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Open Access
INTEGRATED NUTRIENT MANAGEMENT IN YELLOW SARSON - GREENGRAM CROPPING SYSTEM UNDER RAINFED CONDITION
(2016) Gogoi, Bebi; Ojha, N. J.
A field experiment entitled “Integrated nutrient management in yellow sarson - greengram cropping system under rainfed condition” was carried out at the Instructional-cum-Research farm of Assam Agricultural University, Jorhat during two consecutive rabi (Oct-Feb) followed by summer (Feb-May) seasons of the year 2017- 2018 and 2018-2019. The experiment was laid out in randomized block design for first crop and split plot design for second crop with three replications. The eight INM practices viz., 100% RDF (60-30-30 kg/ha N-P2O5-K2O) (Y1), 100% RDF + biofertilizer consortium (Y2), 75% RDF + 25% N through vermicompost (Y3), 75% RDF + 25% N through vermicompost + biofertilizer consortium (Y4), 50% RDF + 50% N through vermicompost (Y5), 50% RDF + 50% N through vermicompost + biofertilizer consortium (Y6), 25% RDF + 75% N through vermicompost (Y7) and 25% RDF + 75% N through vermicompost + biofertilizer consortium (Y8) were applied to yellow sarson crop. In greengram crop the residual effect of the treatments applied to yellow sarson were allotted in main plots and two different integrated nutrient management practices viz., 100% RDF + biofertilizer consortium (G1) and 50% RDF + biofertilizer consortium (G2) in the sub plots. The soil of the experimental site was sandy loam in texture, acidic in reaction (pH 5.40 and 5.56), medium in organic carbon (0.69 and 0.72%), available N (274.86 and 290.75 kg/ha), available K2O (138.16 and 140.89 kg/ha) and low in available P2O5 (17.90 and 20.30 kg/ha) in the year 2017-18 and 2018-19, respectively. Experimental findings revealed that application of 75% RDF + 25% N through vermicompost + biofertilizer consortium (Y4) resulted in significantly higher growth as well as yield attributing characters like plant height, number of branches per plant, dry matter accumulation, crop growth rate, relative growth rate, number of siliquae per plant, length of siliqua, number of seeds per siliqua in both the years. The highest seed yield of 998.34, 1026.22 and 1012.28 kg/ha, stover yield of 2393.97, 2420.65 and 2407.31 kg/ha during 2017-18, 2018-19 and in pooled analysis, respectively, were recorded with treatment having 75% RDF + 25% N through vermicompost + biofertilizer consortium (Y4). The seed oil content of 36.40 and 36.97% and seed protein content of 13.27 and 13.44% were also recorded in Y4 in 1st and 2nd year, respectively. Similar effects of this treatment were also observed in respect of N, P and K content and uptake by both seed and stover. However, soil microbial population, microbial biomass carbon, phosphomonoesterase activity and fluorescein di-acetate hydrolase activity after harvest of yellow sarson were significantly higher in treatment having 25% RDF + 75% N through vermicompost + biofertilizer consortium (Y8). The crop recorded the highest gross return (` 56105 in 2017-18 and ` 57652 in 2018-19), net return (` 35407 during 2017-18 and ` 36954 during 2018-19) and benefit-cost ratio (2.71 during 2017-18 and 2.79 during 2018-19) with the treatment containing 75% RDF + 25% N through vermicompost + biofertilizer consortium (Y4). 7 In case of greengram, residual effect of 25% RDF + 75% N through vermicompost + biofertilizer consortium (Y8) resulted in significantly higher growth as well as yield attributing characters like plant height, number of branches per plant, dry matter accumulation, crop growth rate, number of pods per plant and number of seeds per pod in both the years. The effect of these was reflected in higher seed yield (849.56, 806.56 and 828.06 kg/ha in the year 2018, 2019 and in pooled analysis, respectively) and stover yield (2012.68, 1935.58 and 1974.13 kg/ha in 2018, 2019 and in pooled analysis, respectively) under the same integrated nutrient management practices. The maximum values of N, P and K uptake by seed and stover, soil microbial population, microbial biomass carbon, phosphomonoesterase activity and fluorescein di-acetate hydrolase activity after harvest of greengram were also observed under this treatment (Y8). However,direct application of 100% RDF + biofertilizer consortium (G1) brought about higher values in growth parameters, yield attributes, yield of seed (804.21, 724.68 and 764.45 kg/ha during 2018, 2019 and in pooled analysis, respectively) and stover yield (1830.89, 1763.80 and 1797.35 kg/ha during 2018, 2019 and in pooled analysis, respectively), protein content in seed (22.39 and 22.26% in 2018 and 2019 respectively), content and uptake of N, P and K by both seed and stover, soil microbial population, microbial biomass carbon, phosphomonoesterase activity and fluorescein diacetate hydrolase activity after harvest of greengram over 50% RDF + biofertilizer consortium (G2). The highest gross return (` 50726 in 2018 and ` 48922 in 2019), net return (` 33611 during 2018 and ` 31807 during 2019) and benefit-cost ratio (2.96 during 2018 and 2.86 during 2019) were observed under treatment Y8G1 containing 100% RDF + biofertilizer consortium (G1) + residue of treatment Y8 (25% RDF + 75% N through vermicompost + biofertilizer consortium). In regards to yellow sarson-greengram cropping system the highest yellow sarson equivalent yield (1678.57 and 1614.02 kg/ha in 2018 and 2019, respectively) were obtained by treatment Y4G1 containing 100% RDF + biofertilizer consortium (G1) + residue of treatment Y4 (75% RDF + 25% N through vermicompost + biofertilizer consortium). The highest gross return (` 93518 in 2017-18 and ` 89981 in 2018-19), net return (` 55705 during 2017-18 and ` 52168 during 2018-19) and benefit-cost ratio (2.47 during 2017-18 and 2.37 during 2018-19) of yellow sarsongreengram cropping system were observed under treatment Y4G1, containing 100% RDF + biofertilizer consortium (G1) + residue of treatment Y4 (75% RDF + 25% N through vermicompost + biofertilizer consortium). The performance of yellow sarsongreengram cropping system was assessed on the basis of yellow sarson equivalent yield, net monetary returns and B-C ratio. The application of 75% RDF + 25% N through vermicompost + biofertilizer consortium to yellow sarson and 100% RDF + biofertilizer consortium to greengram was the most beneficial combination compared to rest of the treatments.
Open Access
CRITICAL COMPONENT ANALYSIS OF CLIMATE, SUSTAINABILITY, PREFERENCE AND PERFORMANCE OF LIVESTOCK IN ASSAM
(College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati, 2017-07) TALUKDAR, JUPI; SAHARIA, K. K.
A “Critical Component Analysis of Climate, Sustainability, Preference and Performance of Livestock Sector in Assam” has been planned with a random sampling technique in Kamrup, Dibrugarh and Bongaigaon districts of Assam to fulfill the above specified reasons. The method of random sampling technique got established when the Deputy Commissioners of each district were discussed. Further after going to the Block office, the villages were also selected as per the directive and facilitations provided by the block/field officials. It was in the village where Snow Ball sampling method was adopted. Based on the needs PCA method was also applied for getting the information relating to the social dynamics of animal husbandry in the study. Data were collected in three sets of pre-tested, reliable and valid interview schedule containing the features of climate, sustainability, preference, and performance. Collection of data were done based on the person actually who is involved in farming, considering analysis on the basis of 20 per cent confidence level and then finding the critical factors, analysis were done. The data such collected were arranged, tabulated, and analyzed so as to arrive at useful conclusion and interpretation so that they become benchmark for animal husbandry policies with regard to production system, supply chain and promotional livestock rearing. Results showed that the average age of the respondents was around 39 years. A good number of the respondents (45.67 %) had medium family size as high as 66.00 per cent of the respondents had nuclear type of family. The average educational qualification of majority (44.33%) of the respondents was of lower primary level. Educational status of majority (63.00 %) of the other member of the family of the respondents was higher secondary level. Average 14.58 numbers of livestock in the pooled sample could be considered towards a healthy sign considering the fact that large majority of farm people in whole of the districts had landless to marginal categories of farmers. The average annual family income of the respondents was Rs.1, 62,095/- and majority of them fell in middle income group. The average respondents own income was found to be Rs.116393/- and majority of them fell in middle income group. Majority (74.00%) of the respondent’s received medium income of Rs 29056 from livestock farming. The major sources of personal income of the respondents was Agriculture (29.80%) followed by animal husbandry (22.18), business (10.55%), fishing (8.28), art and culture (7.37%) , handicraft (5.90%), transport of item (5.62%), services (5.48) and household items (4.82%). Food (35.36%) and Education (22.66 %) were the two main areas in which maximum expenditures were made by the respondents in this study. Most of the respondents were having medium social participation with 3.47 numbers of times per year with the society and bringing it at a reflection of development, proliferation or non-orthodox atmosphere among the people of the districts. Most of the respondents were having medium to higher level of extension contact with 7.07 numbers of times