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Open Access
Evaluation of ornamental flowering shrubes for tropical landscapes
(Department of Pomology and Floriculture, Colege of Horticulture, Vellanikkara, 2012) Najeeb, Naduthodi; KAU; Valsalakumari, P.K.
The present study entitled “Evaluation of ornamental flowering shrubs for tropical landscapes” was carried out at the Department of Pomology and Floriculture, College of Horticulture, Vellanikkara from Jan. 2011 to Dec. 2011. The objectives were to evaluate ornamental flowering shrubs for suitability to various landscaping uses and to compute Air Pollution Tolerance Index. The study involved evaluation of 30 tropical ornamental flowering shrub species or varieties. The selected shrubs were four years old, maintained in the shrubbery of the Department of Pomology and Floriculture. The experiment was laid out in CRD with three replications. Various vegetative and floral characters were recorded and data analysed and correlation studies were made with weather parameters. Shrubs selected for the study were described based on morphological characters. Growth of shrubs was measured in terms of height and spread. Based on the manageable height, they were classified into three groups, i.e. Tall (height above 2 m), Medium (height 1m- 2m) and Dwarf (height below 1m). Among the 30 shrubs evaluated, the maximum height was observed for Calliandra haematocephala (319.4 cm) and the minimum for Lonicera japonica (49.9 cm). Plant spread varied from 43.4 cm in Wrightia antidysenterica to 269.7 cm in Calliandra haematocephala. Regression equation of height for predicting spread was formulated using the monthly data on height and spread. Foliage characters like leaf length, leaf area, petiole length, girth and internodal length were measured. Based on leaf area, plants were categorized into medium coarse, medium, medium fine and fine textured. Qualitative characters of the foliage like shape of leaf, base, tip, margin and colour of leaf were observed and used for plant description as well as categorizing them into different texture classes. Shrub canopy shape (silhouette) was observed and used for making schematic diagram. Qualitative characters of flowers like type of inflorescence, position of inflorescence, colour and fragrance were observed. Time taken to open up the inflorescence from bud stage, persistence of single flower as well as the inflorescence were also observed. Quantitative characters like inflorescence diameter, single flower length and diameter and number of flowers per inflorescence were also recorded. Flowering seasons of the shrubs were observed and accordingly they were categorized into four different phenological phases i.e. Dec-Feb, Mar-May, June- Aug and Sep-Nov. Sideruns were observed and phenological configurations were made. Air Pollution Tolerance Indices of the shrubs were calculated. Calliandra haematocephala (31.7) showed the highest APTI value and the minimum value was observed for Allamanda cathartica ‘Dwarf’ (9.2). Shrubs were categorized into sensitive (value ≤14), intermediate (15- 19), medium tolerant (20-24) and tolerant (> 24) groups based on their APTI values. Based on the different characters studied, shrubs were classified into different landscape utility groups such as, accent plant, foundation planting, screening and privacy, hedges and topiary, shrub border, background planting, corner planting, Shrub group and mass planting, Pot and Container planting, fragrant garden, moon garden, xeriscaping, rock garden, covering sloppy banks and butterfly garden. Shrubs were observed for pest and disease incidence. Major pests were leaf eating caterpillars in Mussaenda erythropylla, Nerium indicum, Calliandra haematocephala and Ixora coccinea, flower bud borer in Wrightia antidysenterica, mealy bug and scales. Shrubs were not severely affected by diseases. Minor leaf spots were observed in certain shrubs. In the present study, shrubs were recommended for various functional uses in the landscapes based on their growth, flowering and morphological characters. Based on flowering season, they were categorized into four phenological phases. Side-runs were observed and phenological configurations were made. Air Pollution Tolerance Indices of the shrubs were also computed and the plants were categorized according to their APTI values.
