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Open Access
User centered design, development, and end-user assessment of an M-tool for vegetable cultivation in polyhouse
(Department of Agricultural Extension, College of Agriculture,Vellanikkara, 2022-05-20) Poornima C P; KAU; A Sakeer Husain
Hi-tech farming is gaining grip in Indian farming system. Polyhouse farming which is a subset of hi-tech farming is an alternate new system of crop production which reduces dependency on climatic factors along with economic use of water, fertilisers and other inputs necessarily needed for farming. In a state like Kerala where per capita availability of land is less and density of population is increasing, the polyhouse can be a boon to the farmers. With advancing technologies, proper information delivery system must be there to make f armers get updated with the progress in agriculture. As Information and Communication Technology (ICT) tools are acquiring its foothold even among the rural communities, proper utilisation of suitable tools can help farmers to get more insight of the advances and in turn aid in efficient decision making.
Open Access
Performance analysis of farmer producer companies (FPCs) in Kerala
(Department of Agricultural Extension, College of Agriculture, Vellanikkara, 2022-05-28) Akhil Ajith; KAU; Bonny,Binoo P
Farmer Producer Companies (FPCs) are institutional innovations that hold tremendous potential in influencing the agricultural value chains by creating economic profit and social value. As such, the standard measures of financial analysis alone cannot provide an overall indication of the performance of these organisations.Therefore, an attempt to use integrated dimensions of socio-economic parameters were pursued in the present study to delineate the factors affecting the performance of FPCs and in the development of a performance index to grade the FPCs. The results of thestudy also helped in evolving policy recommendations that could improve the performance of FPCs in a sustainable way. The study followed ex-post facto research design conducted among 30 FPCs selected randomly from the 14 districts of Kerala. Proportionate random sampling was employed to ascertain the number of FPCs selected from each district and to identify 120 shareholders. Random and exhaustive sampling was followed respectively in the selection of 60 director board members and 30 CEOs to make the total sample size of 210.
Open Access
Institutionalization of decentralized planning in agriculture in Kerala: trends, determinants and policy imperatives
(Department of Agricultural Extension, College of Agriculture,Vellanikkara, 2022-03-30) Abdul Jabbar P K.; Jiju P Alex
Kerala has successfully evolved a paradigm of decentralized planning by utilizing the provisions of the 73rd and 74th amendments of the constitution. Local governments have been transformed as effective instruments for formulating and implementing development programmes through people’s participation. They are empowered to discharge such functions through strategic devolution of functions, functionaries and funds. Though a robust framework has been evolved over time to make decentralized planning operational, several bottle necks related to local governance affect the efficacy of planning and implementation processes at the grassroots level. This is evident in the productive sector in general and agriculture in particular. It was in this backdrop the present study was conducted. The study was primarily intended to describe the process of institutionalization of decentralized planning in agriculture in Kerala. In this connection, transitions in the administrative framework and policy environment of decentralized planning were also explored. The determinants of the efficacy of decentralized planning in agriculture and the nature of their influence as experienced by major actors of the process were also identified. The study also explored the accomplishments in the agricultural sector since institutionalization of decentralized planning. Alongside, policy imperatives of the experiences of institutionalization were delineated. The sample consisted of 160 respondents comprising of agricultural officers, panchayat presidents and members of the agricultural working group of various development sectors. Respondents were drawn from 40 grama panchayaths selected from five districts representing the five major agroclimatic regions. The study has revealed that there are 15 distinct processes of decentralized planning in the productive sector at the LSGI level. They have evolved over a period of three five-year plans through various iterative processes and drawing lessons from diverse field experiences. The state government plan allocation to local selfgovernments showed decreasing trend from Ninth Five Year Plan onwards. While local self-government institutions (LSGIs) had been provided with 29.29 per cent of state plan fund allocation, it was reduced to 22.9 per cent and 24.2 per cent in the tenth and eleventh five-year plans respectively. Plan expenditure of LSGIs was found to range from 74.81 per cent to 105.25 per cent during this period. It could also be observed that the mandatory sectoral ceilings for productive sector enforced in various plans have succeeded in ensuring investment in various sub sectors of agriculture. Many institutional innovations were initiated to foster people’s participation in planning. Introduction of ward development committees and Ayalsabhas was a major step towards this direction. However, attempts towards additional resource pooling, collaboration with academic institutions to enhance quality of projects and attempts to avoid thin spread of resources were found to be ineffective. Formulating agricultural projects with the assistance of cooperative sector and integrating central and state schemes were also not effective. In spite of the guidelines for formulating joint projects and muti year projects, local bodies were not venturing to such projects, suggesting that a motivational measure to promote joint projects among local bodies be introduced. Moreover, selection of members to the working group and PPC have to be according to their capabilities adjudged based on a state wide criteria. Employing modern technologies for primary processing and value addition, better provision of services, networking of producers and efficient marketing were not adequately mainstreamed by LSGIs in their plans. The efficacy of processes involved in decentralised planning was perceived differently by different categories of actors. Out of the 15 processes, plan appraisal, integration and implementation were perceived to have low efficacy. Plan formulation and resource allocation were also found to have low efficacy. Integration of projects had the lowest efficacy perception score. However, approval of plans by the District Planning Committee, preparation of detailed