Suitable Planting Regions, Variety Selection and High-Yield Cultivation Key Points for Ratoon Rice

It is now the season for sowing and raising rice seedlings, so farmers who want to grow rice need to start choosing varieties. For some growers, choosing to plant ratoon rice is the best option, as it not only allows two harvests from one season, but the ratoon rice also has excellent grain quality. So which places are suitable for cultivating ratoon rice? What varieties are good to choose? How to plant for high yield?

Suitable planting regions:

1. Production conditions

Generally speaking, if mechanized harvesting is not adopted, most regions can develop ratoon rice. Of course, double-season rice production is encouraged to be safeguarded, and ratoon rice should be developed in areas where the light and temperature for two seasons are insufficient but there is more than enough for one season. If mechanized harvesting is adopted, mechanical crushing is unavoidable, so ratoon rice production requires fields to be as large as possible, with contiguous fields having as little slope as possible between them to reduce damage to the seedlings. Small terraced fields in mountainous areas and low-lying fields with poor drainage are not suitable for developing machine-harvested ratoon rice.

2. Variety growth period

Many varieties can be used as ratoon rice, but for high-quality mid-season and late-season rice varieties, their own heat tolerance is not strong. If used as ratoon rice, the quality of the first season becomes worse, and it is instead not as good as planting them as mid-season or late-season rice. From the perspective of both quality and benefit, it is not worthwhile.

Good ratoon rice varieties

The general principle is: moderate growth period, good tillering ability, strong heat tolerance in the first season, high seed-setting rate, excellent quality, good stable and high yield, and a high head rice rate in the ratoon season.

Specifically, it is generally mid-season rice varieties with a long growth period that are cultivated as ratoon rice, but there are risks, namely that varieties with poor heat tolerance will have poor quality. At present, the new model of “early planting of late-season rice varieties + low-stubble harvesting of ratoon rice” is relatively advocated. For the first season, choose varieties with a high seed-setting rate and good quality under high temperatures. Medium-maturity late-season rice varieties can be chosen, sowing early so that the first season reaches full heading in early July, avoiding high temperatures. For full heading in mid-July, heat-tolerant mid-season rice varieties with a longer growth period should be chosen.

High-yield cultivation techniques:

1. Pre-sowing seed treatment: Select Dongxiang wild rice, which has cold-resistance and well-developed root genes, as the male parent, and local late-season glutinous rice as the female parent. After many years and multiple repeated crossings, the perennial rice seed “Heping rice” is obtained. Before sowing, sun the seeds for 1-2 days, then soak the seeds in chemicals. After soaking, rinse them clean with water and then germinate them;

2. Sowing: In early May, sow the treated germinated seeds to be sown into the already prepared seedling field in separate beds at the standard of 12-13 kg of dry seed per 667 m2 of seedling field. After sowing, press the grains into the mud;

3. Seedling stage management: Before full emergence, mainly keep shallow water and moisture; after emergence, irrigate frequently with shallow water. At the two-leaf-one-heart stage, apply paclobutrazol per mu, diluted with water and sprayed quickly and finely to dwarf the seedlings; at the three-leaf stage, topdress with carbon-hydrogen nuclear fertilizer compound fertilizer per mu. Apply farmyard manure well 5-7 days before transplanting so as to go to the field with fertilizer. Preferably, at the two-leaf-one-heart stage, use 60 g of 5% paclobutrazol per mu, diluted with 100 kg of water and sprayed quickly and finely to dwarf the autumn seedlings; at the three-leaf stage, topdress with 10 kg of carbon-hydrogen nuclear fertilizer compound fertilizer per mu.

4. Transplanting: Transplant at the right time, with seedling age controlled at 30-35 days, and transplant promptly after the field is prepared. Transplanting density is: 13,000-15,000 hills per mu, using wide-narrow row planting. Preferably, insert 3 seedlings per planting hill; inserting 3 seedlings per hill and wide-narrow row planting help the rice seedlings receive sufficient sunlight, improve photosynthesis, and facilitate ventilation and air movement;.

5. Water management: Release water 2-3 days before planting and maintain a water layer 2-3 cm thick to ensure planting quality and favor tillering; 15-20 days after planting, when the number of seedlings reaches the high-yield population base of 180,000-200,000 seedlings, drain and dry the field (until cracks appear) to control ineffective tillering; at the jointing stage, rewater and fertilize to promote large panicles; before harvest, maintain shallow water irrigation or alternate wetting and drying; at harvest time, the paddy field should be moist or under shallow water irrigation;

6. Harvest management: When the rice grains are at nine-tenths yellow, harvest promptly on a sunny day. Use a small harvester for harvesting machinery. First, it favors returning straw to the field; second, it causes less damage to the rice stubble and less impact on axillary bud damage. After harvest, use 8 kg of compound fertilizer per mu to promote seedling emergence and axillary bud differentiation. By mid-to-late October, use small machinery for mowing, with the rice stubble retained at a height of 20-25 cm, return straw to the field, and maintain shallow water for overwintering;

7. Overwintering first-crop management: In early to mid-March of the second year, when applying bud-promoting fertilizer, apply basal fertilizer and tillering fertilizer at the same time. Reduce the amount of carbon-hydrogen nuclear fertilizer applied by 10 kg, and add 1 kg of lime nitrogen to promote early and rapid growth. Rice is set for 2 seasons of grain. First-crop harvest and bud-promoting fertilizer application: harvest the first crop promptly when it is 9.5 tenths yellow-ripe, leaving stubble height at about 30 cm. From 7-15 days before harvest, use 25-35 kg of carbon-hydrogen nuclear fertilizer per mu; after harvest, water 2-3 times; at the booting stage of ratoon rice, use 10 kg of carbon-hydrogen nuclear fertilizer per mu.