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Voorspelling van die aanpassingsvermoë van koringkultivars gebaseer op daglengte- en vernalisasiereaksie
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: G.D. Joubert --- ,Die koue- en daglengtereaksies van koringkultivars in groeikaste is ondersoek as aanduiding van die produksiegebiede waar die betrokke kultivars sal aanpas. Die resultate toon dat die 24 koringkultivars wat ondersoek is, uiteenlopende koue- en daglengtereaksies vertoon. Klassifikasie van die kultivars... -
Refinement and validation of the PUTU wheat crop growth model 1. Phenology
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A. Singels --- Department of Agrometeorology, Republic of South Africa J.M. de Jager --- Department of Agrometeorology, Republic of South AfricaThe phonological submodel of the PUTU wheat crop growth model was refined to account for the variation in sensitivity to vernalization and photoperiod. Crop development rate was simulated in five phenological phases making use of temperature and photoperiod. Base values... -
Evaluering en kalibrering van CERES-Maize 2. Groeistadia voorspellings
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.S. du Toit --- , Republiek van Suid-Afrka J. Booysen --- Departement Plantkunde, Republiek van Suid-Afrika J.J. Human --- Departement Agronomie, Republiek van Suid-AfrikaMidsomerdroogte tydens blom het 'n vernietigende effek op mielie-opbrengs. Deur die plantdatum te manipuleer kan die effek van midsomerdroogte op oesopbrengs verminder word. Gewasgroeisimulasiemodelle kan gebruik word om die optimum plantdatum per cultivar te bepaal. CERES-Maize se fenologiese voorspellingswaarde is... -
Calibration of CERES3 (Maize) to improve silking date prediction values for South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.S. du Toit --- , Republic of South Africa J. Booysen --- , Republic of South Africa J.J. Human --- Department of Agronomy, Republic of South AfricaSilking which coincides with the mid-summer drought in South Africa, could have a significant negative effect on maize yield. Errors in the prediction of silking date could contribute to errors in kernel number simulation, and consequently to errors in yield... -
Acoustic fish biomass assessment in a deep Tunisian reservoir: effects of season and diel rhythm on survey results
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: I Djemali --- Institut National des Sciences et Technologies de la Mer, Tunisia H Laouar --- Centre Technique de l’Aquaculture, TunisiaTo determine the best acoustic sampling period for obtaining fish biomass estimates of a Mediterranean deep reservoir in Tunisia, day and night surveys were performed in spring (April), summer (September), autumn (December) and winter (March). A Simrad EK60 echosounder, equipped... -
Diel activity patterns in a captive colony of rinkhals, Hemachatus haemachatus
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: GrahamJ. Alexander --- University of the Witwatersrand, South Africa CatherineL. Marshall --- University of the Witwatersrand, South Africa