projects by the working group, holding of Gramasabha, preparation of draft plan proposals and discussion in the development seminar were reported to have high efficacy. Analysis of the attributes of the actors which contributed to their perception on the efficacy of decentralized planning process revealed that four major factors viz. participation, group decision making, experience and knowledge mediation could explain 77.22 per cent variance. Majority of agricultural officers had medium level of perceived efficacy, significantly influenced by their participation-performance interdependence factor and decentralization- development facilitation factors. Role performance of Agricultural Officers in decentralised planning was found to be high. They had performed their roles actively in budgeting of project proposals, planning, monitoring and evaluation, in the order of involvement. Lowest performance level of Agricultural Officers was found to be in functions related to agricultural extension. Accomplishments of decentralized planning in agriculture were quantified in terms physical targets and financial achievements. Plan fund allocation in the productive sector was found to be the highest in the high range zone, followed by problem zone. Plan expenditure in the districts selected from high range zone, northern region and problem zone was higher than 80 per cent. Projects on various aspects of rice, vegetables and banana had received more funds than other sub sectors during the reference period. With regard to the allocations spent, assistance to labour cost for rice farmers was the major intervention while those for coconut development and promotion of intercropping were less than 10% and 3% of respectively. Compared to other crops, the attention paid by local bodies to development of tuber crops, spices and pulses was less. Cashew being a hardy crop for waste lands did not find any place in decentralized plans of north, central and high range zones. Several deficiencies were found in the process of decentralised planning. Most importantly, there should be focused efforts for enhancing the capacities of working groups and Planning Committees. Integration of development interventions by various agencies at the local level have to be ensured through better coordination. Collective deliberations on sectoral working group reports coordinated by panchayath planning committee will foster shared vision and convergence among functions of various officials transferred to the Grama panchayath. The panchayath level data base, Peoples’ Bio Diversity Register formulated through Bio Diversity Management Committees and the watershed master plan have to be updated through massive farmer participation to ensure data base support to local planning and foster the opportunities for local resource mobilization. Further, assistance for conservation and multiplication of local germplasm, traditional seed reserves by local farmer clusters, community seed banks and seed growers’ networks have to be initiated and the subsidy guidelines have to be broadened to include such initiatives. The perception of poor marketing infrastructure was the most ranked among various constraints analyzed. With regard to projects to bridge the skill gaps in farming and improved service delivery, the existing Agro Service Centres (ASC) at block level and Farmer Service Centres should be networked for technologybased services with supporting projects from decentralized plan allocations. A KVKATMA- LSGD linkage will resolve the issues of less propagation of technologies in projects and less expertise of working group members. To enhance participation of youth in gramasabha a drive on decentralization, gramasabha literacy and the need to participate for youth was suggested as part of school and college syllabus.
Open Access
Endophytic fungi for the management of spotted pod borer, Maruca vitrata Fab.(Lepidoptera:Crambidae) in cowpea.
(Department of Agricultural Entomology, College of Agriculture ,Vellanikkara, 2022-12-09) Smitha Revi; Madhu Subramanian
The spotted pod borer, Maruca vitrata Fab. (Lepidoptera: Crambidae) is a major constraint in the production of legumes because of its wide host range, distribution and destructiveness. In cowpea, the loss due to pod borer infestation varies from 20 to 60 per cent, often reaching upto 80 per cent in severe cases. Application of pesticides can hardly be recommended in cowpea as the pods are harvested at alternate days. Biological control of M. vitrata using entomopathogenic microorganisms has received considerable attention in recent times. Previous studies have demonstrated the potential of entomopathogenic organisms to colonise an array of plants and confer protection from insect pests. In this context, a study entitled “Endophytic fungi for the management of spotted pod borer, Maruca vitrata Fab. (Lepidoptera: Crambidae) in cowpea” was undertaken with an objective of isolation and characterization of endophytic entomopathogenic fungi in cowpea, standardization of method of inoculation of entomopathogenic fungi in cowpea, and evaluation of selected endophytic fungi for management of the spotted pod borer, M. vitrata. Purposive sampling surveys were conducted in the major cowpea growing areas of Kozhikode, Thrissur, Kottayam and Thiruvananthapuram districts of Kerala. A total of 235 endophytic fungal isolates were obtained from the cowpea plant samples collected from 40 locations. This comprised of 103 isolates from roots, 63 from stems, 31 from leaves, 33 from pods and five from flowers. Nine accessions of cowpea with different levels of resistance were also screened for the isolation of fungal endophytes. All the accessions were found to harbor endophytic fungi and yielded 32 isolates. Among these accessions, Palakkadan thandan payar yielded the maximum number of seven endophytic fungi. Lola and Mysore local had the lowest number of isolates. In contrast to the results of survey, the leaves of cowpea plant harbored more endophytic fungi than other plant parts. A total of 267 isolates were obtained from survey samples and cowpea accessions. Three isolates were found to be pathogenic to M. vitrata. They were identified as Fusarium oxysporum (EEF 1) and two isolates of Purpureocillium lilacinum (EEF 4 and EEF 64) through morphological and molecular characterization. These isolates were evaluated along with Beauveria bassiana (NBAIR strain) for their bioefficacy against M. vitrata. The best two organisms in the bioefficacy studies, viz., B. bassiana (NBAIR strain) and P. lilacinum (EEF 4) were used for standardizing the inoculation technique for endophytic colonization in cowpea plant. Three different methods of inoculation viz., seed, soil and foliar inoculation were evaluated for identifying the best method for colonization of entomopathogenic fungi in cowpea plants. The effect of fungal colonization on infestation of