Articles by Author: J A Holtzhausen

Search results for J A Holtzhausen

We found 12 results for you
  1. Evaluation of five Pecan cultivars [<em>Carya illinoensis</em> (Wang.) R. Koch] for yield, precocity, alternate bearing, leaf:nut ratio and length of growing season in the Transvaal middleveld

    Evaluation of five Pecan cultivars [<em>Carya illinoensis</em> (Wang.) R. Koch] for yield, precocity, alternate bearing, leaf:nut ratio and length of growing season in the Transvaal middleveld

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The average yield of five pecan cultivars over a 22-year period was 25, 1 kg per tree per annum. The extrapolated average yield for the last 10 years of bearing was 2 642 kg ha-1, which compares favourably with results...
  2. Evaluation of five pecan (<em>Carya illinoensis</em>) cultivars for nut quality

    Evaluation of five pecan (<em>Carya illinoensis</em>) cultivars for nut quality

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Five pecan [Carya illinoensis (Wang.) K. Koch] cultivars, commercially recommended for the Transvaal middleveld areas were evaluated for nut quality (nut size, kernel %, kernel colour, nut shape and shell thickness). New South African grading standards are suggested for nut...
  3. Die invloed van voedingsoplossingkonsentrasie op groei van growweskilsuurlemoen en Troyer citrange saailinge

    Die invloed van voedingsoplossingkonsentrasie op groei van growweskilsuurlemoen en Troyer citrange saailinge

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    In sitruskwekerye word vegetatiewe groei gestimuleer deur die konsentrasie van voedingstowwe in die groeimedium so hoog moontlik te handhaaf. Dit kan egter te hoƫ konsentrasie teweegbring. In die ondersoek is gevind dat growwe- skilsuurlemoensaailinge (GS) optimaal groei waar sproeibemes was...
  4. Megagametogenesis and embryology of the pecan (<em>Carya illinoensis</em>)

    Megagametogenesis and embryology of the pecan (<em>Carya illinoensis</em>)

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    A timetable is presented for megasporogenesis, megagametogenesis, embryo and endosperm development of the pecan [Carya illinoensis (Wang.) K.Koch] under Transvaal Middleveld conditions. Differences between seasons and cultivars were minimal. The fertilized endosperm nucleus was observed about 5 to 7 days...
  5. Anatomy of staminate flower ontogeny of the pecan as determined by scanning electron microscopy

    Anatomy of staminate flower ontogeny of the pecan as determined by scanning electron microscopy

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    A new method of investigation for hard winter buds of the pecan [Carya illinoensis (Wang.) K. Koch] was developed and used successfully. The development of pecan catkins under summer rainfall conditions at Roodeplaat followed the grouping of cultivars according to...
  6. Storage root formation at individual nodes of the sweet potato (<em>Ipomoea batatas</em> (L.) Lam)

    Storage root formation at individual nodes of the sweet potato (<em>Ipomoea batatas</em> (L.) Lam)

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Little or no information is available on the contribution of individual subterranean nodes to the storage root formation in sweet potatoes. Therefore, two field trials were conducted where apical vine cuttings of various cultivars were planted vertically or horizontally, with...
  7. An acoustic and perceptual analysis of Xhosa vowels

    An acoustic and perceptual analysis of Xhosa vowels

    Item type: Journal Article • Journal: South African Journal of African Languages
    There is a specific need for quantified phonetic data for linguistic and non-linguistic purposes in most of the African languages. Acoustic and perceptual qualities of vowel articulations of a fluent mother-tongue speaker of Xhosa are investigated by means of various...
  8. Observations on the linefish resources of Namibia, 1990?2000, with special reference to West Coast steenbras and silver kob

    Observations on the linefish resources of Namibia, 1990?2000, with special reference to West Coast steenbras and silver kob

    Item type: Journal Article • Journal: South African Journal of Marine Science
    The Namibian linefishery is a multisector fishery, with recreational and commercial sectors targeting overlapping species. Prior to 1990, catch data were recorded for the boat sector, but little research was done on the population dynamics of any of the species...
  9. Age and growth of two populations of West Coast steenbras Lithognathus aureti in Namibian waters, based on otolith readings and mark-recapture data

    Age and growth of two populations of West Coast steenbras Lithognathus aureti in Namibian waters, based on otolith readings and mark-recapture data

    Item type: Journal Article • Journal: South African Journal of Marine Science
    Age and growth of West Coast steenbras Lithognathus aureti, sampled from two separate populations (northern and southern) along Namibia's coast, was determined using sectioned otoliths, and the results were validated using mark-recapture data. For both populations, the special three-parameter Von...
  10. An assessment of the current status and potential yield of Namibia's northern West Coast steenbras <em>Lithognathus aureti</em> population

    An assessment of the current status and potential yield of Namibia's northern West Coast steenbras <em>Lithognathus aureti</em> population

    Item type: Journal Article • Journal: South African Journal of Marine Science
    Two distinct populations of West Coast steenbras Lithognathus aureti are found in Namibian waters; one, the northern population, is exploited recreationally and commercially. Data collected between 1995 and 1999 were used to evaluate its current state and potential yield, using...