Title

Environmental Conditions on Red Drupelet Incidence

School Name

South Carolina Governor's School for Science & Mathematics

Grade Level

12th Grade

Presentation Topic

Botany

Presentation Type

Mentored

Oral Presentation Award

3rd Place

Abstract

Blackberry growers and packers have long realized the difficulty of preserving the black pigment of fruit when preparing for consumers. Red drupelet reversion is when fully mature black drupelets return to a red, burgundy color after harvest. Reversion occurs between the time of fruit harvest and consumer purchase, causing it to one of the most difficult postharvest problems to control. The relative humidity (RH) and temperature at time of harvest in addition to direction of rows in relation to the sun could all be variables that affect this reversion of color. In this experiment, two cultivars ‘Arapaho’ and ‘Natchez’ were picked at two different times (7:30 AM and 10:00 AM) from two different sides (east or west), and then immediately delivered into cold storage. The fruit was taken out of storage at one-week and two-week periods, where the number of red drupelets was then counted and recorded for each berry. Sensors that recorded relative humidity and temperature every 30 minutes were set up around the berry perimeter. We found that red drupelet reversion was lower in ‘Navaho’ compared to the ‘Arapaho’ cultivar. We also found that in warmer weather, fewer red drupelets are present on the berries and reversion was most common when RH was between 80% and 60%. Warmer weather and increased hours of sunlight also appear​ to decrease the incidence of reversion on west-facing rows. With additional studies and confirmation of our results, pickers may be able to use this information to harvest higher yield of desirable fruit.

Location

Founders Hall 111 B

Start Date

3-30-2019 11:00 AM

Presentation Format

Oral Only

Group Project

No

COinS
 
Mar 30th, 11:00 AM

Environmental Conditions on Red Drupelet Incidence

Founders Hall 111 B

Blackberry growers and packers have long realized the difficulty of preserving the black pigment of fruit when preparing for consumers. Red drupelet reversion is when fully mature black drupelets return to a red, burgundy color after harvest. Reversion occurs between the time of fruit harvest and consumer purchase, causing it to one of the most difficult postharvest problems to control. The relative humidity (RH) and temperature at time of harvest in addition to direction of rows in relation to the sun could all be variables that affect this reversion of color. In this experiment, two cultivars ‘Arapaho’ and ‘Natchez’ were picked at two different times (7:30 AM and 10:00 AM) from two different sides (east or west), and then immediately delivered into cold storage. The fruit was taken out of storage at one-week and two-week periods, where the number of red drupelets was then counted and recorded for each berry. Sensors that recorded relative humidity and temperature every 30 minutes were set up around the berry perimeter. We found that red drupelet reversion was lower in ‘Navaho’ compared to the ‘Arapaho’ cultivar. We also found that in warmer weather, fewer red drupelets are present on the berries and reversion was most common when RH was between 80% and 60%. Warmer weather and increased hours of sunlight also appear​ to decrease the incidence of reversion on west-facing rows. With additional studies and confirmation of our results, pickers may be able to use this information to harvest higher yield of desirable fruit.