spotted pod borer in cowpea was further assessed under field condition. Foliar inoculation with B. bassiana registered the lowest mean pod damage of 12.53 per cent. B. bassiana applied as foliar application resulted in the highest marketable pod yield of 152.83g plant-1 , followed by P. lilacinum as foliar application (149.33g plant-1 ). Based on the polyhouse and field studies, it was inferred that foliar application of B. bassiana was found to be the best treatment against the target pest, M. vitrata. In addition, the results of the current study suggested that that endophytic colonization in cowpea had little adverse impact on plant growth and yield. Foliar application of B. bassiana, which was identified as the most effective treatment against pod borer in the previous studies, was selected for comparative evaluation with the diamide insecticide, flubendiamide against M. vitrata. Cowpea plants treated with both flubendiamide and B. bassiana had significantly less number of infested pods than control, with 8.41 and 15.05 per cent infestation respectively. Control plants recorded the highest infestation of 21.28 per cent. Mean marketable pod yield showed significant difference between flubendiamide (166.14g plant-1 ) and foliar inoculation of B. bassiana (155.14g plant-1 ). Both these treatments also had significantly higher marketable pod yield compared to control plants (139.29g plant-1 ). In conclusion, the present study revealed that use of B. bassiana as an endophyte could be a useful tool in integrated pest management of pod borer in cowpea. However, further studies are needed to understand the mechanisms through which the endophyte
Open Access
Breeding yard long bean(Vigna unguiculata subsp.sesquipedalis (L.) Verdcourt) for anthracnose resistance through conventional and molecular marker analysis
(Department of Vegetable Science College of Agriculture ,Vellayani, 2022) Merin Elza George; Sarada,S
The study entitled ―Breeding yard long bean (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt) for anthracnose resistance through conventional and molecular marker analysis‖ was carried out at the Department of Vegetable Science, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala, during 2019-2022. The objective of the study was to identify molecular marker(s) linked with anthracnose disease resistance in the F2 segregating population of yard long bean, using bulk segregant analysis to enable marker assisted selection along with conventional breeding. The study was undertaken in six experiments. In experiment I, 50 genotypes of vegetable cowpea collected from different parts of India, including the released varieties of SAUs and ICAR institutes were screened against the most virulent isolate of Colletotricum gloeosporioides through artificial inoculation. Among the 50 genotypes tested, VU 53, with semi-trailing growth habit was found to be highly resistant with disease severity of 3.67 ± 0.13 %. Three susceptible, high yielding long podded varieties viz., KAU Deepika, Vellayani Jyothika and Githika, selected as female parents were crossed with VU 53, the most resistant genotype as male parent for the development of three hybrids. In experiment II, two crossing blocks were laid to produce the seeds of three hybrids and their F2 progenies. The three hybrids were evaluated along with the parents under replicated trial in the main field for trailing nature, yield and quality in experiment III. Significant variation was noticed on mean performance of yard long bean parents and hybrids for most of the characters studied. Earliest flowering was observed in KAU Deepika x VU 53 (57.33 ± 0.57 days) and delayed flowering in Githika x VU 53 (71.66 ± 1.15 days). Among the hybrids, the highest pod length was recorded in KAU Deepika x VU 53 (24.50 ± 1.00 cm), while the Vellayani Jyothika x VU 53 had the maximum pod girth (2.90 ± 0.10 cm). Maximum pod weight and pods per plant was recorded in KAU Deepika x VU 53 (19.22 ± 0.58 g and 79.33 ± 0.59 respectively) among hybrids. The cross Vellayani Jyothika x VU 53 (16.55 ± 0.20 g) exhibited maximum seed weight. Among the three hybrids, KAU Deepika x VU 53 (1416.00 ± 126.09 g) recorded the highest yield per plant and was on par with Githika x VU 53 (1343.33 ± 75.06 g). Among the hybrids, KAU Deepika x VU 53 (67.85 ± 0.96 days) was significantly superior for days to harvest. The longest duration among hybrids was observed in KAU Deepika x VU 53 (126.56 ± 0.37 days) and the shortest duration was recorded in Vellayani Jyothika x VU 53 (121.31 ± 0.58 days). High heritability and genetic advance was recorded for vine length, days to first flowering, pod length, pod weight, pods per plant, yield per plant, yield per plot, hundred seed weight and keeping quality. Yield per plant had significant positive phenotypic and genotypic correlation with pod weight, followed by pods per plant, length of terminal leaf, seeds per pod, pod length, crop duration, keeping quality and days to harvest. Pods per plant could be considered as the most important yield trait for enhancing the yield in yard long bean because of its high, positive correlation and direct effect with yield per plant along with high heritability and genetic advance. In experiment IV, parents, three hybrids and F2 progenies were evaluated for resistance to natural incidence of C. gloeosporioides in the main field, as unreplicated trial and without any plant protection measures. All the three F1 were found to be field tolerant. Out of 175 F2 plants of the cross KAU Deepika x VU 53, 164 plants were susceptible and 11 were resistant. In the case of Vellayani Jyothika x VU 53, 175 plants were susceptible among the 187 individual F2 progenies observed. Similarly, in the cross Githika x VU 53, 188 plants were susceptible while 12 plants were found to be symptomless. The F2 progenies of the high yielding hybrid KAU Deepika x VU 53 were evaluated for resistance to C. gloeosporioides through artificial inoculation in experiment V. Out of 196 plants, 185 plants were found to be susceptible whereas 11 plants were resistant which could be utilized in marker assisted breeding programme. The segregation for anthracnose resistance in F2 plants was in the ratio 15:1 (185 susceptible plants out of 196), which suggests that the inheritance of anthracnose resistance may be controlled by two recessive genes. Bulked segregant analysis was done using the DNA from the resistant parent, susceptible parent, resistant F2 bulk and susceptible F2 bulk in experiment VI. Bulked segregant analysis with the SSR primer CLM0008 revealed a polymorphic band at ≈ 300 bp which was appeared in the resistant parent and bulk. Bulked segregant analysis with ISSR primer UBC 811 produced polymorphic bands at ≈ 1100 bp, which were present in resistant parent and resistant bulks. The identified markers linked with resistance were validated over the resistant F2 lines obtained.
