基于机插晚稻分蘖成穗特性获取基本苗定量参数

为精确定量机插晚稻适宜的群体起点,合理利用分蘖成穗,以3个晚稻(H优518、H优159和五优308)高产品种(组合)为材料,研究了机插晚稻分蘖成穗特性及基本苗公式参数。结果表明,机插晚稻1次分蘖集中在主茎第3～7叶位,第3～6叶位为分蘖发生与成穗的优势叶位；2次分蘖在3/0～5/0上均有发生,但成穗以1/3和1/4为主；主要依靠1次分蘖成穗,2次分蘖成穗较少；单株分蘖成穗数4.5个左右；主茎及优势蘖位穗部性状较好,穗粒结构协调,产量较高,对群体产量贡献大。晚稻在4叶1心期机插,移栽分蘖缺位叶龄(bn,blemish number)为0.7～0.8,校正系数(a)为0.6左右,有效分蘖发生率(r)在0.8左右。生产中机插晚稻应在保证合理基本苗的基础上,争取分蘖早生快发,在充分发挥1次分蘖的分蘖成穗优势的同时,合理利用低位2次分蘖成穗,以获取适宜的穗数而实现高产。该研究揭示了高产条件下机插晚稻分蘖成穗规律及基本苗公式参数,为大面积生产中机插秧基本苗精确定量及分蘖高效利用提供技术参考。

Calculation of quantitative parameters of basic population of machine transplanted late rice based on its tillering and panicle formation characteristics

Mechanically transplanted rice has many advantages, such as stable yield, high efficiency, saving cost and freeing labor, and the area of mechanically transplanted double-rice has been larger and larger in China in recent years.However, the combination of agricultural machinery with its supporting agronomy technology, such as the optimal basic population and the rule of tillers, still needs to be further studied.In order to accurately determine planting density and make reasonable use of tillers for mechanically transplanted late rice, we examined the characteristics of tillering and panicle formation and the parameters related to basic population formulae using the combination of 3 high-yield late rice (Hyou 518, Hyou 159 and Wuyou 308) as study material.The 3 experimental materials were grown in the field of Shanggao, Jiangxi Province, China in 2013 and 2014.And the experiment was conducted under the condition of mechanically seeding and transplanting with high-yield agronomy technology during the whole growth period of late rice, and 3 replicates were for each treatment.Using the method of the tillering tracking, 10 holes of seedlings were set in each replicate to investigate the leaves and tillers emerging, panicles formation, and panicles traits on different nodes of each stem.The results showed that the primary tillers of the mechanically transplanted late rice were initiated mainly from the leaf positions of 3~7 on main stems, and the leaf positions of 3, 4, 5 and 6 was the superior positions for tiller initiation and panicle formation.The secondary tillers emerged from 3/0 to 5/0, such as 1/3, 2/3, 3/3, 1/4, 2/4 and 1/5, but panicles were formed mainly in 1/3 and 1/4.The panicle formation was mainly from the primary tillers, and the secondary tillers could form a few panicles.The panicle number per plant was about 4.5 for late hybrid rice in mechanically transplanting.Panicles on both main stems and tillers of superior leaf positions showed better properties and higher productivity, thus making greater contributions to the group yield.Appropriate number of panicles per stem, especially the panicle number of tillers of superior leaf positions is the premise of high-yield cultivation, which particularly increases the grain yield, not only for the panicle number, the branch number, the grain number, the setting percentage, the grain weight, and the spike weight, but also for more harmonious yield factors.For late hybrid rice mechanically transplanted at the stage with 4~5 leaves, the leaf age without tillering was 0.7~0.8, with the adjusting factor of 0.6 and the effective tillering rate of 0.8.In conclusion, in order to obtain a high yield of mechanically transplanted late rice, the key strategy is to ensure a reasonable number of basic seedlings, and then promote tillering as early and as much as possible, by increasing the effective tillering rate.The experiment indicates the rules of tillers emergence and panicles formation for late rice in mechanically transplanting, which provides a theoretical reference for the accurate density of planting and efficient utilization of the farm equipment in field production.According to the tilling characteristics of late rice transplanted by machine, the optimal management measures of seedling, manure, water and planting density should be further studied for giving full play to the middle tillers(tillers of superior leaf positions) of main stems.In addition, this study just includes the experimental datum of 2 years in the same late rice field, and further studies about the validation and perfection of multiple years and sites should be considered.