Effects Of Different Sowing Dates And Sowing Quantities On Yield, Quality Formation Of Wheat In Different Planting Ways

In the Huang-Huai-Hai plain, the late sowing of winter wheat (Triticum aestivum L.) due to postponed harvest of preceding rice (Oryza sativa) affects the grain production and quality of wheat adversely. Therefore. it is important to investigate the effects of sowing date and sowing quantitiy on grain production and quality in different planting ways, to explore better means of wheat cultivation and regulation in rice-wheat rotation. The winter wheat cultivar Yannong 19 was used in this study to investigate the impact of sowing date and sowing quantitiy on grain production and quality in different planting ways (sowing in drill or broadcast) on the population performance, carbohydrate and nitrogen metabolism, grain yield and quality. Main results were following:1. The effects of sowing date and sowing quantitiy on wheat population performance in different planting ways The pre-winter development of wheat was improved by early sowing date and broadcast sowing. After the regeneration period, the difference in growth and development decreased under different treatments, from 1-9 day (s) at jointing to only 1-2 day (s) at maturity. Early sowing date, hence increased the number of tiller, especially in broadcast sowing with large sowing quantity; however, more tillering occurred from the regeneration to booting period with late sowing date. In addition, the peak of total tillers was decreased and the peaking time was close to booting stage with later sowing date. The SPAD value of wheat flag leaf reached the peak at anthesis with earlier and appropriate sowing (D1 and D2). while the peak was deferred by late sowing until 10 days after anthesis. Moreover, large sowing quantity reduced the SPAD value.20 days after anthesis. the SPAD value was higher in drill than in broadcast sowing. The leaf area index (LAI) was higher at booting and anthesis stage under the treatment with early sowing date and large sowing quantity in broadcast sowing (SD1Q3 and SD2Q3). while decreased rapidly after anthesis. Under the treatment with appropriate sowing date and middle sowing quantity in broadcast sowing. LAI maintained in a high value at maturity. In both planting ways, the dry matter accumulation amount per ha showed a decreased trend by late. At maturity. dry matter accumulation amount was highest with appropriate sowing date and large sowing quantity with sowing in drill. It was the consistent trend both in drill (T) and broadcast (S) sowing with different sowing quantity and sowing date. However, the accumulation of dry matter per ha in broadcast sowing (S) was higher than in drill (T) before anthesis. while higher in drill than in broadcast sowing. In different planting ways, the redistribution amount of dry matter stored at pre-anthesis (TAR) and the accumulation amount of dry matter after anthesis (PAA) were both affected by sowing date and sowing quantitiy significantly (P<0.01). TAR was higher with later sowing in drill and larger sowing quantity.2. The effects of sowing date and sowing quantitiy on carbohydrate and nitrogen metabolism in different planting ways The transport of total soluble sugars in vegetative organs was affected slightly by planting ways, while significantly by sowing date and sowing quantitiy, despite of slight difference in the contribution to grain. Broadcast sowing increased the transport amount of nitrogen stored at pre-anthesis in sheaths, and later sowing date decreased the N transport amount stored at pre-anthesis in all vegetative organs, while the N transport rate stored at pre-anthesis showed different trends in different organs. The large sowing quantitiy increased the N transport amount stored at pre-anthesis in sheaths, whereas reduced that in leaves. No difference in redistribution of N stored and accumulated at pre-anthesis was found between both planting ways. The earlier and appropriate sowing (D1 and D2) enhanced the accumulation of N after anthesis and its contribution to grain N content. In addition, low sowing quantitiy increased the contribution rate of N stored at pre-anthesis to grain N. accumulation amount of N after anthesis. and even its contribution to grain N.3. Effects of sowing date and sowing quantitiy on wheat grain yield and yield components in different planting ways The spike number per ha. grain number per spike and final yield were all affected significantly. The weight of 1000 grains was influenced by planting ways remarkably. while slightly by sowing date and sowing quantitiy. The grain yield was obtained with sowing in drill with appropriate sowing date and middle sowing quantitiy. However, the highest grain yield was found in broadcast sowing with large sowing quantitiy. The peak of filling rate was found at 20 days after anthesis (DAA) in appropriate and later sowing date treatments, and which were still higher than the earliest and latest sowing date treatments;The peak value of grain filling rate was reduced along with the increased sowing quantitiy; Further, the filling rate was higher with sowing in drill than that of broadcast sowing. It was suggested that sowing in drill with appropriate and later sowing date and low sowing quantitiy benefited the grain filling after anthesis to increased the accumulation of dry matter in grain after anthesis.4. Effects of sowing date and sowing quantitiy on wheat flour quality in different planting ways Affected falling number and wet-gluten concentration significantly, while faintly affected gluten index and ash concentration. The falling number was increased by later sowing date and larger sowing quantitiy, and broadcast sowing was higher than sowing in drill in falling number. The wet-gluten concentration was firstly increased and then reduced following the sowing date, with the highest in moderate late sowing date treatment. Furthermore, it was also increased by large sowing quantitiy and sowing in drill. In starch paste traits of wheat, the peak, trough and final viscosity were all increased by late sowing date and large sowing quantitiy, besides, the peak viscosity of broadcast sowing was higher than sowing in drill. They all had no effect on pasting temperature. In farinographic parameters of wheat, they all affected dough development time (except planting ways), dough stability time and softening degree significantly. The dough development time was increased by late sowing date and low sowing quantitiy, with the best in moderate late sowing with lower sowing quantitiy; the highest dough stability time and softening degree was found in later broadcast sowing with low sowing quantitiy and with large sowing quantitiy. respectively.5. The high and stable yield potential of wheat after rice The best cultivation methods for highest yield appeared in the treatment of appropriate sowing date and middle sowing quantitiy under different planting ways. The highest yield of drilling wheat was 7593 kg ha-1. the highest yield of broadcasting wheat was 8460 kg ha-1. which was significantly higher (11.4%) than that of drilling wheat. The results showed that under appropriate soil and sowing condition, drilling wheat had higher yield potential than broadcasting wheat. But the rice harvest was always late in the wheat after rice region in the Huang-Huai-Hai plain, the physicochemical property of the rice soil caused serious influence to the growth of seeding stage of wheat. In addition, it was hard for the drilling wheat sowing on the appropriate date. When the sowing date delayed, the yield of drilling wheat declined sharply compared with the appropriate sowing date, while the yield of drilling wheat declined slow, adding the sowing quantity can increase the yield of wheat. Under the treatment of moderate late and late sowing, the highest yield appeared in the multi-sowing quantity of broadcasting wheat, the yield was 7122 kg ha-1 and 6667 kg ha-1 respectively, which was 13.1%and 11.5%higher than the same treatment of drilling wheat. The stable yield of late sowing wheat needed a multi-sowing quantity. In the wheat after rice, adding the sowing quantity and taking the broadcasting methods, can make sure a appropriate sowing date and stable yield.6. The optimal regulation in sowing techniques of wheat after rice The practice condition should be taked into consideration in the application of the sowing techniques. In the wheat after rice, if the date of the rice harvest was early and the field drying was carried out in time, then the wheat can be sowed on the appropriate date, in this condition, appropriate sowing date and sowing quantity under drilling methods were the best choice. If the sowing date of wheat after rice was delayed seriously, the field can't be dried in time, in this condition, the physicochemical property of the soil was too bad to choose drilling methods, choosing the broadcasting methods and adding the sowing quantity can ensure the growth of seeding stage and the stable yield.