Browsing by Author "Parameswaran, N K"

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Diversity mapping and characterization of landraces of mango (Mangifera indica.L)
(Department of Pomolgy and Floriculture, College of Horticulture, Vellanikkara, 2016) Harikumar, V; Parameswaran, N K
Dwarfing potential of indigenous mango varieties
(Department Of Pomology And Floriculture, College Of Horticulture, Vellanikkara, 2001) Chacko Priya Marie; Parameswaran, N K
The Project on 'Dwarfing potential of indigenous mango varieties' was undertaken at the Department of Pornology and Floriculture, College of Horticulture, Kerala Agricultural University, Vellanikkara during the period 1999- 2000. Observations on the shoot extension growth of the parent rootstock trees for a period of one year, showed a rhythmic growth with periods of active growth and quiescence, except in the variety Moovandan. However no definite synchrony between the climatic parameters and flushing pattern of the varieties could be . noticed. Among the different morphological characters, a fair amount of variation could be noted with regard to number of shoots per half meter square, internodal length and number of leaves. But as such, no definite relationship could be noted between the growth potential of the tree and other characters. The varieties viz., Moovandan, Olour and Vellaikolumban exhibited distinct polyembryony, whereas only one sprout per stone could be noted in the case of other varieties including the variety Chandrakkaran. Mechanical manipulation through splitting of endocarp of the seed stone was advantageous by reducing the days taken for germination, enhancing the rate of germination and increasing the extent of polyembryony. Anatomy of the roots and leaves, made it possible to approximately place the varieties into groups of 'low growth potential' (LGP) and 'high growth potential' (HGP). Accordingly Vellaikolumban, Kalapady and Olour could be brought under the former and Moovandan, Chandrakkaran and Mundappa under the latter. The varieties showed a clear variation with respect to the stomatal density of leaves. Stomatal density was highest in Moovandan and lowest 111 Vellaikolumban. Anatomy of the graft union indicated higher accumulation of calcium containing crystals in the conducting phloem of Bangalora/Vellaikolumban graft combination. The electrical resistance of the rootstock seedlings was found to be higher in Moovandan and Chandrakkaran and lower in Vellaikolumban, Olour and Kalapady. The apparent velocity of sap flow/transpiration stream in the grafted plants showed higher rates in the graft combinations involving Moovandan, Chandrakkaran and Mundappa and lower rates in Vellaikolumban, Kalapady and Olour as rootstocks. The rate of leaf respiration 111 one year old graft combination of Bangalora/Moovandan and Bangalora/ Vellaikolumban and their seedlings showed relatively higher rate of respiration in the grafted plants on Moovandan rootstocks than those on Vellaikolumban. Total phenol content in the dormant buds as well as in leaves of the mango rootstocks varieties showed higher values in Vellaikolumban and Kalapady and lower values in Moovandan and Chandrakkaran. Observations of the one year old graft plants in the nursery in terms of the maiden shoot growth did not reflect an immediate expected effect of the rootstock on the total growth and vigour of the combinations.
Factors affecting yield in cashew (Anacardium occidentale L.)
(Department of Horticulture (Pomology & Floriculture and Landscaping), College of Horticulture, Vellanikkara, 1979) Parameswaran, N K; Damodaran, V K
Investigations on the different vegetative, flowering and fruiting characters, influencing yield in cashew, were undertaken at the main campus of Kerala Agricultural University at Vellanikkara. These studies were made during the period from November 1978 to April 1979. Important vegetative characters studied were the percentage of flowered shoots per unit area of tree canopy and the growth parameters of the tree represented by spread and height. The major flowering and fruiting characters studied were the pattern of flower opening, percentage of bisexual flowers, factors affecting pollination, fruit-set, fruit-drop and the mean weight of nuts harvested. The results showed that among the vegetative characters, percentage of flowered shoots per unit area of tree canopy was found to be the most important factor, contributing to yield. Tree-spread was also found to have a positive correlation with yield. The influences of this character on yield was not direct but indirectly through the former character. There was no significant correlation between yield and height of the tree. Pattern of flower opening in cashew panicles was found to have three phases viz., the first male phase followed by a mixed phase which is again followed by a second male phase. The duration of these three phases was found to be varying in the different trees. It was found that some trees had only the mixed phase throughout and those trees yielding above the median had a longer mixed phase as compared to the trees yielding below the median. A positive correlation was found between yield and percentage of bisexual flowers in the tree. Among the flowering and fruiting characters affecting yield, this factor was found to influence yield much more than any other character. Examination of a random number of bisexual flowers revealed that a large proportion of bisexual flowers remained unpollinated in nature. So, lack of pollination was found to be one of the reasons for poor fruit-set and yield in cashew. This was further confirmed from the high fruit-set obtained in the hand pollinated panicles. Receptivity of the stigma was found to be continuing up for 48 hours after flower opening and hence it was not a limiting factor for securing high yield. Supplementing the natural pollination with the help of insect pollinators met with some success. Keeping bee-hives in the orchards during flowering season is advisable for facilitating better pollination. A positive correlation could be observed between yield and percentage of fruit-set but the ultimate yield was found to be adversely affected by the severe shedding of young fruits before reaching maturity. The intensity of fruit-drop was found to be high in the early stages of development but it declined during the later stages. The causes of fruit-drop that could be identified were those resulting from the attack of insect pests, adverse climatic conditions etc. Studies did not reveal any significant correlation between yield and mean weight of nuts harvested.
