Impacts Of Environmental Conditions On Crops

Environmental Conditions

Different crops require different environmental conditions for optimal growth. An example of this is beans and onions are sown between autumn and early winter (cool to cold period) whereas tomatoes and cucumbers are sown in spring after the last frosts of winter (warmer months).

It is therefore important to select the correct crop and cultivar for the particular time of year, and also the one best suited to your environment. You can consult with an extension officer or crop specialist or read about the crops and their various cultivars before you decide on the planting stock you buy. Planting the wrong crops or during the wrong time of the year is a common cause of crop failure. In addition, also consider the market you intend for the specific crop.

Excessive humidity can cause the development of a fungal disease known as ‘damping off’. Similarly, cold conditions may lead to germination failure or cold damage to seedlings.

Mixtures of fertiliser can also be used to provide different nutrients for specific crops. The farmer will be aware of the requirements for such plants. The planting site for the crop should be watered once or twice before planting to allow the fertiliser and soil to settle. Seedlings should be transplanted with as much soil as possible from the original site surrounding the roots. Remember that in a natural situation plant roots are never exposed to the wind, so it is important that as much of the original soil is kept with the seedling. This exposure is commonly called root shock and will kill young seedlings very quickly.

The planting area should be watered thoroughly a day before transplanting seedlings into the soil and the soil should be moist and not wet.

Avoid planting seedlings on windy days, as the wind will dry out young seedling plants, exacerbating the effects of wind shock. You should also avoid planting seedlings before a heavy rainfall. Heavy rain not only increases the likelihood of damping-off fungus developing but also causes erosion of freshly prepared soils. Heavy rain can destroy the seedling habitat and wash away the newly planted seeds or plants.

Long term crops such as fruit trees and vines are established towards the end of winter. These are planted in holes at least one meter wide 60 cm deep.

The bottom of the hole is layered with manure and well-decomposed compost. The tree should be planted, carefully and no deeper than it was at the nursery, with the hole forming a small dam for the collection of water. Each plant will require 15 - 20 litres of water immediately upon planting.