Browsing by Author "Sreekala, G S"

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Biomass production and partitioning of photosynthates in ginger (Zingiber Officinale R.) under different shade levels
(Department of Horticulture, College of Agriculture, Vellayani, 1999) Sreekala, G S; Jayachandran, B K
A pot culture experiment was conducted at the College of Agriculture, Vellayani during the year 1997 - 1998 to study the effect of shade on biomass production and partitioning of photosynthates in ginger cv. Rio-de-Janeiro. The experiment was laid out in completely randomised design with five shade levels (open, 20, 40, 60 and 80 per cent) and four replications. Artificial shade was provided using high density polyethylene shade nets and calibrated using quantum photo sensors. Two months after planting, ginger plants were labelled using 14C . After tagging, one set of samples were collected immediately. Subsequently, harvesting of the tagged plants were done once in sixty days after labelling. Monthly observations of various growth parameters were taken from two months after planting. At six months after planting photosynthetic related parameters were measured using leaf chamber analyser. The various growth parameters like number of tillers, leaf area, leaf dry weight, dry matter production, crop growth rate, relative growth rate, net assimilation rate at final stage, leaf area index which contributed to yield was highest under 20 per cent shade. This shows that the plant prefers low shade intensity compared to open. The yield recorded under 20 per cent shade was significantly superior compared to open. But the yield at open and 40 per cent shade were on par. Higher shade levels decreased the yield. This shows that the crop can tolerate shade up to 40 per cent. Different shade levels influenced the quality of ginger rhizomes. While volatile oil was maximum under heavier shade levels in general ( 60 and 80 per cent ), non- volatile ether extract was higher under 20 per cent shade. Starch as well as crude fibre content was more in plants grown under open condition. The photosynthetic rate and related parameters of ginger were measured at six months after planting using leaf chamber analyser. Photosynthetically active radiation on leaf surface as well as stomatal conductance was high under open condition. But leaf internal carbon dioxide concentration as well as stomatal resistance was high under heavier shade levels (60 and 80 per cent). Photosynthetic rate as well as the transpiration rate was maximum in plants grown in open. Though, at 20 per cent shade, the photosynthetic rate was less, the yield was high. This might be because of the photo oxidation that has taken place at high light intensities or due to the inefficient translocation of the photosynthates in open condition compared to 20 per cent shade. Radio tracer analysis done using labelled 14C has shown that under open condition, though initial intake of carbon dioxide was more, most of the carbon dioxide taken are seen in the above portion itself. While in 20 per cent shade most of the carbon dioxide taken in has translocated to the lower portion. This shows that under low light intensity the photosynthates produced has translocated efficiently to the lower portion while in open condition efficient translocation has not taken place. The results indicate that 20 per cent shade level is favourable for growing ginger plants to get higher rhizome yield. The yield at 40 per cent was on par with that of open. This shows that crop can tolerate shade upto 40 per cent. Thus the partially shaded coconut gardens can be exploited for increasing the area under ginger which may help in doubling the production.
Characterisation of boron deficient coconut palms (Cocos nucifera L.)
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2017) Athulya S Nair; Sreekala, G S
Characterisation of coconut palms (Cocos Nucifera L.) showing general yellowing
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2017) Aparna, K; Sreekala, G S
The study on “Characterisation of coconut palms (Cocos nucifera L.) showing general yellowing” was undertaken in selected coconut palms coming under Thiruvallam of Thiruvananthapuram district from March 2016 to March 2017. The objective was to evaluate the field characteristics and nutritional status of soil and coconut palms showing general yellowing and to formulate a management strategy. Coconut palms of variety WCT showing general yellowing which advance from lower to upper whorls of leaves were identified from farmer’s field of Thiruvallam. Fifteen palms showing uniform pattern of general yellowing and five healthy palms were selected from five farmer’s fields. Field, soil, plant and management practices followed by farmers were studied in the selected palms to identify the pre disposing factors leading to general yellowing. Observations on morphological and yield characteristics of selected coconut palms were recorded for one year at 60 days interval. Soil and plant samples were collected and analysed for macro and micronutrients. Based on soil test results the quantity of deficient macro nutrients were calculated and applied as per package of practices recommendation of Kerala Agricultural University. The soil and plant sample was again analysed six months after the application of fertilisers. Data generated on field characterization revealed the type of soils as red loam soils with good drainage in all the selected coconut palms. High soil organic matter was seen in all the healthy coconut palms while eighty percentage of coconut palms showing general yellowing were under medium status of organic matter. Of the coconut palms showing general yellowing, fifty three percent belonged to the age group of 31-35.The disease and pest incidence in the healthy palms was only twenty percent while it was more than fifty percent in palms showing general yellowing. The morphological, physiological and yield parameters of selected palms indicated significant variation in number of leaves showing yellowing, chlorophyll content, membrane integrity, relative water content, number of bunches, number of female flowers per bunch of inflorescence, number of nuts set per bunch, weight of nut, weight of copra and oil content in coconut palms showing general yellowing compared to healthy palms. However after the application of nutrients significant increase in chlorophyll a content, total chlorophyll content, membrane integrity and relative water content was noticed in coconut palms showing general yellowing. The soil and leaf nutrient analysis revealed a significant variation in N, P, K, Ca, Mg, S and B content between coconut palms showing general yellowing and healthy palms. However, observations made at six months after the application of manures and fertilisers revealed a significant increase in soil pH, organic carbon, N, P, K, Ca, Mg, B and Cl in the soil and N,P,K of index leaf of coconut palms showing general yellowing. There was no significant variation in the S, Fe, Mn, Zn and Cu before and after the application of manures and fertilisers. The present study based on nutritional status and visual symptoms revealed that low soil nutrient status of N, P, K, Ca and Mg have resulted in the general yellowing in coconut. The application of fertilisers as per average management recommended by KAU (2016) could only enhance the soil N, P, K and Mg status to medium level while for calcium it still remained in low status. Thus a higher dose of N, P, K, Ca and Mg are required for the palms showing general yellowing to substantially improve the nutritional status of the palm.
