Browsing by Author "Nampoothiri, C.K."

Now showing 1 - 9 of 9
  • Thumbnail Image
    Item
    Dynamics and Nutrient Release Pattern of Silica Sources in a Typical Entisol of Tropical Humid Region of Kerala
    (2017) Jeena Mathew; Krishnakumar, V.; Nampoothiri, C.K.; Vijayaraghava Kumar; Narayanan Namboothiri, C. G.
  • Thumbnail Image
    Item
    Dynamics of rhinoceros beetle damage as influenced by pheromone trapping
    (2016-12) Joseph Rajkumar, A.; Subaharan, K.; Chandrika Mohan; Shanavas, M.; Sunny Thomas; Nampoothiri, C.K.
  • Thumbnail Image
    Item
    Growth and vigour of coconut seedlings raised from eriophyid mite (Aceria guerreronis Keifer) infested seed nuts
    (2004-12) Thomas, R.J.; Nair, R.V.; Nair, C.P.R.; Nampoothiri, C.K.; Cherian Mathews
    Considering the wide spread apprehension regarding suitability of mite infested seed nuts for raising seedlings, a study was undertaken to evaluate the growth and vigour of coconut seedlings raised from mite-infested seed nuts. The maximum values for all the growth characters were recorded in seedlings raised from grade-3 infested seed nuts. However, higher percentage of vigorous seedlings (with Z score of 22 and above) was obtained in seedlings raised from uninfested I grade-0 nuts. The faster germination recorded in grade-3 infested nuts and their subsequent better establishment may be the reasons for the superior performance of seedlings raised. On the basis of the present investigation, it is recommended that mite infested seed nuts should be sorted into lots. depending on severity of infestation. and nursery raised separately for each lot so that competition between seedlings, raised from different grades of mite infested nuts, can be minimized. This will help in obtaining more vigorous seedlings from the mite infested seed nuts.
  • Thumbnail Image
    Item
    INFLUENCE OF TEMPERATURE, GERMINATION DURATION AND CULTIVAR ON IN VITRO POLLEN GERMINATION AND POLLEN TUBE GROWTH IN COCONUT (COCOS NUCIFERA L.).
    (2017) Chaturvedi, V. K.; Hebbar, K.B.; Chandran, K.P.; Regi Jacob Thomas; Shareef, M.; Nampoothiri, C.K.; Jinu Sivadasan
  • Thumbnail Image
    Item
    Morphometric Variability in Radopholus Similis
    (2007-02) Koshy, P.K.; Jasy, T.; Jacob Mathew; Nampoothiri, C.K.
    Morphometric studies were carried out to determine differences, if any, among the 12 populations of Radopholus similis collected from different localities of South India. Most of the measurements and ratios recorded in these studies fall within the range of measurements of R. similis reported previously. Out of the 39 characters/ratios examined, stylet length (C.V. 3.91%) and ratio V(C. V. 3.10%) were the most stable characters in R. similis. The populations developed from a single adult female on carrot discs recorded minimum variations. Comparisons of adult and gravid females of a coconut population (C17 H) from host root showed that most of the measurements were higher in gravid females, indicating the need for recording the measurements of gravid females separately in all morphological studies. D2 analysis of 39 characters of males and females grouped the 10 populations into three clusters and 12 populations fell into 4 clusters with population cultured on host root alone forming a separate cluster. Significant correlation was found between the pairs of characters constituting the ratio c and body length of females and males and ratio V of females. Body length (BL) has been found to be a good descriptive ratio in R. similis where the correlations was highly significant between the constituting characters.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Standardization of seednut storage techniques for Kalpasree variety of coconut
    (2018-12) Shareef, M.; Regi Jacob Thomas; Nampoothiri, C.K.
  • Thumbnail Image
    Item
    Studies on fruit set in coconut upon artificial pollination in various cross combinations
    (2012-03) Regi J. Thomas; Nair, R.V.; Mathews, C.; Ajith Kumar, R.; Sasikala, M.; Nampoothiri, C.K.
    Studies on fruit set in coconut have important implications in nut yield. A detailed study was carried out to determine the fruit set in coconut as influenced by variety, cross combination, climatic variables such as rainfall, temperature and relative humidity. Artificial pollination was carried out on selected parental palms of West Coast Tall (WCT), Chowghat Green Dwarf (CGD) and Chowghat Orange Dwarf (COD) in farmer’s plots over a period of five years commencing from 1996-2000. The various cross combinations tried among the three varieties, viz., WCT, CGD and COD were three selfing, two inter se and three crosses. The mean fruit set for the different cross combinations was 24.67%. The maximum fruit set (39.54%) was in COD (self) followed by WCT (self) and COD x WCT, and minimum in CGD x WCT (19.16%) indicating that COD variety as a female parent gave significantly higher fruit set compared to other varieties. Generally, the varieties WCT and CGD under selfing gave a higher fruit set (27.43 and 24.65%) when compared to inter se (21.63 and 21.22%). Fruit set was maximum (28.73%) during March and minimum (18.80%) during May but the year-to-year variation was not significant. The bimonthly average relative humidity (%), number of rainy days and rainfall (cm) had a significant negative correlation (-0.504, -0.428, -0.395, respectively) with fruit set. Studies also revealed that there was a significant reduction in fruit set to the tune of 35%, when climatic conditions are not favourable. The present investigations revealed that fruit set in coconut vary significantly due to genotype, cross combination and climatic variables.
  • Thumbnail Image
    Item
    Studies on vivipary in dwarf coconut cultivars
    (2014-12) Shareefa, M.; Regi J. Thomas; Nampoothiri, C.K.; Anitha Karun
    Vivipary is a problem in some dwarf varieties of coconut as their seed nuts show low germination compared to Talls. An experiment was carried out to study the extent of vivipary in dwarf coconut varieties (MGD, MYD, MOD and CGD) with WCT as control. Observations on nut traits like shape, colour, length, weight and water content of the seed nut, thickness, weight and polyphenol content of the husk, length and weight of embryo, TSS of nut water were recorded from 10-, 11- and 12-month-old nuts of each variety. Observations were also recorded at bimonthly intervals during November 2011-September 2012. None of the ten-month-old seed nut exhibited vivipary. However, few 11th old MOD nuts (3%) harvested during November showed vivipary. The results showed that the extent of vivipary was highest during September and least during January. Among the varieties, MYD exhibited maximum vivipary (24%) followed by MOD and MGD (16%) and the least was in WCT (0.6%). Vivipary was negatively correlated with various nut characters, husk thickness and weight. However, prevailing climatic conditions like amount of rainfall, number of rainy days and relative humidity during the preceding 30-day of harvest had significant positive correlation with vivipary. It is suggested that vivipary in dwarf varieties can be avoided by harvesting the seed nuts at the proper stage.