Pecan industry expansion

SOLUTION AT Australian Expert Writers

Pecan industry expansionJuly, 2016, Primefact 1439, second editionJacquelyn Simpson, Research Horticulturist, Horticulture Unit, Yanco Agricultural InstituteIntroductionGlobal awareness of the health benefits of nuts, including pecans, is driving an increased demand for nutsand nut products. Pecans are native to the central south and south eastern regions of the US and Mexico.The first commercial planting of pecans commenced in the 1880s in the US, today pecans are alsocommercially grown in other regions including Mexico, South Africa, Israel, Argentina and Australia.This information package is supplementary to high-resolution maps available online. The informationprovided should be used as a guide to find potential regions for expansion. However, specific andcomprehensive site analysis must precede the final decision regarding site suitability for any orchardestablishment. A further use of this work would be to provide information on suitable regions for sentinelplantings to determine those most appropriate for expansion of the Australian pecan industry.PecansPecans (Carya illinoinensis) are an alternate-bearing, wind pollinated and self-incompatible tree. A varietyof cultivars are required within a pecan farm to ensure cross pollination. Wind pollination occurs duringSeptember and nuts mature until May when they are harvested. Pecan trees can grow 20 to 40 m tall withtrunks up to 2 m in diameter. The large alternate leaves of the pecan tree consist of up to 15 small pinnateleaflets and are deciduous. As pecan trees age, pruning is critical to maximising light interception (amountof sunlight which penetrates tree canopy) and yields.Australian Pecan IndustryThe majority of the Australian pecan industry is located in northern New South Wales (NSW) and southeastern Queensland (QLD). Stahmann Farms Trawalla property near Moree in northern NSW is thelargest pecan operation in the southern hemisphere. There are over 100 pecan growers in Australia withmore than 180,000 trees planted. Growers belonging to the Australian Pecan Growers Association(APGA) produce approximately 95% of nuts in Australia (APGA, 2011). Australian pecan production hasplateaued at around 3,000 tonnes (in shell) since 2006 (ANIC, 2015). There is strong interest in industryexpansion, and production is expected to increase to approximately 9,500 tonnes in shell by 2025.Identifying regions suitable for pecan production is a key factor for expanding the industry.Pecan Growth RequirementsChill and heatPecan trees are best grown in regions with hot, humid summers. Pecans, like other nut trees, require aminimum chill accumulation throughout dormancy (1 May to 31 August) for phenological processes,including budbreak and flowering. The quantity of chill units required varies between cultivars, rangingfrom 38.8 to 44 (Table 1). During spring time the accumulation of heat units is necessary for flowering andnut maturation. The quantity of heat units required also varies between cultivars, however, on averagepecan trees require 750 heat hours to accumulate throughout the growing season (approximately31 August to 31 October).Pecan industry expansion2 NSW Department of Primary Industries, December 2016Table 1 Chill portions (low from Schley variety, high from Wichita variety), heat units (degree days) and water(1 October to 30 April mm) requirements of pecan trees
WaterPecans are native to regions with humid summers and interrogation of literature revealed that pecansrequire at least 7 ML water during the growing season (1 October to 30 April). Research from theUniversity of Georgia reports pecans can use as much as 13 to 20 ML water annually. Disparities invalues between literature sources indicate the need for local research into pecan tree growth. Theaverage water requirement reported in literature has been applied as a rainfall contour to thebioclimatology model.SoilPecans prefer deep well drained, fertile soils. Australian soils are often poorly structured and have lowfertility and high salinity. Establishment of highly productive, sustainable and long term pecan plantingsrequires individual site analysis followed by careful planning and preparation. The depth, clay content,structure and previous use of the soils at each site has the potential to vary greatly within a small area.With chemical and physical amendments and additions, the scope of potentially suitable and productivesoils is broadened. Using the Australian Soils Classification and data obtained from the Australian SoilResource Information System (ASRIS, 2011) the soil layer was added as a 5th layer to the pecanbioclimatology model map.Risk factorsPecans and other nut crops are susceptible to certain risk factors including late spring frosts, high heatevents, and rainfall during harvest, but there are many other risks that affect different locations. Theseverity of the impact of risks varies each year, from region to region and even within small areas on anorchard. Furthermore, these risks are potentially negated or reduced by orchard management strategies,and are influenced by orchard size and local infrastructure. These factors are not incorporated into themodel as we are not able to accurately account for the high variability between locations, farmmanagement, infrastructure and the severity of each risk factor from year to year. We strongly recommendlocal research to assess the potential for negative climatic conditions.Pecan industry expansion3 NSW Department of Primary Industries, December 2016Bioclimatology model for pecan industry expansionPotentially suitable regions for pecan industry expansion throughout Australia have been modelled usingbioclimatology – the study of the effects of climate on living organisms. The aim of this work is to providean objective basis for expansion of the Australian pecan industry.Figure 1 Bioclimatology model for pecan industry expansion.The bioclimatology model was generated based on pecan tree phenology requirements. The DynamicModel of Chill Portions (Dynamic Model) quantifies chill hours (hours between 0 °C and 7.2 °C) accountingfor the cancelling effect of heat. This model has been extensively tested on many crops in Australia andCalifornia (Luedeling, 2011; Zhang, 2011). Chill portions were determined as the most limiting factor toregional suitability so were the primary factor to be modelled.Additional layers were added to the chill portion map to incorporate water availability and soil suitability.Water availability has been added in the form of blue contour lines for rainfall, blue shaded vectors forirrigation schemes, and grey lines show the river catchment areas. The depth of green shading