Characterization and quality analysis of black pepper (Piper nigrum L.) genotypes of Kerala
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2021) Reshma, P; Sreekala, G S
The present study entitled “Characterization and quality analysis of black pepper (Piper nigrum L.) genotypes of Kerala” was taken up with the objectives of survey, characterization and quality analysis of black pepper genotypes of Kerala based on morphological and biochemical parameters. The survey conducted in black pepper plantations and homesteads in fourteen locations of six Agro-Ecological Units (AEUs) identified twenty one genotypes. Five genotypes designated as G1 (Wayanadan), G2 (Chumala), G3 (Vellayaranmunda), G4 (Nadan), G5 (Nadeshan) from AEU 21 (Wayanad Eastern Plateau), six genotypes designated as G6 (Karimunda), G7 (Neelamundi), G8 (Cheppukulamundi), G9 (Vattamundi), G10 (Thulamundi), G11 (Manjamunda) from AEU 12 (Southern and Central Foothills), three genotypes designated as G12 (Chengannurkodi), G13 (Vellanamban), G14 (Jeerakamunda) from AEU 14 (Southern High Hills), three genotypes designated as G15 (Kuthiravally), G16 (Kottanadan), G17 (Arimulak) from AEU 3 (Onattukara Sandy Plains), two genotypes designated as G18 (Padappan), G19 (Karivilanchy) from AEU 8 (Southern Laterites) and two genotypes designated as G20 (Narayakodi) and G21 (Panniyur 1) from AEU 4 (Kuttanad) were selected for the study. Twenty one genotypes were morphologically characterized for both qualitative and quantitative characters. Thirty four qualitative characters were observed and among those only twenty two characters showed variability. Characters such as runner shoot production, pubescence on stem, type of veining, leaf texture, spike colour, spike orientation, spike shape, spike fragrance, spike proliferation, colour change while fruit ripening, fruit taste and seed texture were uniform in all the selected genotypes. The UPGMA dendrogram divided all the genotypes into 15 clusters at 73 per cent similarity. Sensory evaluation of the selected black pepper genotypes showed a significant variation for colour, odour, taste and flavour. G16 (Kottanadan) was significantly superior in taste while G15 (Kuthiravally) was superior in odour and flavour. Thirty four quantitative characters were recorded for plant, leaf, inflorescence, fruit and seed characters. Summarizing these quantitative characters using descriptive statistics revealed wide range of variability in number of well developed fruits per spike, number of spikes per 30 cm2 , number of spikes per vine, bulk density and specific leaf area. Principal component analysis was undertaken to examine the variation and to estimate the relative contribution of various trait for total variability. The principal component analysis for twenty three yield related characters revealed seven principal components at 85.53 per cent variability. The eleven quantitative characters such as juvenile leaf length, leaf length, leaf width, number of spikes/30 cm2 , number of spikes per lateral branch, number of spikes per vine, number of nodes per lateral branch, number of well developed berries per spike, berry diameter, support height and vine column diameter contributed more to the yield. The score plot identified fifteen clusters in which genotypes with superior yield namely, G1 (Wayanadan), G4 (Nadeshan), G5 (Nadan), G15 (Kuthiravally) and G21 (Panniyur 1) formed unique clusters. Minimal data set generated for black pepper included four characters namely, number of nodes per lateral, number of well developed berries/spike, number of spikes/30 cm2 and berry diameter. The principal component analysis for five physiological parameters revealed one principal component at 73.34 per cent variability. Genotypes with high leaf thickness, high relative water content, high epicuticular wax, low specific leaf area and low stomatal density were associated with drought tolerance in black pepper. Sixteen clusters were identified based on score plot. Biplot analysis identified genotypes G16 (Kottanadan), G13 (Vellanamban), G6 (Karimunda), G7 (Neelamundi), G18 (Padappan) and G20 (Narayakodi) as most desirable genotypes for drought tolerance. The principal component analysis for six quality attributes revealed two principal components at 66.62 per cent variability. The genotypes were grouped into seventeen clusters based on score plot while the biplot identified genotypes G16 (Kottandan), G15 (Kuthiravally), G21 (Panniyur 1), G19 (Karivilancy), G17 (Arimulak), G13 (Vellanamban) and G6 (Karimunda) as the high quality ones. The genotypes studied for qualitative, quantitative, physiological and quality traits showed a moderate variability and can be used in the selection of suitable parents for breeding purpose and gene mapping studies.
Cost effective technology for home scale and small scale production of virgin coconut oil
(Department of plantation crops and spices, College of Agriculture, Vellayani, 2015) Thanuja, T T; Sreekala, G S
The investigation on “Cost effective technology for home scale and small scale production of virgin coconut oil” was carried out during the period 2013- 2015 at the Department of Plantation Crops and Spices, College of Agriculture, Vellayani, Kerala to standardise the cost effective technique for home scale and small scale production of virgin coconut oil through fermentation, induced fermentation and centrifugation and to compare the technology developed with the traditional boiling method.The study was conducted in four experiments and the coconuts for the experimental purpose were collected from the variety WCT (West Cost Tall). Standardisation of fermentation method was done by extracting coconut milk with coconut water (CM+CW 1:1) and with water in the ratio 1:1 (CM+W 1:1) and 1:2 (CM+W 1:2) and kept for 24, 36 and 48 hours for fermentation. The oil recovered was subjected to drying at 40, 45 and 50°C and the sensory parameters and percentage oil recovery were significantly superior at 50°C. The fermentation method was replicated during June- July, Nov- Dec and March- April. The atmospheric conditions was not congenial for the VCO production during Nov- Dec. The oil recovery was nil below an atmospheric temperature of 31.05°C. The maximum relative humidity when the oil was separated ranged from 90.50 per cent to 97 per cent. The minimum relative humidity during that period ranged from 67 per cent to 83 per cent. For the standardisation of induced fermentation method, isolation of microorganisms from fermented coconut milk at 24 and 36 h was done and the best isolate identified belonged to the genus Lactobacillus. Induced fermentation with one per cent of Lactobacillus broth showed significantly higher oil recovery compared to natural fermentation.Standardisation of virgin coconut oil production by centrifugation was also carried out by extracting coconut milk after 10 hours of chilling at different revolutions per minute (rpm) and time. The coconut milk extracted with coconut water at 12000 rpm for 15 minutes and dried at 50°C recorded significantly higher oil recovery (28.087 per cent). The virgin coconut oil produced by fermentation, induced fermentation and centrifugation were compared with traditional boiling method. A higher oil recovery and B:C ratio with minimum refractive index was observed under centrifugation while moisture content, specific gravity, relative density, acid value, peroxide value, iodine value, polenske value and saponification value did not vary significantly between different methods of extraction. The yellowing index and sensory parameters like odour and taste were significantly superior for traditional method while unsaponifiable matter, total phenolic content, free radical scavenging activity, total antioxidant capacity and the reducing power were significantly superior for fermentation method. The shelf life of the VCO produced by different methods was less than 3 months. The fermentation, present study implies that virgin coconut oil produced by induced fermentation and centrifugation had better quality parameters, antioxidant properties and cost effectiveness compared to traditional boiling method. Fermentation method can be adopted for home scale production while centrifugation and induced fermentation can be suggested as a better method for small scale production of virgin coconut oil.
