Characteristics and High-Yield Cultivation Techniques of the Premium New Japonica Rice Variety Jiudao 53

The new japonica rice variety Jiudao 53 was developed by the Jilin City Academy of Agricultural Sciences through sexual hybridization using Jiudao 14 as the female parent and Heixiangzhan as the male parent, combining early-generation simultaneous identification of grain quality and resistance with shuttle breeding, and bred by the pedigree method. It was approved by the National Crop Variety Approval Committee in 2005 (approval number: Guoshen Dao 2005049). After years of trials and demonstrations, this variety has shown characteristics of a moderate growth period, excellent grain quality, strong resistance, good adaptability and outstanding yield stability. In 2005, 20,000 mu were planted in Meihekou, a major premium rice-producing area in Jilin Province, and it was well received by rice farmers and rice merchants, with broad prospects for promotion and application.

1 Variety Characteristics

1.1 Agronomic Traits In the northern rice region, Jiudao 53 has a whole growth period of 148 days, with a maturity period comparable to the control variety (Jiyujing); from emergence to maturity it requires an accumulated temperature of ≥10°C of 2850°C, and it is insensitive to photoperiod and temperature responses. The average plant height is 97 cm, the plant type is compact, tillering ability is strong, it establishes quickly after transplanting, turns yellow quickly in the later stage, and matures with green stems. The average panicle length is 17.5 cm, the main and tiller panicles are uniform, the grain-filling rate is fast, the average number of grains per panicle is 115, the seed-setting rate is above 95%, and the 1000-grain weight is 23.4 g. The grains are oval, with sparse short awns, and the glumes are yellow.

1.2 Stress Resistance In the northern regional trials, artificial inoculation with different fungal strains and multi-location natural induction identification at the adult-plant stage in disease areas were used, and the comprehensive evaluation results were: Jiudao 53 is moderately susceptible (MS) to seedling blast and leaf blast, and moderately resistant (MP) to panicle blast. In large-scale production planting, it shows strong cold resistance and salt-alkali tolerance, with hard stems resistant to lodging; the occurrence of striped stem borer and sheath blight is light, and its comprehensive stress resistance is outstanding.

1.3 Yield Performance From 2002 to 2003, it continuously participated in the northern regional trials, and Jiudao 53 had an average yield of 583.8 kg per mu, comparable to the control variety (Jiyujing); in 2004, it participated in the northern Jiyujing group production trial, with an average yield of 549.3 kg per mu, an average increase of 8.3% over the control. Years of multi-location production demonstration planting and AMMI model analysis showed that this variety has good yield stability and wide adaptability; in medium-fertility fields the yield is about 630 kg per mu, and in high-yield plots the yield is above 700 kg per mu.

1.4 Rice Grain Quality The average results of grain quality analysis in the northern regional trials from 2002 to 2003: Jiudao 53 has a head rice rate of 66.7%, a chalky grain rate of 11.0%, a chalkiness degree of 1.3%, an amylose content of 16.2%, and a gel consistency of 73 mm, with grain quality reaching Grade 2 of the national "Premium Rice" standard. The cooked rice has good palatability, a natural delicate fragrance, and does not become hard after cooling.

2 High-Yield Cultivation Techniques

Jiudao 53 is suitable for planting in the upper limit of the first accumulated temperature zone in Heilongjiang, the medium-maturity and medium-late rice areas of Jilin Province, northeastern Liaoning, the Ningxia Yellow River irrigation area, as well as Chifeng in Inner Mongolia, southern Tongliao, central and northern Gansu, and the Hexi rice area. The cultivation points are as follows:

2.1 Cultivating Strong Seedlings with Tillers Use large-hole pot tray seedling technology, plastic flat tray seedling raising or dry seedling raising, sow early and thinly at the right time, with a sowing rate of about 60 g of sprouted seed per flat tray, and 200 g per square meter for dry seedling raising. The optimal seedling age is about 4.5 leaves, with a seedling height of 12-15 cm, upright leaves, and green with a yellow tinge. During the seedling stage, pay attention to ventilation to control the temperature inside the shed and prevent excessive seedling growth. Strictly use chemicals to control damping-off disease.

2.2 Reasonable Sparse Planting Sow early and transplant shallowly at the right time, with reasonable sparse planting. The general density is 30.0 cm × 16.5-20.0 cm, with 2-3 seedlings per hill; in rice areas with superior light, temperature and water conditions, planting can be appropriately sparser. Whether by hand transplanting, machine transplanting or seedling throwing, it is required to maintain 25,000 basic seedlings per mu. Seedling throwing is recommended, as it saves labor and effort.

2.3 Scientific Fertilizer and Water Management Fertilization should combine farmyard manure and chemical fertilizer with formula whole-layer fertilization, promote steadily, maintain tillers through roots, and allow natural yellowing at the end of tillering. Base fertilizer should be applied before harrowing. For medium-fertility fields, apply about 150 kg of pure nitrogen per hectare over the whole growth period, and about 75 kg each of phosphorus and potassium per hectare. Phosphorus fertilizer should be applied once as base fertilizer, and depending on the situation, a small amount of silicon, magnesium fertilizer, etc. may be applied at the same time; nitrogen fertilizer and potassium fertilizer should be applied in three split applications: 60% as base fertilizer, 20% as tillering fertilizer, and 20% as panicle fertilizer.

Water management should mainly use shallow water; at the end of tillering, it is not advocated to drain and sun the field uniformly, and for fields with excessive growth, the method of light drying and multiple dryings should be used. During the grain-filling period, alternate wetting and drying. Stop irrigation about 15 days before harvest to improve the seed-setting rate and maturity, thereby reducing the chalky grain rate and chalkiness degree and improving processing quality.

2.4 Pest and Disease Control According to climate, field plots and field growth conditions, pay attention to integrated control of damping-off disease, rice blast, striped stem borer and other pests and diseases, and reduce the use of high-residue pesticides.