Lecture 5: Population Density Flashcards
POPULATION DENSITY
- number of plants per unit area
BENEFITS OF OPTIMUM POPULATION DENSITY
- early build up of sufficient leaf index
- better control of weeds
- increase efficiency in use of land, light, and water
FACTORS AFFECTING POPULATION DENSITY
- crop species and varieties
- soil fertility and management practices
- season
- method of propagation
- mechanization employed
- cropping system
PARAMETERS FOR CROP SPECIES AND VARIETIES
- plant height
- canopy shape and size
- growth habit
- horizontal spread of root system
CONDITIONS IN ADAPTING LOWER POPULATION DENSITY
- fertile soils
- rainy season
CONDITIONS IN ADAPTING HIGHER POPULATION DENSITY
- use of dwarfing rootstock in grafting
PD COMPUTATION FOR ANNUAL CROPS
- hill method
- drill method
PD COMPUTATION: HILL METHOD
PD = [(Area)(No. of plants/hill)] / [(Distance between hills)(Distance between furrows)]
PD COMPUTATION: DRILL METHOD
PD = [(Area)(No. of plants/linear meter)] / (Distance between rows)
PD COMPUTATION FOR PERENNIAL CROPS
- square
- triangular (hexagonal)
- quincunx (diagonal)
- contour
SQUARE SYSTEM
- plants placed at corners of the square
- equidistant with one another
PD COMPUTATION: SQUARE
PD = (Area) / (s^2)
TRIANGULAR SYSTEM
- plants placed at corners of the triangle
- 15% higher PD than square system
PD COMPUTATION: TRIANGULAR
PD = (Area) / [(s^2)(0.866)
PD = [(Area) / (s^2)][1.15]
QUINCUNX SYSTEM
- modification of square system
- additional plant at the center of each square
- higher PD than square and triangular systems
PD COMPUTATION: QUINCUNX
PD = [(Area) / (s^2)] + [(L/s - 1)(W/s - 1)]
CONTOUR SYSTEM
- planting based on the contour line
- planting distance varies between contour lines, but same within the contour lines
