Tillering Characteristics of Multi-tiller Maize and Influence of Plant Density and Sowing Date Tillering Characteristics and Its Relationship with Population Productivity of Super-High Yield Rice Population of Yongyou 12 Tillering Characteristics and Its Relationships with Population Productivity of Super Rice under Different Cultivation Methods in Rice-wheat Cropping Areas Tillering Characteristics of Indica Hybrid Rice under Mechanized Planting Tillering and Panicle Formation Characteristics of Machine-transplanted Early Rice and Its Parameters of Basic Population Formulae