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Open Access
Land evaluation and suitability rating of the major soils of Onattukara region
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1998) Premachandran, P N; KAU; Subramonia Iyer, M
The need for a scientific approach in inventorying and utilizing land resources most economically and efficiently is now universally accepted. Agricultural prosperity, to a great extent, depends on judicious use of soils and rational application of soils data. A reconnaissance soil survey of Onattukara region was undertaken to study the extent and distribution of the different soils for soil classification, land capability and irrigability classification and for subsequent land evaluation. The study reveals that Onattukara region extends over an area of 40,948 ha. The soil map showing the distribution of the identified twenty soil series has been prepared. The climatological data reveals that the soil moisture regime is , ustic and the soil temperature regime is isohyperthermic. The soils have been classified as per Soil Taxonomy (U.S. Soil Survey Staff, 1975) and Keys to Soil Taxonomy( U.S. Soil Survey Staff, 1994 and 1996). Ten series were classified under Entisols, SIX under Inceptisols, three under Ultisols and one under Alfisols. Based on the inherent soil characteristics and landscape features, the soils have been grouped into three land capability classes, nine capability subclasses and land capability map prepared. The soils were classified into five land irrigability classes, eight land irrigability subclasses and land irrigability map prepared. The soils were evaluated based on principles of land evaluation and rating of productivity parameters. The productivity rating of the soil propertIes agamst the productivity index for nee, coconut, sesamum ,cassava and banana were made and conclusions arrived at. Productivity rating shows that Kottakakam series is best suited for rice, Palamel, best for coconut and banana, Artuva and Mahadevikad, for sesamum and Palamel and Vallikunnam, for cassava. On the basis of the studies carried out, a land use is proposed for the twenty soil series of Onattukara region based on crop suitability ratings and crop suitability map prepared for the five crops taken for study. A proper soil survey interpretation provides information on soil potential, productivity and limitations in their sustained use. Soil survey information forms the major basis for land evaluation. A thorough knowledge of the potentialities and limitations of every piece of land is a prerequisite in its efficient utilization. A systematic survey is essential for the evaluation and classification of the soils based on their inherent soil characteristics, land capability, land irrigability and land suitability. A systematic survey and evaluation of the soils of Onattukara region was taken up to study, interpret, classify and to show their location and extent on base maps. It is hoped that the present study would open up avenues for further investigations on land evaluation, crop suitability and other management aspects for sustained use of soil resource data to the best advantage. This will also form the basis for microlevel planning for integrated and sustainable development of the region under Panchayat raj.
Open Access
Management of foot rot of black pepper (piper nigrum L.) with va mycorrhiza and antagonists
(Department of Plant Pathology, College of Agriculture, Vellayani, 1998) Christin Robert, P; KAU; Sivaprasad, P
Extensive investigation was carried out to develop a native microbial inoculant based technology involving Arbuscular Mycorrhizal Fungi (AMF) and fungal antagonists for the foot rot disease management and growth improvement of black pepper in the nursery and field. Phytophthora capsici Leonian emend A. Alizadeh and P.H. Tsao, the foot rot pathogen isolated from Peringammala, Thiruvananthapuram district was found most virulent isolate. Seven native AMF cultures and fifty fungal antagonists were isolated from Kerala soils. AMF isolates were screened in the green house for plant growth improvement and disease tolerance in comparison with identified species-Glomus fasciculatum, G.clarum and Gigaspora margarita. Of the ten AMF tested isolates Is - 6, Pi - 11, Pi - 9, G. fasciculatum and Gigaspora margarita were very effective in stimulating growth and nutrient (P, K, Ca, Mg, Cu, Fe, Mn and Zn) uptake of black pepper. Regarding the ability of AMF in reducing the foot rot incidence, Glomus fasciculatum recorded the lowest plant mortality and root rot index (53.35% and 62.50%) followed by Is - 6 (60.00% and 64.77%) and Pi - 11 (60.64% and 68.18%) as against 100 per cent mortality and 98.60 per cent root rot index noticed in control. The above five cultures were subjected for further studies. Characterisation of AMF associated with different genotypes of black pepper grown in various soil types indicated the definite influence of soil type on AMF colonization. Sandy soil (oxyaquic quartpsamment) harboured maximum root colonization while forest soil (haplic argiustoll) had the lowest. Species of Glomus particularly G. fasciculatum was the predominant AMF associated with black pepper irrespective of soil type. As an exception Acaulospora and Gigaspora species were frequently noticed in sandy soils. Based on the ability of the fungal