Citrus yields get a boost

These brothers installed computerised irrigation and fertigation systems to improve their citrus yields.

Applying irrigation water for optimum tree growth and crop production has always been a headache in the orange-producing areas of Citrusdal. Although the water used from the Olifants River is excellent, the sandy soils have poor retention, and with summer temperatures often exceeding 46°C, evaporation losses are high.

Small wonder that the Vissers of Hex River have been experimenting with irrigation systems ever since an alternative to flood irrigation became available.

“As long ago as 1936 my father, Dirk Visser, installed the first overhead sprinkler system seen here,” says Dirk Visser, who together with his brother, Hermann, farms four citrus units.“It was subsequently replaced by a huge German overhead sprinkler cannon, mounted on a mobile 90kW, dieselpowered pump unit. This giant machine was capable of spraying a 70m radius circle.”

Conventional sprinkler systems were used, but the Vissers were always on the lookout for something better. “Drippers were found to be unsatisfactory here, as there is insufficient lateral distribution of water in the sandy soils. Eventually, during the mid1970s, a neighbour started experimenting with simple home-made microjets.”