Quality Analysis Of Apples Of Individualplant And Research On Harvest Dates

This paper takes'Gala'apples and'Fuji'apples as experiment samples. We studied the different distribution of'Fuji'apple qualities on the same tree and correlation degree of quality indexes. This paper gives a tentative study on the feasibility of forecasting the inner qualities of apples through single-fruit weight and colorimetric values. We concretely measured and quantized the apple color using color difference meter to study the rule of color variation during harvest dates and after harvest. We also studied the effects of different harvest dates on qualities of post-harvest'Gala'apples to find the suitable harvest period of'Gala'apples.The main results were as follows:(1)The coefficient of variation from small to large order of the'Fuji'apples quality indicators are the rind brightness(6.18),firmness(11.23),soluble solid(15.18),rind yellowness(16.19),titratable acid(16.53),single-fruit weight(27.87)and the rind redness(47.77).(2)The single-fruit weight is significantly negative correlated with the firmness. The rind redness is significantly positive correlated with the soluble solid content and the single-fruit weight, but negative correlated with the rind brightness and rind yellowness. There were significantly negative correlation between the soluble solid and the titratable acid. The absolute-magnitude of correlation coefficient between rind redness and the rind brightness is the biggest (-0.82063). The rind brightness is an important index to understand the quality of'Fuji'apples.The quality difference of'Fuji'apples is basic to classifying storage of apples.(4)The single-fruit weight and the colorimetric values of'Fuji'apples are high correlated with the fruit firmness. We can predict the fruit firmness through single-fruit weight and the chroma value. The error will be about 6.64%. There are obvious errors to predict soluble solid and the titratable acid with single-fruit weight and the colorimetric values of'Fuji'apples, and the predictable errors are 9.64% and 14.43% respectively.(5)'Gala'apples of picking before 117 days after full bloom (DAFB)are superior in pulp brightness but inferior in chroma,'Gala'apples of 124 DAFB are good in rind chroma,'Gala'apples of 124 DAFB change slightly in the soluble solids and titratable acid, lose few water, and have better quality. The optimum harvest date of'Gala'apples should be from 117 DAFB to 124 DAFB. There are obvious differences in chroma during different harvest dates. The different chroma of different harvest dates can be used to measure the optimum harvest date and the fruit quality.