antagonists to suppress P. capsici in vitro either through mycoparasitism, antibiosis or soil fungistasis, 24 isolates were selected for green house studies. In the further testing isolates A1, A13, A21, A22and A35 significantly reduced the foot rot infection and increased the plant growth. They showed better population build up in the soil and suppressed the P. capsici population considerably. These native antagonists were further tested in combination with selected AMF in the green house and field. Under green house condition, combination of G. fasciculatum x A1 or A21 showed significant influence on growth stimulation, while Is - 6 x A22 recorded lowest mortality of 32.90 per cent due to foot rot incidence as against 97 per cent in control. The dual inoculation of Is - 6 x A21 and Pi - 11 x A1 was highly effective in plant growth stimulation and disease suppression. Both the combination recorded less than 60 per cent infection and mortality due to the disease, while control showed 95.66 per cent infection and plant mortality. Bordeaux mixture and copper oxychloride recorded 66.67 and 59.68 per cent mortality respectively. AMF colonization and multiplication of antagonists were also favoured by dual inoculation. The potential AMF isolates Is - 6 and Pi - 11 were identified as species of Glomus while, the antagonistic isolates A1, A13, A21, A22, and A35 were confirmed as aspergillus fumigatus Fres., Fusarium oxysporum Schlecht. Ex Fr. Aspergillus sydowii (Bain. & Sart.) Thom. & Church, Trichoderma viride Pers. Ex Gray. And Gliomastix murorum (Corda) Hughes respectively. A technique for AMF inoculation to established pepper vines was developed using ‘carrier plants’. Raising sorghum with AMF inoculation around the pepper vines was found effective to achieve intense colonization in pepper roots by the introduced AMF in the field. This technique developed for the pepper vines may be tried for extending to other perennial crops for AMF inoculation. Promising AMF cultures Pi - 11, Is - 6, G. fasciculatum and antagonists Aspergillus fumigatus, A. sydowii, Trichoderma viride were further tested on eight year old established pepper vines following ‘carrier plant’ based AMF inoculation and cowdung - neem cake based antagonist inoculation. The treatment Pi - 11 x A. Sydowii was most effective with no symptom development, followed by Is- 6 x T. Viride or A. sydowii with disease score of 2.0 as against 7.0 recorded for control. The disease score for bordeaux mixture and copper oxychloride application was 3.5 and 3 respectively. Neem cake-cowdung food base was highly favourable for multiplication and activity of fungal antagonists. The amino acids, total sugar and reducing sugar and total phenols and orthodihydroxy phenol content and activity of cellulose and chitinase were influenced by AMF colonization particularly by Is - 6 and Pi - 11. The positive change could be related with the relative disease tolerance recorded for various AMF isolates. The development of native AMF and antagonists through extensive testing in the green house and field and also the technology of AMF inoculation for established pepper vines are the first record of work.
Open Access
Effect of certain biopesticides and irradiation on the developmental stages of myiasis producing flies
(Department of Parasitology, College of Veterinary and Animal Sciences,Mannuthy, 1998) Subramanian, H; KAU; Rajamohanan, K
A study was undertaken on the prevalence of cutaneous myiasis in domestic animals and its control using bio-pesticides and gamma irradiation. The prevalence of cutaneous myiasis in domestic animals was found to be 205 (2.08 per cent) among .the 9861 animals screened. The peak of infestation was noted in the month of January. In host-wise and parasite-wise the highest incidence was noted in cattle (63.41 per cent) and the majority of infestation was produced by Chrysomya bezziana larvae (90.73 per cent). Methoprene at 1 to 50 ppm concentration caused only moderate mortality on larvae but significantly increased the mortality rate on eggs, prolonged the larval phase, increased the formation of larval pupal intermediaries and adult deformities and reduced the adult emergence. Diflubenzuron at 0.5 to 5 ppm caused 55 to 100 per cent larvicidal effect due to lowered chitin content of 18.42 to 52.11 per cent in larval cuticle. Bacillus thuringiensis var israelensis produced only moderate larval mortality at 160 to 800 ppm in myiasis producing flies. Azadirachtin at 10.5 to 15 ppm produced 100 per cent mortality in eggs and larvae. Significant antifeedant, ovipositional deterrent and repellant effects were also produced by Azadirachtin. Among the extracts of Acarus calamus, studied, petroleum ether extract at 2.5 per cent concentration gave 82.5 to 100 per cent mortality of the larvae. Moderate antifeedant, ovipositional deterrent and repellant effects were also noticed. The petroleum ether extract produced 100 per cent sterility at 0.1 to 1 per cent concentration by preventing the development of ovarian follicles. Three day old pupae of myiasis producing flies exposed to r-rays gave excellent sterility effect at 2000 to 4000 rads radiation exposure without any other deleterious effect in the flies. Diflubenzuron at 5 ppm concentration showed the highest larvicidal effect (88.5 per cent) in natural cases of cutaneous myiasis.