per year among the respondents in different districts, which was definitely an encouraging phenomenon. More than 80 per cent of the farmers were having awareness about different farm related problems. Farmers involved in mass media contact belonged mostly to medium level category with 6.62 average numbers of areas per year. Majority of the respondents (76%) were involved in progressive livestock rearing practice. Land ownership was the most preferred indicator of progressive livestock farming in all the three districts. Different indicators of progressive livestock farming can be listed from highest to lowest impact as follows- Land ownership (6.19%), Association with the society (5.97%), Innovativeness (5.95%), Ideal family members to help farming (5.76%), More time to spend with animals (5.75%), Entrepreneurship Habit (5.73%), concern for quality (5.58%), Enduring livestock keeping (5.55%), Leadership Quality (5.51%), Willingness of people for farm products (5.27%), Contact with extension worker (5.18%), Economic orientation (5.06%), Self employment (4.87%), Religious mindedness (4.85%), Good market (4.83%), Educational qualification (4.72%), Good size of the farm (4.50%), Keeping hope for future generation (4.44%), Mass media contact (2.65%) and Political affiliation (1.64%). Most of the farmers realizing factors that affected animal husbandry development belonged to medium group level. Flood has been recognized as the most important factor affecting Animal Husbandry in all the three districts. Different micro-climatic factors affecting animal husbandry can be ordered in terms of their impact as follows- Flood (6.09%), Less availability of grass (5.82%), Parasitic infestation (5.72%), Education (5.66%), Draught (5.56%), Increasing cost of animal husbandry (5.39%), High temperature (5.37%), Less per capita availability of land (5.16%), Misunderstanding with neighbors (5.03%), Low rainfall (4.96%), Land used for infrastructure (4.83%), Social standing (4.71%), Lack of technical people in field (3.82%), No departmental support (3.66%), Pollution in water (3.62%), Soil erosion (3.41%), Job in public/private sector (3.22%), Frequency of visiting dignitaries (3.15%), General atmosphere (2.95%), Pollution (2.88%), Traditional rituals and festivals (2.78%), More dust in air (2.34%), Vehicular traffic (2.11%), Stringent rules and regulations (1.77%). Cattle was the highest preferred species in all the three districts, Kamrup (70.00%), Dibrugarh (65.00%), Bongaigaon (62.00%) while Bee keeping remained the least preferred farming practice in all the cases. Number of years of involvement in farming by the farmers of the Dibrugarh district was highest against Kamrup district to be the lowest. The overall ranking of the six different livestock species in terms of their profitability was as follows, Cattle (1575.00), Pig (692.33), Goat (503.67), Buffalo (453.00), Sheep (128.67) and Bee keeping (95.33). Flood was regarded as the most serious problem by the respondents of Dibrugarh and Bongaigaon districts while the same for Kamrup was the scarcity of fodder. The average degrees of changing status of livestock farming were 2.56. This in equivalent value revealed that the sector was slowly progressing. Association of the respondent with the market of the district Kamrup was highest and for Bongaigaon was found to be the lowest. The price of the farm product of the district Kamrup was highest and for Bongaigaon was found to be the lowest and the mean prices in the three districts varied significantly from each other. The mean transaction in market among the respondents in the districts of Kamrup was significantly higher than that of Bongaigaon district but it was marginally lower than that of Dibrugarh district. Most of the respondents preferred to sell their livestock product and produces to whole sellers. The mean satisfaction of the Kamrup district was found to be highest and the same for Bogaigaon was the lowest. Whenever and wherever animal husbandry produces and products were traded, there was no difficulty in selling them off and as such the chance of spoilage was minimum. The local sources in different extent and that could be ranked (overall) in terms of the gradually decreasing local procurement as follows Cattle (79.49%), Pig (52.13%), Goat (47.50%), Honey bee (24.37%), Sheep (23.50%) and Buffalo (11.97%). Cattle enjoyed highest demand and high profit oriented, because of traditional more acceptance of cattle milk over the milk produced by other species. Majority of the changes taking place in livestock sector were in medium group of distribution i.e. 71.67%. Marketing (6.91%) is the highest degree of changes occurring in the livestock sector.
Open Access
DEVELOPMENT OF INTEGRATED PEST MANAGEMENT MODULES AGAINST INSECT PESTS OF BHUT JOLOKIA (Capsicum chinense Jacq.)
(2019-09) Bora, Sasanka Sekhar; Saikia, D. K.
