Phenology-Changes that occur in plants- (Requirements)

Phenology is one of the parts of science that most influences changes in plants and animals, relating the climate to their reproduction, migration, etc.

What is the phenology of plants?

Plant phenology studies the changes that occur in it, related to climatic changes.

It is therefore important to observe:

  • Agricultural calendars.
  • Consider the climate requirement of each crop.
  • Assess the climate of the area.
  • Plan agricultural activity.

Fundamentally, phenology influences:

  • The latency or period in which the buds are dormant.
  • Shoot development and bud appearance.
  • Flowering.
  • Flower pollination.
  • Fructification.
  • Fruit development and ripening.

These changes depend on the phenological state before and after.

Phenology in latency

The tree enters a dormant period in late autumn and gradually. It lasts as long as the temperature does not exceed 7.2ºC and there are few hours of light.

In this period we can see that:

  • The capacity of biological processes is reduced.
  • Bud growth is minimized.
  • Breathing slows.
  • Enzyme activity is reduced.
  • Increase the starch.
  • In some plants the leaves fall off.

Influence of phenology on shoots

The shoots overflow at the end of the cold hours to give rise to a new outbreak, when the winter rest ends and the temperatures begin to be mild.

The cold hours establish the period of accumulation of low temperatures by the plant, which indicates the date of departure from latency.

Plantae ofrece la posibilidad de su recuento con la weather station.

The end of the number of cold hours marks the beginning of the outbreaks. If it is too early, we run the risk that the flowering suffers late frosts. Flowers can also be damaged by unforeseen frosts, even when the bud is in its ideal season. Vine and almond trees frequently suffer from this problem in some areas.

As a result of the start of sprouting as the development of the mother cell or meristem, the buds appear that will give rise to the flowers, the leaves and the branches.

These buds are for the following year, that is, the flowers and leaves will come out of a bud that was formed the previous year, and that has accumulated the cold hours demanded.

Types of buds

The buds can therefore be:

  • Fruitful or flowery.
  • Vegetative.

In some plants the flower bud appears first and in others the vegetative flowers such as the quince and the vine.

Yema apical de pistacho- La fenología estudia las horas de frio de la planta
The phenology indicates the hours of cold that make the first apical buds of the pistachio appear


Flowering is the process that leads to the formation of the flower and its full development. They are formed from the development of apical meristems.

Irrigation control with sensors is very important because the plant needs a lot of nutrients and does not suffer from water stress.

Types of flowers:

  • Hermaphrodites: when the flower has the female part (pistil) and the male part (stamen). It is the perfect flower. Examples, apple trees, citrus fruits, tomatoes, etc.
  • Monoecious: when the plant has female and male flowers such as corn, wheat, etc.
  • Dioecious: when the male flowers are on the male tree and the female ones are on the female tree such as pistachio and kiwi, etc.
Flowering fruit tree with flow meter in irrigation
Flowering fruit tree with irrigation controlled by humidity sensors- Late frosts impair flowering


It is the process by which the pollen passes from the stamen to the stigma where it fertilizes the ovules of the flower. From that moment on, the formation of the fruit and also of the seeds begins.

Pollination is carried out by pollination vectors such as birds, insects, water and wind. In some cases, several of these factors play a role. In the case of pistachios, for example, the best thing is the wind and good planning of the male trees on the farm.

Spring storms can spoil pollination

The fruit

It is the transformation of the flower into the edible part of the plant. It originates from the pistil of the flower. The ovary gives rise to the rind of the fruit. It depends on the weather and on each plant.

Heat hours and humidity control influence development.

Nogal con nueces en su desarrollo
Walnut in full fruit development


The flowering, fruiting and ripening phases depend on the hours of heat.

With the Thermal Integral the availability of heat for the development and maturation of plant species is defined.

Plantae Meteo offers us the possibility of its count, to predict at all times, when the plant has enough degrees accumulated above the threshold temperature of each species, and collection can be started.

The phenology indicates the thermal integral of the Mandarin-ripe fruit
Tangerine- phenology studies the thermal integral and the moment of ripening

Plantae specialist in phenology and irrigation

Plantae technology is wireless, controls phenology in your crops and increases quality and productivity through:

All wireless and controlled by a Hub/receiver with a solar panel that sends information to a online platform so that the farmer has graphic data on the mobile or tablet in real time.

Graph to control phenology
Graph to control phenology
Relative humidity sensor (probe) -Effects it produces on crops
Plantae Meteo station in vineyards controlling cold hours and thermal integral

Approximate table of the temperature requirements for the different phenological states in some crops controlled by Plantae

Cold hours (CH)200 to 550 hours
Bud shoots and floweringFrom 7º to 10ºC
GrowthBetween 20º and 25ºC
Thermal integral between swollen bud and harvest1000 to 1200 hours
Late frost damage to flowersLess than -1ºC
Cold hours (CH)600 to 2000 hours maximum
Bud shoots and floweringFrom 7º to 15ºC
GrowthBetween 20º and 25ºC
Thermal integral between swollen bud and harvest3000 a 3500 horas
Late frost damage to flowersLess than -1.5ºC
Cold hours (CH)150 to 400 hours
Bud shoots and floweringFrom 7º to 15ºC
GrowthBetween 20º and 25ºC
Thermal integral between swollen bud and harvest2000 to 3500 hours
Late frost damage to flowersLess than 0ºC
Cold hours (CH)300 to 450 hours
Bud shoots and floweringFrom 14º to 24ºC
GrowthBetween 25º and 35ºC
Thermal integral between swollen bud and harvest1250 to 3250 hours
Late frost damage to flowersLess than -1ºC




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