Open Access
Screening of vegetable cowpea (Vigna unguiculata (L)Walp)germplasm for yield,quality and resistance to collar rot and web blight
(Department of Olericulture, College of Agriculture, Vellayani, 2012) Sivakumar, Vavilapalli; KAU; Celine, V A
The present investigation on “Screening of vegetable cowpea (Vigna unguiculata (L) Walp.) germplasm for yield, quality and resistance to collar rot and web blight” was conducted at the Department of Olericulture, College of Agriculture, Vellayani, during the period 2011-2012. The objective of the study was to assess the genetic variability for yield, quality and resistance to collar rot and web blight and elucidating the morphological, anatomical and biochemical basis of collar rot and web blight resistance. The study was conducted in two separate experiments. 1. Evaluation of cowpea accessions for genetic variability, yield, quality and resistance or tolerance to pests and diseases. 2. Screening vegetable cowpea accessions for collar rot and web blight resistance under artificial conditions. In experiment I, 44 accessions of yard long bean and 22 bush cowpea accessions were collected from different parts of country and grown in the field in RBD with three replications as two separate experiments. Analysis of variance revealed that significant difference among the accessions for all the characters studied. Among the accessions, VS 29 (Malappuram local) had the highest yield (1127.52 g) and pods per plant (87.09), while VS 45 was noted that highest pod length, pod girth and pods weight. Correlation studies revealed that characters like primary branches per plant, pods per plant, pod length and pod weight in yard long bean and length and breadth of leaflets, peduncle length, pod length, pod girth and pod weight in bush cowpea observed high positive correlation with yield, whereas peduncle length, days to first harvest and 100 seed weight in yard long bean were negatively correlated with yield. The path coefficient analysis indicated that pods per plant, pod weight, and pod length had direct effect on yield per plant. Phenotypic and genotypic coefficients of variation were high for days to first harvest, pod weight, pod protein and pod borer infestation in yard long bean and in bush cowpea for pod weight, vine length, seeds per pod and pod length while genotypic coefficient of variation was low for days to first flowering in yard long bean and peduncle length in bush cowpea. In yard long bean VS 34 followed by VS 4, VS 29, VS 9 and VS 1 were having the highest selection index values based on discriminant function analysis. VU7, VU 1, VU 14, VU 16 and VU 6 were having the highest selection index values in bush cowpea. On screening the accessions for legume pod borer resistance, VS 44 in yard long bean and VU 24 in bush cowpea were found to be most tolerant, while VS 5 in yard long bean and VU 3 were more susceptible. In field condition, among 44 accession of yard long bean only 12 namely, VS 1, VS 2, VS 9, VS 14, VS 20, VS 21, VS 23, VS 24, VS 29, VS 30, VS 32 and VS 40 were infected with R. solani and shown collar rot symptoms, the remaining accessions were free from collar rot. All the accessions were free from web blight. In bush cowpea, among 22 accessions only four (VU 11, VU 15, VU 17 and VU 19) had shown collar rot symptoms and none of accession showed web blight symptoms. Experiment II was conducted in net house by artificially inoculating the pathogen to all the accessions which were used in experiment I. In screening for collar rot and web blight, the incidence ranged from 0 to 99.81 per cent and 14.32 to 53.78 per cent for collar rot and web blight respectively in yard long bean whereas in bush cowpea collar rot ranged from 0 to 99.64 per cent and web blight ranged from 17.12 to 43.60 per cent. However, 12 accessions of yard long bean viz., VS 6, VS 10, VS 13, VS 18, VS 19, VS 22, VS 32, VS 33, VS 37, VS 38, VS 39 and VS 43 and six accessions of bush cowpea viz., VU 2, VU 5, VU 7, VU 13, VU 16 and VU 18 showed moderately resistance to collar rot and web blight. In both yard long bean and bush cowpea, high positive phenotypic and genotypic coefficient of variation were noticed between collar rot and web blight resistance and proline content phenol content, trichome density, cuticle thickness and number of vascular bundles, while negative correlation was observed with stomatal density. The study revealed that moderately resistant accessions had more number and well developed vascular bundles, high trichome density and cuticle thickness and less stomatal density compare to susceptible ones. High phenol and proline content were responsible for tolerance to collar and web blight resistance. Pod colour was related to collar rot tolerance. Light green and green coloured pods were more susceptible compared with red pod accessions in yard long bean as well as bush cowpea.
