The high-yield agricultural model in Almería is based on eight different crops. Having led fruit and vegetable exports in Spain for more than 50 years, a decrease in melon and watermelon growing areas in Almería caused a change in supply that affected the model’s profit. Papaya cultivation could reactivate the profit of the agricultural model in Almería and also improve the available product range. The papaya crop needs greenhouse infrastructures high enough to contain the growth and size of the plants during a cycle crop, which is possible in most of the greenhouses of the Horticultural production model of Almería. The papaya harvests obtained in the region meet the quality requirements demanded by European markets. Furthermore, yields obtained are equal or higher than yields obtained by other producing countries. This crop improves profit compared with the profit obtained from the rotation of other horticultural crops that have been traditionally grown in the region.

In Europe, papaya consumption is growing due to its nutritional properties. The proximity of consumer markets to Southeast Spain allows fruits to be harvested at a more advanced stage of maturity compared to exporting countries from outside Europe, a timeline which improves the quality of the papaya. Experiments have been carried out to assess the adaptation of papaya to protected cropping systems (under greenhouse) in the region. In this paper, we showed the results obtained in an experiment with five varieties, taking the most cultivated variety as control, which was grafted on its own female rootstock, in addition to another four new varieties that were introduced. Transplanting was made with early sex-identified plants in the nursery. Cultivation was developed in a 446-day cycle, almost 15 months and fruits were always harvested from the soil, due to the height that the plant reached in that period. The best yield parameters and fruit characteristics were obtained from hermaphrodite Intenzza papaya grafted on female papaya rootstock, although there were also other varieties which gave results that made possible its cultivation under this production system.

Soil mulching materials play an important role in regulating the greenhouse crop microclimate, as they influence light distribution, plant physiological activity, and crop yield. The aim of this study was to evaluate the effects of two plastic mulches (black polypropylene and white polyethylene mulch) on the microclimate, photosynthetic activity, crop development, yield, and fruit quality of sweet pepper (Capsicum annuum L.) grown under greenhouse conditions. The trial was developed during a spring–summer growing cycle in a single multispan greenhouse divided into two compartments (sectors) separated by a vertical polyethylene sheet. In the eastern sector of the greenhouse (control treatment), a black polypropylene agrotextile mulch with a thickness of 2500 μm was installed, while in the western sector, a white polyethylene plastic mulch (black on the inner side) with a thickness of 30 μm was used. The use of white polyethylene mulch resulted in slightly higher mean and maximum PAR inside the greenhouse by up to 3.7% compared with black polypropylene mulch, leading to slightly higher leaf-level PAR and net photosynthetic rate. Although no significant differences were observed in plant morphology or fruit quality parameters, marketable yield increased by 66% and total yield by 40% under white polyethylene mulch. Slight increases in internal air temperature were recorded without exceeding critical thresholds, while relative humidity remained largely unaffected. The use of reflective mulches may represent a promising low-cost and sustainable strategy to improve pepper yield and radiation-use efficiency in passively ventilated greenhouse systems under Mediterranean climatic conditions.

Soil mulching materials play an important role in regulating the greenhouse crop microclimate, as they influence light distribution, plant physiological activity, and crop yield. The aim of this study was to evaluate the effects of two plastic mulches (black polypropylene and white polyethylene mulch) on the microclimate, photosynthetic activity, crop development, yield, and fruit quality of sweet pepper (Capsicum annuum L.) grown under greenhouse conditions. The trial was developed during a spring–summer growing cycle in a multispan greenhouse divided into two compartments(sectors) separated by a vertical polyethylene sheet. In the eastern sector of the greenhouse (control treatment), a black polypropylene agrotextile mulch with a thickness of 0.225 μm was installed, while in the western sector, a white polyethylene plastic mulch (black on the inner side) with a thickness of 30 μm was used. The use of white polyethylene mulch resulted in slightly higher mean and maximum PAR inside the greenhouse by up to 3.7 % compared with black polypropylene mulch, leading to slightly higher leaf-level PAR and net photosynthetic rate. Although no significant differences were observed in plant morphology or fruit quality parameters, marketable yield increased by 66% and total yield by 40 % under white polyethylene mulch. Slight increases in internal air temperature were recorded without exceeding critical thresholds, while relative humidity remained largely unaffected. The use of reflective mulches represents a low-cost and sustainable strategy to improve pepper yield and radiation-use efficiency in passively ventilated greenhouse systems under Mediterranean climatic conditions.