Experiments were carried out under field conditions at the Experimental Farm, Department of Horticulture as well as in the Department of Entomology and Department of Plant Pathology, Assam Agricultural University, Jorhat during 2017-18 and 2018-19 to study the major sucking and chewing pests of Bhut Jolokia causing substantial losses in fruit yield. At present, IPM has been attaining immense importance in the agricultural scenario of India and abroad. Therefore, evaluation of sustainable IPM modules was felt very much necessary in Bhut Jolokia. The result revealed that altogether twenty three numbers of insect pests were associated with the crop and among them aphid (Aphis gossypii Glover/Myzus persicae Sulzar), Whitefly (Bemisia tabaci Gennadius), thrips (Scirtothrips dorsalis Hood), yellow mite [Polyphagotarsonemus latus (Banks)], Cutworm (Agrotis ipsilon Hufuagel) and fruit fly [Bactrocera dorsalis (Hendel)] were considered as the key pests of Bhut Jolokia. Highest incidence of major pests was obtained in the 1st fortnight of April during 2018 as against 2nd fortnight of April during 2019, respectively. A new invasive pest, spiraling whitefly (Aleyrodicus dispersus Russel, Aleyrudidae:Hemiptera) was also reported for the first time in Bhut Jolokia from Assam. Five IPM modules were evaluated against insect pests of Bhut Jolokia, of which module I comprised of recommended dose of fertilizer and farm yard manure+ application of microbial consortium + growth promoter viz., Tricontanol + weeding at 30, 60 and 90 Days after transplanting (DAT) + imidacloprid 17.8 SL 0.4 ml per lt @ 40 days interval was found to be the most effective module in respect of B: C ratio (3.02: 1) followed by module III (Vermicompost 1.25t/ha+ neem cake 500 kg/ha + application of microbial consortium + black polythene mulching + garlic extract @ 10% at 20 and 70 DAT +NSKE 5% at 35 and 100 DAT + installation of sticky trap @ 25 traps /ha) where the B:C ratio was 2.96 with maximum yield of 740.74 gm per plant with next higher yield of 712.13 gm per plant in module I. Hence, module III in comparison to module I seems to be quite promising strategy as it did not require any insecticidal interference keeping natural enemies and ecosystem undisturbed. Out of eight cultivars collected cv. Assam 1 (King) contributed maximum yield of 719.85 gm per plant followed by Assam 4 with 626.67 gm per plant with minimum susceptibility towards pests and diseases. Correlation studies between sucking pests and phenotypic characters indicated that only number of leaves and leaf area index had negative significant impact while other parameters viz., plant height and branches showed no effect. Result of different shade level, 75 per cent shade showed highest plant height and leaf area index of 90.01 cm and 1.81 as against open condition where it was only 53.18 cm and 1.46. The number of leaves and branches of Assam 1 cultivar were to be highest 220.51 cm and 8.75 in open condition, while they were 80.75 cm and 5.13 in 75 per cent shade level. Likewise, for flowering, 116.75 days required in case of 75 per cent shade level, whereas it was only 93.25 days in case of open condition. Similarly, fruit numbers also reduced in case of 75 per cent shade level which was only 27.0 while 92.13 was in case of open condition. Yield per plant was also around 718.13 gm per plant in open condition, whereas it was only 223.63 gm per plant in 75 per cent shade level. The major sucking pests and coccinellid predator population found to be in higher side in open condition also. In 75 per cent shaded area the pooled infestation of aphid, whitefly, thrips and mite was 0.62, 0.35, 0.26 and 0.54 numbers per three leaves whereas, it was 1.69, 1.58, 1.25 and 2.58 numbers per three leaves in open condition. Predatory spider population found highest with 0.34 numbers per plant while coccinellid population was lowest with 0.15 numbers per plant at 75 per cent shade level. But coccinellid population was highest with 0.40 numbers per plant in open condition while 0.18 numbers per plant spider also found at open condition, respectively. RT PCR method confirmed the presence of Cucumber mosaic virus (CMV) on whole seed and seed coat, which indicates that CMV transmitted through seed.
Open Access
MORPHO-BIOCHEMICAL CHARACTERIZATION OF ROUGH LEMON (Citrus jambhiri Lush.) OF ASSAM
(2019-07) Pathak, Purnima; Khangia, B.