Open Access
Integrated nutrient management in minisett cultivation of elephant foot yam {Amorphophallus paeoniifolius (Dennst.) Nicolson}
(Department of Agronomy, College of Agriculture, 2022) Dhanalakshmi V N.; Rajasree G
The study entitled “Integrated nutrient management in minisett cultivation of elephant foot yam [Amorphophallus paeoniifolius (Dennst.) Nicolson]” was conducted at the Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram to standardise the minisett size in elephant foot yam and to investigate the effect of integrated nutrient management practices on growth, yield, quality and economics of cultivation and to study the rooting and tuberisation pattern of minisett planted elephant foot yam. The investigation consisted of two experiments; standardisation of minisett corm size and integrated nutrient management practices (field experiment) and rooting and tuberisation pattern study (pot culture) and was undertaken during April to November 2018 and 2019. The first experiment was laid out in RBD with 15 treatment combinations and a control, replicated thrice. The treatments comprised three minisett corm sizes (s1-200 g, s2-300 g and s3-400 g) and five integrated nutrient management practices (i1-100 per cent NPK, i2-75 per cent NPK with 50 per cent N substitution through coir pith compost, i3-75 per cent NPK with 50 per cent N substitution through coir pith compost + PGPR mix-I + AMF, i4-50 per cent NPK with 50 per cent N substitution through coir pith compost, i5-50 per cent NPK with 50 per cent N substitution through coir pith compost + PGPR mix-I + AMF). The minisett corms and control corms (1 kg) of elephant foot yam var. Gajendra were planted at a spacing of 60 x 60 cm and 90 x 90 cm respectively. The recommended dose of N, P and K (100:50:150 kg NPK ha-1 ) for elephant foot yam was modified based on soil test data. Substitution of N with coir pith compost was carried out on N equivalent basis, and P and K were given through chemical sources. The pot culture experiment was laid out in CRD with 14 plants per treatment with the same treatments as the field experiment. The number of days taken for 100 per cent sprouting of seed corms varied between minisett corms and control corms and the latter sprouted early. The minisett corm s3 (400 g) recorded taller plants, higher leaf area index, pseudostem 281 girth and canopy spread. Application of 100 per cent NPK (i1) as chemical fertilizer produced taller plants and higher canopy spread during later stages compared to INM practices. Among the INM treatments, i3 (75 % NPK with 50 % N substitution through coir pith compost + PGPR mix-I + AMF) found superior with respect to growth attributes such as plant height and canopy spread. The treatment combination s3i1 (400 g + 100 % NPK as chemical fertilizer) produced taller plants and recorded higher canopy spread. Among the interactions including INM practices, taller plants were produced by s3i3 and s3i5 and higher canopy spread was recorded with s3i2, s3i3 and s3i5. Control plants (1 kg) showed taller plants, higher pseudostem girth and canopy spread at all stages of observation. The s3 recorded higher yield attributes, corm yield (48.81 and 50.57 t ha-1 during first year and second year, respectively) and pooled corm yield (49.69 t ha1 ). The treatments, i1 (100 % NPK) recorded significantly the highest yield attributes and yield. Among the different INM practices, i3 recorded higher yield attributes and corm yield (38.26 and 45.37 t ha-1 during first year and second year, respectively), while corm yield in pooled mean analysis (41.82 t ha-1 ) was also higher in this treatment. The s3i1 (400 g + 100 % NPK as chemical fertilizer) produced significantly the highest yield attributes and yield among all the treatments. Among the INM combinations, s3i3 recorded higher yield attributes, corm yield and higher pooled mean of corm yield (51.29 t ha-1 ). Control recorded higher yield attributes than minisetts. Pooled analysis of corm yield ha-1 indicated that s3i1, s3i2, s3i3 and s3i5 were superior to control and s2i1, s2i2, s2i3 and s3i4 were on par with control. Quality attributes like starch, total sugar, crude protein and crude fibre content of corm were non significant with respect to the treatments. Higher dry matter content was obtained in i4 (50 % NPK with 50 % N substitution through coir pith compost). The lower content of oxalic acid was recorded with i5 and i4 and the higher content was in i1 (100 % NPK). The minisett corm s3 recorded superior results for nutrient content, uptake and nutrient harvest indices. The INM treatment, i3 recorded higher nutrient content and uptake, however the highest was recorded in i1 among all the treatments. The treatment s3i1 (400 g + 100 % NPK 282 through chemical fertilisers) recorded significantly the highest K uptake. Among the combinations including INM practices, s3i3 recorded higher K uptake during second year. The combinations, s3i1, s3i2, s3i3, s3i4 and s3i5 were found superior to control in case of nutrient uptake. Soil chemical properties after the field experiments were not significantly affected by the treatments. The treatment s3i1 (400 g + 100 % NPK) recorded the highest net income and BCR during both the years. The highest net income and BCR were recorded from s3i2 during first year and s3i3 during second year, and the two year mean of net income and BCR were also highest in the case of INM treatment s3i3. In pot culture study, chemical properties of potting medium at monthly intervals up to harvest were not significantly affected by the treatments except for organic carbon content. The treatment i3 (75 % NPK with 50 % N substitution through coir pith compost + PGPR mix-I + AMF) recorded higher organic carbon content at 5 MAP. The minisett corm s3 excelled in rooting pattern and root anatomical parameters. Higher number of roots per plant was recorded in i2 and i3, however, these treatments were on par with i1 (100 % NPK). Higher weight of roots per plant was observed in i5, i4 and i3 and, root anatomical parameters were superior in i3. The interactions, s3i5, s3i4 and s3i3 recorded the highest weight of roots per plant. Higher root parameters were recorded in control than in minisetts and, in case of number of roots per plant s3i1, s3i2 and s3i3 at 4, 6 MAP and harvest, and s3i1 at 5 MAP recorded on par results with control. In the case of weight of roots per plant, s3i3 was on par with control at harvest. The roots of plants applied with AMF showed mycelial network from 3 MAP up to the harvest, and in the maximum growing stage of 5 MAP, vesicles were found in between the cells of the roots of AMF applied plants. Higher root colonization was observed in s3i3 at 5 MAP. Corm initiation was observed between 1 MAP and 2 MAP in control and between 2 MAP and 3 MAP in all other treatments. The s2 (300 g) during 3-4 MAP and s3 (400 g) during all other stages had significantly the highest corm bulking rate (CBR). Higher corm bulking efficiency (CBE) was recorded in s2 during 3-4 MAP, s1 during 4-5 MAP and 6 MAP-harvest and s3 during 5-6 MAP. 283 The INM treatment i3 showed superior results for CBR and CBE, however, higher CBR and CBE were recorded in i1 (100 % NPK) among all the treatments. The s3i1 (400 g + 100 % NPK)showed the highest CBR and CBE during 4-5 MAP and 5-6 MAP among all the treatments. Among the INM interactions, s3i3 during 3-4 MAP and 5-6 MAP; s3i2 during 4-5 MAP and s3i4 during 6 MAP-harvest recorded higher CBR. The s2i3 during 3-4 MAP, s1i3 during 4-5 MAP, s3i3 during 5-6 MAP and s1i5 during 6 MAP-harvest recorded higher CBE. Higher corm weight per plant was recorded with s3. The i1 recorded the higher corm weight per plant among all the treatments, and at 5 MAP, i1 was on par with i3. Among the INM treatments i2 at 3 MAP and i3 at all other stages recorded higher corm weight per plant. Among interactions, s3i3 produced higher corm weight, however, among all the treatments the highest corm weight was noted in s3i1 at all stages except at 4 MAP. Control produced significantly higher corm weight per plant than minisetts. Uptake of nitrogen at 3 MAP and uptake of phosphorus at harvest were higher in s3. The INM treatment i3 recorded higher microbial population and dehydrogenase activity in the potting medium and among the interactions, higher dehydrogenase activity was recorded with s3i3. Significant and positive correlations were observed between corm weight per plant vs. root anatomical parameters and nutrient uptake vs. root anatomical parameters. It is evident from the present study that planting of 400 g minisett corm resulted in better growth, yield and quality of elephant foot yam. Application of 75 per cent NPK with 50 per cent N substitution through coir pith compost + PGPR mix-I [@ 10 g per pit (dry cow dung: PGPR mix-I in 50:1 proportion) - at planting and 2 MAP] + AMF (@ 10 g per pit - at the time of planting) in elephant foot yam resulted in superior growth, yield and quality under INM system. Planting of 400 g minisett and application of 75 per cent NPK with 50 per cent N substitution through coir pith compost + PGPR mix-I + AMF under an INM system could be recommended for economic production of minisett elephant foot yam. Rooting and tuberisation of elephant foot yam were found superior in planting of 400 g minisett corm with application of 75 per cent NPK with 50 per cent N substitution through coir pith compost + PGPR mix-I + AMF.
Open Access
Gene action and gene expression analysis in yardlong bean(Vigna unguiculata ssp. sesquipedalis(L.) Verdcourt) for drought tolerance
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2022) Rahana, S N; KAU; Beena Thomas
Yard long bean (Vigna unguiculata ssp. sesquipedalis (L.) Verdcourt) is a highly remunerative legume vegetable of Kerala. Due to climate change and erratic rainfall, in summer season the crop growth and pod production is heavily affected by moisture stress. Development of high yielding varieties of yard long bean with drought tolerance is essential for its sustainable production. In this context, the present study entitled "Gene action and gene expression analysis in yard long bean (Vigna unguiculata ssp. sesquipedalis (L.) Verdcourt) for drought tolerance" was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, with an objective to identify drought tolerant genotype from the available germplasm and to understand the nature and magnitude of gene action and gene expression involved in the inheritance of drought tolerance in yard long bean. The study comprised four experiments. First experiment dealt with the seedling stage evaluation of 100-yard-long bean genotypes for drought tolerance in field. The moisture stress was imposed by withholding irrigation and later irrigation was restored in order to ensure the survival of the tolerant lines. The results of the analysis showed significant variations among genotypes. Out of the 100 genotypes screened, 15 drought tolerant genotypes were identified based on their better performance in terms of high RLW, low PWP, more number of days for reaching critical stress level and high recovery percentage. The genotypes identified were G1 (Acc 5), G5 (Acc 1339), G6 (Adoor local), G14 (Anchal local II) G15 (Aranmula local), G24 (Elamadu local), G36 (Kattampally local), G42 (Kollam local), G45 (Kottarakara local), G46 (Kottayam local), G50 (Kulashegarapuram local), 051 (Kulathupuzha local), G60 (Muttathukonam local), G74 (Nilamcl local) and G89 (Pongamoodu local). The fifteen selected genotypes from the first experiment were evaluated for drought tolerance in the second experiment by imposing moisture stress at the reproductive stage. Based on the biometric and physiological evaluations, the top seven genotypes with high yield and drought tolerance A4 (Anchal local II), A5 (Aranmula local), A7 (Kattampally local). All (Kulashegarapuram local), A13 (Muttathukonam local), A14 (Nilamel local), and A15 (Pongamoodu local) were selected as parents for further hybridization in experiment in. In the third experiment, LxT crosses were performed by using seven selected tolerant genotypes as lines with three popular yard long bean varieties as testers to generate twenty one hybrids. The genetic analysis of hybrids and parents were evaluated based on eight morphological and eight physiological parameters. Mean performance, combming ability, gene action and heterosis were estimated. Based on the mean performance and gca effects, L4 (Kulashegarapuram local) and L3 (Kattampally local) are identified as outstanding general combiners and can be exploited as parents for drought tolerance breeding in yard long bean. Three superior crosses, Kattampally local x Vellayani Jyothika (L3 x T3), Nilamel local X Lola (L6 X T2) and Kulashegarapuram local x Lola (L4 x T2) were identified as promising combinations for drought tolerance and yield xmder water stress. In the final experiment quantitative real time PCR was conducted to analyze the gene expression of drought responsive genes in tolerant hybrids and parents. The elevated expression of DREBs and NCEDl genes in tolerant hybrids and genotypes in gene expression analysis reflects the increased drought tolerance ability of those genotypes. The gene expression analysis was in conformity with the field studies. All the hybrids mamfested significant amount of dominance variance for commercial exploitation. Existence of significant amoimt of dominance variance and non-additive gene action suggests that hybridization as the best strategy for improving the drought tolerance character in yard long bean. The identified genotypes can be used for isolation of purelines with enhanced drought tolerance and the transgressive segregants from the identified crosses can be used for the development of drought tolerant high yielding cultivars in the fixture. The work can be continued with the identified genotypes and crosses for the development of climate smart drought tolerant varieties of yard long bean.