Development of heteroploids in ginger (Zingiber off zingiber officinale Rosc.)
(Department of Plantation Spices Medicinal and Aromatic Crops, College of Agriculture, Vellayani, 2024-01-24) Silpa, S G; Sreekala, G S
An experiment entitled “Development of heteroploids in ginger (Zingiber officinale Rosc.)” was carried out in the Department of Plantation, Spices, Medicinal and Aromatic Crops, College of Agriculture, Vellayani, during October 2018 to October 2022 with an objective to develop heteroploids using colchicine for yield and quality in ginger cultivars. The present study to develop heteroploids in ginger (Zingiber officinale Rosc.)” was carried out as three experiments (i) Development of heteroploids in ginger cultivars using colchicine in vivo (ii) Development of heteroploids in ginger cultivars using colchicine in vitro and (iii) Screening of heteroploids for stability. Experiments conducted at Department of Plantation, Spices, Medicinal and Aromatic Crops during 2018 recorded four promising genotypes of ginger. Rhizomes of these genotypes along with rhizomes of ginger varieties Athira, Aswathy, IISR Varada and IISR Mahima were collected from College of Agriculture, Vellanikkara and ICAR- Indian Institute of Spices Research respectively and heteroploidy was induced in vivo as per the method developed by Sheeba (1996). A total of sixteen treatments including eight respective controls were tried in Completely Randomized Design.
Effect of organic manures and microbial inoculants on growth, yield and quality of ginger
(Department of Plantation Crops and Spices, College of Agriculture,Vellayani, 2004) Sreekala, G S; Jayachandran, B K
Field experiments were conducted at College of Agriculture, Vellayani during April 2000 to January 2001 and April 2001 to January 2002 to assess the effect of organic manures and microbial inoculants on growth, yield and quality of ginger grown as intercrop in coconut garden, to evaluate its effect on the physical and chemical properties of the soil and to develop a suitable economic organic farming practice for producing export quality ginger free of pesticide residues. Factorial combination of four organic manures (FYM, vermicompost, neemcake and green leaves) and four microbial inoculant treatment (no microbial inoculant, AMF, Trichoderma, AMF + Trichoderma) and two controls (package of practices recommendation of Kerala Agricultural university and absolute control) in RBD were studied. FYM @ 30 t ha-1 was applied uniformly to all plots except for absolute control. Organic manures were applied on nitrogen equivalent basis. The main effects of organic manures, microbial inoculants and their interaction were studied. The application of FYM and AMF + Trichoderma increased plant height, number of tillers, number of leaves, root length, root spread, root weight, root volume, DMP, CGR, NAR, LAI, LAD, root shoot ratio, green ginger yield, dry ginger yield, shoot weight, bulking rate, rhizome spread, rhizome thickness, volatile oil, NVEE and uptake of N, P and K. The starch content as well as crude fibre content was less for FYM and AMF + Trichoderma treatment. Soil physical characters viz., bulk density, particle density, water holding capacity and soil aggregate index were superior for FYM + green leaf treatment and AMF+ Trichoderma application. The available N, P and K content of the soil after the second year of experiment was higher for FYM + green leaves treatment and AMF + Trichoderma treatment. The organic carbon content of the soil was higher for FYM treatment. The soil pH was found to decrease after each experiment for organic manures, microbial inoculants as well as their combinations. Among organic manure microbial interaction, application of FYM + AMF and FYM + neemcake + AMF + Trichoderma promoted significant growth and physiological characters, favoured green ginger yield, dry ginger yield, shoot weight, bulking rate, rhizome spread, rhizome thickness, quality parameters viz., volatile oil and NVEE. The application of FYM + AMF and FYM + neem cake + AMF + Trichoderma enhanced crop uptake of N, P and K and at the same time resulted in appreciable build up of available N, P and K in the soil. The balance sheet for available N, P, K indicated a deficit balance during first year for all treatment except for absolute control. A gain in soil potassium content was noticed during the second year of experiment for all organic manures, microbial inoculants and organic manure microbial inoculant combinations. The shoot borer attack was higher during the first year for FYM treatment at four month after planting and six month after planting compared to the second year. The nematode population in the soil was not significant before and after the experiment to cause economic damage. The residue analysis of plants treated with mancozeb, malathion and dimethoate as per package of practices recommendation of Kerala Agricultural University revealed no detectable level of residues. The FYM + AMF and FYM + neemcake + AMF + Trichoderma generated a higher profit during the first and second year. All organic manure microbial inoculant combination (except FYM + no microbial inoculant, FYM + vermicompost + no microbial inoculant, FYM + neemcake + no microbial inoculant, FYM + green leaf + no microbial inoculant) produced significantly higher yield and profit compared to treatments as per the package of practice recommendation of Kerala Agricultural University. Correlation of yield with plant height, number of leaves, number of tillers, root length, root spread, root weight, root volume, dry matter production, crop growth rate, leaf area index, leaf area duration, shoot weight, bulking rate, rhizome spread, rhizome thickness, volatile oil, oleoresin and uptake of N, P and K showed significant positive correlation, which is an indication that these characters can be used as a criteria for the selection of yield. To sum up FYM + AMF and FYM + neemcake + AMF + Trichoderma can be used as organic manure microbial inoculant combination with equal efficiency for ginger intercropped in coconut garden. The result of two year study revealed that application of organic manure microbial inoculant combination produced better yield and improvement in soil health and nutrition than the application of organic manures or microbial inoculants alone. Increase in the profitability during the second year and reduction in the intensity of pest attack indicates the feasibility of switching over from integrated farming to organic farming.