Open Access
Standardisation of agrotechniques in phalaenopsis orchids
(Department of pomology and floriculture, College of horticulture, Vellanikkara, 2012) Narender Negi; KAU; Devadas, V S
The present study entitled “Standardisation of agrotechniques in Phalaenopsis orchids” was carried out at the Department of Pomology and Floriculture, College of Horticulture, Vellanikkara from May 2011 to April 2012. The studies were conducted to find out the best plant type and environment suited for commercial cultivation of Phalaenopsis and to standardise the agrotechniques like type of pot, growing media and growing method for better plant growth and quality spikes. The study involved comparison of 32 treatment combinations involving two plant types, two types of pots, two types of potting media, two growing conditions and two methods of growing. The experiment was laid out in CRD with three replications. Various vegetative and floral characters were recorded, analysed and correlated with weather parameters. Results indicated that of the two growing structures used in the study i.e., fan and pad and rain shelter, the latter promoted vegetative growth manifested by enhanced leaf length, leaf breadth and leaf area. Plant height was not influenced in both the situation. The plant types viz., pot plant and cut flower, differed in their growth rate. Pot plant type recorded higher growth rate in terms of length, breadth and area of leaf but per se length, breadth and area of leaf was higher in cut flower type. Regarding the media, brick + coconut husk bits was found better for vegetative growth as compared to brick + charcoal. The other two factors, method of growing and type of pots did not affect the vegetative growth. But root growth outside the pot was recorded more in black pot compared to that on white pot. Percentage of flowering was also influenced by growing structure, type of plant and media. Plants grown under fan and pad, pot plant type and brick + coconut husk bits medium recorded higher flowering percentage than those under rain shelter, cut flower and brick + charcoal medium. Correlation values with weather parameters indicated positive correlation between increase in leaf area and minimum temperature under rain shelter and fan and pad system whereas negative correlation with light intensity was seen under fan and pad system. Considering the overall effect by pooled analysis, only minimum temperature had a significant influence on increase in leaf area.
Open Access
Development of protocol for tissue culture of papaya (Carica papaya L) from mature explants
(Department of pomology and floriculture, College of agriculture, Vellayani, 2012) Hutke Vikram, Rajendra; KAU; Jayachandran Nair, C S
For lateral bud explants running tap water wash for 10 min. and for apical bud explants rinsing in water with wetting agent for 30 min. were effective. For removal of fungal contamination 1.0% bavistin for 60 min. was found to be the best treatment. For removal of bacterial contamination treatment with chloramphenicol, streptomycin and cephalexin each 250 mg -1l for 24 hours was the best. For lateral bud explants use of mercuric chloride 0.1% for 10 min. and for apical bud explants 0.08% mercuric chloride for 10 min. was the best. In case of survival percentage full strength MS medium and full strength MS medium + 0.1% activated charcoal equally recorded the highest survival percentage. Highest number of cultures showing bud initiation in culture establishment media was observed in full strength MS medium and full strength MS medium + 0.1% activated charcoal. The number of buds initiated per culture was the highest in full strength MS medium + 0.1 % activated charcoal. The number of days taken for bud initiation from lateral bud explants of variety Pusa Nanha was the lowest in full strength MS medium + 0.1 % activated charcoal while for apical bud explants full strength MS medium was the best. For variety Pusa Dwarf using lateral bud explants half strength MS medium and for apical bud explants full strength MS medium + 0.1 % activated charcoal recorded the lowest number of dsys. Survival percentage of lateral and apical bud explants of Pusa Nanha was the highest in NAA 0.5, BA 3.0 mg l -1. In Pusa Dwarf, the highest survival percentage of lateral bud explants was noted in the treatment NAA 0.5, BA 5.0 mg l -1. In apical bud explant NAA 0.5, BA 5.0 mg l -1 and NAA 1.0, BA 3.0 mg l -1 were effective. In lateral bud explant of Pusa Nanha NAA 0.1, Kinetin 1.0 mg l -1 showed the lowest number of days for bud initiation while in apical bud explants IAA 0.5, BA 