Effect Of Training Type And Spraying KH₂PO₄ On Seeds Yield And Quality In Carrots (Daucus Carota L.)

This article studied the effects of spraying KH2PO4 and training type on seeds yield and quality in carrot to solve the problems on rough management, poor quality and low yield in the process of collecting seeds. A series of indexes on photosynthetic characters, growth and development, seed yield, germination vigor and enzyme activity were estimated and analyzed. The results could be concluded as follows: 1 Foliar application of 2g/L KH2PO4 could raise photosynthetic rate, prolong the growth phase, improve the resistance and promote the steckling growth in the latter phase of carrot steckling development. It could influence significantly not only photosynthetic rate and transpirational rate, but also stem diameter, umbel diameter, internode length and biomass. When foliar application of KH2PO4 was 2g/L, the net photosynthetic rate and transpirational rate were both higher than that of 5g/L and control group. The stem diameter and plant height are highest, as compared to other treatments, the disparity was not significant. The diameter of primary and secondary umbel and internode length were higher markedly than that of the other treatments. The biomass was higher than that of control group significantly. 2 Foliar application of 2g/L KH2PO4 could increase the seed yields and improve the seed quality, which influenced seed yields, 1000 seed weight, seed size and germination energy most markedly. When the concentration was 2g/L, 1000 seed weight and seed size were highest and up to 2.73g and 7.1 mm2 respectively. At the same time, the application of 5g/L increased the seed size and 1000 seed weight most markedly. The highest germination vigor, the fastest germination speed, the highest germination percent and vigor index were obtained, which were higher than that of other treatments most markedly. 3 The foliar application of KH2PO4 also influenced markedly enzyme activity and penetration of cell membrane. When the concentration was 2g/L, the highest markedly SOD, POD and CAT activity and negative EC value were obtained. So the foliar application of 2g/L KH2PO4 could make the carrot seeds obtain higher activity, whole membrane and strong resistance. 4 The growth, development and photosynthetic character of steckling, the seed yields and quality were different due to different training types. When using the training type of '1+3', the stem diameter and umbel diameter were higher than that of '1+6'type markedly. It...