Seasonal variations in peel colour in relation to fruit development of grapefruit (Citrus paradisi Macf.) Singh Sukhchain*, Aulakh Pushpinder Singh, Gill Parmpal Singh Department of Fruit Science, Punjab Agricultural University, Ludhiana – 141004, Punjab, India *Corresponding author: boparai.sukhchain@yahoo.com
Online published on 18 May, 2015. Abstract The studies on seasonal variations in peel colour of grapefruit cv. Star Ruby were carried out in order to explain the relationship between fruit growth and colour development. The fruit diameter of the grapefruit increased from 90 days after fruit set to the maturity of fruit. The seasonal variation in fruit diameter was recorded 12.83% during fruit development. The increase in a* coordinate, which represented the gradual loss of greenness, continued until mid-November at 210 DAFS. Calorimetric coordinate b* values always remained positive and increased until the fruit maturity and showed yellow tinge. The hue angle values decreased continuously from start of sampling to the harvest of fruit with appearance of pinkish-yellow tone. Seasonal variation in the hue angle was recorded 26.80%. The negative correlation was observed between hue angle and the fruit development with the advancement of fruit maturity. However, studies have reported positive correlation was recorded between colour space values (L*, a*, b* and C*) with fruit development. The maximum seasonal variation was noted in colour parameter a* (CV = 189.99%) and minimum seasonal variation was noted in L* (CV = 9.42%). Highlights Top Keywords Grapefruit, colour, fruit development, correlation, seasonal variations. Top |