1.0 mg l -1 registered the shortest number of days. In lateral bud explants of Pusa Dwarf IAA 0.5, Kinetin 2.0 mg l -1 resulted in lowest number of days for bud initiation while in the apical bud explant NAA 1.0, BA 3.0 mg l -1 gave the best results. The treatment NAA 0.5, BA 3.0 mg l -1 resulted in the highest number of shoots per culture from the lateral bud explants of Pusa Nanha whereas in apical bud explant NAA 0.5, Kinetin 3.0 mg l -1 was the best. NAA 0.5, BA 5.0 mg l -1 resulted in the highest number of shoot per culture in the lateral bud explants of Pusa Dwarf while in apical bud explant IAA 2.0, Kinetin 3.0 mg l -1 gave the best results. Length of shoot was the highest in Pusa Nanha lateral bud explant when BA 3.0 mg l -1 was used while in the apical bud explants NAA 0.5, Kinetin 3.0 mg l -1 was the best treatment. In case of both types of explants in Pusa Dwarf IAA 0.5, Kinetin 1.0 mg l -1 recorded the longest shoots.
Open Access
Chemical regulation of cropping in mango
(Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 2012) Randeep, K R; KAU; Radha, T
The experiment on ‘Chemical regulation of cropping in mango’ was taken up at Department of Pomology and Floriculture, college of Horticulture, Vellanikkara during September 2008 to June 2010. The objective of the experiment was to regulate flowering and fruiting in mango varieties Prior and Alphonso using growth regulators and chemicals for sustained crop production and to ensure market supply. Alphonso and Prior varieties were selected for the study since they have alternate/irregular bearing habit but at the same time are superior and popular varieties in Kerala. The treatments involved ethrel application alone and in combination with NAA, potassium nitrate alone and in combination with NAA, paclobutrazol alone and in combination with NAA as well as with KNO3. Paclobutrazol was applied as soil drench and all the other chemicals in the form of foliar sprays. Ethrel, potassium nitrate and paclobutrazol were applied once during September. NAA application at full bloom stage was included as treatments to tackle the premature fruit drop. In both varieties, paclobutrazol treatments induced early and profuse flowering compared to control. The percentage of hermaphrodite flowers produced in an inflorescence was not affected by treatments in Prior. Paclobutrazol treatments significantly influenced the number of hermaphrodite flowers produced in the inflorescence of Alphonso. Inflorescence size was significantly influenced by different treatments in both varieties however, ethrel and potassium nitrate treatments were found effective in Prior and paclobutrazol treatments were the best in Alphonso. Paclobutrazol treatments improved the initial fruit set in both varieties and were also highly effective in controlling fruit drop at different stages after fruit set. Fruit drop at 60 days after set ranged from 81.74 to 95.13% in variety Prior and 84.31 to 96.77% in variety Alphonso, the minimum values being recorded by paclobutrazol treatments. During the second year of experiment (2009-10), rainfall during October-November resulted in poor flowering of mango in the state. The results of the present experiment showed that in trees under paclobutrazol treatments, flowering was good in both the varieties even under adverse climatic conditions which gives an indication that though weather conditions go unfavourable for flowering, the trees can be induced to get substantially good flowering by this chemical. In the present study, quantitative (fruit weight, length, breadth and stone weight) and qualitative parameters (TSS, total sugars and acidity) of the fruits were not influenced by the different treatments in a specific pattern in both the varieties. Irrespective of treatments and varieties, Carbohydrate/nitrogen ratio increased at monthly intervals after treatment and recorded maximum value just before flowering and finally reduced at the time of flowering. Paclobutrazol treatments recorded significantly higher values for this parameter in both varieties. Overall perusal of the results clearly indicates the potential of paclobutrazol application @ 5g/tree to regulate flowering and fruiting in mango varieties Prior and Alphonso. The beneficial effects of the chemical noticed were early and profuse flowering, increased fruit set and reduced fruit drop in turn resulting in higher yield in both the varieties. Further trials involving other varieties of mangoes of different age groups at same location as well as in different locations are suggested as the future line of work in this aspect.