Effect of pre treatments and curing methods on the quality characters of processed cardamom (Elettaria cardamom (L) Maton
(Department of processing technology, College of horticulture, Vellayani, 2012) Sonia, V; Sreekala, G S
Evaluation of elite clove (Syzigium aromaticum (L.) Merr. and Perry) accessions and standardization of pollination techniques
(Department of Plantation Crops and Spices, College of Agriculture , Vellayani, 2020) Reddappa, J B; Sreekala, G S
The present study entitled “Evaluation of elite clove (Syzigium aromaticum (L) Merr. & Perry) accessions and standardization of pollination techniques” was taken up with the specific objective to evaluate elite clove accessions and to standardize pollination techniques for hybridization. The twelve elite accessions identified from estates of Trivandrum and Kollam districts of Kerala designated as BRC-1, BRC-2, BRC-3, BRC-4, MRC-5, MRC-6, MRC-7, MRC-8, AMC-10, AMC-11, AMC-12 and AMC-13 were evaluated during the period of 2018-2020. Quantitative characterization was done with 25 quantitative characters including tree, leaf, bud, flower, yield, fruit and seed characters. The girth of the tree at 30 cm height was maximum in BRC-3 (165 cm). Highest number of inflorescence/m2 was recorded in AMC-12 (156.25). The number of flower buds/inflorescence was maximum in MRC-6 (17.25) while single bud fresh and dry weight was highest in BRC-3 with 398.72 mg and 127.26 mg respectively. The mature bud length among the clove accessions was the maximum in BRC-1 (19.34 mm) whereas the mature bud diameter was maximum in BRC-3 (6.45 mm). The dry bud yield per tree was the highest in MRC-7 (8.13 kg) followed by BRC-1 (7.48 kg). Quantitative characters summarized based on the descriptive statistics revealed wider range of variability in single bud weight fresh, number of inflorescence/m2, single bud weight dry and girth of the tree. Multi Dimensional Scaling (MDS), a multivariate analysis done on 25 variables with 12 observations revealed 10 dimensions and the contribution of MDS Dimension-1 and Dimension-2 were 75.76 and 17.21 percent with cumulative variance of 92.97 percent respectively. Based on the scree plot of MDS, first 2 dimensions were selected for generating the biplot. Based on MDS configuration eight clusters of selected clove accessions were identified. Dendrogram representing the relationship among 12 elite accessions based on Euclidean distance also identified same eight clusters of clove accessions that identified in MDS configuration. The linkage analysed based on the biplot of two dimensions of multidimensional scaling of biplot coordinates revealed a strong positive association between most of the characters measured except, girth at 30 cm height, number of inflorescence per m2, single bud weight fresh and single bud weight dry. Minimum Data Set for identifying a promising clove accession generated revealed accessions BRC-1, MRC-5 and MRC-6 had better ideotype and can be suggested as elite or superior accessions. The experiment on floral phenology and biology was carried out in clove plants at Braemore estate, Trivandrum district. The flower opening time of the clove flowers observed were between 2:30-6:30 pm. However the percentage of flower opened was maximum between 3.30- 5.30 pm. The number of stamens per flower varied from 167 to 343. The rupturing of anthers started 36 hours before anthesis and maximum anther dehiscence occurred between 36 h before anthesis till anthesis. The pollen grains were monad, radially symmetrical, triangular, trizonosyncolporate and were having exine ornamentation. The polar diameter of pollen grain ranged from 17.06-18.22 µm and the equatorial diameter of pollen grain ranged from 19.40-20.70 µm. The stigma receptivity by hydrogen peroxide test revealed stigma receptivity was there upto six days from anthesis and maximum stigma receptivity was observed on fifth day of anthesis with highest number of bubbles (31.40 per cent). The emasculation should start from 48 hour before flower bud opens which was revealed by the starting of separation of the petals since anthers started rupturing from 36 hour before anthesis. Pollen viability by iodine potassium iodide method revealed that pollen viability was maximum at 12 hour before anthesis (94.02 per cent). Pollen fertility was also maximum on the pollen collected 12 hour before anthesis (82.83 per cent). Thus the pollen collection should be undertaken 12 hour before anthesis. Pollen collected and dried at 50°C and stored upto two months of storage in refrigerator had maximum pollen viability whereas pollen fertility was maximum in pollen dried at 50°C and stored in desiccator. The hybridization was carried out on selected five clove plants as male and female parents. The percentage of fruit set ranged from 15 per cent to 42.5 per cent and average fruit set from all the plant combinations was 28.87 per cent. The study on “Evaluation of elite clove (Syzigium aromaticum (L) Merr. & Perry) accessions and standardization of pollination techniques” revealed that clove accessions such as BRC-1, MRC-5 and MRC-6 had superior ideotype and superior in effective yield. The floral phenology of clove was studied and pollen collection, storage and artificial hand pollination in clove was standardized.
Identification and characterisation of nutmeg (Myristica fragrans Houtt.) genotypes of southern Kerala
(Department of Plantation Crops and Spices, College of Agriculture , Vellayani, 2021-11-21) Nainu Joseph.; Sreekala, G S
The research work on “Identification and characterisation of nutmeg (Myristica fragrans Houtt.) genotypes of Southern Kerala” was undertaken during 2020-21 at the Department of Plantation Crops and Spices, College of Agriculture, Vellayani. A survey was conducted in the nutmeg growing belts of Agro-Ecological Unit (AEU) 4 of Kottayam and Pathanamthitta districts, AEU 8 of Thiruvanathapuram district, AEU 9 of Kottayam, Pathanamthitta and Thiruvanathapuram districts, AEU 12 of Kottayam and Kollam districts and AEU 14 of Pathanamthitta district for identification of nutmeg genotypes with superior yield and variability. Among the fifty nutmeg genotypes surveyed twenty one genotypes were selected for characterization and in situ evaluation. The twenty one selected nutmeg genotypes from homesteads and estates were denoted as KDR 1, MNA 2, MNA 3, MNA 4, MPY 5, MPY 6, MPY 7, MPY 8, NLD 9, NLD 10, PND 11, PND 12, PKM 13, PLA 14, PLA 15, PLA 16, PLA 17, PRA 18, VNI 19, VNI 20 and VNI 21 based on the location of study. Qualitative and quantitative characterization of twenty one genotypes was undertaken for tree, leaf, flower, fruit and seed characters. Based on the DUS guidelines provided by PPV & FRA (2015) and minimal descriptor developed (Vikram, 2016) on nutmeg, thirty