Fruit Harvest Time Research Articles

Studies on Lactuca dracoglossa, MAKINO : II. On yielding seeds

1. It was observed at the harvest time of fruits in Lactuca dracoglossa, Makino that the increase in number of stools planted per unit area caused the decrease of the numbers of clusters of cypsela of a stool. Removing of green leaves from the stem made the change more conspicuous, the number of cypsela per stool being 683, 577, 562, and 405 respectively in each control plot against 651, 641, 538 and 391 in each leaf-harvested plots. 2. The length of time for yielding seeds was usually found ranging from 21 to 25 days in control plots but from 35 to 38 days in the leaf-harvested ones. 3. The increase of stools per unit area evidently induced the decrease of cypsela in number per cluster in control plots and the decrease was remarkable in the stool in the leaf-harvested ones. 4. The weight of 100 fruits from dried cypsela ranged from 0.12. gr. to 0.15 gr. in control plots but from 0.09 gr. to 0.14 gr. in the leaf-harvested ones. 5. The cypsela yield was much larger in the plot which consisted of 64 stools per 9.68 square meters (in Japanese 1/100 TAN), than in the plot with 72 stools. namely, it ranged from 3.317 l. to 3.720 l. (in Japanese from 18.39 to 20.63 GO) in control plots and from 2.768 l. to 3.336 l. (in Japanese from 15.35 to 18.50 GO) in the leaf harvested ones. 6. Planting increased number of stools for unit area made the yield of cypsela decrease especially in the leaf-harvested stools. The percentage of decrease of cypsela yield was 10% in the plot which consisted of 64 stools but 20% in the plot composed of 74 stools.