Open Access
Efficacy of biofertilizers in tomato (Solanum lycopersicum L)
(Department of Olericulture, College of Horticulture, Vellanikkara, 2012) Smitha, K O; KAU; Baby Lissy, Markose
An experiment was carried to study the response of biofertilizers (Azospirillum, AMF and Frateuria each @ 2 kg ha -1) on growth, yield and quality of tomato at Department of Olericulture, College of Horticulture, Vellanikkara during 2011-12. Anagha, a bacterial wilt and crack resistant variety of tomato developed by Kerala Agricultural University was selected for the study. The experiment was laid out in Randomised Block Design with 10 treatments and 3 replications. The treatments included inoculation of anyone of the biofertilizer along with FYM (T1, T2, T3), inoculation of any two along with FYM (T4, T5, T6), inoculation of all the three biofertilizers along with FYM (T7), inoculation of all the three biofertilizers along with FYM and inorganic ( ½ and full dose) fertilizers (T8, T9) and control (T10 KAU POP). The study revealed that integrated application of farm yard manure, full dose of inorganic fertilizers and biofertilizers (T9) exhibited superiority in terms of plant height and number of leaves. The number of branches was maximum when all the three biofertilizers were applied along with FYM (T7). The earliest flowering was recorded in plants inoculated with all the three biofertilizers along with FYM (T7) and individual application of FYM along with AMF (T2). The treatments T7, T2 and T9 recorded early harvests. The treatment T7 recorded the maximum fruit weight (34.15 g), fruit volume (38.20 cm3), fruit girth (15.31 cm) and number of seeds per fruit (136.75). It was followed by the treatment T9. The flesh thickness was maximum in T2 (3.43 mm) followed by T7 (3.27 mm). Integrated application of FYM, full dose of inorganic fertilizers and biofertilizers (T9) recorded the highest number of fruits per plant (28.16), fruit yield per plant (814.70 g) and total fruit yield (20.81 t ha-1). Total soluble solids of tomato fruit was the highest in treatment T9 where FYM, inorganic fertilizers (full NPK) and biofertilizers were applied. The treatment T7, where FYM and all the three biofertilizers were applied, recorded the highest vitamin C (24.66 mg/100 g) content. Shelf life (18.66 days) of fruits was more in plants treated with FYM and AMF (T2). Higher uptake of nutrients was observed in integrated application of full dose of NPK and FYM along with all the three biofertilizers (T9). Application of biofertilizers improved available N, P2O5 and K2O contents in soil. The population of Azospirillum, AMF and Frateuria in the rhizosphere was also enhanced by the use of biofertilizers and was maximum in integrated application of FYM, ½ NPK and biofertilizers (T8). Regarding the economics of cultivation, the highest B:C ratio of 1.76 was recorded when full dose of NPK was applied along with all the three biofertilizers and FYM (T9). It was followed by the treatment T8 and T10 which recorded a B:C ratio of 1.45 and 1.40 respectively. From the study it can be concluded that inoculation of biofertilizers enhanced the growth, yield and quality of tomato. The available nutrient status, microbial population and health of soil were also improved by biofertilizer application. Overall assessment indicated that integrated application of all the three biofertilizers and FYM along with full dose of chemical fertilizer was the best for better growth, yield and soil health. The second best performance was obtained when FYM, inorganic fertilizers (½ NPK) and biofertilizers were applied, signifying that a reduction of 50 per cent chemical fertilizers is possible by using biofertilizers. Application of FYM and all the three biofertilizers together improved the biometric characters like weight, volume and girth of fruits.
