Detailed Explanation of the Characteristics and Main Cultivation Techniques of Brazilian Upland Rice

Brazilian upland rice LAPAR-9 is one of a batch of improved crop varieties that the Brazilian government presented to our country in 1992 during Premier Li Peng's attendance at the United Nations Conference on Environment and Development.

Since 1993, our institute has planted it successively on hillside land, water-deficient fields, orchards and tea gardens in Beijing, Tianjin, Hebei, Shandong, Henan, Anhui, Chongqing, Sichuan, Shaanxi, Shanxi, Zhejiang and **, with an average yield of 200-300 kg per mu; on plots with good fertilizer and water conditions, the yield can reach 400 kg per mu, and at its highest more than 500 kg per mu. Trials show that this variety has the characteristics of drought resistance, lodging resistance, tolerance to poor soil, relatively strong resistance and wide adaptability, which are briefly described below.

I. Main Characteristics

The leaves and glumes of Brazilian upland rice IAPAR-9 are both smooth, with no leaf hairs or glume hairs; it is a smooth-hulled rice and belongs to the japonica rice category. The leaf sheath and glume tip are purplish brown, and the grains are slender in shape. Plant height is 119.4 cm, the culm is thick and sturdy, the roots are numerous, thick and long, the flag leaf and the 2nd-3rd leaves from the top are about 34.4 cm long and about 1.7 cm wide. Effective panicles are about 4, panicle length 26.0 cm, filled grains 1398, empty grain rate 19.4%, total grains per panicle 212, 1000-grain weight 27.5 g, yield per plant 12.4 g, grain-to-straw ratio 0.8. Brown rice rate 83.8%, milled rice rate 75.0%, head rice rate 62%, amylose content 21.4, protein content (dry basis) 11.2%, gel consistency 90 mm, gelatinization temperature (alkali spreading value) 6.3 grade; the main quality indices reach the ministry-issued second-class standard for high-quality rice.

II. Main Cultivation Techniques

Brazilian upland rice can be sown in spring or summer, and in the south it can be planted in early, middle and late seasons. Here we mainly introduce the two cultivation techniques of spring and summer sowing. Spring sowing is illustrated with the Beijing area as an example:

(I) Sowing. Generally direct sowing is done from late April to early May, and it matures in mid-to-late September, with a whole growth period of 140-150 days. 1. Water the soil thoroughly before sowing to ensure full emergence; 2. Treat the seeds before sowing with a special seed coating agent for early rice (northern type) to achieve full and strong seedlings; 3. The sowing rate is 2.5-3.0 kg per mu, row spacing 24-27 cm, sowing depth 2-3 cm. Apply as basal fertilizer 50 kg per mu of compound fertilizer containing 15% each of N, P and K along with other organic fertilizers at the time of sowing; this gives good results. 4. Press the soil after sowing.

(II) Field Management

1. Watering: Generally water 4-5 times during the whole growth period. The amount of water used is only equivalent to 20%-30% of that used for ordinary rice; if rainfall is sufficient, watering can be omitted. 1) Pre-sowing soil moisture water: sow when soil moisture is sufficient. From 30-40 days after sowing (before the 4-leaf stage), the plants should be kept in a dry-growing state; during this period, generally do not water, otherwise yellow seedlings or even dead seedlings easily occur; 2) Tillering water: during the effective tillering period when the 5th, 6th and 7th leaves (sometimes including the 8th) appear, water and topdress fertilizer in time; 3) Booting, heading and flowering water: at this stage transpiration is greatest and physiological activity is very intense; it is the most important period of reproductive growth, and soil moisture should be kept as close to saturation as possible. If fertilizer deficiency appears, apply a small amount of surface fertilizer, 0.15 kg urea per mu plus 0.20 kg potassium dihydrogen phosphate, diluted in 30-40 kg water for spraying; 4) Grain-filling water: after full heading, mainly manage by keeping the field moist. If water is lacking too early at this stage, empty and shriveled grains increase sharply, 1000-grain weight decreases, and rice quality is affected.

2. Topdressing: Topdress in time according to seedling conditions. According to the experience in Shunyi in 1998, generally from late June to early July, apply 15 kg urea per mu, and afterward spray foliar fertilizer as appropriate according to seedling conditions to promote balanced yield increase.

3. Weed control: 1) After sowing, use "Special Herbicide No. 1 for Early Rice" for soil sealing; 2) After emergence, at the 1-2 leaf stage, preferably at the needle stage, spray again with Special Herbicide No. 1 for upland rice or mix it with a modified seed for stem and leaf treatment. Weeds not controlled by chemical herbicides should be pulled by hand.

