烯效唑对不同落谷密度机插水稻秧苗素质及产量的影响

Effects of uniconazole on seedling quality and yield of different sowing density mechanical transplanting rice

为探索出适宜于杂交中籼稻的配套机插育秧技术,提高水稻产量,在硬盘方式育秧的情况下,以水稻品种‘徽两优6号’为试验材料,采用烯效唑和落谷密度二因素试验,研究落谷密度对秧苗素质、栽插质量、产量及其构成的影响以及烯效唑的调控效果。结果表明：在相同的化控处理情况下,随着落谷密度的增加,秧苗素质逐渐恶化,表现为单株根系数量、百株干质量、茎基宽、根系活力迅速下降,叶片丙二醛含量急剧上升;各处理千粒质量、结实率无显著差异;在8 000-18000 grains·m-2密度范围内有效穗呈增加趋势,18 000-30 000 grains·m-2密度范围内呈减少的趋势,最终使产量先增加后降低,其中以18 000 grains·m-2产量最高。烯效唑对不同落谷密度的秧苗素质及产量存在显著的调控效果。用100 mg·L-1烯效唑浸种的同时于2叶1心时喷施150 mg·L-1烯效唑的处理效果最好,与对照以及只用100 mg·L-1烯效唑浸种相比,能显著提高秧苗素质和栽插质量,缩短大田缓苗期,显著增加有效穗数、穗粒数以及结实率,最终使产量显著提高。因此,针对江淮杂交中籼稻特点,采用100 mg·L-1烯效唑浸种的同时于2叶1心时喷施150 mg·L-1烯效唑并配合18 000 grains·m-2的落谷密度为较好的育秧方式,能保证较高秧苗素质和栽插质量,稳定千粒质量,增加有效穗数、穗粒数以及结实率,增加库容量及库容充实度,最终使产量显著提高。

In order to develop the suitable technology for seedling nursery and increase the yield of mechanical transplanting middleseason indica hybrid rice ,the experiment of two factors of uniconazole and sowing density was conducted in plastic tray seedling nursery using the variety＇ Huiliangyou 6＇ , and then the effects of uniconazole and sowing density on seedling quality, transplant quality and yield of rice were researched. The results showed that the seedling quality decreased rapidly with the increasing of sowing density in the same chemical regulation treatment. There existed a decreasing trend in the number of roots, dry weight per 100 plants, basal stem width and root vigor. Meanwhile,the MDA content of seedling leaf was significantly increased. There was no significant difference in seed set- ting rate and 1 000-grain weight among the different sowing density treatments. The number of effective panicles showed an increasing trend within the sowing density range from 8 000 to 18 000 grains.m-2 ,but decreasing from 18 000 to 30 000 grains.m-2. Finally,the yield of rice displayed the same trend as the number of effective panicles. The yield of 18 000 gains· m-2 treatment was significantly higher than that of other treatments. There existed significant effects of uniconazole on seedling quality and yield of different sowing density. The method of soaking seeds with 100 mg.L-~ uniconazole and spraying seedling leaf with 150 mg·L-2 uniconazole in 2.5 leaf age was better than the other chemical regulation method and control. It not only significantly increased the seedling quality and trans- plant quality, but also promoted seedling turn green and increased the number of effective panicles,grains per pancile and seed setting rate significantly, so that the yield was significantly increased. Accroding to the characters of mechanical transplanting middle-season indica hybrid rice, soaking seeds with 100 mg· L-1 uniconazole and spraying seedling leaf with 150 mg·L-1 uniconazole in 2.5 leaf age combined the sowing density of 18 000 grains.m-2 was the better seedling nursery method. It can help to keep great seedling quality, transplant quality,and stabliz 1 000-grain weight and increase the number of effective panicles,grains per pancile and seed setting rate. The sink and its effective filling rate were significantly enhanced. Finally,the yield was significantly increased.