six qualitative characters were observed in the study in which height of tree, sex form, presence of caruncle and fruit length were non variable characters. The thirty two variable qualitative characters were subjected to hierarchical cluster analysis. UPGMA (Unweighted Pair Group Method with Arithmetical Averages) dendrogram was generated from the qualitative characters and fourteen clusters were formed at 65 percent similarity. Based on the clusters formed in the dendrogram, genotypes namely, MNA 3, NLD 9, NLD 10, PRA 18 and PLA 16 were closely related (cluster II), MPY 5 and PKM 13 (cluster III), PKD 11 and PLA 15 (cluster IV) and PLA 17 and VNI 20 (cluster VI). KDR 1 with yellow mace formed a separate cluster (Cluster I). The monoecious genotype VNI 21 was distinctly different from other clusters. Thirty two quantitative characters including biochemical characters were observed in the selected genotypes. Under the multivariate analysis for quantitative characters, principal component analysis was used as a statistical tool to interpret the parameters. The thirty two quantitative characters were reduced to eight principal component groups contributing a total variance of 84.518%. Based on the loadings in principal components 1 and 2, score plot and biplot was generated. The score plot grouped genotypes into 15 clusters in which genotypes with superior yield namely, PKD 11, PLA 14, NLD 9, PKM 13 and PRA 18 formed unique clusters. The pooled mean of yield characters revealed that five genotypes namely PKD 11, PLA 14, NLD 9, PKM 13 and PRA 18 were superior in yield. Significantly superior number of fruits per tree, fresh and dry mace yield and fresh nut yield per tree was observed in PKD 11 which was followed by PLA 14 with high yield in terms of number of fruits per tree, mace, nut and kernel yield. Significantly superior dry nut and kernel yield was obtained in NLD 9. PKM 13 and PRA 18 also recorded significantly high number of fruits per tree, dry mace, dry nut and dry kernel yield as compared to other genotypes. Thirty six qualitative characters were reduced to a minimal descriptor of eight characters namely, crown shape, shape of leaf blade, number of flowers per cluster, nature of fruit bearing, colour of mace (fresh), mace covering pattern, attachment of mace to nut and seed colour. Thirty two quantitative characters was reduced to a minimal data set of five characters such as number of flowers per cluster, height of tree, fruit weight, single kernel weight (dry) and fruit set percentage. Those genotypes with best combinations of these qualitative and quantitative characters can be selected for yield in nutmeg. Thus based on the identification, characterization and in situ evaluation for two years, PKD 11, PLA 14, NLD 9, PKM 13 and PRA 18 with superior yield and yellow maced genotype KDR 1 were selected for future crop improvement studies in nutmeg.
Molecular characterization of Ginger genotypes (Zingiber officinale Rosc.)
(Department of Plant Biotechnology, College of Agriculture , Vellayani, 2021-12-22) Anaswara, P A; Sreekala, G S
The study entitled “Molecular characterization of ginger genotypes (Zingiber officinale Rosc.)” was carried out at the Department of Plant Biotechnology and Department of Plantation Crops and Spices, College of Agriculture, Vellayani during 2020 to 2021. The objective of the study was to assess the genetic diversity of ginger genotypes using simple sequence repeats (SSR) and inter-simple sequence repeat (ISSR) markers. Leaf samples of twenty ginger genotypes maintained in the germplasm of Department of Plantation Crops and Spices were collected and subjected for DNA isolation using CTAB method. Quality and quantity of the isolated DNA samples were determined using Agarose gel electrophoresis and spectrophotometric analysis. Fifteen ISSR (ISSR 26, ISSR 14, ISSR 53, ISSR 54, ISSR 69, ISSR 79, ISSR 11, ISSR 12, ISSR 72, ISSR 04, UBC 835, UBC 809, UBC 829, UBC 818 and UBC 828) and 15 SSR (GES 440, GES 452, GES 454, GB-ZOM-033, GB-ZOM-040, GB-ZOM-055, GBZOM-064, GB-ZOM-103, GB-ZOM-107, GB-ZOM-111, GB-ZOM-140, RM 154, RM 171, RM 135, and RM 125) markers were selected from previous studies for molecular characterization of ginger genotypes. Out of these fifteen SSR primers four were rice SSR primers (RM 154, RM 171, RM 135, and RM 125) with high Polymorphic Information Content (PIC) value. Isolated DNA samples showed good quality and their concentration ranged from 132 to 3162 μg/ml. Average polymorphism of ginger genotypes using ISSR and SSR primers were 56% and 67.6% respectively which revealed a moderate level of polymorphism within the twenty ginger genotypes. ISSR markers UBC 829, ISSR 53, ISSR 54, ISSR 72 and SSR markers GB-ZOM-055, GB-ZOM-103, GB-ZOM-064, RM 154, RM 171, RM 135 showed 100 percentage of polymorphic loci. PIC value of ISSR primers ranged from 0 (UBC 818, UBC 828, ISSR 69 and ISSR 12) to 0.49 (UBC 829) and SSR primers ranged from 0 (GES 452, GES 454, GES 440, GB-ZOM111, GB-ZOM-033, GB-ZOM-140) to 0.45 (RM 154). The Mantel’s statistic (r) value based on Spearman's rank correlation obtained as 0.01652 with a significance value (p) of 0.4457 indicated no significant correlation between SSR and ISSR marker information. In this study Jaccard’s similarity coefficients using ISSR and SSR marker data ranged from 0.69 to 0.98 and 0.54 to 0.98. Dendrogram generated using ISSR and SSR data separated twenty genotypes into three clusters and PCoA of twenty ginger genotypes using ISSR and SSR data revealed 11 and 9 clusters respectively. A low to moderate level of polymorphism between these twenty ginger genotypes were observed using ISSR and SSR marker analysis. Divergent lines identified from the Dendrogram of ISSR and SSR data are Mananthavady (T1), Murickassery (T14), Thalavur (T20), Mannarkkad (T9), Plamoodu (T21), Kazhakoottam 1 (T11) and Kazhakoottam 2 (T22). Compared to all other ginger genotypes Plamoodu (T21) and Mannarkkad (T9) showed high variation in ISSR and SSR marker analysis. The marker analysis revealed a higher similarity between ginger genotypes Kottarakkara (T5) and Kothamangalam (T7). The results of the study indicated the efficiency of SSR markers over ISSR markers in evaluating the genetic diversity of ginger genotypes. Polymorphic bands produced by the rice-SSR markers revealed that they are suitable for crossamplification studies in ginger. Among the twenty ginger genotypes characterized using molecular markers, higher variation was noticed in Plamoodu (T21) and Mannarkkad (T9) showing their suitability in future selection programs. The variation detected at genetic level among these ginger genotypes from this study will be useful for future genetic diversity studies.
Nutrient scheduling in bush pepper (piper nigrum L.)
