The Effect Of Wheat Sowing Time On Growth Development And Yield In Sichuan Basin

Nowadays, the main wheat planting mode in Sichuan basin is planting alternatively between rice and wheat once a year, and the harvest time of rice is from the end of August to the beginning of September, meanwhile, the sowing time of wheat is from the end of October to the beginning of November. Therefore, the farmland will be in a free time for nearly two months, which cannot make full use of luminous energy, thermal energy, and rainfall. Based on above, it have been more than ten years to breed some new early-sowing and early-maturing type wheat lines for Ecological Agriculture Research Institute of Sichuan Agriculture University, which could be sowed in the middle of October. Using early-sowing and early-maturing type wheat lines as study materials, the purpose of sowing time experiment during two growth seasons from 2013 to 2015 is (1) to further confirm the suitable sowing date for early-sowing and early-maturing type wheat lines, (2) to study on the relationship between sowing time and growth development progress as well as grain yield, (3) to further confirm the yield potential, (4) to provide theoretical basis of breeding and promotion for the new varieties with higher yield potential. Materials and methods are as follows.In this study, using new early-sowing and early-maturing type wheat lines R801, R802, and R8O3, and high-yield varieties in Sichuan basin Chuanmai 64 and Chuannong 27 as materials sow in different dates in Qianjin town of Qionglai city from 2013 to 2015. These two years divide into five sowing dates, respectively. 2013-2014, sowing dates are ? (October 12th), ? (October 19th), ?(October 26th), ?(November 2nd) and ? (November 9th); 2014-2015, sowing dates are ? (October 10th), ? (October 17th), ?(October 24th), ?(October 31st) and ? (November 7th). Investigation of growth process of each variety in different sowing time, and periodic investigation of leaf area, leaf age and totalleaves on the main stem, dynamic state of dry matter accumulation and seedling growth, measurements of spike numbers per m2, kernel numbers, thousand kernel weight and yield, etc. of each variety in different sowing time, these all above results are as follows.1. The number of total leaves on the main stem is not influenced by sowing date; the earlier sowing wheat, the greater leaf age measured at the same time under the range of suitable sowing time.2. Dry matter accumulation and wheat sowing time have positive correlation, and the earlier sowing date, the greater the amount of dry matter accumulation.3. Sowing date effected on wheat tillering are positively correlated, and the earlier sowing date, the stronger wheat tillering ability, so that the greater number of field maximum tillers leads to significantly increase the number of field effective spike number seventually, but untimely sowing has no obvious difference in the variation of tiller numbers.4. Sowing time in advance can promote wheat development process in advance and extend the whole growth period and each growth stage of wheat at the same time. Ultimately, it has a positive impact on the wheat yield and its group structure.5. The earlier sowing date, the earlier reaching to the peak of leaf area coefficient, and leaf area coefficient peak of each varietyis increasing along with the sowing time in advance, leaf area duration coincidently shorten with the delay of sowing time. It fully proves that sowing date and leaf area duration are in a positive correlation.6. Leaf area duration has a positive effect on the yield of early-sowing and early-maturing type wheat. When sowing date in advance, leaf area duration increases that wheat could make full use of luminous energy and resources in order to accumulate nutrients and eventually increase wheat production.7. Yields of R801, R802 and R803 are significantly increased with the sowing time ahead of schedule. In the year of 2013-2014, yields of ?, ?, ? and ? these four sowing dates for R802 are all higher than the yield of common practice sowing date ?, which are 25.01%,13.95%,9.79% and 6.18%, respectively; yields of R803 in the first four stages are higher than that of ?, which are 29.49%,22.31%,15.77% and 8.24%, respectively.In the year of 2014-2015, yields of ?, ?, ? and ? these four sowing dates for R801 are all higher than the yield of common practice sowing date ?, which are 16.45%,1.32%,6.32% and 2.93%, respectively; yields of R802 in the first four stages are higher than that of ?, which are 20.02%,12.02%,8.30% and 4.91%, respectively; yields of R803 in the first four stages are higher than that of V, which are 16.09%,10.78%,4.44% and 1.35%, respectively.In conclusion:the best sowing time of early-sowing and early-maturing type wheat used in this experiment is about October 10th to 15th, and the suitable sowing time of traditional wheat is from the end of October to the beginning of November. Meanwhile, the yield of early-sowing and early-maturing type wheat has already reached or exceeded that of traditional wheat. Based on the growing development and yield formation characteristic of wheat in Sichuan basin, we found the whole growth period is strongly influenced by sowing time, which means that sowing time had a large effect on the yield of wheat. In order to further improve the wheat yield, we could select early-sowing type wheat from high yield wheat. Therefore, it is completely feasible to break the present yield potential of wheat in Sichuan basin through selecting the early-sowing and early-maturing type wheat.