Yesizhan: Main Agronomic Traits and High-Yield Cultivation Techniques of a High-Quality Conventional Rice

Yesizhan is a temperature-sensitive, early- and late-season dual-purpose, high-quality, high-yield variety bred by the Foshan Institute of Agricultural Sciences through sexual hybridization of Xiyepzhan 10 and Zhong'er Ruanzhan, and was approved by the Crop Variety Approval Committee of Guangdong Province in March 2005. Its main agronomic traits and high-yield cultivation techniques are introduced as follows:

1 Main agronomic traits

Yesizhan is early to mid-early maturing in the early season, with an average full growth period of 127 days; it is early maturing in the late season, with an average full growth period of 108 days. The plant is short and sturdy, with strong tillering ability, green leaf color, narrow and upright leaves, and the capacity to hold many panicles, with large panicles and dense grains, high seed-setting rate, and good ripening color in the later stage. Plant height is 93.1 cm, panicle length 20.4 cm, seed-setting rate 85.5%, 1000-grain weight 17.7 g, and the grains are slender and attractive in color. It is moderately resistant to rice blast and bacterial leaf blight, and sheath blight incidence is relatively light in field production. It has strong cold tolerance at the seedling and late stages, is tolerant to fertilizer and resistant to lodging, has fewer pests and diseases, good comprehensive resistance, wide adaptability, and is easy to cultivate and manage.

It was promoted and planted for two consecutive years from 2004 to 2005 in the Jingkou Economic Zone, Sanshui District, Foshan City. In 2004, the average yield per mu was 481.7 kg, and in 2005, the average yield per mu was 427.1 kg, showing high and stable yield and good application prospects. Rice quality: Special Grade 2 of Guangdong Province in the early season, and National Standard Grade 2 in the late season. The grains are slender, crystal-clear and white, with an attractive appearance. The cooked rice is suitably soft and firm, with good flavor, a soft and smooth texture that does not stick to the mouth, good cooked-rice appearance, and the grains elongate well without bursting. Its market price is higher than that of general high-quality varieties, and it sells well, making it very popular among farmers.

2 High-yield cultivation techniques

2.1 Timely sowing and raising strong seedlings. Use the soft-tray seedling-raising method, with a seeding rate of 1.5 kg per mu of paddy field. The suitable sowing period for the early season is March 5-10, with film-covered insulation seedling raising, seedling age 20-25 days, and transplanting at the 3-leaf 1-needle stage. The sowing period for the late season is July 15-20, with a suitable seedling age of 15 days and transplanting at the 3-leaf stage. Apply sufficient base fertilizer in the seedbed, with 1000 kg of organic farmyard manure and 15-20 kg of compound fertilizer per mu, laying the nutritional foundation for raising strong seedlings. During the seedling-raising period, for the early season, cover with film for insulation; when encountering sunny and high-temperature weather, open both ends during the day for ventilation and cooling to prevent high-temperature scorching of the seedlings, then cover again at night. In the late season, temperatures are higher and heavy rain is frequent, so build a flat shed over the seedbed and cover it with shade netting to prevent high-temperature scorching and heavy rain washing, and pay attention to maintaining moisture in the seedbed. Open both ends for ventilation 7 days before transplanting to adapt to the external environment; completely remove the film for hardening 5 days before transplanting; 2 days before transplanting, spray the leaves with 2%-3% urea solution, and if the weather is fine, immediately spray clear water to reduce the fertilizer solution concentration to prevent leaf scorching; 1 day before transplanting, spray a "send-off" pesticide to prevent pests and diseases from moving to the paddy field, which can largely reduce the cost of control in the paddy field.

2.2 Timely transplanting and rational close planting. In the early season, transplanting is generally carried out in early April and completed around Qingming; in the late season, transplanting is generally carried out in early August and completed around Liqiu. The transplanting spacing is 20 x 20 cm, with 15,000-18,000 hills per mu, 4-5 seedlings per hill, and a basic seedling population of 75,000-85,000 seedlings per mu, with shallow and even transplanting. Check for and fill gaps within 3 days after transplanting to ensure a full stand.

2.3 Apply sufficient base fertilizer and topdress in stages. Fertilization in the paddy field adopts the method of promoting at the early stage, controlling at the middle stage, and supplementing at the late stage, with the ratio of nitrogen, phosphorus pentoxide, and potassium oxide controlled at 1:0.6:1.2 throughout the growth period. Apply sufficient base fertilizer to the whole layer: generally 1 day before transplanting, apply 1000 kg of decomposed organic manure, 25 kg of superphosphate, 7.5 kg of urea, and 7.5 kg of potassium chloride, incorporated into the whole layer while harrowing the field, then harrow evenly and level. Topdressing in stages: apply frequently and lightly in the early stage; in the middle stage, insist on not applying fertilizer as long as the plants do not fade in color; in the late stage, supplement as appropriate according to growth. Generally, 4-5 days after transplanting, apply 7.5 kg of urea per mu, mixed evenly with 100 ml of butachlor and broadcast; 10-12 days after transplanting, broadcast 10 kg of compound fertilizer and 5 kg of potassium chloride mixed evenly; 15-20 days after transplanting, broadcast 15 kg of compound fertilizer; after full heading, depending on plant color and weather conditions, grain fertilizer may be applied as appropriate. Applying potassium chloride in the early stage has the effect of strengthening stems and dwarfing, which can effectively improve rice lodging resistance, increase yield, and improve quality.

2.4 Thin-water intermittent irrigation and scientific water use. Adopt thin-water intermittent irrigation technology. In the early stage, use muddy skin water for greening, muddy water for tillering, and when 80% of the target tillers are reached, expose and dry the field, with the degree increasing from light to heavy. In the middle stage, irrigate and drain quickly with thin water, alternating wet and dry, keeping the field moist, promoting deep rooting, and improving the rice's wind and lodging resistance. At the heading and flowering stage, return to shallow water to ensure sufficient water supply and improve the seed-setting rate. At the grain-filling and yellow-ripening stage, irrigate and drain quickly, keep the field moist, and release running horse water once a week. Do not cut off water too early in the late stage; cut off water and dry the field 10 days before harvest.

2.5 Integrated control of pests and diseases. Pest and disease control should implement the policy of prevention first and integrated control. Through rational fertilization, increased application of phosphorus and potassium fertilizers, scientific water use, and regulating fertilizer with water, improve plant resistance and reduce the occurrence of pests and diseases. Yesizhan has relatively good resistance and relatively light pest and disease occurrence. Field management mainly focuses on controlling the damage of rice leaf roller and late-stage rice planthopper. Do a good job in forecasting and timely pesticide application for control.