) increased the plant height, enhanced the production of panicles and flowers, reduced dropping of immature capsules and increased the yield. The uptake of nutrients revealed that cardamom is a heavy feeder of potash. The Vazhukka and Malabar cultivars developed less nutrients than the Mysore cultivar for producing unit yield of capsules. Radiotracer studies showed that the photosynthetic efficiency of cardamom was more under low light intensities. The rhizome was found to be the main sink in a cardamom tiller. Gas chromatographic estimation of cardamom oils indicated that the Mysore genotype (PR-107) was superior in quality aspects (because of high content of the esters, alpha terpenyl acetate, geranyl acetate and linalyl acetate) when compared with the Vazhukka genotype (PV-5) and Malabar genotype (PV-1). For consumption as a spice as well as for distillation of the essential oils, the black seed stages (‘karimkai’) was the most idel stage in cardamom.
