PRODUCTION and QUALITY of STRAWBERRY FRUITS IN VITROPLANTS CULTIVAR xCHANDLERx TREATED with GIBBERELLIC ACID

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            In Venezuela the production areas are limited by the temperature requirements for this reason, they are located at 1000 MSL where the temperature ranges are considered adequate for the growth and fruit production of strawberry. In order to compensate the temperature requirement and increase the production areas, in this country, the aim of this research was to evaluate the effect of exogenous gibberellic acid on production and quality fruit in ‘Chandler’ strawberry (Fragaria x ananassa Duch.). The vitroplants were acclimatized for two months and then potted in plastic containers with substrate of vermicompost + sand + shell of rice in proportion 1:2:2 v/v. The plants were grown in shed condition with range of temperature between 24 to 33 ^oC and 50 to 80 % of relative humidity at 510 MSL. The treatments were four concentrations of gibberellic acid (0, 10, 20, and 40 mg . L^-1), which where applied as sprays to the foliage of the plants in unique application at the initial vegetative growth. The fruits were harvested between January to May 2008 and the production was recorded, as well as, the physical and chemical proprieties of fruit quality were determined. The higher pick of production was in February for all the treatments; however the biggest fruits were harvested from April to May with the largest values of fresh weight (6.1 g/fruit) for the doses of 10 mg. L^-1 with 22.9 and 20.00 mm of diameter polar and equatorial, respectively. In relation to chemical quality, the total soluble solids (TSS) contents were between 3. 21 to 3.44 ^oBrix and it were not affected by treatments. However, there was significant difference for pH (3,55 – 3.83), titratable acidity (TA) expressed by citric acid (0.71- 0,94 %) and the relation TSS/TA (3.10 – 4. 22), but for these variables there was not defined tendency for the specific gibberellic acid doses. The results showed the different pick of production and variation for the physical and chemical characteristics of the quality fruit during the period of evaluation and this could be due to the climatic conditions more than effect of gibberellic acid treatments.

Keywords: Fragaria x ananassa Duch., Growth regulator, quality