Abstract:

Compared to high stubble harvesting by hand, ratoon rice by low stubble machine harvesting （LSMH） causes the change of morphological development of ratoon rice tillers and requires corresponding varieties and cultivation techniques. In order to promote the mechanized production of ratoon rice, the morphological characteristics and fertilization techniques of ratoon rice tillers by LSMH were studied, using Tianyouhuazhan as material. The results showed that: （1） LSMH of main crop lost the axillary buds in the 2nd and 3rd nodes from the top. The tillers and their filial tillers of ratoon rice were derived from the 4th and 5th nodes from the top. Compared to high stubble harvesting by hand of main crop, the tillers of LSMH had 2-3 leaves, the growth period were delayed 15 days, and possessed 3-4 rooting nodes. This resulted in germinating more vigorous root systems, which led to germinating more ratoon tillers, developing larger panicles and laying a morphological foundation for high yield. （2） Among the tillers of different nodes, the largest difference was effective panicle numbers, the second was grains per panicle, and the seed setting rate and 1000-grain weight were stable. This indicates that grains per panicle has larger potential for amplification and is the main factor to determine the yield. Ratoon rice tillers germinated rapidly and subsequently arrived the critical period of effective tillering at 15 days after LSMH in main crop.（3） The nutrient content of available P and K for the tested paddy soil was low. Under no applying P and K fertilizer, the germination of ratoon rice tillers were obviously inhibited, the panicle numbers and grain yield were significantly reduced, the yield of treatment 4 with balanced fertilization was the highest.

Key words: ratoon rice, mechanized production, regeneration tillers, morphological development, fertilization technology

摘要：

相比高桩手割，再生稻头季实行低桩机割，再生季分蘖的形态发育出现了新的变化，要求改变相应栽培技术才能适应这种变化，提高再生季产量。以适应闽中山区机械化生产的中偏早熟品种天优华占为材料，研究了天优华占低桩机割再生分蘖的形态发育特性及施肥技术。结果表明：（1）头季成熟期低桩机割，割去倒2、3节腋芽，再生季萌发倒4、5节分蘖及其子蘖，比头季高桩手割的再生分蘖多长2~3片叶子，生长期延长15 d，并具有3~4个发根节，萌发较旺盛的根系，从而促成萌发较多的分蘖，发育较大的穗子，为丰产奠定了形态学基础。（2）不同节位分蘖之间，以穗数的差异最大，每穗粒数次之，结实率和千粒重比较稳定。显示穗粒数具有较大的扩增潜力，是决定产量的主要因素。再生分蘖萌发迅猛，头季机割后15日达有效分蘖临界期。（3）供试稻田土壤速效磷钾养分含量偏低，不施磷钾肥明显抑制分蘖萌发，穗数显著減少，产量显著降低，再生季氮肥施用以“平衡施N、配施PK肥”的处理产量最高。

关键词: 再生稻, 机械化生产, 再生分蘖, 形态发育, 施肥技术