The researchers studied the best time to plant rice in a specific area. They used different rice varieties and found that planting too early or too late reduced the number of seedlings. The best time for stable ripening varied between the rice types, but planting in mid-May gave the highest grain weight and ripening rate. The ideal air temperature after the rice plants flowered was around 22 degrees Celsius. For the highest yield, planting in early to mid-May was best for all rice varieties.