A little over five years ago, the trials for the cultivation of papayas in greenhouses started at the Experimental Station Cajamar 'Las Palmerillas' in the framework of the work dealing with the protected cultivation of fruit species. The objective is to contribute to diversifying the production of vegetables under plastic and offer alternatives to Almerian growers, taking advantage of the knowledge gained in the field of intensive horticulture in Almeria (design of structures, cover materials, climate control, management, biological control, etc.) and of the auxiliary industry that has been created around this sector.
To this end, Cajamar has been working in close partnership with the University of Almeria, integrated in the research group AGR-222 'Subtropical and Mediterranean Fruit farming'.
In the period between 2014 and 2016, a total of seven varieties from Mexico, Brazil, South Africa and Asia were tested. The objective was to determine which of them would best adapt to the growing conditions of Almeria's greenhouses.
After the planting in June 2014, the flowering began in mid-August. The fruits that ripened and developed during the autumn were harvested from late March 2015 until early July. The fruits harvested at the end of winter had a low content of soluble solids. The second harvest (with fruit setting from the beginning of winter) arrived in September 2015 and continued to be harvested until the end of the trial (February 2016), with fruit reaching 12, 13 and up to 14 Brix degrees. The commercial production accumulated over the 19-month trial ranged from the 19.1 kg/m2 of the Sensation variety to the 9.1 kg/m2 of the BH-65. Other noteworthy varieties were the Intenzza and Siluet, with production volumes ranging between 16 and 18 kg/m2. In contrast, the Red Lady had a low commercial production, of around 10 kg/m2, with fruit of excessive size and a high amount of discards.
During the same period, there was also a study of the behaviour during various papaya productive cycles (spring, summer and autumn) with the variety BH-65. The spring cycle is the one that had the fastest entry into production (8 months) and the one when the biggest fruits were produced, with 5.5 kg/m2. The autumn cycle yielded a slightly higher production than the spring (6.6 kg/m2), but it is the one with the slowest entry into production (12 months). The transplant in June was the most productive (12.5 kg/m2) and needed 10 months to enter the productive period with smaller fruits. In general, a strong peak of production is observed in spring, another smaller one in autumn and a staggered harvest during the winter.
Regardless of the date of transplant, there is a production gap in summer (July and August) due to lack of settling in the previous winter and another one in March-April due to lack of settling in the previous summer.
Determining the optimum harvesting point to reach the market with quality fruit is key to the successful marketing of papayas. In this line, several tests have been carried out with different varieties, harvesting fruit at different stages of maturity and at different times and studying their behaviour during the harvest and post-harvest. After the harvest, it has been proven that the fruit's colour and texture continue developing, but the sugar content remains stable, so it is recommended to harvest the fruit with at least a 40% colouration in most of the varieties studied in order to reach the market in the best conditions.
Source: elalmeria.es
