IMPROVED PRODUCTIVITY BY SPLIT ROOT FERTIGATION IN GREENHOUSE-GROWN CUCUMBER

In greenhouse production, the optimal fertilization to maintain maximum production depends on the water use and nutrient requirements of the plants. A high concentration of nutrient salts in the fertigation solution (i.e., high electrical conductivity EC) causes water stress whereas a low concentration (low EC) results gradually in nutrient deficiency in plants. Split root fertigation (SRF) is a novel method that may provide complementary benefits over traditional fertigation (TF). In the SRF approach the plant’s root is divided into two separate compartments that are given fertigation solutions with different EC values. To compare TF and SRF methods, we conducted seven experiments in which cucumber (Cucumis sativus L.) plants were grown in a high-wire cultivation system with supplemental lighting (top- and interlighting) and comparable with commercial greenhouse production conditions. In a high-yielding environment the SRF method improved the overall water uptake and water use efficiency by 13%. In general, the water uptake was highest in the root compartment with low EC values. The experimental data revealed that the SRF method decreased fruit abortion, thus leading to an improved fruit set. The accurate management of the EC values in the SRF growing medium enhanced the yield of Class I cucumbers by 12% as compared with TF. In summary, our results indicate that in cucumber plants cultivated in peat and perlite using the split root fertigation method with low and high EC values, significant yield increases can be gained in comparison to traditional fertigation with a constant EC value.