Studies On The Regulation Of Sulfur Nutrition On Yield And Quality Of Two Spike Type Winter Wheat Cultivars

The effects of different sulfur application on the grain yield and quality of multi-spike wheat cultivar Yumai 49 and Yumai 70,heavy-spike wheat cultivar Yumai 66 had been studied in the experiment farm of Henan Agricultural University and in the sand loam field of Xinzheng in Henan during the period 2000-2002, respectively. The main results were as follows:1.The dynamic change of dry matter accumulation (DMA), leaf area index (LAI) and colony number showed as a single-peaked curve on different sulfur treatments. The appropriate sulfur-application could improve DMA, LAI and colony number. All of the whole treatments, the effect of B4 treatment (ie base-application S 60 kg.hm"2 plus dressing-application S 60 kg.hm"2) was the most obvious. The results on the larger sulfur-application of Yumai 66 were better than that of Yumai 49, and effect of little amount sulfur-application treatment was better than any other. The BI (ie base application S 60 kg.hm"2) and 84 treatment of Yumai 49 and the 82 treatment (ie base application SI 20 kg.hm"2) of Yumai 66 could improve wheat leaf chlorophyll content. The flag leafs NR activity of two spike type cultivars could be improved on appropriate sulfur-application conditions, and BI treatment was superior to any other and its NR activity was always higher than BO ( no S ). The improvement of dissoluble protein content of flag leaf, respectively, the 82, 64 and BI, 83 (base application S 180 kg.hm"2) treatment of Yumai 49 and Yumai 66, had better results. In this experiment, the physiology index of BI and B4 treatment in two cultivars was better.2.The results of two spike type cultivars in canopy apparent photosynthesis (CAP) and flag leafs net photosynthesis (Pn) showed little difference in two cultivars CAP during early growing period, and Yumai 66 could maintain the higher CAP during later growing period. In the whole growing period, the Pn of Yumai 66 on all sulfurtreatments was higher than that of Yumai 49.There were higher CAP and Pn in Yumai 66 during later growing period, and these established foundation to increase kernels per ear and fertile spikelet rate. The CAP and Pn of different sulfur-application on two spike type cultivars were all higher than B0.To Yumai 49,the B2 treatment had higher CAP during later growing period, the B3 treatment maintained higher CAP during the key growing stage (Jointing and Booting stage), the B4 treatment maintained the higher CAP during the whole growing period. To Yumai 66,the B3 and B4 treatment had higher CAP. The B! and B4 treatment of Yumai 49 had higher Pn than that of treatment, particularly BI treatment showed more obviously. And the B4 treatment of Yumai 66 had aslo higher Pn, and in the later growing stage the 83 treatment showed higher Pn. The B4 treatment of two spike type cultivars had apparent advantages in CAP and Pn on different sulfur application.3. There were differences among the grain filling course and the grain yield characteristics on different sulfur-application, which indicated that Yumai 49 had faster grain filling course, higher grain yield, more ears, higher kernel's weight and higher economic index than Yumai 66, but Yumai 66 had more kernels and higher fertile spikelet rate than Yumai 49.Compared to the BO, the grain yield of the B2 or B4 treatment for Yumai 49 reached significantly different level. The difference of grain yield between B4 and BO treatment of Yumai 66 was extremely significant level, and there were also significant differences between BI, 83, B4 and BO respectively. Generally, the grain yield of multi-spike wheat cultivar Yumai 49 increased gradually along with the increment of sulfur-application, the grain yield of heavy-spike wheat cultivar Yumai 66 increased with larger scopes than Yumai 49(comparing with no 8,82 increased 20.90% ), but the more sulfur application came to increase slowly grain yield. Moreover, the results on supplemental experiment in the sand loam for Yumai 70 showed that the grain yield of C2 treatment was the highest in all treatments, ie dressing applyin...