On Farm Trials

Background

Cucumber is one of the most important greenhouse crops in Saudi Ariba. A very fast-growing plant, it takes only 2 to 3 weeks after the transplant of young cucumber plants for harvest to start. The downside of this fast-growing is that if the plant is trained to grow along a vertical wire (the training wire), it quickly reaches the fixing point of the wire. This fixing point of the training wire is called the crop wire. Traditionally, when this point is reached, growers simply bend the top of the crop over the crop wire. Due to gravity, the top of the crop then grows downward. When this downward growing top of the crop gets some length (say 1,5 meters), the top is picked up and bent over the crop wire again. This can be repeated a third time, but after that, the bunch of leaves and stems becomes so messy that the crop has to be removed. After the removal of the old crop, a new crop has to be planted. Due to this practice, cucumber cultivation traditionally has three cycles a year and, therefore, remains three times in some weeks without production (Estidamah Cucumber Report, 2018).

Estidamah tested a new cropping system called the “high-wire system”. In this case, the training wire can be elongated and shifted aside to cope with the continuously growing stem (up to 60 cm a week). Of course, the continuously growing stems will just as well create a large bunch of stems. But in the high-wire system, the bunches result from de-leaved stems and are at the bottom side of the crop. Therefore, the bunch of stems will be much less messy. Hence, one crop cycle can stay productive for a longer period and increase product per kg. This reduces the initial costs for seeds, propagation, and planting, as well as the number of weeks without production (Estidamah Cucumber Report, 2018).

Estidamah's experimental results on high-wire cucumber in a low-tech compartment showed that by adopting the “carousel system” in a high-wire cultivation system, the cucumber crop remained productive for a longer period. The high-wire crop had a harvest period of 146 days, whereas, in the reference (umbrella system), the crop was worn out after a harvest period of 110 days. Besides, in the high-wire system, the fruit quality and productivity remained equal for the whole period where the reference greenhouse showed 10 to 20% malformed fruits and a serious drop in productivity by the end of the harvest period (Estidamah Cucumber Report, 2018).

To improve farmers' income by increasing cucumber productivity, a field trial was conducted to evaluate the cucumber productivity of two cropping systems in a commercial farm using two med-tech glass-covered greenhouses (5000 m2 each). In the first greenhouse, the traditional cropping system (umbrella system) was used, while in the second one, a new high-wire system was applied (Fig. 1).