Open Access
Improvement of Anthurium andreanum Lind. in Vitro
(Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 1998) Mini Balachandran; KAU; Ramachandran Nair, S
For refining and establishing micropropagation system for Anthurium andreanum cv. Dragon's Tongue, studies were carried out, to solve many of the problems faced in the micropropagation of the variety, such as, improper foliage development, prolonged period for callus induction and multiplication. Investigations were conducted also to explore alternative explants for micropropagation, induction of somatic embryogenesis and development of artificial seeds, crop improvement through induction of somaclonal variation and radiation breeding in vitro. The study was carried out during 1995-98 at the Plant Tissue Culture Laboratory, Kerala Horticulture Development Programme (R & D), Kerala Agricultural University, Vellanikkara. Surface disinfestation with 70 per cent ethyl alcohol wipe followed by treatment with 0.1 per cent HgCl2 for eight minutes recorded maximum survival (99.74%) of cultures in the case of leaf explants. For spadix explants, ethyl alcohol wipe (70%) + emisan (0.1 %) dip for three minutes followed by HgCI2 (0.1 %) for 10 minutes recorded maximum survival (87.56%) of the cultures. , Among the different explants tried (in vivo and in vitro derived explants) callus induction was maximum in the case of in vivo leaf explants. Callus was initiated (86.50%) within 51 days compared to 90 days reported earlier, when cultured In darkness on to the culture media, Nitsch-white (NW) + kinetin 0.5mgl-1 + 2.4-0 0.3 rngl-1 + sucrose 20 gl-1+ glucose 10 gl-1 + agar 6.0 gl-1. Spadix explants and in vitro derived explants (leaves, nodes, petiole and roots) showed good response to callus induction treatments. Among the in vitro derived explants, root explants recorded the maximum callus multiplication. Callus induction from spadix explants was better (59.85%) in half strength MS basal medium supplemented with 2,4-0 0.3 mgl-1 + kinetin 0.5 mgl-1 +Sucrose 30 gl-1 + agar 6 gl-1. Maximum shoot regeneration (92%) was observed after 46 days in Nitsch media supplemented with BAP 0.5 mgl-1 in the case of leaf callus. In the case of callus derived from spadix explants, half strength MS media supplemented with BAP 2.0 mgl-1 + kinetin 2.0 mgl-1 recorded maximum response (71.42). Multiplication rate (22 per culture vessel) of the shoots and growth and development of the leaves and shoots were better in conical flasks (200ml size). For quicker establishment of the plantlets, mud pots gave the best results (85.33%). Incorporation of vesicular -arbuscular mycorrhizae (VAM) Glomus so., into the potting mix improved the growth of the plantlets ex vitro. Among the explants tried for somatic embryogenesis, in vitro derived leaves (53%) and petiole (18.90%) and immature seeds (8.33%) showed positive response. Induction of somatic embryoids was observed in the media, Nitsch-White (NW) supplemented with 2,4-0 1.5 mgl-1 + kinetin 0.15 mgl-1 + sucrose 20 gl-1 + glucose 10 gl-1 + glutamine 200 mgl-1 + agar 6 gl-1 in explants derived from in vitro leaves and petiole. For immature seeds, response was observed in Nitsch media supplemented with 2,4-02.0 mgl-1 + kinetin 0.3 mgl-1 + sucrose 20 gl-1 + glucose10 gl-1 + glutamine 200 mgl-1. Germination of the somatic embryoids was highest in half strength MS media supplemented with BAP 0.1 mgl-1 + glutamine 200 mgl-1 . Viability of the somatic embryoids was observed to be very low (5-10 days). Encapsulation of somatic embryoids was achieved with calcium chloride at 50 ~M and sodium alginate at 3 per cent level • "j After encapsulation, somatic embryoids can be stored up to 20 days without much loss in capacity for germination (15.50%). Germination per cent of encapsulated somatic embryos was improved (39%) after a low temperature storage (4 0C) for 20 days. Rudimentary leaves were observed in plantlets regenerated from ninth and tenth subculture. The colour of the leaves in such plantlets was observed to be pale green. After transplanting also, the plants exhibited poor leaf growth. In such plants the leaf area remained smaller than other plants. But, chlorophyll