(Department of Plantation Crops and Spices College of Agriculture, Vellayani, 2018) Farhana, C; Sreekala, G S
Pollination biology of black pepper (Piper nigrum L.)
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2019) Pooja, S; Sreekala, G S
Postharvest management practices in papaya (carica papaya L) for improving shelf life
(Department of Processing Technology, College of Agriculture, 2014) Jayasheela, D S; Sreekala, G S
Protocol development for gel stabilization and nutraceuticals in aloe vera (L.) Burm. f.
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2021) Maheswari R S Nair; Sreekala, G S
The investigation entitled “Protocol development for gel stabilization and nutraceuticals in Aloe vera (L.) Burm. f.” was carried out in the Department of Plantation Crops and Spices, College of Agriculture, Vellayani during March 2016 to December 2019. The project envisaged formulation of a low cost stabilization technique for aloe gel using herbal extracts and aromatic oils and development of protocols for the preparation of dried latex and marketable nutraceuticals using aloe gel. The study was carried out as four experiments. The first experiment was to study the keeping quality and natural spoilage flora of fresh gel while the second experiment was for the standardization of curacao aloe (dried latex). The third experiment was on gel stabilization using herbal extracts and essential oils. Preparation of nutraceuticals from the stabilized liquidized aloe gel juice was the final experiment. The keeping quality and natural spoilage flora of fresh gel were assessed by subjecting the liquidized aloe gel juice to storage in glass bottles under ambient condition for seven days. The liqudized aloe gel juice was off white in colour for first three days of extraction with mild vegetative odour and got sedimented with foul smell from fourth day onwards. The liquidized aloe juice could not be stored for more than a day due to increased microbial population from the second day of storage. Preliminary trails conducted by pasteurizing the liquidized aloe gel juice at 65 0C and 15 psi pressure for 13 minutes followed by flash cooling registered no microbial population even after seven days of storage. The latex collected from aloe leaves was subjected to different methods of drying such as boiling followed by cooling, sun drying, shade drying and oven drying. Appearance, colour and aloin content (271.62 mg/ml) of dried latex was significantly higher for shade drying. Liquidized aloe gel juice was pasteurized and added with varying concentrations of three forms (aqueous, tincture, decoction) of herbal extracts and essential oils after adjusting the pH to 3.5 by adding 0.5 per cent of citric acid for gel stabilization. The treated samples were kept for a month and based on microbial population and minimum inhibitory concentration best treatment of each form was selected from preliminary trials for aloe gel stabilization. Gymnema sylvestre aqueous extract (1 ml), tincture (1 ml), decoction (2 ml), Centella asiatica aqueous extract (1 ml), tincture (2 ml), decoction (1 ml), Achyranthes aspera aqueous extract (2 ml), tincture (2 ml), decoction (1.50 ml), Tridax procumbens aqueous extract (2 ml), tincture (2 ml) , decoction (1 ml), Terminalia chebula aqueous extract (1 ml), tincture (1 ml), decoction (1 ml), Punica granatum aqueous extract (1 ml), tincture (2 ml), decoction (1 ml), green tea aqueous extract (2 ml), tincture (1 ml) and decotion (2 ml) and 1 ml each of sacred basil oil, lemon grass oil, cinnamon bark oil, clove oil and cardamom oil were selected and added to pH adjusted , pasteurized and liquidized aloe gel juice (25 ml) for gel stabilization. The gel stabilization was thus done using the selected twenty six treatments in a Completely Randomised Design replicated five times and compared with 0.08 per cent sodium benzoate as control and stored for six months. Appearance, colour and odour of all forms of the herbal extracts reduced on storage while those treatments with aromatic oils showed lesser percentage reduction in these parameters. Total solids, amylase and lipase activity decreased on storage. The amino acid content was the highest for liquidized aloe gel juice added with aqueous, tincture and decoction of Achyranthes aspera (0.08 ppm).Vitamin A and C were highest for treatment with green tea leaf aqueous extract which decreased subsequently on storage. An increase in microbial load was observed for all the treatments with herbal extracts from first month of storage. But addition of 1 ml clove oil resulted in stabilization of liquidized aloe gel juice which could be stored upto five months without microbial contamination or affecting the nutritive and sensory parameters. Nutraceuticals were prepared using stabilized liquidized aloe gel juice containing clove oil blended with lemon juice, orange juice and honey in proportions of 50 : 50, 75 : 25 and 90 : 10 followed by pasteurization, flash cooling and stored for 6 months. Appearance, colour and vitamin C were significantly higher for Lemon juice (50 ml) + Liquidized aloe gel juice (50 ml) + 2 ml clove oil while odour, taste, overall acceptability, pH, TSS, carbohydrates and calories were significantly superior for Honey (50 ml) + Liquidized aloe gel juice (50 ml) + 2 ml clove oil. Growth of microbes could be detected from third month of storage for all the treatments. Aloe health drink with honey in the ratio 50 : 50 added with clove oil were selected as the accepted drink which could be preserved for two months without microbial contamination. The preparation of aloe herbal powder by solar drying, air drying, oven drying or freeze drying resulted in a sticky product which could not be reconstituted with distilled water for quality comparison with fresh gel, thus warranting further investigation. The present study revealed that liquidized aloe gel juice pasteurized and mixed with clove oil (4 per cent) is a low cost stabilization method which can be taken as a base material for the preparation of health drink. The nutraceutical with liquidized and stabilized aloe gel juice mixed with equal proportion of honey and preserved with clove oil is a palatable drink having higher calories which could be stored for two months. The dried aloe latex a byproduct produced by shade drying is superior with high aloin content and can also be used for the development of marketable product.
