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Studies On Yield And Quality Formation And Regulation Of High-Yielding Maize In Cold Region

Posted on:2003-06-23Degree:DoctorType:Dissertation
Country:ChinaCandidate:M LiFull Text:PDF
GTID:1103360065461157Subject:Crop Cultivation and Farming System
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The study was carried out at Xiang-Fang Experimental Station of NEAU in 1999-2001. The station is located at Harbin, Heilongjiang province (45?N and 126?E), PAR is about 1474MJm"2 during growing period, mean monthly temperature is 18.5 between May and September. Effective accumulated temperature is 2800 . Average annual precipitation is around 550mm. The study includes three parts: fertilizer amount and plant density, cultivars, and source-reducing and sink-limiting. Four-factor saturated experimental design (416A) and randomized block were used in the study. The objective of the study is: (1) to evaluate the source sink traits of different cultivars; (2) to investigate the source and sink in relation to high-yielding potential of maize, and the effects of fertilizers and plant density on source and sink traits and yield in maize; (3) to analysis the components of grain yield in cold region; and (4) the effects of fertilizers and density on nutritive quality of maize kernels with quantitative analysis, The results show as follows.The LA, DM and LAD of high-yielding population are all higher than that of the low one. The significant positive relationship between LAD after anthesis and grain yield (r =0.891**) was found. The directness path coefficient of LAD and NAR after anthesis to grain yield is 0.910 and 0.028, respectively. And the directness path coefficient of YB and EI to economic yield is 0.438 and 0.374, respectively. The average PAR-use efficiency of high-yielding treatment increased 37.6% when compared with the low one.The relationships between sink characters and source characters in different period are closed. There are significant positive among grains of population and LAI or LAD in middle maturity. The relationships between grain weight and LAI or LAD in middle maturity are negative, but the effect of LAD in late maturity on grain weight is positive.A two-member quadratic regression model of source effect (average LAI after anthesis) and sink (kernel number per sq.m.) on yield was established (R=0.97007**). The results revealed that the yield was increased with adding of source or sink when the sink or source is very small, but the edge-effect of increasing is diminishingly. The yield would decrease with the adding of source or sink when the sink or source is very high. Sink: Source ratio is affected by plant density or fertilizer. It is small when plant density or fertilizer is very low or very high. In general, with increasing of yield from very low to high, the positive relationship between yield and Sink: Source ratio was found, but in high-yielding interval, the relationship is not significant or even negative. It means that Sink: Source ratio is changing by self-regulation in plant.The source and sink traits of maize were mainly affected by plant density and nitrogenous fertilizer, and the influence of potassium and phosphorus were relatively small. Each effect in four factors all can be expressed by parabola equation. The effects of density on source characters or sink characters are different between individual and population.The effect of plant density on grain yield ranged first among the four factors, and the second is nitrogen fertilizer. The mainly effects of phosphorus and potassium on yield arenegative at the - Y level. The effects of all the four factors could be fitted with parabola in the zero level. There is obvious positive effect between fertilizer and density. The highest yield with optimum fertilizer was 52% higher than that of non-fertilizer treatment. The mutual effects between N, P and K were presented. The results show that the order of effects of fertilizer on yield are NPK>NK>NP>PK. The optimum proportion of N: P: K is 2: 1:1.3.Path coefficient analysis indicated that ear number contributed the largest part to maize grain yield among the yield components in cold region. The contribution of kernel number per ear, usually, exceeds the grain weight. The contribution of kernels to yield is decreasing in sink-limiting treatment. However, the contrib...
Keywords/Search Tags:Maize, Source and Sink, High-yielding, Quality, Fertilizer and Density
PDF Full Text Request
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