development was normal. For radiation breeding using y-rays, the irradiation doses above 150 Gy were found to be lethal to callus as well as for shoot tips. Maximum response in terms of plant height, plant spread and leaf area was recorded at lower dose of 50 Gy. Most significant variation observed in in vitro regenerated plantlets compared to mother plants was the reduction in leaf area of mutants regenerated from explants irradiated with 150 Gy. Height of the plant was also less at higher doses of ƛ-irradiation. The plants obtained from the trial on induction of somaclonal variation and radiation breeding were screened for possible mutants and somacional variants using morphological characters, biochemical markers and cytological technique. Morphological characters were recorded for observing possible variability, at periodical intervals after transplanting. Dwarf mutants were observed at higher doses of y-irradiation. The biochemical studies using isozymes revealed no difference among the plants regenerated from different subcultures and different doses of irradiation. But, difference was observed between the non-irradiated and the irradiated plants for the number of bands produced. Peroxidase isoenzyme was found to be the most stable and was expressed in plants regenerated from different subcultures as well as those from irradiated cultures. Five bands were resolved in the case of plants from the repeated subculturing and two bands were resolved in the case of those regenerated from irradiated cultures. Cytological study showed no alteration in the somatic chromosome number, which remained uniform at 2n=30+2B, in all the plants regenerated from the different subcultures and the irradiated cultures.
Open Access
Genetic analysis of high yielding rice varieties of diverse origin
(Department of Plant Breeding and Genetics, College of Horticulture, Vellanikkara, 1998) Vanaja, T; KAU; Luckins, C Babu
The research project 'Genetic Analysis of High Yielding Rice Varieties of Diverse Origin' was carried out in the College of. Horticulture, Kerala Agricultural University, Vellanikkara, Thrissur during the period 1995-'98. The major objectives of the study were to understand the genetic architecture of high yielding rice varieties of diverse origin so as to evolve appropriate breeding methodology, to isolate promising lines having the new ideotype concepts from the segregating generations and to identify alternative source of cytoplasmic male sterile system suitable to warm humid climatic conditions experienced in Kerala. The study, about components of heritable variation revealed that the characters, number of panicles m-2 number of tertiary branches panicle-1, yield ha-1, spikelet sterility percentage and alkali spreading value exhibited high broad sense heritability coupled with high expected genetic advance and high genotypic coefficient of variation. High broad sense heritability and high expected genetic advance coupled with moderate genotypic coefficient of variation were manifested by the characters, namely, height of plant at harvest, second uppermost internodal length, length of flag leaf, ratio of vegetative phase to reproductive phase, number of spikelets panicle-1 number of grains panicle-1, LIB ratio of grain, milling percentage, amylose content, volume expansion ratio and water uptake. '1 Correlation studies revealed that the principal yield determining components in rice are harvest index, number of tertiary branches panicle-1 number of panicles m-2 number of grains panicle-1 number of spikelets panicle-1. ratio of vegetative phase to reproductive phase, 1000 grain weight, number of days to 50 per cent flowering, number of days to harvest and spikelet sterility percentage. While selecting genotypes for higher yield potential, emphasis should be given for comparatively long vegetative period, short period from panicle initiation to 50 per cent flowering and long ripening period. A selection model was formulated consisting of the characters, namely, yield ha-1 harvest index, number of days to harvest, number of tertiary branches panicle-1 ratio of vegetative phase to reproductive phase and number of grains panicle-1 Cluster analysis