COCOS - Journal of the Coconut Research Institute of Sri Lanka

Permanent URI for this collectionhttps://dl.nsf.gov.lk/handle/1/7343

Browse

Start date: 1990Subject: search.filters.subject.Cocos nucifera L.

Search Results

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Effect of mulches and cover crops on water status and gas exchange of coconut (Cocos nucifera L.) palms in gravelly soils
    (CRI. Lunuwila, 2003) Ranasinghe, C.S.; Premasiri, R.D.N.; Silva, L.R.S.
  • Thumbnail Image
    Item
    The impact of soil type , soil compaction and water stress on above and below ground components of coconut (Cocos nucifera L.) seedlings
    (CRI. Lunuwila, 2000-2002) Nainanayake, N.P.A.D.; Bandara, D.C.; Ranasinghe, C.S.
  • Thumbnail Image
    Item
    Response of rapid decline affected coconut (cocos nucifera L,) palms to micro-nutrients and common salt
    (CRI. Lunuwila, 2004) Wijebandara, D.M.D.I.; Ranasinghe, C.S.
  • Thumbnail Image
    Item
    Soil water extraction pattern of coconut (Cococs nucifera L.) in relation to soil compaction
    (Coconut Research Institute. Lunuwila, 1998/1999) Vidhana Arachchi, L.P.; Yapa, P.A.J.; Mapa, R.B.; Somapala, H.
    Effect of soil compaction on the gowth and activity of coconut roots in two soil series, namely, Andigama series (gravelly soil) and Madampe series (sandy loam soil) was studied. The effective root zone of coconut in relation to water sbsorption process under natural soil compaction were also investigated. Soil compactin and soil moisture absorption ability was determined using cone penetrometer and neutron scattering methods, respectively. Coconut root distributution in Andigama and Madampe series showed that 75%-80% of roots of adult coconut palms were localised in a depth ranging from 20 cm to 100 cm. About 5% of the roots were located beyond the 100 cm depth and 15% -20% was confined to the top layer (0-20 cm) of soil. Root growth of coconut in the two series did not show any significant differences. However, the root activity in the Madampe series, with respect to moisture absorption was higher that that of the Andigama series due to low compaction of the former. Results also showed that soil compaction higher than 250N/cm restricted the activity of coconut roots in the Andigama series for moisture absorption up to a distance of 2m away horizontally from the base of the tree and the highest moisture extraction was observed at m distance. High moisture extraction by coconut roots was confined to a depth ranging of 20 to 120 cm and of 20 to 250 cm in soils of Andigama and Madampe series, respectively, due to differences in soil compaction levels. It was condluded that soil compaction limits the water absorption ability of coconut roots vertically from the base of the tree, rather than coconut root growth and penetration.
  • No Thumbnail Available
    Item
    Assessment of the effects of environmental factors on yield of coconut (Cocos nucifera L.)
    (Coconut Research Institute of Sri Lanka. Lunuwila, 1997) Peiris, T.S.G.; Thattil, R.O.
    The long term nut yield data and climate data of eight variables (1976-1992) were analyzed to understand the effects of climate and weather on the yield variability between picks. The yield variation over the years had no systematic pattern. The order of contribution of the picks to total yield is not significantly consistent between years. Explanatory models were developed at monthly lag periods prior to harvest of each pick. The most and least influential picks in respect of climate variability are picks 5 and 2 respectively. The critical period with respect to climate and weather variability of picks 1-6 are February , June July, Septermber, December and February respectively. The climatic models fitted at these periods explain the yield variability between picks. The influence of climatic variables during these periods vary from pick to pick. Maximum air temperature and relative humidity in the afternoon are the two most significant environmental variables influencing yield irrespective of picks.
  • No Thumbnail Available
    Item
    Vegetative reproductive ad physiological changes in coconut palms affected by coconut rapid decline
    (Coconut Research Institute of Sri Lanka. Lunuwila, 2005) Ranasinghe, C.S.; Wijeratne, A.