Open Access
Exploration on the links between soil carbon storage and root biomass and elucidation of drivers of carbon stabilization
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2022) Geethu Jacob; KAU; Manorama Thampatti, K C
The study entitled ―Exploration on the links between soil carbon storage and root biomass and elucidation of drivers of carbon stabilization‖ was conducted at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani during November 2019 to September 2021 with the objective to study the links between soil carbon storage and root biomass in soils of different agro ecological units and to identify the key drivers of C stabilization and NP fluxes under different management practices. The study area comprised of three Agro ecological units (AEUs) of Southern Kerala viz. Southern and Central Foot Hills (AEU 12), Southern High Hills (AEU 14) and Kumily High Hills (AEU 16). The study was carried out in three parts namely exploration on the links between soil organic C and NP pools with root biomass in soils of different AEUs, assessment of carbon storage under different land use system and identifying the drivers of C stabilization and field experiments to study the effect of management practices on the link between root and shoot biomass C and SOC and NP pools. For the study exploration on the links between soil organic C and NP pools with root biomass in soils of different AEUs, the study area was surveyed and geocoded soil samples from 0-20 cm and 20-60 cm depth were collected using core samplers. The root biomass from the soil samples were separated out and weighed. The soil samples were analyzed for its various physical, chemical and biological properties. For assessment of carbon storage under different land use system and identifying the drivers of C stabilization, the most prominent land use system of each AEU was identified and five samples were collected from each system. The sampling size was one sq.m to a depth of 60 cm. The plants of the same area were uprooted and their shoot and root biomass were recorded. Both the soil and plant samples were collected and analysed for various parameters. The field experiment in split plot design on grain cowpea – fodder maize cropping sequence was laid out with the main plot treatments as m1: conventional tillage, m2: deep tillage (30 cm depth) and m3: no till and sub plot treatments as s1: POP recommendation, s2: soil test based POP, s3: organic nutrient management (TOF-F), s4: POP + AMF, s5: soil test based POP + AMF, s6: TOF-F + AMF and s7: absolute control. After the harvest of grain cowpea, shoot biomass were removed and roots were retained in three replications and in the other three replications total biomass of grain cowpea were added into the soil and left for decomposition. After that fodder maize was raised in the field and the crop and soil samples were collected and analysed for various parameters. The results of the Part I revealed that the physical properties like bulk density (BD) and gravel per cent of all the AEUs showed an increase towards depth while the electrochemical properties showed a decrease. Among the different AEUs, AEU 16 recorded lowest BD (1.22 Mg m-3 ) and gravel per cent (30.53 %) and had a subsoil increase of 12 per cent and 17 per cent for BD and gravel per cent respectively. The different fractions of soil C and N showed a decrease with depth for all AEUs. The soil total organic carbon (TOC-5.94 %) and recalcitrant C (RC-1.64 %) content were highest for AEU 14 with a decrease of 26 per cent and 31 per cent respectively for subsoil. The highest dissolved organic C (DOC-54.63 mg kg -1 ) and labile C (LC- 877.50 mg kg -1 ) content were for AEU 16 with a subsoil decrease of 45 per cent and 27 per cent respectively. AEU 12 recorded lower values for C fractions which may be due to decreased root biomass by 38 per cent and 25 per cent in surface soil and 55 per cent and 70 per cent in subsoil than that of AEU 14 and AEU 16 respectively. The root biomass and soil C fractions were positively and significantly correlated at both sampling depths. The highest correlation coefficients between root biomass and soil C fractions were recorded by DOC (0.976) followed by RC (0.931) and LC (0.975) followed by DOC (0.953) for surface and subsoil respectively. From the regression analysis perfect fit towards linear regression model, expressed as R2 value, was highest for DOC (0.95) and LC (0.94) at sampling depths of 0-20 cm and 20-60 cm respectively. The different fractions of N were highest for AEU 12 and surface soil showed an increase in total nitrogen (TN) by 6 per cent and NH4-N by 20 per cent, NO3 – N by 18 per cent and organic N (ON) by 5 per cent than subsoil. For soil P fractions an increase was observed with depth and AEU 12 recorded highest values for P fractions. Among soil N and P fractions, ON and labile P (LP) were found to be more correlated to root biomass and with higher