revealed that there was no parallelism between geographical distribution and genetic diversity. The 56 genotypes representing different eco-geographical regions were grouped into nine clusters based on genetic distances. Combining ability studies showed that both additive and non-additive gene effects were important, with predominance of non-additive gene action, for all the characters except for 1000 grain weight, second uppermost internodal length and height of plant at harvest. The varieties Vytilla3, Mahsuri, Mattatriveni and Karthika were identified as good general combiners. The varieties Mahsuri, Karthika, Vytilla 3, Mattatriveni and IR62030-18-2-2 showed pronounced cytoplasmic effect on yield and various yield contributing characters. The crosses Vytilla 3 x Mattatriveni, Mahsuri x Vytilla-3 an,d Mahsuri x Mattatriveni are recommended for recombination breeding. The crosses Vytilla 3 x IR36, Vytilla 3 x IR60133-184-3-2, PK3355-5-1-4 x Bhadra, Vytilla 3 x Mattatriveni, Karthika x Bhadra, PK3355-5-1-4 x Karthika and PK3355-5-1-4 x IR620'30-18-2-2 are recommended for heterosis breeding. The cytoplasm of Vytilla 3 (an improved saline tolerant variety of Kerala) was identified as an alternative source for cytoplasmic male sterility in rice, suitable to warm humid tropical climate, experienced in Kerala. The varieties IR36 (international check) and Hraswa (extra short duration high yielding variety of Kerala) are the proposed maintainer lines. Mattatriveni is the proposed restorer line for the proposed IR36 'A’ line and Hraswa 'A’ line. The generation mean analysis using six parameter model revealed that both additive and non-additive gene effects played an important role in the inheritance of yield and important yield components, with predominance of dominance, additive x additive and dominance x dominance type of gene effects. Results of inbreeding depression indicated absence of reduction in vigour in the F2 generations for yield and all other yield attributes. Investigation on pattern of inheritance of kernel colour revealed that kernel colour in rice is a complex qualitative character. Each red and white colour may be separately controlled by two or more sets of genes having both inhibitory and duplicate type of gene interactions with predominance of inhibitory type gene interaction. From 22F2 generations, seven early stabilized promising lines and 26 promising segregants were selected. Two early stabilized lines were found to possess most of the ideotype features proposed by IRRI with preferable cooking quality characters. Their further evaluation and multiplication are being carried out at the Agricultural Research Station, Mannuthy, Kerala Agricultural University. By hybridization, it was possible to successfully transfer the non sticky nature and red kernel colour of Mattatriveni to a high yielding Taiwan variety whose kernel is white and sticky on cooking. The gene action studies revealed that there is ample scope for yield improvement in rice both through pedigree breeding and heterosis breeding. As yield and yield components were found to be under the control of all the three types of gene actions namely, additive, dominance and epistasis, intercrossing of early segregating generations derived from multiple crosses seems to be the best suited method of breeding for yield improvement in rice. Future line of studies suggested 1. Conversion of the already obtained cytoplasmic male sterile F1 crosses to fully sterile CMS lines by repeated back crossing with the respective recurrent parents. 2. Screening from the segregating populations of these cytoplasmic male sterile crosses for 100 per cent cytoplasmic male sterile lines. 3. Confirmation of the restoring ability of the proposed Mattatriveni 'R' line and identification of other restorers. 4. Incorporation of the sterile cytoplasm of Vytilla 3 into other elite genotypes other than IR36 and Hraswa. 5. Screening for cytoplasmic male sterile system in other saline tolerant lines. 6. Screening of promising segregants selected, for high yield and quality with multiple resistance to pest and diseases, for developing varieties suited to various climatic and soil conditions of Kerala.
