播栽期对机插超级杂交籼稻分蘖成穗的影响及与气象因子的关系

Effect of Different Seeding and Transplanting Dates on Tillering Characteristics of Super Indica Hybrid Rice with Mechanized Seeding and Planting and Its Relationships with Meteorological Factors

为探讨不同播栽期对机插超级杂交籼稻分蘖成穗的影响,以2个超级杂交籼稻品种F优498和宜香优2115为材料,设置3月21日（S1）、3月31日（S2）、4月10日（S3）、4月20日（S4）和4月30日（S5）5个播期,秧龄均为30 d,移栽期依次为4月21日、5月1日、5月11日、5月21日和5月31日,研究其分蘖发生成穗特点及与气象因子的关系。结果表明,不同播栽期水稻产量差异显著,随着播栽期推迟,产量呈降低趋势,早播S1的产量最高、迟播S5的产量最低。不同播栽期处理下水稻主茎对产量的贡献表现为（S1~S4）S5,S1优势蘖位为第3~第6叶,而S2~S5优势蘖位为第3~第5叶。随播栽期推迟,分蘖发生和成穗叶位趋于集中,F优498一次分蘖发生在S1~S4以3/0~7/0为主,而在S5以3/0~6/0为主;宜香优2115在S1以3/0~7/0为主,在S2~S5以3/0~6/0为主。一次分蘖成穗率在S1以3/0~6/0为主,而在S2~S5以3/0~5/0为主;二次分蘖发生和成穗以第3~第4叶为主。气象因子对分蘖发生和成穗的影响为一、二次分蘖发生率与日平均相对湿度呈显著负相关,而与平均气温日较差、积温、日照时数呈显著或极显著正相关;一次分蘖成穗率与分蘖期日平均相对湿度、平均气温呈显著负相关,与分蘖期平均气温日较差、积温、日照时数呈显著正相关,与幼穗分化期日平均相对湿度呈显著负相关,与抽穗开花期日照时数呈显著正相关。综合看来,成都平原地区机插超级杂交籼稻在4月11日前播种5月11日前移栽有利于产量的提高,在4月21日前播种5月21日前移栽有利于稳产,在4月21日以后播种5月21日后移栽产量显著降低。

In order to explore tillering characteristics and its relationships with meteorological factors in super indica hybrid rice with mechanized seeding and planting with different seeding and transplanting dates, a split plot field experiment was conducted using super indica hybrid rice F you 498 and Yixiangyou 2115 with seedling age of 30 days and treatments of five seeding dates including March 21（S1）, March 31（S2）, April 10（S3）, April 20（S4）, April 30（S5）, and five transplanting dates including April 21, May 1, May 11, May 21, and May 31. Rice yield was significantly different under different seeding and transplanting dates, and decreased with delaying sowing dates. Yield of rice seeded on March 21 was the highest, while that on April 30 was the lowest. The main stem contribution to yield was（S1–S4） S5. The total contribution of primary tillers and secondary tillers group to yield was（S1–S4） S5. Leaf 3 to leaf 6 with seeding date on S1, and leaves 3 to 5 from S2 to S5 were the superior leaf positions. Leaf positions of tiller emerging and earbearing tended to centralize with delaying sowing and transplanting dates. Primary tillers of F you 498 emerged mainly from 3/0 to 7/0 when seeding from S1 to S4, while emerged mainly from 3/0 to 6/0 when seeding on S5. Primary tillers of Yixiangyou 2115 emerged mainly from 3/0 to 7/0 when seeding on S1, while emerged mainly from 3/0 to 6/0 when seeding from S2 to S5. Primary tillers earbeared mainly from 3/0 to 6/0 when seeding on S1, while that was mainly from 3/0 to 5/0 when seeding from S2 to S5. Secondary tillers emerged and earbeared mainly from leaf 3 to leaf 4 on main stem. Primary and secondary tillers emerging rate was significantly negatively correlated with average relative humidity, while significantly positively correlated with average diurnal temperature range, accumulated temperature and average sunshine hours at tillering stage. The primary tiller earbearing rate was significantly negatively correlated with average relative humidity and average temperature at tillering stage, while significantly positively correlated with average diurnal temperature range at tillering stage, while significantly negatively correlated with average relative humidity at inflorescence differentiation stage, while significantly positively correlated with average sunshine hours. In comprehensive view, planting before May 11 will be more beneficial to higher yield, planting before May 21 will be in favour of stable yield, while planting after May 21 will decrease yield of rice in Chengdu plain.