Quality assessment of coconut oil and detection of adulteration
(Department of Plantation Crops and Spices, College of Agriculture , Vellayani, 2020) Rakhi Jose; Sreekala, G S
The research programme entitled “Quality assessment of coconut oil and detection of adulteration” was undertaken at the Department of Plantation Crops and Spices, College of Agriculture Vellayani during the period 2018-2020. The study was conducted in order to assess the quality parameters of coconut oil and to detect adulteration by different techniques and to validate an easy and efficient method for the detection. Coconut oil was adulterated with 1, 5, 10, 15, 20 and 30 per cent of palm kernel oil and mineral oil. Apart from this pure coconut oil, pure palm kernel oil, pure mineral oil and five branded coconut oils were also collected altogether contributing twenty samples. These samples were analysed for physical and chemical characteristics, microbial contamination, thin layer chromatography, fatty acid composition by GCMS and FTIR spectroscopy to detect adulteration and to find an easy and efficient method for detection of adulteration. Physical and chemical characteristics analysed revealed refractive index and relative density of pure coconut oil, branded coconut oil and coconut oil mixed up to 30 per cent palm kernel oil were within the codex standard range. The apparent density of pure coconut oil differed significantly from adulterated samples. Insoluble impurities of all the samples were in the range 0.024-0.047 per cent which was within the standard prescribed by Codex (< 0.05 per cent). Saponification value of pure sample and all the branded coconut oil samples showed a value above 250 mg KOH g of oil-1 which was in tune with standard specified by FSSAI. Palm kernel oil and mineral oil as adulterant in different percentage showed less than 250 mg KOH g of oil-1. FSSAI standard for iodine value of coconut oil is in the range 7.5-10g and the iodine value of pure sample and all the branded coconut oil samples tested were within the range 7.5-10g. Iodine value of coconut oil adulterated with 5 per cent palm kernel oil and above exceeded the standard value (10) while adulteration with mineral oil above 1 per cent showed less than 7.5g. Standard Polenske value as prescribed by FSSAI and Codex (not less than13) was noticed in all samples except coconut oil with palm kernel oil 5 per cent and above and all mineral oil combinations. Pure sample, branded coconut oil and coconut oil mixed with varying percentage of palm kernel oil had unsaponifiable value within the limit of standards (not more than 1 per cent) while that of coconut oil mixed with even 1 per cent mineral oil and above exceeded the limit (1.18 per cent). Acid value of not more than 6 was the standard put forward by FSSAI and Codex and all oil samples except palm kernel oil and coconut oil mixed with 15 per cent palm kernel oil and above recorded values above 6. FSSAI standard for peroxide content in fresh coconut oil is below 10 meq/Kg and higher peroxide value were obtained from coconut samples mixed with palm kernel oil at 5 per cent and above and mineral oil at 15 per cent and above. Codex standard for matter volatile at 105°C is < 0.2% and all samples were within the limit. Principal component analysis (PCA) performed on physical and chemical characteristics of oil revealed high coefficient in PC1 for unsaponifiable matter and it contributed to maximum variation followed by relative density, apparent density, Polenske value, refractive index, saponification value and iodine value. In PC2, high coefficient was noticed for acid value followed by peroxide value and iodine value . Microbial contamination assessed by total plate count was within the APCC standard of less than 10 (< 10) colony forming units/ml. Fungal and actinomycete population was however not detected in the oil samples. Thin layer chromatography revealed yellow streaks in the profile of pure coconut oil sample, branded coconut oil samples and coconut oil mixed with different concentrations of palm kernel oil while yellow streaks were absent in coconut oil samples mixed with mineral oil. Gas chromatography coupled with mass spectrometry revealed the fatty acid composition in the oil samples. Principal component analysis carried out to analyze the variation contributed by the fatty acids revealed C16:0, C 12:0 and C 14:0 contributed the maximum variation in PC1. In PC2 high coefficient was noticed for C8:0 and C10:0. Percentage of oleic (C18:1) and linoleic (C18:2) acids were found to increase with increase in concentration of palm kernel oil and fatty acids were not detected in mineral oil. FTIR spectra formed peaks at regions of 2800-2900 cm-1, 1743 cm-1, 1465 cm- 1, 1417 cm-1, 1377 cm-1, 1229 cm-1, 1155 cm-1, 1111 cm-1, 962 cm-1, 722 cm-1 in pure coconut oil sample. Branded coconut oil samples and palm kernel oil adulterated samples obtained peaks at similar regions. Intensity of the peak at 3006 cm-1 increased with increasing concentration of palm kernel oil. The peaks for mineral oil were obtained at 2954 cm-1, 2923 cm-1, 2854cm1, 1466 cm-1, 1378 cm-1 and 721 cm-1. Intensity of the peaks at 1743 cm-1, 1229 cm-1, 1155 cm-1 and 1111 cm-1 were found to decrease with increase in percentage of mineral oil which indicated the absence of carbonyl group in mineral oil. Economics of adulteration of coconut oil by palm kernel oil and mineral oil revealed that maximum of Rs 4800/- per quintal was obtained by adulteration when 30 per cent of coconut oil was substituted by mineral oil followed by 20 per cent mineral oil ( Rs 3200/- per quintal) and 30 per cent palm kernel oil ( Rs 3150/- per quintal). The present study implies that among the physical and chemical parameters, unsaponifiable matter, relative density, apparent density, Polenske value and refractive index could be used to identify the adulteration in coconut oil by mineral oil. Similarly thin layer chromatography could also detect the presence of mineral oil. Saponification value, iodine value and Polenske value could detect the adulteration due to palm kernel oil. The use of FTIR spectroscopic technique is an easy method to identify adulteration in coconut oil through identification of specific peaks. GCMS analysis could provide information about the fatty acid composition.
Standardisation of agro techniques for transplanted ginger ( Zingiber officinale rosc.)