Rough lemon (Citrus jambhiri Lush.), commonly known as ‘Gol Nemu’ is an underutilized citrus fruit of Assam. It is mostly grown as backyard crop in homestead garden. The fruit is a rich source of vitamins, minerals, flavonoids, limonoids etc. It is polyembryonic in nature and highly cross pollinated. Most rough lemon plants are of seedling origin in the region and thus tend to exhibit a wide range of variability in terms of morphological and biochemical parameters. Therefore, an investigation was undertaken during 2016-2017 on ‘Morpho-biochemical characterization of rough lemon (Citrus jambhiri Lush.) of Assam to study the existing variability. One district in each of the six agro climatic zones was chosen and five plants were selected in each district, comprising of thirty plants. Wide variability was observed among the selected rough lemon accessions for qualitative characters of tree, leaf, flower, fruit and seed. Four different fruit shapes were recorded viz. spheroid, obloid, obovoid and ellipsoid. Wide variations in pulp colour i.e. ivory white, orange, orange-red, yellow were recorded in the selected rough lemon. Cluster analysis of 45 qualitative and 25 quantitative characters using SPSS resulted in grouping of the rough lemon accessions into three broad groups. Group I consisted of 17 accessions (AR01T1, AR01T2, AR01T3, AR02T1, AR02T2, AR02T3, AR02T4, AR03T2, AR03T3, AR04T4, AR05T1, AR05T2, AR05T3, AR05T4, AR06T2, AR06T3, AR06T5) of all locations. Group II consisted of six accessions (AR01T5, AR03T1, AR03T4, AR03T5, AR04T1, AR06T1). Group III consisted of seven accessions (AR01T4, AR02T5, AR04T2, AR04T3, AR04T5, AR05T5, AR06T4). No groups were formed based on geographical location indicating that qualitative and quantitative traits were largely influenced by genetic factor. The quantitative characters of flower, leaf and fruit showed significant variation among the rough lemon accessions. The maximum fruit weight was recorded in accession number AR02T5 (144.34 g) and the minimum was recorded in AR03T1 (17.36 g). In terms of biochemical constituents, the highest TSS was recorded in accession number AR06T4 (8.87 °B) and the lowest was recorded in AR02T1 (6.13 °B). The highest TSS-acid ratio was recorded in accession number AP06T4 (2.12) and the lowest was recorded in AR02T1 (1.00). HPLC quantification of limonin showed significant variations among the rough lemon accessions which ranged from 10.42 to 24.07 mg/100ml. Among the 30 rough lemon accessions, two main groups were recognized based on 12 biochemical constituents with strong genetic similarity within a location. All the morphological quantitative traits i.e. fruit length, fruit diameter, rind thickness, seeds per fruit, seed weight, juice content, juice per cent showed significant variation among different locations. Significant differences among the locations were observed with respect to biochemical constituents except essential oil content. The highest TSS, total sugar, TSS-acid ratio were recorded in location L6 (Cachar) and the lowest value was recorded in location L4 (Biswanath). Present study on propagation of rough lemon through seed showed an average germination percentage of 87.67 % and air layering recorded a success percentage of 92.11%. However, propagation through stem cutting was found to be comparatively difficult with moderate success percentage (79.11%). Three elite types i.e. AR03T1, AR06T1 and AP06T4 were identified in terms of high overall acceptability (>8), TSS-acid ratio (>2.00), less seed content (≤10 per fruit), low limonin content, high essential oil (>4%), high ascorbic acid and antioxidant activity (>80mg/100ml juice) and thin to medium rind thickness.
Open Access
GENETIC ENHANCEMENT IN TOMATO (Solanum lycopercicum L.) FOR RESISTANCE TO BACTERIAL WILT AND QUALITY THROUGH INTRA AND INTER-SPECIFIC HYBRIDIZATION
(2019-07) Das, S. Yasmin; Borkakaty, R. P.
Tomato is the most important solanaceous vegetable crop. To estimate its production under the challenges of bacterial wilt disease, it is important to identify potential genotypes with resistance to bacterial wilt disease of tomato. To achieve this goal an investigation on ‘Genetic enhancement in tomato for resistance to bacterial wilt and quality through intra and inter-specific hybridization’ had been taken up to study the performance of few genotypes, their heterosis and combining ability and nature of gene action. The experiment was carried out at the experimental field of Horticultural Research Station, Assam Agricultural University, Kahikuchi, Guwahati during rabi seasons of 2015-16, 2016-17 and 2017-18. Evaluation of six parents, fifteen F1, fifteen F2, three BC1 and three BC2 generations of tomato revealed existence of sufficient variability and interaction effects in the genotypes. Combining ability analysis in Diallel mating design without reciprocals involving six diverse tomato cultivars/lines, viz., Singimari Local, Megha, Solan Lalima, Arka Abha, Arka Alok and Kon bilahi and their 15 cross combinations in bacterial wilt sick plots revealed importance of both additive and dominance effects. Two parents, Singimari Local and Kon