R2 values at both sampling depths. The MBC (26.89 mg kg -1 ) and DHA (34.94 µg TPF g-1 24 hr-1 ) were highest for AEU 16 and surface soil showed an increase in MBC by 28 per cent and DHA by 30 per cent, than subsoil. For part II, the most prominent land use system of each AEU were identified as rubber plantations for AEU 12 and AEU 14 and cardamom plantations for AEU 16. The rubber plantations of AEU 14 recorded highest C storage (434.0 t ha-1 ) and lowest value was observed for cardamom plantations of AEU 16 (329.9 t ha-1 ). The soil physical properties and electrochemical properties behaved similar to that of Part I. Cardamom plantations of AEU 16 recorded lowest BD (0.97 Mg m-3 ) and gravel content (28 %) while AEU 12 had highest pH (5.61) and lowest EC (0.39 dS m-1 ). Among the different land use systems, rubber plantations of AEU 14 recorded highest values for soil TOC (6.72 %) and DOC (55.16 mg kg-1 ) content while cardamom plantations had highest soil LC (910.91 mg kg-1 ) and surface soil RC (1.92 %) content but subsoil RC content was more for rubber plantations of AEU 14. In rubber plantations the root biomass were correlated to all C fractions and more correlated to RC and TOC and in cardamom plantations root biomass were significantly correlated to TOC (0.98) and DOC (0.95) fractions only. A significant and positive correlation between root lignin and soil C fractions (RC and TOC) was also observed. The different fractions of N and P were highest for cardamom plantations of AEU 16 and surface soil showed an increase in TN by 5 per cent, NH4-N by 14 per cent, NO3– N by 22 per cent and ON by 4 per cent than subsoil and a subsoil increase of TP by 12 per cent, LP by 29 per cent and NLP by 11 per cent were also observed. The shoot biomass were more correlated to soil N and P fractions than root biomass and were more correlated to ON and TN and to TP and NLP among soil N and P fractions respectively. A significant positive correlation between N and P removal and soil NP pools were also obtained. The MBC and DHA were highest for cardamom plantations of AEU 16 and surface soil showed an increase in MBC by 25 per cent and DHA by 23 per cent than subsoil. In the field experiment, among the various nutrient management treatments, soil test based POP + AMF (s5) recorded the highest plant height, shoot biomass and grain yield plant-1 (107.70 g) and TOF-F + AMF (s6) showed highest values for root characteristics and quality parameters for grain cowpea. Similarly for fodder maize grown under both conditions, the treatment soil test based POP + AMF (s5) gave highest shoot biomass, fodder yield and quality parameters while highest root biomass were recorded by the treatment, TOF-F + AMF (s6). Among the tillage levels, the no till treatment (m3) performed best in connection with growth, yield and quality characteristics throughout the cropping period. Tillage and nutrient management had significantly influenced various soil properties. The lowest soil BD and higher WSA per cent and soil pH were reported by the treatment TOF-F + AMF (s6) throughout the cropping sequence. Among tillage levels, deep tillage (m2) remained superior for soil BD and pH and no till treatment (m3) for WSA per cent respectively. The treatment, TOF-F + AMF (s6) remained superior for soil C fractions viz., TOC, LC and RC content, mineralizable N fractions (NH4-N and NO3-N), labile P and MBC content and dehydrogenase activity throughout the cropping sequence. The treatment, soil test based POP +AMF (s5) recorded higher values for NP fractions like TN, ON, TP and non labile P (NLP). Among the tillage levels, the no till treatment (m3) remained superior in connection with soil chemical and biological properties especially towards the end of cropping period. As the cropping sequence advances an improvement in soil physical, chemical and biological properties were observed and this is mainly attributed to the crop residue addition of grain cowpea and more improvement was observed for total residue incorporation than root residue alone addition. The soil C pools were highly linked to root biomass and NP pools to shoot biomass. The root biomass and root lignin were the main drivers of C stabilization. The treatments with AMF remained superior in various soil properties and yield and growth attributes emphasizing the favourable role of AMF in C storage and nutrient cycling in soils. With regard to nutrient management, soil test based POP + AMF recorded the highest yield in cropping sequence while organic nutrition (TOF-F) + AMF contributed more to soil properties indicating the need for further research on nutrient translocation and assimilation under organic nutrition. The no tilled condition with total residue incorporation responded better than root residue alone incorporation, hinting to the fact that more organic matter contributing practices improved the physicochemical and biological conditions of soils favourably.
