Population And Individual Characteristics Of Growth And Development And Yield Components Of Super-high-yielding Winter Wheat In Hebei Province

In recent years, the records of high-yield of winter wheat were reported in Shandong and Henan province. Also, the rule of growth and development and the cultivation practice of super high yielding winter wheat were studied. These records, however, usually were created in superior fertility and water conditions. The study on the cultivation practices of super high yielding under the conditions of water limitation has not been reported. In order to determine the rule of growth and development and the cultivation practice of super high yielding winter wheat under the conditions of water limitation of Hebei Plain, a field experiment was conducted during 2004-2006 wheat growing seasons in Gaocheng County, Hebei Province. Two types of winter wheat varieties, SM12 and SX828 as multi-spike type, and TM1 as a big-spike type of wheat variety, were used as materials, to study the population and individual characteristics of growth and development, and yield components of super high-yielding (9000 kg/hm~2 or more) winter wheat under limited water condition of Hebei plain. The results were summarized as follows:1. The analysis on yield components of super-high-yielding winter wheat showed that, both the multi-spike type and big-spike type wheat varieties could achieve 9000 kg/hm~2 in mid-south parts of Hebei Province, but it was much easier to reach super high yield by using the multi-spike type wheat variety, with about 8000 thousand spikes per hectare, 30 to 34 grains per spike, and the 1000-grain weight 40 g or more. The appropriate yield components of big-spike type for super high yield were about 4700 thousand spikes per ha, 48 grains per spike and the 1000-grain weight 44-45g.2. The dynamics of population architecture of different types varieties for supper high yield was different. For multi-spike wheat variety, on the basis of seedlings 2.3-3.5×10~6/ha, the ideal dynamics of population culms was, 1.2～1.7×10~7/ha before winter, 1.3～2.0~ 107/ha for maximum, and the spikes 7.2～8.4×10 6/ha at maturity. The basic seedling of big-spike wheat variety was higher than that of multi-spike type, but the tiller-bearing rate of the big-spike type was lower. The average basic seedling of the big-spike type was about 3.7×10~6/ha, the maximum culms was 1.7～2.0×10~7/ha, and the spike number at maturity was 4.6～4.8×10~6/ha. The rapid rising temperature in spring was one of the climate characteristics of mid-south parts of Hebei Province, which made the spike differentiation time of wheat shorten, was unfavorble to big-spike wheat variety to take its advantages of more grains per spike. Therefore, wheat varieties with higher spike capacity per heactare and middle spike weight were easier to achieve super high yield in Hebei Province.3. The highest LAI, occurred at booting, was 7～9 for super high-yielding wheat. It was only reported in Henan that the LAI reached 10 in the super high-yielding wheat, which was more than 7 for wheat with a yield of 9000 kg/ha. The LAI of some plots in this study was higher than 8, and approached 9. That indicated that the higher LAI had a general significance to winter wheat with a yield of 9000 kg/ha, In addition, the LAI maintained high values during the whole growing period of wheat, and decreased slowly during late period. The LAI was higer than 4 after 20 days of post-anthesis, and there was still green leaf area on 30 days after anthesis.4. Besides LAI, the dry matter accumulation of super high-yielding wheat also had a great breakthrough. Most of the varieties and plots in the experiment had a dry matter accumulation above 18000 kg/ha, with an average 20000 kg/ha. The harvest index was stable and exceeded 0.42. Moreover, the super high-yielding wheat also had a high grain-leaf ratio and a coordinative source-sink relationship. The spike-leaf ratio, grain-leaf ratio and grain-leaf weight ratio in the test were 98～112 spikes/m~2, 0.332 grains/cm~2 and 11.986 mg/cm~2, respectively.5. The super high-yielding wheat had such plant characteristics as follows: middle plant height (generally 73～79 cm), strong lodging resistance, good internode configuration, i.e. shorter basal internode length (the total length of the two basal internodes were less than 8 cm; longer top first internode (internode beneath the spike was longer than 20 cm), spikes with middle length and higher percentage of productive tillers (percentage of fruitful was 2.5 spikes per plant).