Flower bud forcing in humid tropic mangoes using dormancy breakers
(Department of Pomology and Floriculture,College of Horticulture, Vellanikkara, 2007) Hima, K; Parameswaran, N K
Growth, flowering, fruit set and fruit development in kodampuli
(Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 1994) Sherly, R; Parameswaran, N K
The present investigations were carried out in the Department of Pomology and Floriculture, College of Horticulture, during the year 1993 – 94. The study was undertaken with the objectives of understanding the growth and flowering pattern of the tree, floral biology, fruit set, fruit development and fruit drop in ‘Kodampuli’. The studies were conducted on four male trees and three hermaphrodite trees of about seven years age, receiving similar cultural practices. The studies indicated that shoot growth in ‘Kodampuli’ was seasonal with one main flushing period commencing from January and extending upto May. The shoot activity noticed during the remaining period of the year was very low. However, scattered flushes occurred throughout the year. The mean growth varied significantly from month to month with a peak growth during the summer months. Individual trees also showed significant variation among them in mean growth. However, there was no significant difference among the two types of trees, viz., male and hermaphrodite trees. The colour of emerging leaves showed marked difference among the male and hermaphrodite trees. In male trees, the emerging leaves were light green in colour while they showed a pinkish red colour in hermaphrodite trees. Flowering pattern of male and hermaphrodite trees were almost similar. However, male trees of ‘Kodampuli’ showed a protracted period of flowering extending over four to five months starting from the month of November onwards. In hermaphrodite trees, flowering started a little later in December and confined only to two to three months. Peak flowering in both type of trees was during January to April. The flower bud development took 32 days from visual emergence to anthesis in male flowers but only 28 days in bisexual flowers. ‘Kodampuli’ was observed to be androdioecious with male and bisexual flowers borne on separate trees. In male trees, the flowers occurred as cymose inflorescence having three to seven flowers per inflorescence. Bisexual flowers of hermaphrodite trees were borne singly and rarely in groups. In male flowers peak anthesis was between 16 30 and 17 00 hours and in bisexual flowers it was between 17 00 and 17 30 hours. Anther dehiscence occurred 10 hours prior to anthesis. Stigma became receptive 30 hours before anthesis and retained receptivity upto 12 hours after anthesis. Anther number and pollen per flower varied significantly among the two types of flowers. Number of pollen produced per anther was significantly higher in male flowers. The pollen fertility was also higher for male flowers. Sucrose at concentrations of 2, 4, 6, 8 and 10 and boric acid at concentrations of 25, 50, 75 and 100 ppm were found to promote pollen germination. However, calcium nitrate at all concentrations tried (25 to 100 ppm) drastically reduced the pollen germination. A combination of four per cent sucrose and 75 ppm boric acid gave maximum germination (67.00 per cent). Pollen was found to be viable for six days in the dehisced bud condition and the viability was greatly reduced thereafter. Low temperature storage conditions gave better results when stored as staminal column or as pollen grain alone. The pollination in ‘Kodampuli’ was found to be effected by insects. ‘Kodampuli’ was found to be an often cross pollinated crop. Hand pollination with pollen from male flowers increased the percentage fruit set as compared to self pollination or open pollination indicating the importance of male trees in a population for improved fruit set. There was no apomictic fruit development in ‘Kodampuli’. The fruit drop after set was found to be 35.50 per cent and the major part of the drop occurred during the first thirty days. The fruit attained maturity in 130 to 140 days after fruit set. The developing fruits followed a sigmoid growth pattern. The chemical composition of the rind showed an increase in T. S .S. content till maturity. Total acidity increased upto 80 days after fruit set and showed a gradual decline towards ripening. Ascorbic acid content was also high in the initial stages and decreased towards maturity at ripening the rind of the fruits had on an average 6.68 per cent acidity, 7.2 mg/100 g ascorbic acid, 80 Brix T. S. S. and 1.04 per cent reducing sugar. The mucilage developed around the seed towards ripening had 2.04 per cent reducing sugar and 3.3 per cent acidity. There was a loss of 75 per cent fresh weight on drying. The trees varied for the number of fruits harvested.
