Effects Of Sowing Time, Seeding Rate And Nitrogen Application On Yield And Protein Content Of Wheat Variety Xinong 2000

The new wheat variety Xinong 2000 was developed recently by College of Agronomy, Northwest A & F University, with high yield, good quality, early maturity and multiple resistances. Split plot experimental design and randomized block experimental design were used to analyze the effects of sowing time, seeding rate and nitrogen application on grain yield and protein content of Xinong 2000. Wheat seeds were sowed on October 3rd, 10th and 17th in four seeding rates of 1.20, 1.80, 2.40 and 3.00 million grains per hectare, respectively, and in two nitrogen rates, 180kg/hm~2 and 250kg/hm~2, which applicated in four different methods, specificly, all nitrogen applied as basal fertilizer (T1), 60% nitrogen as basal fertilizer and 40% nitrogen as topdressing at jointing stage (T2), 60% nitrogen as basal fertilizer and doouble topdressing 25% nitrogen at jointing stage and 15% nitrogen at bootinging stage (T3), and 60% nitrogen as basal fertilizer and 40% nitrogen as topdressing at booting stage (T4). Fertilizers of phosphorus and potassium were fixed, 150 kg/hm~2 and 120 kg/hm~2 respectively, and applied along with plowing. The main results were shown as below:1. The effect of seeding rate on the grain yield of Xinong 2000 was more significant than that of sowing date within the tested scope. When Xinong 2000 was sowed from the October 3rd to October 17th, the grain yield was stable, which indicated that Xinong 2000 has a good adaptability to sowing date. The appropriate seeding rate was 2.4 to 3 million grains per hectare.2. High nitrogen rate could improve grain yield of Xinong 2000 more significantly than medium nitrogen rate, with increase rate of 1.7%. Yield gain was primarily related to the increase of spikes per hectare.In both nitrogen rates, compared with the T1 treatment (all nitrogen as basal fertilizer), nitrogen topdressing treatments improved grain yield significantly. Of which, the highest grain yield gained in T3 treatment (ratio of basal fertilizer and topdressing at jointing and booting stages was 6:2.5:1.5), with 9% yield increase, followed by the treatment of topdressing at jointing stage. The grain yield gain caused by the coordinated increment of spikes, grains per spike and 1000-grain weight. 3. High nitrogen rate could improve grain protein content of Xinong 2000 more significantly than medium nitrogen rate, with the increase of 0.39 percent point. The increase of protein content was consistence with the enhanced activities of nitrate reductase (NR), glutamine synthase (GS) in flag leaves after anthesis.In both nitrogen rates, compared with T1 treatment (all nitrogen as basal fertilizer), nitrogen topdressing treatments significantly improve grain protein content. The highest content of grain protein was obtained in T4 treatment (ratio of basal fertilizer and topdressing at booting stage was 6:4), with the increase of 1.04 percentage points, followed by the treatment of double topdressing at jointing and booting stages (T3). The increase of protein content was probably related to high level of average free amino acid content in flag leaves during 30 days after anthesis, which was caused by high activities of NR and GS in flag leaves.Based on the above results, when aiming at coordinated increase of grain yield and protein content in Guanzhong, the following technical points should be referred: Xinong 2000 should be sowed from October 3 to October 17 at the seeding rate is 2.4 to 3 million grains per hectare, and 250kg/hm~2 nitrogen applied as basal fertilizer and double topdressing at jointing and booting stage in the ratio of 6:2.5:1.5.