Open Access
Development of diagnosis and recommendation integrated system (DRIS) in black pepper (Piper nigrum L.) in relation to yield and quality characteristics
(Department of Agronomy, College of Horticulture, Vellanikkara, 1998) Sreekumaran, V; KAU; Neelakandan Potty, N
An investigative analysis was undertaken during 1993-96 to work out an objective and effective technology for nutritional management of black pepper based on cause and effect relationship. A critical and comparative evaluation of the available methods in this connection, viz. critical level concept, DRIS concept and management based on soil test data, soil analysis was envisaged. Approved standard procedures m estimating soil available and plant contents of nine elements, viz. N P K Ca Mg S Fe Zn and Mn and standard statistical methods were used in the study. A total of 1200 plants aged 14 years maintained at RARS, Ambalavayal were used as the test material in the study. A non-genic variability in yield ranging from 0.16 to 13.8 kg plant-1 was manifested by tile crop which indicated that variability shall be bridged upwards through managerial techniques. The range of available status of the elements in the soil analysis was very high. The lowest range of 0.9 to 4.5 ppm and the highest range of 144 to 1324 ppm were recorded by Zn and Ca, respectively. Soil pH ranged from 4.3 to 6.8. These were at the individual plant level. Foliar content as well as the range of the elements were much less and did not exactly related to soil available contents. Results also indicated that elements showed significant and specific interactions among themselves which varied with the elements. The pattern and magnitude of interactions at soil and plant level were different. Evaluation of soil test data of the study against approved soil test 0 - 9 scale classification showed that rhizosphere environments belonged to medium rich to very rich class and that it could not explain the yield variability and hence could not be a reliable basis of nutritional management in fertile soil. Examination of the foliar content of elements and their comparison with critical levels and ranges fixed by De Waard (1969) and Nybe (1986) respectively, showed that foliar content of all the elements in the study were above the critical levels which suggested that the critical level concept cannot be an adequate guiding principle in nutritional management of black pepper. It may be adequate only in situations where any element becomes specifically critical. Its inadequacy may also be due to the positive and negative interactions of elements in the plant system as well as due to the fact that yield is the resultant of a process involving several elements simultaneously. Negative relationship of P in the early stages and yield level of 6.5 and <1 kg berries at 2.33 and 2.35 per cent level and similar observations confirmed the above contention. DRIS concept was found to be more adaptable to explain the yield variability as it takes into account the content as well as interaction represented by ratios of every element with the others of the high yielding plants and tries to simulate them in low yielding plants. Results of the present study showed that by employing the DRIS concept and nutrient ratios, the content of every element can be identified at any time as absolutely deficient, relatively deficient, relatively sufficient, relatively excess and absolutely excess. This classification enabled to define the nature of recommendation as additive, deletive or ameliorative/corrective. Testing of the classification of the population into discriminative low and high - yielding sub-populations employing mean ± one SD showed that the system may be perfect when the magnitude of yield limiting factors in the entire range of low yield is the same. Possibility of variability in yield limiting factors could be accommodated by sub-dividing the lower yield group into smaller groups as was done in deciles in the study. The results appeared to show that the per plant variability can be accommodated with reasonable accuracy in such a system of micro level yield group identification and application of DRIS norms to them. The unique advantage of the DRIS system to reach the maximum realizable yield through progressive diagnosis based on progressive experimentation shall be substituted by the decile classification proposed in the study to a very good extent. Results of the present study showed that yield and quality factors are largely independent of each other and both can be improved by integrating the respective components even at the higher yield levels obtained in the present study. Analysis of inter-correlation matrix among elements at soil and plant level revealed the possibility of making specific recommendations to achieve progressive yield increases by working out quantity, intensity and rate of release characteristics. of elements in the soil in relation to absorption. Results in the present study showed that scientifically speaking the captions of DRIS indices or index values as " order of requirement" be modified as "order of limiting influences" - the former part of which is relative to metabolic deficiencies and the latter part to the metabolic excess. Imbalance indices have to be viewed as qualitative and not quantitative indices as they are relative, primarily based on the relative deficiencies and excesses which in turn are dependent upon the relative contents and valencies of the ions. The results of the study also revealed that with progressive increase in yield, causing .higher nutrient removal, will make the soil not only more deficient but also increase the frequency of application of nutrients more. The progressive increase in the number of limiting factors with yield improvement caused by higher rate of removal calls for more frequent monitoring and not treating the norm as static for a long period. The results of the experiment have brought to light a graded pattern of nutritional management for black pepper. The primary limiting factors were found to be high native content of Fe and Mn which will have to be ameliorated. Secondly, at the low yield level the yield is limited by a relative deficiency of Zn caused by high P calling for a temporary skipping of P; supplemented with N and K which can take the yield up to 5 kg plant-1. Excess S through the incidental application of prophylactic sprays of Bordeaux mixture and shortage of Ca and Mg appear to be the limiting factors at the higher yield class. Amelioration of acidity by supplying Ca + Mg carbonate, substitution of S containing fungicides and application of N and K shall constitute the recommendation, beyond which P may have to be applied.
