Agronomist dictionary

Growth and development

Harvest index

A ratio representing the efficiency of a crop in converting its total biomass into the harvested economic yield.

Storage and economics

Harvest maturity

The physiological stage of a crop when it reaches the peak of quality and quantity required for effective harvesting, processing, and storage.

Crop protection

Hazard class

A rating of the toxicity level of a pesticide, indicating the risk it poses to human health and the environment during handling and application.

Storage and economics

Header grain losses

This is the portion of the crop that fails to enter the combine harvester and remains on the field due to improper header settings or mechanical issues.

Growth and development

Heading

The growth stage of cereal crops when the ear (spike) emerges from the sheath of the flag leaf, marking the transition to the reproductive phase.

Weather and climate

Heat availability

This is a measure of how well environmental temperature conditions meet the biological growth requirements of agricultural crops during their growing season.

Machinery and irrigation

Hectare meter

A technical device or software module designed to automatically measure the field area actually covered by agricultural machinery during field operations.

Crop protection

Herbicidal effect

This is the pronounced inhibitory or lethal impact of a chemical agent on the growth and vital functions of weeds.

Crop protection

Herbicide safener

A chemical compound used to protect crop plants from herbicide injury without reducing the efficacy of the herbicide against target weeds.

Crop protection

Herbicide selectivity

The ability of a herbicide to kill weeds without causing significant harm to the crop.

Growth and development

Heterosis

Heterosis is the phenomenon where the progeny of two genetically diverse parents exhibit superior traits in growth, yield, and stress resistance compared to the...

Breeding and seed production

Heterosis (hybrid vigor)

The phenomenon where the progeny of genetically diverse parents exhibit superior traits, such as growth rate and yield, compared to either parent.

Crop protection

Hidden pests

These are pests that live and feed inside plant tissues, making them protected from direct contact with conventional insecticides.

Storage and economics

Hidden self-heating

A process of temperature rise inside a grain or seed bulk that occurs without noticeable heating of the upper layers or the external surface of the material.

Soil and tillage

Humification

The biochemical process of decomposing organic matter into stable humus compounds that improve soil fertility and structure.

Soil and tillage

Humus

Humus is the stable, dark organic component of soil formed by the decomposition of plant and animal matter through microbial activity.

Soil and tillage

Humus horizon

The top layer of soil enriched with organic matter (humus), which is the primary driver of natural soil fertility.

Soil and tillage

Humus mineralization

Humus mineralization is the process by which soil microorganisms decompose organic matter into simple mineral compounds that are readily available for plant upt...

Weather and climate

Hydrothermal Coefficient (HTC)

An index of moisture availability calculated as the ratio of precipitation to the sum of active temperatures over a specific period.

Weather and climate

Hydrothermal coefficient per decade

The hydrothermal coefficient per decade is an indicator of moisture availability for crops, calculated as the ratio of total precipitation to the sum of active...

Weather and climate

Hydrothermal regime

It is the combination of moisture levels and temperature conditions in the soil and atmosphere that dictates the growth and development of crops.