Pieter Raath & Coenraad Fraenkel In addition to the negative publicity that the agricultural sector faces regarding the detrimental impact of unnecessary fertilisation on the environment, the cost of fertilisers is forcing producers to pursue ways to reduce fertilisation inputs. A proper balance between unreasonably conservative...

In citrus new vegetative shoots provide the bearing positions from which flowers develop in spring. These new vegetative shoots are strong sinks for carbohydrate supply from both mature leaves and reserve carbohydrates from the previous season. One could expect that citrus trees should be able...

by Pieter Raath (CRI) and Tariena Nel (Labserve) In the light of decreasing availability and quality of water used for irrigation of citrus in many regions of South Africa, producers are compelled to investigate the possibility of using new water sources, i.e., groundwater or wastewater. However,...

Both sulphur (S) and boron (B) are essential plant nutrients. Sulphur is a macro-nutrient of which roughly about 30 kg/ha is utilized by orchards, while B is a micro-nutrient and only about 120 g/ha is annually taken up by trees. For inexplicable reasons, many producers...

  In the light of decreasing availability of water for irrigation, producers are compelled to investigate the possibility of using water sources previously not considered, i.e., boreholes or wastewater. The quality of these sources often raises concern, making producers unsure whether they can rely on them...

Introduction In circa 1500 Leonardo da Vinci said: ”We know more about the movement of celestial bodies than about the soil underfoot”. Although our knowledge of both these fields of science has developed immensely over the last five centuries, this statement undoubtedly remains true. Soil life,...

In hierdie skrywe deel ons graag wat in ‘n onlangse verslag van die Bemestingstofvereniging van Suid-Afrika (FERTASA) gepubliseer is met julle.  Produsente is soms besorg oor die kwaliteit van hul kunsmis, te wete of dit werklik die verklaarde hoeveelheid N, P, K, Ca, Mg en...

As guidelines upon which soil analyses are interpreted and fertilisation is applied, the basic cation saturation ratio (BCSR) concept (now better known as the Albrecht system) has become popular amongst various plant nutritionists.  It is based on a presupposition that plants will only grow optimally...

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