Open Access
Processed aortic allografts for oesophagoplasty in dogs
(Department of Surgery, College of Veterinary and Animal Sciences, Mannuthy, 1998) Balagopalan, T P; KAU; Muraleedharan Nayar, K N
The study was conducted with the objectives of a. Preparation, preservation and evaluation of chrome/ glutaraldehyde cross linked aortic tissue of dogs and to compare the relative acceptability and efficacy of them for cervical oesophagoplasty in dogs, and b. Evaluation of modified pharyngostomy feeding method and its effect on healing at cervical oesophagoplasty site in dogs. The experiment was conducted in thirty, apparently healthy, adult, nondescript dogs of either sex weighing 9-13 kg. The animals were randomly divided into three groups viz.,, group I, II and III. Group II and III were subdivided into two subgroups each, namely IIA, IIB and iilA, IIIB. Group I and the subgroups consisted of six animals each. Animals of group I were subjected to sham operation. Cervical oesophagoplasty using chrome processed aortic allograft and glutaraldehyde processed aortic allograft were performed in animals of group II and III respectively. Pharyngostomy tube feeding was instituted in three animals of group I and all animals of subgroups IIB and IIIB. Tissue samples of thoracic aorta harvested from dogs, processed and crosslinked with chromic sulfate and glutaraldehyde were used as graft materials. Chrome processed aorta showed better biomechanical qualities except for tensile strength than glutaraldehyde processed aorta. The grafts had fairly good handling qualities and shelf life. All the animals were premedicated with triflupromazine hydrochloride and anaesthetized using thiopentone sodium to effect. Wound, oval in shape measuring 3-4 cm long and l/3rd of the circumference of the oesophagus was created in all experimental animals. Oesophagoplasty was performed by fixing the graft material over the defect using 5-0 braided silk thread and continuous lock stitch sutures. Left side' pharyngostomy was performed in 15 dogs. Suitably designed siliconised catheter made up of modified polyvinyl chloride with an attached X-ray opaque line was used as pharyngostomy tube. The tube was kept in situ for a period of 15 days postoperatively for administration of fluid diet. The animals were kept under observation for varying periods of 15, 30 and 60 days postoperatively. The animals of subgroups IIB and IIIB became alert and active earlier than that of IIA and IIIA. At the cervical region, the operated site showed mild inflammatory reaction by 1-2 days postoperatively in all animals. The sutures were removed after normal healing by 7-8th day in all animals except one each in subgroup IIA and IIIB, where it was removed on the 10th day. Mild bleeding while performing pharyngostomy (one dog) and moderate pain and slight swelling around the pharyngostomy tube entrance site (3 dogs) were observed in subgroup IIB. One animal in subgroup IIIB showed severe inflammatory oedema around the tube entrance site. Tolerance of pharyngostomy tube was excellent in 13 dogs. The pharyngostomy wound healed completely by 14-15th day after removal of the tube in all the dogs. All the animals started feeding on liquid food by seventh day postoperatively in subgroups IIA and IIIA following hyperalimentation via intravenous route and by 15th day in subgroups IIB and IIIB following hyperalimentation via pharyngostomy tube. They maintained normal apetite and feeding habits thereafter during the period of observation. Mild swelling at the operated site while swallowing (3 dogs) and vomiting (one dog) were noticed among the animals of subgroup IIA and IIIA. Initial tube obstruction during first feeding (6 dogs), vomiting after first feeding (2 dogs) and mild diarrhoea (one dog) were observed among animals of subgroup IIB and IIIB.
Open Access
Immunopathological response of the duck (Anas platyrrhyncos domesticus) to sublethal dose of selected agro-chemicals
(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1998) Vijayan, N; KAU; Valsala, K V
The study was conducted with the objective of assessing the teratologic, embryotoxic and immunopathologic effects of two agro-chemicals carbofuran and 2,4-D used in agricultural operations, on duck embryos and ducklings. The embryological studies included the observation on the embryonic defects and weight of the lymphoid organs along with the histopathologic and ultrastructural studies of the lymphoid organs like the bursa, spleen and thymus. The results showed that the contamination of the eggs with the above chemicals caused moderate deleterious effects on the lymphoid system, though no teratologic effects could be observed. The histological and ultrastructural changes also confirmed the deleterious effects at the tissue and cellular level. The immune system of the ducks exposed to the above chemicals for two different durations were assessed using a battery of tests. The humoral immune system was assessed based on the body weight, lymphoid organ weight, haematological evaluation, serum biochemical evaluation and the evaluation of HI titre against NDV. The cell-mediated immune system was assessed by the skin reactivity tests to DNCB and PHA. LMIT and GVHR were also employed to assess the cell-mediated immune system. The histological and ultrastructural studies were also conducted after six weeks and ten weeks of the experiment. The assessment of the immunological profile employing these elegant tests revealed that these agro-chemicals caused mild but significant suppression of the cell-mediated and humoral immune response. By this investigation it was clarified that these agro-chemicals have mild to moderate degree of immunotoxic effect when exposed for a short duration, but the changes were severe when exposed for longer duration. From the .studies, it was demonstrated that the immunotoxic effect of carbofuran is more compared to 2,4-D (herbicide) and the changes were dose and time dependent.