Histological and biochemical characterization of Polyembryony in Muvandan and Vellaikoluban Mangoes
(Department of Pomology & Floriculture,College of Horticulture, Vellanikkara, 2005) Dhinesh Babu, K; Parameswaran, N K
The term 'polyembryony' (PE) encompasses a set of processes whereby adventive embryos are formed along with zygotic embryo resulting in the emergence of multiple seedlings from a single seed. Understanding the histological and histochemical changes underlying the PE, a developmentally fascinating phenomenon, generally observed in a number of mango cultivars of south west coast of India is critical for the successful utilization of the same in crop improvement and other aspects. The project on "Histological and biochemical characterization of polyembryony in Muvandan and Vellaikolumban mangoes" - two homestead mango cultivars of Kerala - was hence taken up at the Department of Pomology and Floriculture, College of Horticulture, Kerala Agricultural University during 2002-2004 for tracing and characterizing the various histological and biochemical changes taking place during embryogenesis in polyembryonic Muvandan and Vellaikolumban mangoes vis-a-vis monoembryonic Bangalora; for characterizing the polyembryony involving isozymes as genetic markers and for studying the effect of different seed treatments on the expression of polyembryony at the field level and the 'subsequent seedling growth and vigour. Histological investigations revealed that the sequence of events in zygotic embryo formation was similar in both polyembryonic and monoembryonic cultivars. Fertilization was observed within five days after anthesis in polyembryonic and monoembryonic cultivars. Endosperm formation began by 15 days after fertilization (DAF) when the embryos were at near heart shaped stage In Muvandan and Vellaikolumban. Radicle and plumule initials were visible by 20 DAF when the endosperrn development was near complete in Muvandan. Adventive embryonic initial cells (AEICs) appeared in the nucellus by 10 DAF and 15 DAF in Vellaikolumban and Muvandan, respectively, when the zygotic embryo was at near heart shaped stage and this could be the turning point as far as adventive embryogenesis is concerned. Nucellar embryogenesis was found to be invariably preceded by and closely dependent on zygotic embryogenesis. Such nucellar embryos were distinct with prominent nucleus and dense cytoplasm. The number of nucellar initials ranged from one to eight in the polyembryonic cultivars. Histochemical localization of total insoluble polysaccharides showed that the content increased with the advancement of embryogenesis in both polyembryonic and monoembryonic cultivars up to 25 DAF. The content of RNA showed an increasing trend up to 25 DAF in polyembryonic cultivars during embryogenesis. The protein content also showed an increasing trend up to 15 DAF in both the groups and thereafter it declined. The phenotype of isozyme banding pattern of first sprout was different from that of the mother plant in Muvandan and Vellaikolumban whereas that of subsequent sprouts were identical with the mother plant. The seed stones subjected to different mechanical and hormonal treatments had an overall significant promotive effect on the rate (number of sprouts/seed) of polyembryony and the vigour of subsequent sprouts.
Intercropping in rainfed banana, musa (Aab) 'palayankodan'
(Kerala Agricultural University, 1987) Valsamma Mathew; Aravindakshan, M; Parameswaran, N K
None of the intercrops reduced the vegetative growth and yield of banana. However, the returns from intercrops like cowpea, ginger, colocasia and tapioca were not sufficiently high to compensate for the extra cost on the fertilizers and planting materials. The result suggested that intercropping of banana with turmeric or yam would prove profitable to the banana growers of Kerala under rainfed conditions.
Performance of citrus species under partial shade in coconut garden
(Kerala Agricultural University, 1987) Valsamma Mathew; Aravindakshan, M; Valsalakumari, P K; Parameswaran, N K
Proceedings of the seminar of Post Graduate students (2001-2002) -Vol.VI -Agricultural Economics and Extension
(Department of Agricultural economics,College of Horticulture,Kerala Agricultural University,Vellanikkara, 2002) Parameswaran, N K
Proceedings of the seminar of Post Graduate students (2001-2002) Volume. IV-Agricultural Meteorology, Statistics, Floriculture and Medicinal plants
(College of Horticulture , Kerala Agricultural University, Vellanikkara, 2002) Parameswaran, N K
Proceedings of the seminar of Post Graduate students-Vol. 6 - Social and Other Applied Sciences
(College of Horticulture, Kerala Agricultural University Vellanikkara, 2001) Sajan, Kurien; Parameswaran, N K
Vegetative and floral characters of gladiolus friendship as influenced by corm size and growth substances
(Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 1997) Vidya Gopinath; Parameswaran, N K