4. Insect control and disease prevention: In the middle and late stages, pay attention to timely spraying to control the striped stem borer, rice blast and sheath blight to ensure a good harvest.

Summer sowing is illustrated with the Gaomi area of Shandong as an example. The main methods are: direct sowing after wheat, intercropping in wheat fields and seedling transplanting. The pre-sowing preparation for direct sowing after wheat is the same as for spring sowing; the other technical points are as follows:

(I) Sowing

1. Sowing time: Sow immediately after @#@245@#@ harvest, the earlier the better, generally no later than June 15.

2. Sowing method: drilling and hill sowing. For drilling, wide rows are better, with row spacing of 24-30 cm; for hill sowing, use wide rows and narrow plant spacing, with row spacing of 24-28 cm and hill spacing of 15-18 cm. The practice in Zhugou Township, Gaomi City: use 1.6 m as a strip, with a bed surface of 1.3 m, plant 6 rows, row spacing 26 cm, and bed ridge 30 cm.

3. Sowing rate: Generally the seed rate is 5-6 kg per mu, with about 100,000 basic seedlings. For sowing, use measures such as chemical seed dressing or scattering poison bait to eliminate underground pests.

4. Sowing depth: Generally 3-4 cm; cover with soil and press after sowing.

(II) Field Management and Chemical Weed Control

1. After sowing and before emergence, use Special Herbicide No. 1 for upland rice at 200-250 ml per mu, diluted in 60-75 kg water, and spray evenly over the ground surface; alternatively, herbicides such as thiobencarb, butachlor and oxadiazon may be selected.

2. Check seedlings and fill gaps: After emergence, for plots found to have missing seedlings or broken rows, fill in the seedlings in time; at the 2-leaf 1-heart stage, thin where dense and fill where sparse to ensure full stand.

3. Fertilizer and water management: From emergence to the 2-leaf 1-heart to 3-leaf 1-heart stage, irrigate the soil and apply fertilizer, using 10 kg urea and 10 kg potassium fertilizer per mu to promote more grains per large panicle; from the booting stage to full heading and grain filling, apply 3 kg urea and 5 kg potassium fertilizer per mu. At this stage transpiration is greatest and physiological activity is very intense; it is the most important period of reproductive growth and is called the critical water period, so soil moisture should be kept as close to saturation as possible. If fertilizer deficiency appears, apply a small amount of surface fertilizer, 0.15 kg urea per mu plus 0.20 kg potassium dihydrogen phosphate, diluted in 30-40 kg water for spraying.

4. Insect control and disease prevention: In the early stage, pay attention to timely spraying to control underground pests and damping-off; in the middle and late stages, control borers and rice blast. Wheat field intercropping: Before the wheat is mature, wheat field intercropping can be used, sowing 2-3 weeks before harvesting the previous crop (wheat, rapeseed, etc.). If sowing is too early, the symbiotic period is too long, the rice seedlings grow poorly and weak seedlings easily form. Other field management is the same as for direct sowing after wheat. This method can fully use land fertility and the growing season and increase yield, but it easily causes an insufficient population and is labor- and time-consuming, with low economic benefit.

Seedling transplanting: Seedling transplanting is an effective measure to increase the multiple cropping index and improve land utilization.

1. Raising seedlings: Choose a plot sheltered from the wind and facing the sun, with convenient water sources and loose soil, as the seedling bed. Make beds in the selected seedling bed land, bed width 1.5 m and length varying from 8-10 m. Irrigate the bed thoroughly, evenly scatter the disinfected seeds over the bed surface, then scatter a thin layer of fine soil, just enough to cover the seeds. The seed rate per bed is 2-2.5 kg.

2. Seedling age: Generally control at 25-30 days. Leaf age 3.5-4.5 leaves.

3. Density: Plant 20,000-25,000 hills per mu, 4 seedlings per hill, with 80,000-100,000 basic seedlings per mu; row and plant spacing of 24 x 13 cm is suitable.

4. Pulling seedlings: One day before transplanting, irrigate the seedling bed thoroughly. When lifting seedlings, they must carry soil. Use a plow to open shallow furrows or a small shovel to dig holes for planting; the planting depth should be just enough to bury the roots. When transplanting, irrigate one bed and plant one bed to help the rice seedlings survive. After transplanting, water frequently so the seedlings recover as quickly as possible; management is the same as for direct sowing after wheat.