Planting the rice

 

 

 

 

 

Seeding rates and plant populations

 

 

 

 

 

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Understand the different factors that influence the plant population in the field

 

 

 

 

 

 

 

How much seed do you need?

 

The seeding rate to get the plant population you want depends on several factors:

  • the rice ecosystem,

  • planting technique,

  • planting depth,

  • seed quality and

  • rice variety.  

 

Plant establishment rates for broadcast crops are lower than for transplanted crops. When planted in nurseries, 60 percent of the seeds will establish. This will reduce to 50 percent when you broadcast the seed directly into the fields.

 

The depth of planting affects both crop establishment and lodging potential.

 

Broadcast crops tend to lodge more because with the seed germinating at the surface, the crown of the plant is at or above ground level. Care must be taken with seed placement as rice seeds have difficulty establishing if placed too deep in the soil.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

How many seedlings in 1 hill?

 

Number of seedlings transplanted per hill depends on three factors:

  1. the habits of the farmers,

  2. quality of seed, and

  3. price of seed.

 

Hybrid seed, which is more costly, is often transplanted as one seedling per hill while traditional varieties are sometimes planted with up to 6 seedlings per hill. In most countries, the farmers plant 2 to 3 seedlings per hill.

 

 

 One plant per hill (left)          5 to 6 plants per hill (right)

 

 

 

 

 

How many panicles per m2 should you expect?

 

Total number of panicles required per unit area can vary, depending on soil type and water regime. For most situations, tillers and panicles are thought of as similar although not all tillers produce panicles.

 

For wet season crops, 300 to 400 panicles per m2 are desired; in the dry season density increases to 500 to 600 panicles per m2. In more fertile soils and for irrigated and dry season crops, plant populations should be increased.

 

Rice Panicles

 

The number of tillers per plant will vary according to nutrient status, variety and planting rate (higher seeding rates normally give fewer tillers). Transplanted crops generally produce more tillers than direct seeded crops, and dry season crops often produce more tillers than wet season crops.

 

 

 

 

 

 

 

Go online for more information

 

For more information on Crop Establishment, please visit: http://www.knowledgebank.irri.org/PlantEstablish/WebHelp/default.htm

 

Next lesson

 

This ends our lesson on planting. Next we will describe the concept of water management in rice.