increaseswith increasing soil suitability.Dynamic Model to predict chill portions and heat unit requirementsThe Dynamic Model was used to predict chill portions and heat units for 5 km × 5 km grid points coveringthe entirety of Australia. The Dynamic Model uses daily temperature maxima and minima to generatehourly temperatures for the midpoint of each grid. Chill portions were calculated for 1 May–31 August andheat units for 1 October–30 April. We interpolated chill portion data, from the Bureau of Meteorology(BoM) historical temperature records, gathered since 1996 to overcome special and temporaldiscontinuities within BoM data records.The ‘R’ statistical package was used to plot dark green chill portion contour lines on a digital map ofAustralia for each of six temperate nut industries (Figure 2). The upper dark green contour represents theminimum chill requirement and the lower dark green contour represents the maximum chill requirementsfor a range of commercial cultivars for each nut type.Interpreting the modelPecan industry expansion4 NSW Department of Primary Industries, December 2016A sample section of the hazelnut industry map (Figure 3) outlines the key features of the bioclimatologymodels: chill portion contours, river catchment regions, rainfall contour, irrigation scheme areas and soilsuitability. These are features common to each nut industry model. The two chill portion contoursrepresent the range in chill portion requirements of the range of commercial cultivars for each nut crop (asdescribe further in the following sections for each specific nut crop).Figure 2 Key to interpretation of bioclimatology model. An example using hazelnut bioclimatology mapWater availabilityCatchment areas are outlined on the bioclimatology map (grey). Due to the dynamic nature of wateravailability in some catchment areas these are provided as a guide from which to seek further information.For example, Figure 3 shows the Paroo River, Lake Bancannia and Darling River catchments of northernNSW/southern QLD, however, the water availability in these catchments is variable and depends on manyfactors including rainfall and temperature.Figure 3 Example of river catchments shown on pecan bioclimatology mapThere are some river catchment areas that are highly suitable for establishing nut tree plantings. The mostsuitable river catchment areas contain perennial rivers that constantly flow and are relatively reliablesources of stable water, compared with non-perennial or seasonally flowing rivers.The main perennial river systems with the capability to supply water for irrigation are the Murrumbidgeeand Murray rivers, which run through NSW, Victoria and South Australia (SA). There are also coastalperennial river systems on the east coast of Australia and small perennial rivers in south-western WesternAustralia (WA).RecommendationsSuitable regions for expansion of Australian Pecan industry could be within the irrigation scheme of theMurrimbidgee Irrigation Area (MIA) and areas of central NSW (Figure 4).Pecan industry expansion5 NSW Department of Primary Industries, December 2016Figure 4 – Example of potentially productive regions (MIA and central NSW)There are potentially suitable regions on the QLD/NSW border near Moree and Stanthorpe (Figure 5a)and the NSW/Victorian border near Mildura (Figure 5b).Figure 5 Example of potentially productive regions (a – NSW/QLD border, b – NSW/Vic/SA border)Online resourcesModel available for download as PDFThe model generated is available online as an extremely high-resolution map. This map is able to beinterrogated, by zooming, to a resolution of 5 × 5 km. The model is based on bioclimatology and thephenological requirements pecans. Models for other temperate nut industries (almonds, chestnuts,hazelnuts, pistachios and walnuts) have also been developed and are also available online from the NSWDPI nuts page.Multi-industry information package and mapThis Primefact is one of six industry specific Primefacts available online (NSW DPI nuts page). In addition,we have a multi-industry information package, which includes more information than these industryspecific documents and a more user friendly map. This user friendly map does not include all thePecan industry expansion6 NSW Department of Primary Industries, December 2016information (rainfall, soil or irrigation schemes) that the PDF maps do and we suggest using the two maptypes to get the maximum possible use out of the resources available.Reference ListANIC (2015) Australian Nut Industry Council ANIC 2015APGA (2011) Pecan growing in Australia Australian Pecan Growers Association 2011 Available from:APGA Accessed: Nov 2015ASRIS (2011). ASRIS – Australian Soil Resource Information System. CSIRO Land and Water Availablefrom: ASRIS Accessed Sept 2015.Luedeling, E. & Brown, P. (2011). A global analysis on the comparability of winter chill models for fruit andnut trees. International Journal of Biometeorology 55: 411–421.SoE (2011) Australia’s state of the environment report 2011: Chapter 4– Inland water. AustralianGovernment Department of Environment. SoE2011Zhang, J. & Taylor, C. (2011). The Dynamic Model provides the best description of the chill process on‘Sirora’ pistachio trees in Australia. HortScience 46:420–425.More informationJacquelyn Simpson 02 6951 2611 email: [email protected] project is a collaborative work by Shane Hetherington (Director Horticulture), Jacquelyn Simpson(Research Horticulturist), Lorraine Spohr (Biometrician), Damian Collins (Biometrician) and Jianhua Mo(Entomologist) of NSW DPI and Michael Treeby (Senior Research Scientist, Department of EconomicDevelopment, Jobs, Transport and Resources), formerly NSW DPI.This project has been funded by Horticulture Innovation Australia Limited using the almond and chestnutindustry research and development (R&D) levies, co‐investment from the Australian Nut Industry Counciland funds from the Australian Government.For updates go to © State of New South Wales through the Department of Trade and Investment, Regional Infrastructure and Services 2015. You may copy,distribute and otherwise freely deal with this publication for any purpose, provided that you attribute the NSW Department of Primary Industries as theowner. ISSN 1832-6668Disclaimer: The information contained in this publication is based on knowledge and understanding at the time of writing (December 2016). However,because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currencyof the information with the appropriate officer of the Department of Primary Industries or the user’s independent adviser.Published by the NSW Department of Primary Industries. JT13812; INT15/130650

Order from Australian Expert Writers
Best Australian Academic Writers