Pertaining to broken fragments of volcanic origin - ash and rock material.

The fungus that causes blast disease of rice.

A pyrheliometer is an instrument for direct measurement of solar irradiance. Sunlight enters the instrument through a window and is directed onto a thermopile which converts heat to an electrical signal that can be recorded. The signal voltage is converted via a formula to measure watts per square meter. It is used with a solar tracking system to keep the instrument aimed at the sun. A pyrheliometer is often used in the same setup with a pyranometer.

A pyranometer is a type of actinometer used to measure broadband solar irradiance on a planar surface and is a sensor that is designed to measure the solar radiation flux density (in watts per metre square) from a field of view of 180 degrees.

Combining into one genotype several major genes that control a trait.

It has a high level or purity with little or no contamination of other varieties or species. Seeds give rise to genetically similar plants.

A method of selecting the best progeny for breeding from individual plants of a variety or cultivar.

1) A line that has been made almost completely homozygous by repeated self-pollination and selection of a specific type (or by the removal of off-types) over generations. 2) A group of identical individuals that always produce offsprings of the same phenotype when intercrossed.

The growth of a single species or strain of an organism in the absence of any other living species or strain.

A non-feeding and usually inactive stage in insect development which occurs between the larval and adult stages.

With a depression in the center.

A small wheel that turns by a belt to transmit or apply power.

Turning the soil into a muddy or watertight paste through secondary tillage.

A soil whose structure has been mechanically destroyed, allowing the soil to run together when saturated with water. A soil that has been puddled is usually in a massive nonstructural state.

Having a fuzzy surface; specifically, covered with fine soft short hairs.

Apparent resistance which results from transitory characters in potentially susceptible host plants. Types of pseudoresistance are host evasion, induced resistance, and escape.

Plants which prefer or tolerate sand, particularly fine to medium sand, as a habitat.

To cut off what is not needed, such as to prune tillers so that the number of tillers in each entry is uniform.

An in vitro technique of producing somatic hybrids between two cultivars, species, or genera. Protoplast fusion provides the unique opportunity to exploit cytoplasmic variability in two parental lines.

The isolation and culture of these protoplasts in nutrient medium to form callus and to regenerate plants.