(Department of Plantation Crops and Spices, College of Agriculture, Vellanikkara, 2017) Sandra Merin Mathew; Sreekala, G S
Standardization of propagation and performance assessment of mechanical harvesters in clove (Syzigium aromaticum (L) Merr. & Perry)
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2023-05-08) Rejith, S; Sreekala, G S
The present investigation entitled “Standardization of propagation and performance assessment of mechanical harvesters in clove (Syzigium aromaticum (L) Merr. & Perry).” was carried out in the Department of Plantation Crops and Spices, College of Agriculture, Vellayani during the period 2020-2022 with the objective of standardization of seed treatment for improved seed germination, grafting method and performance assessment of mechanical harvesters in clove. Clove is commercially propagated by seeds but the viability of the clove seed is less and germination is generally poor. Hence, to improve the seed germination rate an experiment was conducted using seven seed pretreatments and were compared with the control. Freshly harvested fully matured clove fruits are collected and subjected to different pretreatments viz. IAA 20 ppm (T1), GA3 50 ppm (T2), GA3 100ppm (T3), PGPR Mix Ⅰ 5 per cent formulation (T4), PGPR Mix II 5 per cent formulation (T5), Piriformospora indica 105cfu/ml (T6), carbendazim 0.1% (T7) and control (T8). These pretreated seeds were sown in protrays and kept under two growth condition viz. polyhouse with temperature and humidity control (C1) and polyhouse without temperature and humidity control (C2). T1 C1 recorded the highest germination and survival percentage of 90% at 3MAS, basal shoot girth of 0.42cm, mean germination time of 33.15 days, mean germination rate of 3.02 x10-2day-1, coefficient of velocity of germination of 3.21x10-2, germination rate index of 26.82 %/day, germination index of 1477.30, root shoot ratio of 0.50 and allometric index of 0.99. At the same time T2C1 recorded the highest number of leaves of 7, leaf length of 6.90cm, leaf breadth of 2.76cm, leaf area of 12.37cm2, shoot length of 15.51cm, fresh shoot weight of 2.28g, dry shoot weight of 0.48g, root length of 13.85cm, fresh root weight of 0.43g, dry shoot weight of 0.17g, seedling vigour index Ⅰ of 2598.26 and seedling vigour index Ⅱ of 55.02. Even though seed treatment of IAA 20ppm along with growth condition in Polyhouse with temperature and humidity control was identified as ideal for better seed germination, seed treatment of GA3 50ppm along with growth condition in polyhouse with temperature and humidity control showed superior seedling growth characters. 138 Clove is commercially propagated by seed and development of any vegetative method of propagation can be helpful in reducing the height of the crop, early yield and true to type. The percentage of success to propagate clove by vegetative method was less. The production of phenol content may be one reason for this. Hence methods to overcome the phenol content was tried along with different grafting methods. The treatments included approach grafting without antioxidant treatment (T1), approach grafting with antioxidant treatment (T2), soft wood grating without antioxidant treatment (T3), soft wood grafting with antioxidant treatment (T4), epicotyl grafting without antioxidant treatment (T5), epicotyl grafting with antioxidant treatment (T6), patch budding without antioxidant treatment (T7), patch budding with antioxidant treatment (T8) kept under two growth conditions viz. polyhouse with temperature and humidity control (C1), polyhouse without temperature and humidity control (C2). At the end of 6 months, T2C1 recorded higher number of leaves (13.30), length of leaves (4.51) and breadth of leaves (2.46). Hence approach grafting with antioxidant treatment with growth condition of Polyhouse with temperature and humidity control is found to be best for the vegetative propagation of clove Performance assessment of mechanical harvesters and manual harvesting in clove were analysed. Mechanical harvesters such as VIMAL 2 stage tree pole pruner (T1), Wolf-Garten Bypass steel Telescopic pruner (T2), SHAFIRE Steel Blade Hand Pruner (T3) and Manual harvesting(T4) were compared. Manual harvesting was found to be more economically feasible, taking only less time for postharvest cleaning operation with significantly lower operator fatigue and high field coverage.
Survey, characterization and evaluation of clove (Syzigium aromaticum (L) Merr. and Perry) accessions
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2018) Avinash, M; Sreekala, G S
The present study entitled “Survey, characterization and evaluation of clove (Syzigium aromaticum (L) Merr. & Perry) accessions” was taken up with the specific objective to characterize and evaluate clove accessions based on morphological and biochemical parameters. The Survey was carried out in the major clove growing plantations of Trivandrum, Kollam and Pathanamthitta districts of Kerala and Kanyakumari district of Tamil Nadu, as these districts harboured the major clove population. Twenty varied accessions were tagged as BRC-1, BRC-2, BRC-3, BRC-4, MRC- 5, MRC-6, MRC-7, MRC-8, AMC-9, AMC-10, AMC-11, AMC-12, AMC-13, MMC-14, MMC-15, BLC-16, BLC-17, BLC-18, MGC-19 and ANC-20 based on the name of the estates/location from where the trees were identified. Twenty one qualitative and thirty four quantitative characters were recorded. Qualitative characters included tree, leaf, bud, flower, fruit and seed characters. Considerable variation was noticed among the accessions for the qualitative characters namely canopy shape, branching pattern, colour of young leaf, colour of mature leaf, leaf lamina shape, leaf apex shape, bud forming season, bud clustering habit, bud size, colour of hypanthium, petal colour, sepal colour, colour of stigma, fruit shape and seed shape. Few characters like leaf arrangement, position of flower, colour of peduncle, mature fruit colour, ripe fruit colour and seed colour were non variable characters among the accessions evaluated. Bivariate analysis of major qualitative characters revealed major association between canopy shape and branching pattern; colour of young leaf and petal colour, sepal colour and colour of stigma; colour of mature leaf and bud size; and fruit shape and seed shape. The multivariate qualitative clustering using UPGMA method resulted in 13 clusters, at default 80% similarity. Quantitative characterisation of bud, flower, fruit, seed and quality parameters summarised based on the descriptive statistics revealed wider range of variability in number of inflorescence per m2 and single bud weight fresh and dry. The quality parameters assessed among the accessions revealed eugenol as the main constituent with a content range of 54.29 to 70.77%. GC MS analysis of the bud oils of the elite clove accessions exhibited 25 constituents, the major being p-eugenol, eugenyl acetate, β-caryophyllene, β-cubebene and α-humulene. The principal component analysis undertaken reduced the thirty two quantitative characteristics to two principal components accounting for 88.8% of total variation. Stem girth at 45 cm height, and single bud weight, fresh and dry; displayed high correlation with the first axis while number of inflorescence per m2 highly influenced the second axis indicating that these characters have an important role in clustering of clove accessions. A score plot generated based on the first two principal components using Minitab version 18 identified fourteen clusters. The parallelism between qualitative and quantitative clusters resulted in intuitive perceived quantitative characterisation, which tells the extent to which one can conceive the quantitative characters of clove based on easily identifiable qualitative characters. The linkage of characters analysed based on the biplot of component loadings revealed strong positive association between all the quantitative characters measured except girth at 45 cm height, number of branches, number of inflorescence per m2, single bud weight (fresh), single bud weight (dry) and fresh bud yield per tree. A near zero correlation was observed between number of inflorescence per m2 and single bud weight (fresh) and single bud weight (dry) as indicated by the perpendicular of the vectors. The results of the study indicated that by observing the qualitative characters and the minimum data set characters in the bearing season, one can optimally sort out the ideotype clove accessions. Identification of an ideotype using existing data revealed accessions BRC-1, MRC-5, MRC-6 and BRC-3 as ideotypes and thus can be suggested as elite accessions for further study and breeding work.
Variability in ginger(Zingiber officinale rosc) for yield and resistance to rbizome rot
(Department of Plantation Crops and Spices, College of Agriculture, Vellayani, 2019) Anargha, T; Sreekala, G S