Orchard Establishment Site Selection Site Requirements 
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One of the most important factors that will determine the success of an intensive pear orchard is the site it is planted on. When establishing an orchard it is important that a number of factors are considered by the growers to minimise any potential site limitations to growth. The following are a number of factors that need to be considered when planning the orchard. SoilsSoils are an important consideration for pear plantings . It is important to understand soil characteristics and site history before planting in order to correct any problems. Soils should be assessed through soil pits and soil sample analysis as well as local soil maps.
Figure 1: Inspecting a soil pit in an orchard. Soil textureSoil texture refers to the proportion of sand, silt and clay sized particles in the mineral fraction of the soil. This is important as it influences the water holding capacity of the soil, the ability for water to move through the soil as well as its fertility. Lighter soils have a high sand content relative to clay and have poor water holding capacity as well as lower fertility. Heavy soils are high in clay content and will generally hold more water and are more fertile. Heavier soils can be prone to waterlogging. Clay loam to sandy loam soils offer the best potential for pear production. Soil structureA good soil structure is important for drainage of water and the movement of air through soil. Soil structure is influenced by texture and soil particle aggregation. Soil particle aggregation can be improved through the addition of organic matter (cover crops and mulching) which helps bind soil particles together. Tillage can also improve soil structure, however this is often only a temporary effect. DepthSoils should have atleast 60cm good quality topsoil. Topsoil depth can be improved by hilling up of treelines (mounding). This will improve depth as well as provide a gradient for surface run-off and seepage into th centre of the row. DrainageInternal drainage characteristics of the soil is one of the most important factor to ensure orchard longevity. Whilst pears are more tolerant of poorly drained soils than other fruit, waterlogging can impact negatively on production and even result in tree death. Soils should be well drained and not prone to waterlogging. In some soil types underground tile drainage may be necessary to safeguard trees from waterlogging. Nutrient levelsIt is important to take a soil test to determine the soil nutrient levels at potential planting sites. This will indicate whether any ammendments are required. Information on soil testing can be found in further information. pHSoil pH should ideally be between 6.0-6.5 anything above or below this can result in nutrient deficiencies. Alkaline soils (pH <6.0), particularly those with high lime or bicarbonate content can result in iron chlorosis (often referred to as lime induced chlorosis), particularly on quince rootstocks.
Figure 2: Assessing soil pH in an orchard. ClimatePears generally require between 500-1500 hours of chilling. Pears grow well in areas with warm and hot summers and low humidity. AspectA north or north easterly aspect is best for providing maximum sunlight during winter months. Slopes facing south are colder and more frost prone.
Figure 3: Orchard planting scenarios In the scenario in Figure 3 the orchard at site A is a warm location and will recieve more sun as it is North facing. It will be less prone to spring frosts as the cold air will drain to the lower lieing area (site B). Site B at the bottom of the valley will be the most susceptible to spring frosts because of the cold air draining to it from higher up the slopes. Site C is colder and will warm up more slowly than at site A because it is south facing. Top SlopeGently sloping sites are best. Steep slopes can pose significant safety issues particularly for machinery and equipment. Frost susceptibilityPears are highly susceptible to spring frosts. The financial risk associated with crop loss in an intensive orchard is high so minimising crop loss through frost damage is important. Initially growers need to avoid planting in frost prone areas. Planting sites need to also have good air drainage to prevent accumulation of cold air (avoid planting at the bottom of slopes or in hollows). Orchards need to be established with considerations for frost protection including warning systems and the installation of frost fans or sprinkler systems.
Figure 4: Frost fan in a stonefruit orchard. Management of the orchard floor is also important to minimise frost damage. All inter-rows should be slashed as close to the tree line as possible and weeds in tree lines sprayed. The aim is to have most of the orchard soil exposed to warming sunshine during the day so that heat accumulated can be released in the early mornings to reduce frost risk. For more information on frost and its management please see further resources. WindWind can damage fruit and reduce fruit quality, increase evaporation, affect pollination and damage newly planted trees. Support structures for trees should be installed prior to or soon after planting to minimise root damage in young trees. Water availabilityIntensive orchards need secure access to water for irrigation, spraying and possibly for frost protection and evaporative cooling. Good delivery infrstructure is essential. It is often recommended that growers ensure they can have atleast six megalitres of water per hectare of orchard. Go to the irrigation page for further information. Further informationThese Australian and international sites may be useful for growers, however they are intended as an information source only. Any specific chemical or other control recommendations may be outdated or irrelevant for Australian conditions and growers should seek local advice. Please note: By electing to visit sites linking from this page you will be leaving the intensivepear.com website. Australian Resources:Soils
Frost
International Resources:
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