Open Access
Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs
(Department of Agricultural Entomology, College of Agriculture ,Vellayani, 2022) Anitha, N; KAU; Mithra, Mohan
The study on “Mealybugs of vegetable ecosystems and tritrophic interactions of brinjal mealybugs” was conducted at College of Agriculture, Vellayani during 2017 to 2020 with the objectives to identify mealybugs and their natural enemy fauna in solanaceous and cucurbitaceous vegetables, to carry out the molecular characterization of mealy bugs in solanaceous and cucurbitaceous vegetables and to find out the tritrophic interactions of mealybugs infesting brinjal. An investigation on mealybug diversity in solanaceous and cucurbitaceous crops of Kerala revealed a total of six mealybug species viz., Coccidohystrix insolita, Ferrisia virgata, Paracoccus marginatus, Phenacoccus solenopsis, Planococcus citri and Pseudococcus jackbeardsleyi. Besides, four mealybugs viz., Crisicoccus hirsutus, Maconellicoccus hirsutus, Planococcus lilacinus and Rastrococcus iceryoides infesting other vegetable crops were also recorded from Kerala. The study also revealed that the population of mealybug, C. insolita collected from different regions of Kerala exhibited significant morphological variation. The molecular characterization studies proved that the population belongs to C. insolita and the variations may be environmental induced. An exploration of the host range of mealybugs infesting solanaceous and cucurbitaceous vegetables in Kerala revealed a total of 113 plants under 73 genera belonging to 31 families, out of which 14 plants were recorded as new host reports. A rich natural enemy fauna on mealybugs belongs to five orders viz., Coleoptera, Lepidoptera, Diptera, Neuroptera and Hymenoptera were documented from Kerala. Twenty species of mealybug predators from five different families were recorded, among which the predominant family was Coccinellidae with 16 species under six genera. Among the various predators collected, Cacoxenus sp. was recorded for the first time as a predator of P. jackbeardsleyi. Eleven hymenopteran parasitoids belonging to five families were documented from mealybugs, of which the majority belongs to the family Encyrtidae. Four new host-parasitoid associations were also recorded for the first 288 time. The study also identified six hyperparasitoids under the family Encyrtidae, of which two species were recorded as new report which includes Cheiloneurus sp. and Prochilonerus sp. associated with the mealybug P. solenopsis. The ants associated with mealybugs in different agroecosystems were also investigated and a total of 14 species of ants belonging to nine genera under three subfamilies were recorded, of which the most dominant subfamily was Formicinae followed by Myrmicinae and Dolichoderinae. The present study also revealed 15 new ant-mealybug associations for the first time. The molecular characterization of eight mealybug species was carried out that complemented the morphological identification of species. A total of eight nucleotide sequences were submitted to NCBI GenBank and accession numbers were generated. The sequences were also submitted to BOLD and illustrative barcodes were generated. The barcodes of C. insolita, C. hirsutus and P. jackbeardsleyi were generated for the first time. The diversity of endosymbionts of the mealybug C. insolita was carried out for the first time. The study revealed a total of 15 phyla of endosymbionts on C. insolita, of which Proteobacteria was the predominant one. An experiment was conducted at Instructional Farm, Vellayani to identify the tritrophic interaction in brinjal, C. insolita and its natural enemies. The study revealed that out of the ten brinjal cultivars evaluated, the lowest mean population of mealybugs was observed in Pusa Uttam whereas the hybrid cultivar, Udit recorded the highest number of mealybugs. The lowest mean per cent leaf infestation was recorded in Pusa Purple Long which was statistically on par with Pusa Uttam whereas the hybrid cultivar, Udit was severely damaged by the mealybugs. Among the tested cultivars, Pusa Purple Long was recorded under the group resistant whereas Udit and Haritha were included under the highly susceptible group based on the mean per cent leaf infestation caused by C. insolita. The cultivar Haritha attracted the highest number of predators whereas the maximum mean population of spiders were observed in Pusa Purple Long. 289 The correlation analysis on the mean population of mealy bugs with biophysical parameters revealed that trichome density, length width ratio of leaf and number of branches exhibited a significant positive correlation with mean population of mealybugs. Correlation studies on the mean population of natural enemies with biophysical parameters revealed that plant height exhibited a significant negative correlation whereas leaf thickness and number of branches revealed a non-significant negative correlation with the mean population of natural enemies. Among the biochemical parameters of brinjal cultivars, total phenol content exhibited a significant negative correlation with the mean population of mealybugs whereas total chlorophyll content showed a significant positive correlation. The correlation between biochemical parameters of brinjal cultivars with the mean population of natural enemies revealed that total phenol and carotenoid content exhibited a non-significant negative correlation whereas total protein content, reducing sugar and total chlorophyll content showed a nonsignificant positive correlation. The info-chemical mediated interactions in brinjal cultivars, mealybug and its natural enemies were studied using a multi-armed olfactometer and Y-shaped olfactometer assay. The results revealed that the cultivar Udit attracted the highest number of natural enemy Chrysoperla zastrowii sillemi while the cultivar Pusa Uttam attracted the lowest number. The variation in preference shown by the natural enemies may be related to the difference in volatile compounds emanating from the host cultivar. The GC-MS analysis of the synomonal compounds of the cultivar, Udit revealed a total of eleven compounds whereas the cultivar Pusa Uttam was recorded with a total of five compounds. The Y shaped olfactometer studies revealed that C. zastrowi sillemi adults showed more preference towards the synomonal compounds of mealybug infested plants than that of healthy plant synomonal extracts. On comparing the volatile profile of synomones of mealybug infested and healthy plants revealed that the synomonal extracts of the mealybug infested cultivar Udit comprised of 11 compounds whereas healthy plant synomonal extracts contained nine compounds. 290 The relative response of C. zastrowi sillemi towards the kairomonal compounds of C. insolita was evaluated in a Y tube olfactometer and the results revealed that the highest mean number of adult lacewings were attracted to the kairomonal compounds of mealybug compared to control. The kairomonal extracts of the mealybug comprised of seven compounds and the composition of these hydrocarbons may determine the selectivity of natural enemies towards the preferred host. The present study recorded a total of six mealybug species infesting solanaceous and cucurbitaceous vegetables and its host range, natural enemies and associated ants in different agro ecological regions of Kerala. The molecular characterization studies supported the morphological taxonomy and the sequences were submitted to NCBI Genbank and BOLD. The study also elucidated the interactions mediated by plant traits and info-chemicals in brinjal-mealybugnatural enemy tritrophic systems. The study recorded Pusa Purple Long as resistant cultivar and Udit and Haritha as highly susceptible cultivar to C. insolita. The plant traits viz., trichome density, length width ratio of leaf, number of branches, total phenol content and total chlorophyll content exhibited significant correlation with mean population of mealybugs whereas plant height exhibited significant correlation with mean population of natural enemies. The study on info-chemical mediated tritrophic interactions revealed that the concentration and composition of volatile compounds determine the differential selectivity of natural enemies. The volatile compounds identified in this study can also be used as a cue in moderating the behavior of natural enemies in the ecosystems. So a thorough knowledge on the tritrophic relations in the ecosystem will aid in manipulating these interactions to devise a better pest management strategy.

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