Abstract：Abstract：The harvesting time of baby greens of pakchoi（Brassica campestris L. ssp. Chinese）is mainly
determined by traditional economic yield and its quality was neglected．Taking pakchoi variety ‘Huawang’
as test material，this experiment designed 4 plug cell sizes，including 72-cell，128-cell，200-cell，and 288-
cell，and conducted sampling 5，8，11，14，17 days after sowing（DAS）．Then，the variation rule of
physiological morphology and nutritional quality of the baby greens cultured in plug cells with different sizes
were studied．Principal component analysis was used to screen out the important indicators for comprehensive
quality of the baby greens．“Harvest index”was put forward to evaluate the comprehensive quality of baby
greens，hoping on the premise of guaranteeing the yield to determine the best harvesting time by nutritional
quality．The result indicated that the morphological variation trend of baby greens under different plug tray
were better matched with quadratic polynomial function．The VC content presented increasing trend along
with the time extending after sowing．The soluble protein content reached the maximum value on 14 DAS．In
earlier stage the nitrate content was high，then increased slightly after a significant reduction．The contents of
total chlorophyll and carotenoid under 72-cell，128-cell and 200-cell plug tray increased to the maximum value
on 14 DAS．While，those under 288-cell plug tray had no big changes on 5-17 DAS．Principal component
analysis extracted 4 principal components，and the cumulative variances contribution rate reached 72.244%．
The value of harvest index of baby greens under all sizes of plug trays reached maximum value on 14 DAS．The
value order from big to small was 288-cell ＞ 200-cell ＞ 128-cell ＞ 72-cell．The harvest indexes of 288-cell，
200-cell and 72-cell all decreased substantially until 17 DAS．While，the harvest index of 128-cell decrease
with smaller margin．Therefore，during the 5 harvesting stages investigated in this study，the best harvesting
period for the production of baby greens in glass greenhouse in spring in Shanghai region was 14 DAS，among
them the harvesting time of 288-cell and 200-cell plug trays was not suitable to delay．While，the 128-cell plug
tray could be properly delayed to 17 DAS．
陈子义 莫克勋 赵 硕 章竞瑾 黄丹枫. 基于营养动态积累的普通白菜最佳采收期综合评价[J]. 中国蔬菜, 2020, 1(12): 61-70.
CHEN Ziyi，MO Kexun，ZHAO Shuo，ZHANG Jingjin*，HUANG Danfeng*. Studies on Comprehensive Evaluation of Optimal Harvest Time of Brassica campestris L. ssp. Chinese Baby Greens Based on Nutrient Accumulation Dynamic. China Vegetables, 2020, 1(12): 61-70.