Bilahi were identified as good general combiner. Ten cross combinations out of total fifteen combinations exhibited high estimates of specific combining ability for different desirable traits. Among them the crosses which merit special consideration were Singimari Local x Solan Lalima for yield per plant(g), harvest duration and bacterial wilt survival (% ); Singimari Local x Kon Bilahi for number of fruits per plant(g) and bacterial wilt survival (%) ; Solan Lalima x Kon Bilahi for number of fruits per plant, harvest duration, pH of pulp and bacterial wilt survival (%); Arka Abha x Arka Alok for harvest duration ,pH of pulp, fruit weight(g), number of primary branches per plant and yield per plant (g); Megha x Kon Bilahi for days to first picking, days to maturity, pericarp thickness(mm), TSS (° Brix) and bacterial wilt survival (%) could effectively be used to exploit heterosis in bringing about desired genetic improvement. Besides, the crosses showing desirable SCA for yield per plant (g) and bacterial wilt survival (%) but without significant heterosis were Arka Alok x Kon Bilahi, Megha x Arka Alok, Singimari Local x Arka Abha and Arka Abha x Kon Bilahi. These crosses could be ideal for further selection to bring them into homozygous genetically improved lines. Generation mean analysis was carried out in three crosses viz. Singimari Local x Megha, Singimari Local x Kon Bilahi and Megha x Kon Bilahi involving six generations (P1, P2, F1, F2, BC1 and BC2). The individual scaling tests were used to test the adequacy of additive dominance model. The gene effects were estimated using three parameter model (Joint Scaling Test) suggested by Cavalli (1952) and six parameter model suggested by Haymen (1958). The analysis of variance among different generations of different crosses revealed significant variation for all the eighteen characters indicating considerable variability in the material studied. All the characters except productive flower retention (%) in cross Singimari Local x Megha recorded significance for at least one of the four individual scaling tests in all the 3 crosses. With respect to interaction effects, all the characters except productive flower retention (%) in cross Singimari Local x Megha, exhibited significant interaction effect for one or more epistatic interactions i.e.[i], [j] or [l] in all the three crosses studied. It is evident that for all the morpho-physiological and yield attributing traits, fruit quality traits and bacterial wilt survival(%) additive, dominance and interaction effects were present indicating the complex inheritance of the traits under study. Further enhancement of the genotypes identified in this study will pave the way for the development of high yielding tomato variety with resistance to bacterial wilt disease.
Open Access
HEAT UNIT INDEXING OF GARDEN PEA IN RELATION TO CLIMATE SHIFT AND NUTRIENT MANAGEMENT
(2019-07) Sangma, Trudy Tengse A.; Saikia, Luchon
An experiment was conducted consecutively during 2016-17 and 2017-18 in the Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat to study the “Heat unit indexing of garden pea in relation to climate shift and nutrient management”. The experiment consist three treatments viz., variety (main), fertility management level (sub) and sowing date (sub-sub) laid out in split plot design with random allocation and replicated thrice. The main treatment consisted Arkel(V1), A1(V2), DS-10(V3) and GS-10(V4); sub treatment was comprised of 5t FYM, 10-46-0 kgha-1 (F1), 10t FYM, 10-46-10 kgha-1 (F2), 10t FYM, 20-46-20 kgha-1 (F3) and 10t FYM, 30-46-30 kgha-1 (F4) and sub-sub treatment was dates of sowing: 10th October (S1), 24th October (S2), 7th November (S3), 21st November (S4), 5th December (S5) and 20th December (S6). Growth, yield attributes, soil related and quality characters viz., plant height(cm), days to 50% flowering, pod plant-1, pod length (cm), pod diameter (cm), seed pod-1, shelling (%), pod yield (tha-1), duration (days), growing degree days, root nodules plant-1, total plant nitrogen (%), total plant phosphorus(%), total potash (%), TSS (0 Brix), crude protein (%), soil organic carbon (%), soil available nitrogen (kgha-1), soil available phosphorus (kgha-1), soil available potash (kgha-1) and soil pH have responded significantly due to treatments as well as their interactions, except pH. Variety evidently produced significant effect on growing degree days (GDD) and results showed V4>V3>V2>V1 with requirement of 955, 948, 933 and 833 GDD for 2016-17 and similarly 958, 949, 942 and 825 GDD. The maximum duration was reported as 76.00days in V4F with (1,2,3,4) and S( with 3,4,5). Duration was closely associated with degree days by sowing date had indicated significant duration among varieties, least with V1(58.73days), to maximum in V4(72.30days). Fertility level had a range of maturity at 68.08 to 68.29days. Sowing dates showed significance as 911(S1), 915(S2), 915(S3), 915(S4), 916(S5) and 918(S6) during 2016-17 and the GDD was found significant as S1
Open Access
MORPHO-BIOCHEMICAL CHARACTERIZATION OF ROUGH LEMON (Citrus jambhiri Lush.) OF ASSAM
(2019-07) Pathak, Purnima; Khangia, B.
