Effect of climate conditions on growth and production of hydroponic papaya crops in the Canary Islands
Optimal papaya production and quality in subtropical areas, such as the Canary Islands, require adequate ambient conditions. Therefore, in this region, commercial papaya is cultivated inside greenhouse structures for protecting plants against pests and adverse ambient conditions. However, since these greenhouses are generally equipped with low-level, or even with no, climate control, the location of the greenhouse on the Islands greatly affects papaya production and quality. In order to characterize this effect, experiments were conducted inside plastic greenhouses in two locations of the Canary Islands, one in the north of Tenerife (TN) and the other in southeast of Gran Canaria (GS). The papaya cultivar 'Sweet Mary' was grown from April 2015 to March 2017 in both locations using a hydroponic system. Crop growth measurements were taken monthly and production variables were determined at weekly intervals, harvesting all fruits with more than 20% of yellow-orange peel color. Air temperature, relative humidity and photosynthetic active radiation (PAR) were monitored inside both greenhouses during the study period. Although average height of first flower emission was similar in both locations (77 cm in GS vs. 74 cm in TN), average height of first fruit emission was higher in GS (105 vs. 80 cm in TN), denoting flower setting problems in relation with the TN location. This may be probably a consequence of higher temperature events in GS location during the first cropping months. Average leaf area was above 10 m2 plant‑1 in GS all year round. This is significantly higher than the values observed in the TN location plants during autumn and winter period, which were below 5 m2 plant‑1, caused by a significant plant defoliation probably associated with adverse climatic events in that area. Leaf area values together with higher PAR levels in GS with respect to TN location, led to higher fruit production in the GS plants (105 vs. 69 kg plant‑1), which may be attributed to a higher proportion of fruits with weight above 900 g. Fruit total soluble solids content was above 11 °Brix all year round, except in the winter season in TN location, with values below 10 °Brix. All these results support the recommendation of incorporating simple greenhouse modifications and crop management techniques adjusted to the limiting climatic factors of each area in order to increase papaya production and quality, especially in north-located greenhouses.
Cabrera, J.A., Raya, V., Lobo, M.G. and Ritter, A. (2020). Effect of climate conditions on growth and production of hydroponic papaya crops in the Canary Islands. Acta Hortic. 1268, 77-84
°Brix, leaf area, PAR, water use efficiency (WUE)