SA Grain October 2017

57 / 116

55
October 2017
Results
The method of Trethovan et al., 2002 was
used to eliminate environmental effect and
to measure the progress made for genetic
grain yield over a period. Trial means and
trial means for ARC-Small Grain cultivars
calculated for the Rûens and Swartland
showed a reduction in yield for both these
regions.
However, the regression of ARC-Small
Grain’s cultivars expressed as a ratio of
the trial means (ratio) against year show-
ed an annual genetic gain of 1,14%/year for
the Rûens whereas a negative genetic yield
gain of -0,01%/year was observed for the
Swartland. The genetic yield gain achieved
in the Rûens correlates well with the inter-
national progress made for yield improve-
ment of between 0,7% and 1,3% per annum.
In order to keep up with the increased de-
mand for wheat and to make it economically
viable for producers to produce wheat, the
primary aim of the ARC-Small Grain wheat
breeding programme is to develop and re-
lease new improved high yielding cultivars
that are well adapted to conditions in the
Western Cape.
That goal in mind, the ARC-Small Grain re-
leased Ratel in 2011 and Steenbok at the
end of 2016. Both Ratel and Steenbok are
mid-season cultivars that are well adapted
to conditions in the Swartland and Rûens.
Future of wheat production
Wheat production in the Western Cape is
here to stay despite a number of challen-
ges in the industry. The ARC however, has
committed itself to the development of high
yielding cultivars that will perform under ex-
treme conditions – even drought.
The ARC is in the process of developing an
exciting range of new wheat cultivars with
improved yield. These lines will be visible
on farmers days in the Swartland and Over-
berg and producers are invited to come and
see these exciting new lines. We wish all
producers good harvests for 2017.
For more information, contact the authors at
malana@
arc.agric.za, -
ric.za or
Reference
Trethowan, RM, Van Ginkel, M and Rajaram, S (2002).
Progress in breeding wheat for yield and adaptation
in global drought affected environments. Crop Sci-
ence 42:1 441 - 1 446.
Yield improvement of dryland wheat
Die uitwissing van onkruid langs kampdrade, paaie en op kontoere
is absoluut noodsaaklik. Dit is ‘n eenvoudige dissipline wat onver-
skoonbaar is as dit nie gedoen word nie.
Opwindende nuwe metodes van meganiese beheer het al die lig
gesien – veral in Australië, waar weerstand ‘n astronomiese uitdaging
geword het. Die fisiese vang en verwydering of vernietiging van
die onkruidsaad in die kaf agter die stroper is ‘n groot fokuspunt.
Een só ‘n voorbeeld is waar saadvernietigingstoestelle agterop
stropers gemonteer word en waarmee saad vernietig word, maar
loop- en onderhoudskoste is ongelukkig te hoog.
Verder kan kaf in vangkarre agter die stroper gevang word en op
hope gegooi word – wat dan gebrand word. Die operasie strem on-
gelukkig die oesproses en ‘n groot volume materiaal word vernietig
– wat dit nie so aantreklik maak nie.
Derdens word die fyn kaf op ‘n enkele ry gekonsentreer – wat dan
agterna gebrand word. Laasgenoemde is ongelukkig uiters ar-
beidsintensief en die risiko dat die hele land afbrand, is goed – wat
‘n groot verlies aan materiaal meebring.
Die mees aantreklike en sinvolle manier van kafhantering is waar
dit in rye op die stroper se wielspoor gegooi word. Dit gaan
hand-aan-hand met ‘n spoorverkeerstelsel, waar die spore goed
gekompakteer is en onkruid glad nie kan oorleef – al het dit ontkiem
– nie. In die afwesigheid van spoorverkeer kan die rye dood ge-
spuit word sou ontkieming plaasvind. In sommige gevalle verrot
die rye as gevolg van die hoë konsentrasie van fyn materiaal – wat
onkruidsaad outomaties vernietig.
Onkruidsaad kan natuurlik ook baie goed uitgewis word met die
maak van hooi of kuilvoer – veral op probleemkampe.
Graan SA/Sasol fotokompetisie