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Cereals & Horticulture Crops


Cereal crops in Ireland can categorised as either Spring or Winter cereals depending what time of year they are sown. The main cereals grown in Ireland are barley, oats and wheat.

Barley is the most widely grown cereal in Ireland. It serves as animal feed and supplies the malting industries.

Maize is grown as a forage crop that is harvested and ensiled for winter feeding to livestock. It requires warm south facing fields and tends to be grown more in the South. It is also popular in Meath, driven by the high prevalence of intensive dairy and beef herds.

Growth Stages of Barley

Phase 2

Leaf Emergence

After germination the first leaf emerges soon after the crop initially emerges. The crop continues to produce leaves at a continuous thermal rate. This thermal rate is a set number of degree days between the emergence of successive leaves.

Phase 1

Leaf Number

Spring sown barley produces fewer leaves than autumn sown barley as the crop has less time to grow. On average the plant will produce eight leaves.

Phase 3


The production of tillers is key in the production of grain and ultimately grain yield. Tillers emerge after the third leaf has emerged on the barley plant. Shoots are produced from the tillers, so therefore the more tillers that are produced the more shoots are produced.

Phase 4

Canopy Formation

The growth of the canopy is slow initially as leaves emerge on the barley plants. As leaves emerge the rate of photosynthesis increases as the plant can absorb more sunlight and the crop canopy expands rapidly.

Phase 5

Stem Extension

Until the stem begins to grow, all crop growth is at ground level. Once the stem starts to grow the crop is more susceptible to frost damage at the growth point. Four of the leaves on the barley plant will grow at ground level and four will be on the stem. The crop will be at its maximum height after the ear emerges and biomass accumulation begins in the grains. At harvest the ear bends over and lies parallel to the stem.

Phase 6

Biomass Accumulation

As the crop develops more leaves and has a bigger canopy, it increases the amount of sunlight it absorbs. In turn, the biomass it produces accumulates at a greater rate. The production of biomass goes through several different stages of production. Initially biomass production centres on leaf emergence, followed by stem and ear production. Once the stem has reached its maximum height, biomass production is focused on grain production, as starch accumulates in the developing grains.

Phase 7

Ear Formation

The greater the number of shoots produced, the greater the number of ears formed on the barley plant. Grain yield is determined by the number of ears per metre squared. The crop ceases vegetative growth when ears start developing. It takes approximately 35 days for an ear to fully form on the barley plant.

Phase 8

Grain Filling

Grains begin to fill once the ear has emerged. It takes approximately 40 days for the completion of grain filling in the barley ear. The products of photosynthesis, which were stored in the stem, are now transferred to the grains. Crop production can be maximised through adequate fertiliser application to ensure the maximum number of tillers on each plant which in turn maximises ear production and grain filling.

Harvesting and Processing

Barley, wheat and oats are harvested with a combine harvester. The combine harvester combines three separate functions. These three processes are carried out by the combine harvester in one continuous operation.

  1. Reaping cuts the stalks from the grain
  2. Threshing loosens the grain seeds from the straw and the chaff, the inedible husks or seed casings on cereal grains.
  3. Winnowing separates the seeds from the straw and the chaff.
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Winter barley is harvested in July and Spring barley is harvested in August.

When barley is ripe, the ear bends over. The grains are hard and dry and the golden colour of the crop fades.  Farmers are paid based on the moisture content of the grain. 

The grain is stored in large ventilated sheds. Grain that is kept in storage is treated with propionic acid which prevents the grain being attacked by pests, fungi and bacteria. Low temperatures and low moisture content are important for grain storage to prevent germination and spoilage. 

Barley straw can be used for animal feed and bedding or ploughed into the soil for winter crops. Straw can be made into round or square bales and used on the farm or sold. Barley straw can also be burned in a biomass boiler to provide energy. 



Apart from the cereal crops, Irish farmers grow maize, beans, oilseed rape, carrots, beet and potatoes. Potato growing in particular has become very intensive.

The crop requires exceptionally good land and is now confined to parts of Meath, Louth, Dublin, Wexford, Donegal and Cork. Donegal has a noted tradition of growing potatoes for the seed trade, while Dublin and Meath growers supply the table market in Dublin, as well as the crisp making requirements of the Largo Foods plant at Ashbourne, Co. Meath.

Potatoes have been in Ireland since around the 1600’s. They are classified into three main categories, first earlies, second earlies and the maincrop. 

First and second earlies are planted as early as February/March. However, potatoes are not frost-resistant and for this reason they are grown in coastal areas of counties Cork and Wexford. The soils in these regions are sandy soils and warm up early in spring. Earlies are harvested immaturely from late May onwards. As a result, there is a lower yield but they obtain a higher price. Home Guard and British Queen are the most popular early varieties grown in Ireland.

Maincrop potatoes are harvested fully mature in September and October and give higher yields than early varieties. Rooster, Kerr’s Pink, Record and Golden Wonder are the most popular maincrop varieties in Ireland. Over half of the land planted with potatoes in Ireland is planted with Roosters. 

The haulms are first killed off using a contact herbicide. The potatoes are left in the ground for up to 3 weeks to allow the skins of the tubers to harden, this prevents them from being bruised when harvesting. The potato crop is then harvested with a potato harvester, usually an elevator digger. The machine separates the potatoes from the soil and either leaves the potatoes on the top of the soil to be gathered by hand or carries them to a storage bin. Potatoes must be stored in purpose built buildings that are well ventilated, leak-proof, insulated and frost-proof. They must allow access to a tractor and trailer as well as being stored in stacks.