Rough lemon (Citrus jambhiri Lush.), commonly known as ‘Gol Nemu’ is an underutilized citrus fruit of Assam. It is mostly grown as backyard crop in homestead garden. The fruit is a rich source of vitamins, minerals, flavonoids, limonoids etc. It is polyembryonic in nature and highly cross pollinated. Most rough lemon plants are of seedling origin in the region and thus tend to exhibit a wide range of variability in terms of morphological and biochemical parameters. Therefore, an investigation was undertaken during 2016-2017 on ‘Morpho-biochemical characterization of rough lemon (Citrus jambhiri Lush.) of Assam to study the existing variability. One district in each of the six agro climatic zones was chosen and five plants were selected in each district, comprising of thirty plants. Wide variability was observed among the selected rough lemon accessions for qualitative characters of tree, leaf, flower, fruit and seed. Four different fruit shapes were recorded viz. spheroid, obloid, obovoid and ellipsoid. Wide variations in pulp colour i.e. ivory white, orange, orange-red, yellow were recorded in the selected rough lemon. Cluster analysis of 45 qualitative and 25 quantitative characters using SPSS resulted in grouping of the rough lemon accessions into three broad groups. Group I consisted of 17 accessions (AR01T1, AR01T2, AR01T3, AR02T1, AR02T2, AR02T3, AR02T4, AR03T2, AR03T3, AR04T4, AR05T1, AR05T2, AR05T3, AR05T4, AR06T2, AR06T3, AR06T5) of all locations. Group II consisted of six accessions (AR01T5, AR03T1, AR03T4, AR03T5, AR04T1, AR06T1). Group III consisted of seven accessions (AR01T4, AR02T5, AR04T2, AR04T3, AR04T5, AR05T5, AR06T4). No groups were formed based on geographical location indicating that qualitative and quantitative traits were largely influenced by genetic factor. The quantitative characters of flower, leaf and fruit showed significant variation among the rough lemon accessions. The maximum fruit weight was recorded in accession number AR02T5 (144.34 g) and the minimum was recorded in AR03T1 (17.36 g). In terms of biochemical constituents, the highest TSS was recorded in accession number AR06T4 (8.87 °B) and the lowest was recorded in AR02T1 (6.13 °B). The highest TSS-acid ratio was recorded in accession number AP06T4 (2.12) and the lowest was recorded in AR02T1 (1.00). HPLC quantification of limonin showed significant variations among the rough lemon accessions which ranged from 10.42 to 24.07 mg/100ml. Among the 30 rough lemon accessions, two main groups were recognized based on 12 biochemical constituents with strong genetic similarity within a location. All the morphological quantitative traits i.e. fruit length, fruit diameter, rind thickness, seeds per fruit, seed weight, juice content, juice per cent showed significant variation among different locations. Significant differences among the locations were observed with respect to biochemical constituents except essential oil content. The highest TSS, total sugar, TSS-acid ratio were recorded in location L6 (Cachar) and the lowest value was recorded in location L4 (Biswanath). Present study on propagation of rough lemon through seed showed an average germination percentage of 87.67 % and air layering recorded a success percentage of 92.11%. However, propagation through stem cutting was found to be comparatively difficult with moderate success percentage (79.11%). Three elite types i.e. AR03T1, AR06T1 and AP06T4 were identified in terms of high overall acceptability (>8), TSS-acid ratio (>2.00), less seed content (≤10 per fruit), low limonin content, high essential oil (>4%), high ascorbic acid and antioxidant activity (>80mg/100ml juice) and thin to medium rind thickness.
Open Access
GENETICS OF DROUGHT TOLERANCE IN RICE (Oryza sativa L.)
(2019-11) Devi, Laishram Monalisha; Sarma, Debojit
The present investigation was carried out at Instructional-Cum-Research Farm of Assam Agricultural University, Jorhat with the objectives - (i) To assess genetic diversity for drought tolerance in rice and (ii) To study the combining ability and gene action. We evaluated 46 rice genotypes in water sufficient non-stress and water-deficit stress conditions during Ahu season of 2018 in PVC pipes. Evaluation of the 6-parent diallel crosses was carried out during Ahu 2019 in plastic tubs. The phenotypic evaluation revealed significant variation for all the characters. Leaf rolling (LR) and drought recovery (DR) had a significant correlation with root traits only, positive with root length and negative with root dry matter and root-shoot ratio. Based on the lowest average LR plus DR score of unity, Basantabahar, Haru Bengunigootia, Lewly, Basmoti Red, Banglami, Ikhojoi, Dimrou, Lachit, Disang and Inglongkiri possessed tolerance to drought stress (7-8% soil moisture content) both at vegetative stage up to 3 weeks and reproductive stage up to 1 week. Root-shoot ratio, root dry weight, proline content, root length, productive tillers, grain yield, grains per panicle and biomass yield registered a high magnitude of PCV and GCV estimates. High heritability coupled with high genetic advance for 1000-grain weights, proline content, grains per panicle, root dry weight, days to first panicle emergence, days to 50% flowering, root-shoot ratio, biomass yield per plant, root