A Brief Introduction to the Characteristics and Traits of the A Dao No. 7 Rice Variety

The new late-maturing, high-yield rice variety A Dao No. 7 was introduced by the Fine Seed Multiplication Farm of the First Agricultural Division in 1992 from the Liaoning Provincial Institute of Saline-Alkali Land Improvement and Utilization, and was systematically selected and bred over 5 consecutive years.

Characteristics and traits: This variety belongs to the late-maturing, japonica rice type. When sown around the end of April in the Tarim River and Shajingzi reclamation areas, it can fully mature by the end of September, with a whole growth period of 150-155 days. The mature plant height is about 90 cm, the plant type is relatively compact, and it has strong tillering ability. Emergence, heading, and maturity are neat and uniform. The plants are clean and robust, maturing while still green without premature senescence; the panicle position is relatively low, with the flowers hidden among the leaves. The grains are long oval-shaped, with the glumes and straw yellow in color, and a 1000-grain weight of 24-25 g; the panicle length is 17-20 cm, the number of grains per panicle is 80-110, and the seed-setting rate is over 90%; the grain-to-straw ratio is 1:0.81, and the brown rice rate is 81%; upon testing: protein content 6.62%, moisture 11.9%, amylose 11.31%, amylopectin 60.56%, gel consistency 76 mm, gelatinization temperature less than 70 degrees C; good transparency, low white belly rate, and excellent eating quality. The seedlings have strong growth vigor, tiller early and are easy to manage; strong tolerance to cold and saline-alkali conditions, and highly resistant to lodging; field quarantine shows high resistance to rice blast.

Yield performance: From 1993 to 1995, participating in the repeated variety (line) trials of the First Agricultural Division, the average yield per 666.7 sq m was 836.7 kg, 803.6 kg, and 890 kg respectively, increasing by 3.04%, 5.2%, and 6.7% respectively compared with the control Shajiao No. 5. In the 1995-1996 variety comparison trials, the average yield per 666.7 sq m was 832.6 kg and 700.5 kg respectively, increasing by 4.67% and 11.3% respectively compared with the control Shajiao No. 5. Through large-field extension and planting, the per-unit yield level stabilized at 600-800 kg, increasing by 7%-10% compared with the control Shajiao No. 5. In 1997, the First Agricultural Division trial-planted 2133.3 hm2, among which the 27.2 hm2 of No. 7 Regiment, Company 13 had an average per-unit yield of 1035.6 kg; the 19.17 hm2 of No. 9 Regiment, Company 16 had an average per-unit yield of 1063.1 kg. In 1998, the First Agricultural Division planted 4793.2 hm2, among which the 19.53 hm2 of No. 16 Regiment, Company 3 had an average per-unit yield of 1053 kg.

Breeder: Fine Seed Multiplication Farm of the First Agricultural Division

Region and techniques: 1. Yield structure: basic seedlings 220,000-260,000 plants/667 sq m, total stems 20 kg/667 sq m, harvested panicles 400,000-450,000/667 sq m, grains per panicle 85-100, 1000-grain weight 25 g. 2. Pre-sowing preparation: irrigation and drainage must be matched, select well-cultivated land of medium fertility, strictly level the land, manually level early plus water leveling, so that the height difference within the field does not exceed one cun, achieving level ground, straight channels, small ridges, neat edges, square corners, clean and free of residual debris. Seed purity should reach 99%, cleanliness 98%, germination rate over 95%, and after mud-coating treatment, the mud-to-seed ratio is 5%-8%. 3. Timely early sowing: the suitable sowing period is April 15 to April 30. Manual water broadcasting 18 kg/667 sq m, aerial sowing 15 kg/667 sq m. Seed fertilizer uses triple superphosphate 8-10 g/667 sq m. Manual seed broadcasting and fertilizer broadcasting require two passes in length and breadth. 4. Water and fertilizer management: throughout the whole period, water layer management should apply the irrigation method of alternating shallow, wet, and dry. Apply per 667 sq m urea 38-40 kg, triple superphosphate 8-10 kg, zinc sulfate fertilizer 3 kg, and oil residue 40 kg. During the seedling and tillering stage, topdress 3 times. Seedling fertilizer: when the seedlings stand upright and turn green to the 1-leaf-1-heart stage, urea 6 kg/667 sq m, sulfuric acid 3 kg/667 sq m; tiller-promoting fertilizer: applied at the 3.5-4 leaf stage, urea 9 kg/667 sq m, oil residue 40 kg/667 sq m; tillering fertilizer: at the 6-leaf stage apply urea 11 kg/667 sq m. During the seedling stage, mainly maintain a shallow water layer, with a water layer of 3-5 cm. At the standing-upright stage, choose sunny days to dry the field for 2-3 days, with the standard being mottled water. During the tillering stage, maintain a water layer of 5-6 cm, and never cut off the water. At the late tillering stage, stop water and sun-dry the field for one week to promote transformation. During the seedling stage, use per 667 sq m 10% Nongdejin 20 g + 96% Hedazhuang 200 g for shallow-water spraying to carry out chemical weed control, and in the middle and later stages maintain a shallow water layer of 5-6 cm. According to the principle of "apply early and more to early-yellowing plants, apply late and less to late-yellowing plants, and do not apply to non-yellowing plants," apply urea 10 kg/667 sq m. At the breaking stage, according to the growth vigor of the rice seedlings, appropriately add one application of grain fertilizer, urea 3-5 kg/667 sq m. At the full heading stage, adopt rotational irrigation measures, maintain alternating dry and wet conditions, and begin to stop water when 80% of the rice has bent heads and loose panicles. Begin harvesting when the grains at the base of the panicle mature.