Open Access
Ovarian response to gonadotrophin releasing hormone in non-cyclic goats
(Department of Animal Reproduction, College of Veterinary and Animal Sciences, Mannuthy, 1998) Aravinda Ghosh, K N; KAU; Mathai, E
The study was conducted to evaluate the effect of Gonadotropic Releasing Hormone (GnRH) on ovarian activity and its usefulness in restoring normal oestrous cycle in adult non-cyclic goats. A total of 60 healthy Malabari, Malabari x Saanen and Malabari x Alpine does aged one to four years, with a record of one or more kiddings and 45 days post partum belonging to Goat Farm of Kerala Agricultural University, Mannuthy were closely observed for a period of 60 days for the occurrence of oestrus and serum samples were collected at fortnightly intervals for the estimation of macro and micro minerals. Serum progesterone profile in eight cyclic and sixteen non-cyclic does, selected at random, were estimated by Radioimmunoassay using a coat-A-count progesterone kit. Out of eight non-cyclic does treated with potent GnRH anologue (Buserelin) three responded to single dose and one responded to a second dose. The oestrus was exhibited at a mean of 87.000 ± 9.950 h after the administration of GnRH analogue. The mean length of oestrous cycle and duration of oestrus in cyclic does were 20.313 ± 1.553 days and 37.500 ± 7.263 hrs while in GnRH responded does were 12.750 ± 0.830 days and 18.000 ± 4.240 hrs, respectively. The mean serum phosphorus level was found significantly higher in GnRH responded does (5.375 ± 0.205 mg per cent) as compared to cyclic does (4.800 ± 0.260 mg per cent) and non-cyclic does (4.770 ± 0.280 mg per cent). There was significantly higher serum copper level in GnRH responded (1.123 ± 0.089 ppm) and in cyclic does (1.160 ± 0.170 ppm) as compared to non-cyclic controls (0.830 ± 0.110 ppm) . The serum zinc level was significantly higher in non-cyclic (1.510 ± 0.430 ppm) as compared to cyclic (1.180 ± 0.120 ppm) and GnRH responded does (1.155 ± 0.091 ppm). There was no significant difference in the serum calcium, cobalt and manganese level between the three groups. The mean serum progesterone in cyclic does for the two consecutive cycles was 0.304 ± 0.087, 1.294 ± 0.382, 2.531 ± 0.758, 3.619 ± 0.794, 2.456 ± 0.430 and 0.871 ± 0.246 ng/ml and in GnRH responded does was 0.158 ± 0.026, 0.800 ± 0.177, 1.475 ± 0.334, 0.675 ± 0.236, 0.280 ± 0.030 and 0.120 ± 0.021 ng/ml on day one, four, six, ten, 14 and 18 of cycle, respectively. The overall mean serum progesterone during induced cycle in GnRH responded does was 0.535 ± 0.139 ng/ml which was significantly lower as compared to cyclic does (1.848 ± 0.339 ng/ml) but significantly higher as compared to untreated non-cyclic does (0.190 ± 0.106 ng/ml), Detailed biometry studies of pituitary ovary, uterus and cervix of GnRH responded does showed non-significant increase in the size and weight as compared to untreated non-cyclic does. The mean number and size of follicles were found significantly higher in GnRH responded as compared to non-cyclic does. The mean tissue ACP, ALP and LDH in the pituitary, ovary and uterus of GnRH responded does showed non significant increase as compared to untreated non-cyclic does. The mean LDH level in both ovaries together was significantly higher in GnRH responded does as compared to non-cyclic does. The present study confirms that GnRH administration in non-cyclic does has reactivated the ovary by increased follicular growth, maturation and corpus luteum formation. However, the length of induced oestrous cycle, duration and intensity of oestrus was significantly less in GnRH responded does

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