length, grain yield per plant, productive tillers per plant, harvest index and shoot length implicating the role of additive gene action and scope of simple selection for these traits. D2 statistics grouped the genotypes into 14 clusters with the highest inter-cluster distance between cluster V-XIII and V-XII. Thousand-grain weights contributed the maximum (74.69%) to the genetic divergence among the genotypes followed by grains per panicle (9.76), proline content (3.29%), root dry weight (3.09%) and grain yield per plant (2.71%). At the molecular level, we detected a total of 86 alleles by using 34 pairs of SSR primers with an average of 2.53 per marker. The Jaccard’s coefficient of similarity ranged from 0.200 to 0.944, with an average of 0.360, suggesting diverse nature of the genotypes. The diallel analysis revealed the significance of both GCA and SCA variances for all the characters in both non-stress and stress environments, indicating the importance of additive and non-additive gene action in their expression. SCA variance was higher than GCA variance for most of the characters except pollen sterility in both the conditions and harvest index in non-stress condition alone. Simple selection would confer rapid improvement of pollen sterility in both the conditions. Among the parents, the good general combiners were IR 64, IR 36, Tamdao and Inglongkiri for early flowering and early maturity; Banglami and Sahbhagi Dhan for low pollen sterility; IR 64, IR 36 and Sahbhagi Dhan for reduced plant height; Banglami and Sahbhagi Dhan for high productive tillers per plant; Sahbhagi Dhan and Banglami for longer panicle with heavier grain weights; Banglami, Inglongkiri and Tamdao for harvest index in both the conditions; Sahbhagi Dhan, Inglongkiri and Banglami for grains per panicle; IR 64, Sahbhagi Dhan and Banglami for biological yield in stress condition. The cross combinations namely, Sahbhagi Dhan/Inglongkiri and Banglami/IR 64 in non-stress condition and Sahbhagi Dhan/Banglami, Sahbhagi Dhan/IR 64, Banglami/Tamdao, IR 36/IR 64, Inglongkiri/Tamdao in stress condition exhibited significant positive yield-SCA effects along with desirable GCA of parents and SCA for other characters. Hayman’s genetic analysis indicated partial to complete adequacy of the additive-dominance model for all the characters in both the conditions. The component of dominance variance was predominant for almost all the characters with mostly overdominance expression of genes demanding a more prudent breeding exercise for genetic manipulation of these traits such as heterosis breeding. The narrow-sense heritability estimates were moderate to high for pollen sterility, plant height, panicle length and harvest index in both the conditions. Partial dominance for pollen sterility in both the conditions suggested its worth for fairly dependable selection. The study also indicated a similar genetic interpretation of the characters with the approaches of Griffing (1956) and Hayman (1954a, 1954b).
Open Access
HEAT UNIT INDEXING OF GARDEN PEA IN RELATION TO CLIMATE SHIFT AND NUTRIENT MANAGEMENT
(2019-07) Sangma, Trudy Tengse A.; Saikia, Luchon
An experiment was conducted consecutively during 2016-17 and 2017-18 in the Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat to study the “Heat unit indexing of garden pea in relation to climate shift and nutrient management”. The experiment consist three treatments viz., variety (main), fertility management level (sub) and sowing date (sub-sub) laid out in split plot design with random allocation and replicated thrice. The main treatment consisted Arkel(V1), A1(V2), DS-10(V3) and GS-10(V4); sub treatment was comprised of 5t FYM, 10-46-0 kgha-1 (F1), 10t FYM, 10-46-10 kgha-1 (F2), 10t FYM, 20-46-20 kgha-1 (F3) and 10t FYM, 30-46-30 kgha-1 (F4) and sub-sub treatment was dates of sowing: 10th October (S1), 24th October (S2), 7th November (S3), 21st November (S4), 5th December (S5) and 20th December (S6). Growth, yield attributes, soil related and quality characters viz., plant height(cm), days to 50% flowering, pod plant-1, pod length (cm), pod diameter (cm), seed pod-1, shelling (%), pod yield (tha-1), duration (days), growing degree days, root nodules plant-1, total plant nitrogen (%), total plant phosphorus(%), total potash (%), TSS (0 Brix), crude protein (%), soil organic carbon (%), soil available nitrogen (kgha-1), soil available phosphorus (kgha-1), soil available potash (kgha-1) and soil pH have responded significantly due to treatments as well as their interactions, except pH. Variety evidently produced significant effect on growing degree days (GDD) and results showed V4>V3>V2>V1 with requirement of 955, 948, 933 and 833 GDD for 2016-17 and similarly 958, 949, 942 and 825 GDD. The maximum duration was reported as 76.00days in V4F with (1,2,3,4) and S( with 3,4,5). Duration was closely associated with degree days by sowing date had indicated significant duration among varieties, least with V1(58.73days), to maximum in V4(72.30days). Fertility level had a range of maturity at 68.08 to 68.29days. Sowing dates showed significance as 911(S1), 915(S2), 915(S3), 915(S4), 916(S5) and 918(S6) during 2016-17 and the GDD was found significant as S1

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