Open Access
Variability and character association in heliconia (Heliconia spp)
(Department of Pomology and Floriculture, College of Agriculture, Vellayani, 2012) Narkar Nikhil, Dileep; KAU; Sheela, V L
Heliconia cultivation is rapidly expanding in tropical areas throughout the world. Heliconia is one of the most important cut flower and landscape plants due to their variation in growth habit and flower characters combined with easy cultivation practices. India has great potential for expanding the cultivation of heliconia considering the rich and diverse germplasm of the crop available with us. The objective of the present study was to assess the extent of variability among the 30 selected species and cultivars. The study also was aimed at the evaluation of morphological and floral variability that exist in heliconia which will serve as a tool for identifying the varieties for further breeding programmes and to exploit the ornamental attributes of Heliconia for the expanding tropical cut flower industry in Kerala There was wide variation in morphological characters such as plant height, plant spread, number of leaves, leaf area and number of shoots and in flowering characters such as length of spike, length of petiole, length of inflorescence, number of flower bracts, number of flowers per bract, size of bract, days taken for flowering and flowering duration. Variation was also observed in pollen size and pollen fertility. Cultivar Heliconia chartacea cv. Sexy Pink registered the highest plant height and also the highest value for plant spread, leaf area, and length of inflorescence, days taken for flowering and flowering duration. However it recorded lower value for number of flowering shoots. Psittacorum species and interspecific hybrids recorded lower value for plant height, plant spread, leaf area, length of inflorescence, flowering duration and less number of days taken for first flowering but highest value for number of flowering shoots compared to heliconias which are having robust growth habit such as cultivar Pedro Ortiz, Jacquinii, wagneriana and stricta species. Interspecific hybrids recorded lower fertility percentage and other species and cultivars recorded higher fertility. Pollen shape varied within same species in different cultivars. PCV was slightly higher than GCV in all characters which were studied. High heritability was recorded in all characters. The character plant height was found to have significant positive correlation at genotypic and phenotypic level with plant spread, leaf area, length of inflorescence, length of spike, days taken for first flowering, flowering duration, number of flower bracts, size of bracts and pollen size. In the present study selection index for 30 species and cultivars was computed on 14 characters viz. plant height, plant spread, Number of shoots, length of inflorescence, length of spike, length of petiole, days taken for first flowering, flowering duration, number of flower bracts, number of flowers per bract, size of bract, number of flowering shoots, pollen size and pollen fertility. The maximum values of selection index were recorded for Heliconia chartacea cv. Sexy Pink, Heliconia wagneriana cv. Yellow, Heliconia collinsiana x Heliconia bourgaeana cv. Pedro Ortiz, Heliconia wagneriana. cv. Red, Heliconia stricta cv. Iris and so on. Lowest value of selection index was recorded for Heliconia densiflora Verlot cv. Fire Flash and Heliconia angusta cv. Christmas Red. Genetic gain was worked out and it revealed that if parents are selected based on selection index values for improvement 45% genetic gain can be expected in the next generation. Much natural variation exists in heliconia. To be commercially viable varieties with potential for high yield, easiness of cultivation, less incidence of pest and disease, high vase life and above all high market demand are preferred by growers. Selection of varieties based on suitable selection index and their further improvement will serve to strengthen heliconia cultivation. Future research programmes aiming at heliconia improvement in this direction using conventional and non-conventional breeding tools will help to achieve this goal and aid in the popularization of these exotic tropical flowers as cut flower and landscaping plants.
Open Access
Drying and storage studies in kizharnelli (Phyllanthus amarus Schum.& Thonn.)
