Refers to the clustering of the soil particles into characteristics aggregates of various sizes, shapes, and stability.

leaf tearing may already occur especially in banana and abaca

Increased concentration of carbon dioxide in the atmosphere

Will flower over a wide range of daylength.

The range of pH in the Philippines is from

Vertical rays are more energy efficient/unit area than oblique rays

That temperature above which the velocity of the reaction becomes zero, due to the desaturation of enzymes.

Plant response as conditioned by daylength

Energy given out by the sun through radiation

Refers to the soil as a factor in crop production

Cloud including smog and fog affect the amount of radiation received by plants.

A trophic level, usually consisting soil microorganisms specifically important in the maintenance of soil organic matter

Expressed in hours per day

Effects of wind in plants

All living elements in the environment that can affect crop production

has edges which are more or less rounded; like the blocky structure, typical in clayey subsoils particularly in humid regions.

pillar-like with rounded tops; like prismatic structure, commonly occur in subsoils and in soils of arid and semi-arid regions.

Effect on plant development

The degree of hotness and coldness of a body

cube-like and has more or less sharp edges and the rectangular faces are distinct

Shade loving Light saturated at about 500 foot candles

Expressed in Angstorm or nanometers or identified by color

Composed of large and small plants and animals

Effect of light on plants

29 consecutive days without rainfall of at least 0.25 mm

The climatic environment one meter above the plant canopy

Is any form of water particles falling on the ground in liquid or solid form.

A collective term that includes pests, diseases, weeds, invertebrates and vertebrates

Generally refers to the climatic environment one meter below the canopy in the case of tall plants or the climate within the leaf canopy for short ( below one meter) plants.

protective shield against the harmful UV rays; it is 6-30 miles above the earth.

Important role in the preservation of species and in biodiversity conservation

The mass (dry weight) per unit volume of soil.

15 consecutive days without rainfall of at least 0.25 mm

The most favourable pH for growing most agricultural plants

Temperature of the environment depends upon

plants on land, economically important plants

seasons are not very pronounced but are relatively dry from November to April and wet during the rest of the year.

Normal wind speed in the Philippines

Classification of plants according to light intensity requirements

Expressed in foot-candle or lux

Temperature where the velocity of the reaction is at maximum

Provide balance in a crop production system particularly in the control of pests

A mixture of organic and inorganic materials which developed on the earth’s surface through weathering process of rocks and minerals and whose properties are conditioned in various degrees by the influence of climate, living organisms, and topography acting on the parent material over a period of time

happens when there is a periodic ocean-warming and atmospheric disturbance characterized by deficient rainfall or prolonged drought in some areas, while heavy rains, storms or hurricanes occur in other areas of the globe.

Structural classes based on the shapes of the aggregates

Low Elevation

Climatic Stresses

Factors affecting amount of distribution of rainfall

Provides beneficial effects on crop production

Requires a dark period exceeding some critical length to induce flowering.

characterized by a more or less even distribution of rainfall throughout the year

Categories of plants based on need for moisture:

The ability of the soil to adsorb and exchange cations with those in the surrounding soil solution as well as with the plant roots.

Three (3) cardinal temperatures

resembles cookie crumbs; commonly found in surface horizons where roots have been growing.

Insuffiently low of rainfall/moisture which seriously affects plant growth

Classification of crops according to temperature requirement

Inhibited from flowering when the dark period exceeds some critical length

aquatic plants

has two pronounced seasons: dry from November to April and wet throughout the rest of the year.

has disc-like aggregates; commonly found in virgin soils and subsoils; generally make the soil poorly drained.

Refers to the totality of all carbon-containing compounds in the soil derived from either plants or animals.

dessert plants

A momentary state of the atmosphere brought about the combination of elements.

Classification of plants according to photoperiodic response

The seasonal pattern of a particular place occuring from year to year.

Proportion/ amount of moisture in the air

Sun loving Light saturated at about 5,000 foot candles

pillar-like with level tops

Biotic Factors

Relative proportion of sand, silt and clay in a particular soil

Three (3) aspects important to plants

Climatic indicators of El Niño in the Philippines include

Direct effect on photosynthesis

characterized by the absence of a dry season but with a very pronounced maximum rain period from November to January

strong winds with speed greater than 21 kph

rounded aggregates which are more porous; characteristics of surface soils especially those high in organic matter content.

High Elevation

For every 100 meters rise in elevation

Effects of organic matter to soil properties

That temperature below which the velocity of the reaction becomes zero, due to the deactivation of enzymes.