Effect of Planting and Harvesting Dates on Strawberry Fruit Quality under High Tunnels (original) (raw)

Abstract

There is an increasing demand in the market to improve strawberry quality by promoting human-health compounds content, as these may play a significant role in the prevention of chronic diseases. Strawberry cultivars, environmental conditions, and agronomical conditions have an effect on fruit characteristics; therefore, it is necessary to constantly generate information about the cultivar response to different production areas and cultural practices. The goal of this work was to evaluate the effect of two planting dates, two harvest dates, and four strawberry cultivars on total phenolic acid (gallic acid equivalent), ascorbic acid (vitamin C), and soluble solid content•titratable acidity-1 (SSC•TA-1) ratio in Huelva, Spain. Sixteen treatments resulted from the combination of four cultivars, two planting dates, and two harvest dates. Strawberry 'Camarosa', 'Sabrosa', 'Aguedilla', and 'Fuentepina' were selected for both seasons and planted on 7 Oct. (early planting) and 21 Oct. (late planting). Mid-February and mid-April were considered early and late harvest, respectively. Nutraceutical and organoleptic responses were specifics for each cultivar. The highest SSC•TA-1 ratio was observed in 'Fuentepina' planted late and harvested early. 'Aguedilla' resulted in the highest phenolic content when harvested in the late season. Additionally, phenolic content was significantly higher when using late planting combined with late harvest in most of the cultivars. Late harvested 'Camarosa' showed the highest TA concentration, whereas 'Sabrosa' resulted in the highest SSC regardless of harvesting date. Additionally, 'Aguedilla' and 'Sabrosa' showed the highest ascorbic content. Strawberry quality could be improved by selecting the adequate planting and harvesting dates according to specific cultivars.

Figures (4)

7Mean temperature. YMaximum temperature “Minimum temperature. Table 1. Environmental conditions inside the high tunnel during 2008-09 and 2009-10 seasons in Moguer, Huelva, Spain.

7Mean temperature. YMaximum temperature “Minimum temperature. Table 1. Environmental conditions inside the high tunnel during 2008-09 and 2009-10 seasons in Moguer, Huelva, Spain.

“Values followed by the same letter do not differ according to Fisher’s-protected least significant difference at the 5% level. Table 2. Effects of cultivar, planting date, and harvest date in phenols anc soluble solids content-titratable acidity ratio in strawberry production durin 2008-09 and 2009-10 growing seasons in Moguer, Huelva, Spain.

“Values followed by the same letter do not differ according to Fisher’s-protected least significant difference at the 5% level. Table 2. Effects of cultivar, planting date, and harvest date in phenols anc soluble solids content-titratable acidity ratio in strawberry production durin 2008-09 and 2009-10 growing seasons in Moguer, Huelva, Spain.

“Values followed by the same letter do not differ according to Fisher’s-protected le significant difference at the 5% level. YEarly and late harvests correspond to mid-February and mid-April, respectively. “Expressed as g of citric acid per 100 g of fresh weight. “Expressed as mg of ascorbic acid per 100 g of fresh weight. *P < 0.05.

“Values followed by the same letter do not differ according to Fisher’s-protected le significant difference at the 5% level. YEarly and late harvests correspond to mid-February and mid-April, respectively. “Expressed as g of citric acid per 100 g of fresh weight. “Expressed as mg of ascorbic acid per 100 g of fresh weight. *P < 0.05.

Table 4. Effects of cultivar and harvest date in vitamin C content in strawberry production during 2008-09 and 2009-10 growing seasons in Moguer, Huelva, Spain. certain types of cancer (Shiow and Zheng, 2001). Flavonoids are consider the nost important group of phenolics in plants, and its concentration has been ‘elated to antioxidant activity against free oxygen radicals. Therefore, there is 1 positive correlation between antioxidant activity and total phenolic content. digh temperature has been related to enhance free oxygen radicals absor- yance, which increases phenolic content of strawberry fruits (Shiow and 7heng, 2001). Thus, warm temperatures inside the high tunnel during the season is a possible explanation to the general increase in phenolic content rom early harvest to late harvest across cultivars in our study. A contrary rend was shown for ascorbic acid content, where the lowest values were collected during late harvest. However, this was not constant for all cultivars. Del Pozo-Insfram et al. (2006) stated that variations in solar radiation and air emperature are factors known to impact photochemical biosynthesis, and his response can vary across cultivars. Higher growth temperatures caused levelopment of fruit color more rapid than that at lower growth tempera- ures. Hence, fruits reach maturity faster than under lower temperatures, siving less time for synthesis and accumulation of compounds. Similar is the case for SSC and TA concentration. All cultivars resulted in the wishact aalive fr8C_ TATE rato recardleee atthernlaniting: date when harvected

Table 4. Effects of cultivar and harvest date in vitamin C content in strawberry production during 2008-09 and 2009-10 growing seasons in Moguer, Huelva, Spain. certain types of cancer (Shiow and Zheng, 2001). Flavonoids are consider the nost important group of phenolics in plants, and its concentration has been ‘elated to antioxidant activity against free oxygen radicals. Therefore, there is 1 positive correlation between antioxidant activity and total phenolic content. digh temperature has been related to enhance free oxygen radicals absor- yance, which increases phenolic content of strawberry fruits (Shiow and 7heng, 2001). Thus, warm temperatures inside the high tunnel during the season is a possible explanation to the general increase in phenolic content rom early harvest to late harvest across cultivars in our study. A contrary rend was shown for ascorbic acid content, where the lowest values were collected during late harvest. However, this was not constant for all cultivars. Del Pozo-Insfram et al. (2006) stated that variations in solar radiation and air emperature are factors known to impact photochemical biosynthesis, and his response can vary across cultivars. Higher growth temperatures caused levelopment of fruit color more rapid than that at lower growth tempera- ures. Hence, fruits reach maturity faster than under lower temperatures, siving less time for synthesis and accumulation of compounds. Similar is the case for SSC and TA concentration. All cultivars resulted in the wishact aalive fr8C_ TATE rato recardleee atthernlaniting: date when harvected

Loading...

Loading Preview

Sorry, preview is currently unavailable. You can download the paper by clicking the button above.