(Department of Processing Technology, College of Horticulture, Vellanikkara, 2012) Manjusha, A; KAU; Jacob John, P
In recent years, an increasing interest in medicinal herbs, as natural regrowing raw material could be observed worldwide. After a period of exploding the synthetic chemicals and its ill effects too, the present situation demands a ‘green wave’ to use nature and natural products. Phyllanthus amarus Schum.&Thonn., known in Malayalam as ‘Kizharnelli’ is one of the most important herbs in Indian medicine. Owing to its phyllanthin and hypophyllanthin content, it is widely used as hepatoprotective, anti-inflammatory, antidiabetic, chemoprotective, antioxidant etc. The plant has been traditionally used to promote liver functions and used as a remedy for jaundice. The plants are available mostly during the months of July to September and are short living. Therefore an attempt has been made to extend the post harvest storage life of P. amarus with minimum quality deterioration. Two experiments were conducted during the course of study; with the first experiment to evolve a suitable drying and packaging technique for the plant as such and the second to evolve an extraction technique and the storage studies of the extractives. Shade drying of whole plant followed with packaging in aluminium laminated pouches was found to be the best drying and storage technique in terms of colour, phyllanthin and hypophyllanthin content for the storage up to 4 months. Hypophyllanthin content was found to be degrading in a faster rate and very less amount was noticed after 4 months of storage. Comparing the drying of whole plant and chopped materials, no advantage was noticed in terms of drying rate. Therefore this additional step of chopping can be avoided. Sun drying, though a common practice of drying; degradation of alkaloids and colour was observed in drying and storage of Phyllanthus amarus. Studies on extraction techniques revealed that the extraction using ethanol was found to be better and regarding to the storage of extractives, dried ethanolic extracts stored in aluminium laminated pouches retained maximum phyllanthin content after six months of storage. However hypophyllanthin content dropped drastically after 4 months of storage. The techniques thus developed will help to store ‘Kizharnelli’ for an extended period of 3 to 4 months than its normal available period as stored material.
Open Access
Seed maturity and seed longevity studies in snake gourd (Trichosanthes anguina L.) Varieties
(Department of Olericulture, College of Horticulture, Vellanikkara, 2012) Rohit Kumar, Dhobi; KAU; Krishnakumary, K
The present investigation on “Seed maturity and seed longevity studies in snake gourd (Trichosanthes anguina L.) varieties” was carried out in the Department of Olericulture, College of Horticulture, Vellanikkara during the year 2010-2012 with the objective of standardising the physiological maturity of snake gourd varieties for better seed quality, understanding the influence of fruit size and position of seeds within the fruit on seed quality and studying the effect of storage conditions on seed quality and longevity. Investigation on physiological maturity indicated that fruits attained maximum weight and length when harvested at 36 days after anthesis in Baby and 39 days after anthesis in Kaumudi. Seed quality parameters viz., number of seeds per fruit, fresh and dry weight of seeds, 100 seed weight, germination percent, speed of germination, seedling length and vigour index were maximum in fruits harvested at 36 and 39 days after anthesis in Baby and Kaumudi respectively. Morphological characters of the fruit at this stage included change in fruit colour turning red at the tip portion and the placenta colour changing to red. Seeds got detached from the mucilaginous placenta and seed coat became hard with well developed ring on the seed surface. Large sized fruits recorded maximum values for length and weight of fruits, and number and weight of seeds. Seed quality parameters viz., germination percent, seedling length and vigour index were found to be high in seeds obtained from medium sized fruits when compared to large and small sized fruits in both the varieties. Among the different portions of the fruit (pedicel, middle and stylar regions), middle portion recorded higher fruit weight, number and weight of seeds, germination percent and vigour index in small, medium and large sized fruits compared to pedicel and stylar regions in both the varieties. The effect of storage conditions influenced seed quality parameters in both varieties of snake gourd. Maximum germination, seedling length and vigour were obtained at 3rd month in ambient storage condition and 4th month in A/C storage condition and a decline in these parameters was observed in later months of storage. Lowest values for germination, seedling length and vigour were recorded at 12th month in both the conditions of storage (ambient and A/C) in both varieties. Seeds stored under A/C condition exhibited higher quality compared to those stored under ambient condition and Kaumudi recorded higher values for seed quality than Baby. Activity of the enzyme dehydrogenase was found to decrease over storage period in both the varieties studied. Generally values were higher under A/C storage condition than open condition and among varieties, values were slightly higher in Kaumudi than Baby. Electrical conductivity values of the seed leachate were found to increase with increase in storage period under ambient and A/C conditions of storage in both the varieties namely Baby and Kaumudi and the increase was more in seeds stored in open condition than A/C condition.

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