| In this paper, different period of applied nitrogen or potassium effect on growth development, dry matter accumulation and distribution, physiological and biochemical metabolic, yield, quality and quality process of rapeseed was investigated systematically. The results are as follows:1. Different period of applied nitrogen or potassium effect on development,dry matter accumulation and distributionPostponed period of applied nitrogen, plant height increased. On 2/3-4/18 applied nitrogen was more evidently than potassium. Rootstock thickness of previous period(11/20-1/4,2/3)applied nitrogen or potassium relatively higher. Early period applied nitrogen had obvious effect on green leaf number of late development stage of rapeseed. To March 29, green leaf number of 11/20,12/5 applied nitrogen was more than 12/20-4/3 to 2-4 leaves/plant. Early period applied potassium had more effect on green leaf number of seedling stage than applied nitrogen.When maturation, 3/4,3/19 applied nitrogen or potassium had the most heavy whole dry weight respectively. Previous period applied potassium could promote root development. When harvest, root dry weight of 11/20-1/4,3/4,3/19 applied nitrogen was heavier than another period to1-2g, of 3/4-4/18 applied potassium was heavier than another period to 1.84-2.22g.At 11/20-1/4 applied nitrogen was beneficial to stabilize leaf dry weight, and prolong the peak time, that was beneficial to improve leaf dry weight proportion. On 11/20,12/5 applied potassium prolonged the peak time, but at 2/3,2/18 delayed it. When harvest, At 12/5-3/19 applied nitrogen had obvious effect on single plant pod dry weight and single pod dry weight. Single pod dry weight of 11/20 and 1/19-4/3 applied potassium was heavier than another period. All period applied potassium was beneficial to improve seed / shell ratio. At the earlier stage of pod development, before1/29 applied nitrogen was beneficial to increased pod dry weight proportion. When maturation, beforel/29 applied nitrogen much decreased root dry weight proportion, pod dry weight proportion of 1/4-2/18 applied nitrogen was the highest (43.8-46%) .Early period applied potassium was beneficial to increased root dry weight proportion and pod of branch development. At stem elongation period applied potassium increased leaf weight proportion. At pod formation stage applied potassium could promote the pod development. On 3/4-4/3 applied potassium increased root dry weight proportion.2. Different period of applied nitrogen or potassium effect on physiological and biochemical metabolismApplied nitrogen or potassium was beneficial to increase the chlorophyll content of leaf and pod. When the content reached the highest (February 28), applied potassium (0. 53-1. 09mg/g) was great difference between the treatments than applied nitrogen (0. 16-0. 31mg/g) . The shell on the reaction of applied nitrogen is earlier than the seed. Applied nitrogen 4/3-4/18 still markedly improved the trend of chlorophyll content of seed and shell. However, on 4/18 applied potassium effect on chlorophyll content of pod was weakened.Applied nitrogen could reduce the soluble sugar content of functional leaf after the bolting. But, applied potassium was markedly improved of soluble sugar content of the leaf through whole growth period .Applied potassium on pre-seedling (11/20-12/20) can be more markedly rising the sugar content when snow, reaching 25.8% -29.0%.At 2/23-2/18 Applied potassium can be delayed peak of sugar content. The shell sugar of applied potassium had been higher than that of control. Applied nitrogen or potassium had the trend of improve total nitrogen content of functional leaf. March 29, the total nitrogen of leaf of1/4, 1/19, 3/4, 3/19 applied nitrogen was the highest.After1/19 applied potassium weakened the effect on total nitrogen content of functional leaf. Applied nitrogen on 2/3-4/3, the total nitrogen content of shell was higher than that of 11/20-1/19.The later applied potassium can be delayed the downward trend in shell total nitrogen. The C/N of applied nitrogen leaves was higher than control before February 28, with the aging of leaves, the control of C / N gradually increased. C/N of applied potassium on 1/4, 1/19 had a reduction trend in functional leaf at low temperature. The shell C/N of applied nitrogen was lower than that of control to 2.3-6.7. The seed C/N of applied potassium was higher than the control, but shell C/N was lower than applied nitrogen. Glucosinolate content had increasing tendency with applied nitrogen, but applied potassium was opposite .However, applied nitrogen and potassium can increase the glucosinolate content during the heavy snow cooling. Shell glucosinolate content of rapeseed with different applied nitrogen or potassium was lower than that of the control finally.March 29,the ABA, IAA content of functional leaf with applied nitrogen or potassium were higher than the control respectively, GA content was lower than that of control. April 9, the ABA, IAA, GA content of oilseed with applied nitrogen were lower than that of the control, while the ABA, IAA content of the shell were higher than that of the control, the ZR, GA content was lower than that of control. The ABA content of oilseed and shell with applied Potassium was lower than that of control. The IAA content in oilseed was lower than that of control, and the IAA content of shell showed up applied potassium at 11/20-2/18 was higher than that of the control. The ZR, GA content of oilseed was lower than that of control. The GA content of shell was higher than that of control.3 .Different period of applied nitrogen and potassium effect on the qualityThe date that applying nitrogen was more later, the seed protein content more higher. Different period of applied potassium also increased the protein content of oilseed, but the protein content applied potassium after March 19 was lower than that before to 1.1-1.5%.Applied nitrogen at 2/3-2/18, the glucosinolate content of oilseed had the increasing tendency, while Appling potassium, the glucosinolate content of oilseed had the decreasing tendency, applied earlier or later, the decreasing tendency was more obviously. With the delayed applied nitrogen, oil content was lower. At 3/4-4/3 applied nitrogen had the lowest seed oil content. Especially in the late applied potassium could increase oil content. The oil of 3/4-4/18 applied potassium was the highest.4 .Different period of applied nitrogen and potassium effect on the yieldThe number of branches 2/3-3/4 applied nitrogen increased more than other period. Applied nitrogen before February 3, the date postponed increased one thousand seed weight. With 2/18 cut-off point for the applied nitrogen, economic indexes increased with the date postponed. On 1 / 4, 2 / 3, 3 / 4, 3 / 19 applied nitrogen that 15-40 percent higher than others was yield increased to 59-67%,With the date postponed applied potassium, the number of main stem, branches pod effective (except11/20) increased significantly. Before 4/3 applied potassium could improve seed weight per pod, the economic factor. On 11/20, 2 / 3, 3 / 4, 3 / 19, 4/3 applied potassium that 24 percent higher than others was yield increased to 31-48%. |
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