广东高产水稻“两叶”诊断调控法研究

Studies on High-yield Cultivation of Rice in Guangdong by means Determination and Control of Chlorophyll content and leaf Area Index

在叶面积指数与产量,叶绿素与品种光合能力、地力、太阳能相互关系的研究基础上,提出了水稻(Oruza sativa L.)高产栽培中以合理的叶面积发展模式为宏观控制指标,以功能叶片叶绿素含量为诊断指标的高产水稻“两叶”(叶面积指数及叶绿素)诊断调控法。高产水稻合理叶面积指数发展动态的控制指标是:幼穗分化期5左右,齐穗期6—8,齐穗后20天5左右。叶绿素的诊断指标为幼穗分化期至齐穗期顶部第二片完全展开的功能叶及剑叶应保持在5mg/dm^2左右为宜,幼穗分化、齐穗及齐穗后20天三期相加值应在13mg/dm^2左右或略高。如低于此值时,应据叶面积控制指标及地力、光照情况适量施肥。据此,1989年晚稻创造了小面积(20m^2)特青产量达674kg/mu的高产纪录。

In the light or researches on chlorophyll (chl ) content and leaf area index (LAI) in rice in terms of plotosynthesis and yield this study probed into the feasibility of guiding high-yield cultivation of rice in Guangdong by means of determination and control of chl content and LAI, which reflect the efficiency of light engrgy conversion and the capacity of light interception in the rice plant canopy. In order to analyse the relationship among Lai, chlorphyll content and yield, in 1988 and 1989 different rice cultivars with different levels of nitrogen application were used to create different LAI and chl content in rice plants. The sum of LAI values in panicle differentiation stage (p), heading stage (H) and 20 days after heading (H_20) was positively related with the applied amount of nitrogen. As there was a ciose relationship between leaf chl content and LAD/LAI as well as the yield, it is possible to control the LAI development by regalating N application level according to the chl content. It is suggested that the appropriate values of LAI for high yielding of rice are about 5 at P, 6-8 at H and about 5 at H_20. The suitble value of chl content of the top second fully extended leaf and the flag leaf was about 5 mg dm^(-2) from P to H, sum of chl content values in P, H and H_20 should be kept at about 13 mg dm^(-2) or a little higher. If the measured chl value is lower than the suitable value, proper amount of N fertilyer should be applied according to the controlled value of LAI. cultivar characters, soil fertility and solar energy conitions. By regalating the LAI and chl content, a high yield record of 674 kg mu^(-1) was achieved in our small experimental plot(20m^2) in late season in 1989.