Option Two (a) Describe the following aspects of potato cultivation: (i) Soil suitability (ii) Sowing (iii) Weed control (iv) Storage - Leaving Cert Agricultural Science - Question 3 - 2017

Potatoes should be sown at a depth of 10 cm below the ridge, with a spacing of 20-35 cm between the plants. Ideal planting density is around 40,000-60,000 plants per hectare, with the optimal planting period being from February to April. Early varieties should be sprouted before planting.

Weed control can be achieved through various methods such as earthing up, shading, manual weeding, or using herbicides. Scuffling of the soil can also help prevent weed growth.

Potatoes should be stored in a well-ventilated area, ideally at a low temperature. They can be stacked correctly to prevent damage and should be kept frost-free and dry, avoiding exposure to light which can cause greening.

For this example, let’s consider barley as the named cereal crop. Barley grows best in warm and moist climates, but it also thrives under conditions of dry sunshine.

Barley is susceptible to fungal diseases such as viral disease. Effective control measures include certified seed treatments, spraying with biological control agents, and maintaining crop hygiene.

Barley is typically harvested between July to September, depending on the climatic conditions and the specific variety being grown.

The yield of barley can vary based on the season: for spring barley, yields can be between 6-8 tons per hectare, while winter barley may yield approximately 8-9 tons per hectare.

During the ripening process, the grains undergo several physiological changes. This includes the bleaching of the colour of the straw and the drying of the grains. For barley, the kernels acquire a plump texture as the liquid content within them decreases, leading to the hardening of the grain.

The moisture test involves weighing a sample of grain and drying it at 100 °C until constant weight is achieved. The mass loss is calculated to determine the moisture content. This is crucial as moisture levels affect grain quality and storability.

The screening test is conducted to determine the purity of the grain. This involves separating impurities and calculating the percentage of pure grain. This is typically done using a sieve or chondrometer, where the total weight of the grain is measured against the weight of impurities.