Protected cultivation of ‘BH-65’, ‘Siluet’, ‘Sensation’,‘Intenzza’ and ‘Red Lady’ papaya cultivars in South East Spain

Abstract

Papaya (Carica papaya L.) is a tropical fruit crop of rapid growth and early yielding. In recent years, papaya cultivation has extended to subtropical regions due to its commercial interest. In South East Spain, protected cultivation is, however, mandatory to ensure the optimal development of the crop. Even more, to assure profitability, the selection of plant material well adapted to the structural constrains and the climatic conditions inside greenhouses is essential. With this objective, different papaya cultivars with diverse geographical origin, characteristics and pedigree have been compared. ‘BH-65’, ‘Siluet’, ‘Sensation’, ‘Intenzza’ and ‘Red Lady’ papaya cultivars were thus grown under a plastic greenhouse in Almería, SE Spain and their growth, phenology, yield and fruit quality compared in a 21-month production cycle. The results showed that ‘Siluet’ and ‘Sensation’ papayas are well-adapted to greenhouse protected cultivation, produce high yield, and optimal fruit quality for long and short distance markets. Cultivars like ‘BH-65’ could be of interest for low-height greenhouses due to its reduced plant vigor and high fruit quality. However, ‘BH-65’ yield is low. According to the European consumer preferences, the cultivation of ‘Siluet’ and ‘Sensation’ is recommended, for the harsh conditions the greenhouse cultivation imposes in subtropics.

Sex determination of papaya var. ‘Maradol’ reveals hermaphrodite-to-male sex reversal under greenhouse conditions

“…These results are consistent with Salinas et al (2020), who mentioned Autumn (September) as the worst season for fruit production of papayas due to functionally male flowers in all cultivars tested. They evaluated the seasonal frequency of different types of flowers of five cultivars of hermaphrodite papaya: ' 'Sensation','Siluet','Intenzza',and 'Red Lady'.…”

Determination of the Best Planting Season for the Protected Cultivation of Papaya

“…Finally, fruit quality was mainly determined by the environmental conditions, so our evaluations support the view that favorable and unfavorable periods affect equally fruit ripening and quality regardless of plant age. Similar total soluble solid changes along the year were also observed in plantations starting in June [16]. Nevertheless, Nascimento et al [20] indicate, on the contrary, that differences in sugar content are related to fluctuations in source-sink relationships throughout the cycle, so higher sugar content might coincide with a larger canopy and/or with a lower number of fruits per plant, and vice versa.…”

“…In this context, our results emphasize the importance of maintaining suitable environmental conditions during the first summer following a plantation in a greenhouse, in order to encourage the formation of fertile flowers in the first nodes of the trunk and thus preventing the loss of the first flowers due to fruit set failures. In the work above cited [16], 'Intenzza' seedlings transplanted in June showed an important frequency of functionally male useless flowers during the following months, thus evidencing that harsh conditions of summer affect negatively flower differentiation weeks later. These results also confirm the different performance of a given cultivar (in this case, 'Intenzza') depending on the planting season and especially according to the prevalent environmental conditions, as stated by Cabrera et al [10].…”

“…According to previous experimentation, transplanting 'Intenzza' seedlings in June is worse, since flowering occurs at a higher height (83.8 cm) than in spring and autumn plants, and the setting of the first fruits takes place at 85.1 cm from the ground [16], higher than in seedlings transplanted either in spring or autumn. Besides, seedlings transplanted in summer started to ripen fruit 307 days after planting, requiring only 76 days to reach flowering but 231 days from flowering to harvest [16].…”

“…According to previous experimentation, transplanting 'Intenzza' seedlings in June is worse, since flowering occurs at a higher height (83.8 cm) than in spring and autumn plants, and the setting of the first fruits takes place at 85.1 cm from the ground [16], higher than in seedlings transplanted either in spring or autumn. Besides, seedlings transplanted in summer started to ripen fruit 307 days after planting, requiring only 76 days to reach flowering but 231 days from flowering to harvest [16]. In this context, our results emphasize the importance of maintaining suitable environmental conditions during the first summer following a plantation in a greenhouse, in order to encourage the formation of fertile flowers in the first nodes of the trunk and thus preventing the loss of the first flowers due to fruit set failures.…”