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Kingaroy, Australia

Chauhan Y.S.,Economic Development and Innovation DEEDI | Wright G.C.,Peanut Company of Australia | Rachaputi R.C.N.,Economic Development and Innovation DEEDI | Holzworth D.,CSIRO | And 3 more authors.
Journal of Agricultural Science

When exposed to hot (22-35C) and dry climatic conditions in the field during the final 4-6 weeks of pod filling, peanuts (Arachis hypogaea L.) can accumulate highly carcinogenic and immuno-suppressing aflatoxins. Forecasting of the risk posed by these conditions can assist in minimizing pre-harvest contamination. A model was therefore developed as part of the Agricultural Production Systems Simulator (APSIM) peanut module, which calculated an aflatoxin risk index (ARI) using four temperature response functions when fractional available soil water was <0.20 and the crop was in the last 040 of the pod-filling phase. ARI explained 095 (P≤0.05) of the variation in aflatoxin contamination, which varied from 0 to c. 800 g/kg in 17 large-scale sowings in tropical and four sowings in sub-tropical environments carried out in Australia between 13 November and 16 December 2007. ARI also explained 096 (P≤0.01) of the variation in the proportion of aflatoxin-contaminated loads (>15 μg/kg) of peanuts in the Kingaroy region of Australia during the period between the 1998/99 and 2007/08 seasons. Simulation of ARI using historical climatic data from 1890 to 2007 indicated a three-fold increase in its value since 1980 compared to the entire previous period. The increase was associated with increases in ambient temperature and decreases in rainfall. To facilitate routine monitoring of aflatoxin risk by growers in near real time, a web interface of the model was also developed. The ARI predicted using this interface for eight growers correlated significantly with the level of contamination in crops (r=0.95, P≤0.01). These results suggest that ARI simulated by the model is a reliable indicator of aflatoxin contamination that can be used in aflatoxin research as well as a decision-support tool to monitor pre-harvest aflatoxin risk in peanuts. © 2010 Cambridge University Press. Source

Chauhan Y.S.,Economic Development and Innovation DEEDI | Wright G.C.,Peanut Company of Australia | Holzworth D.,CSIRO | Rachaputi R.C.N.,University of Queensland | Payero J.O.,University of Queensland
Irrigation Science

Peanut (Arachis hypogaea L.) is an economically important legume crop in irrigated production areas of northern Australia. Although the potential pod yield of the crop in these areas is about 8 t ha-1, most growers generally obtain around 5 t ha-1, partly due to poor irrigation management. Better information and tools that are easy to use, accurate, and cost-effective are therefore needed to help local peanut growers improve irrigation management. This paper introduces a new web-based decision support system called AQUAMAN that was developed to assist Australian peanut growers schedule irrigations. It simulates the timing and depth of future irrigations by combining procedures from the food and agriculture organization (FAO) guidelines for irrigation scheduling (FAO-56) with those of the agricultural production systems simulator (APSIM) modeling framework. Here, we present a description of AQUAMAN and results of a series of activities (i. e., extension activities, case studies, and a survey) that were conducted to assess its level of acceptance among Australian peanut growers, obtain feedback for future improvements, and evaluate its performance. Application of the tool for scheduling irrigations of commercial peanut farms since its release in 2004-2005 has shown good acceptance by local peanuts growers and potential for significantly improving yield. Limited comparison with the farmer practice of matching the pan evaporation demand during rain-free periods in 2006-2007 and 2008-2009 suggested that AQUAMAN enabled irrigation water savings of up to 50% and the realization of enhanced water and irrigation use efficiencies. © 2011 Her Majesty the Queen in Right of Australia as represented by The Government of Queensland. Source

Agegnehu G.,James Cook University | Bass A.M.,University of Western Sydney | Nelson P.N.,James Cook University | Muirhead B.,Gulf | And 2 more authors.
Agriculture, Ecosystems and Environment

This study investigated the effects of biochar and compost, applied individually or together, on soil fertility, peanut yield and greenhouse gas (GHG) emissions on a Ferralsol in north Queensland, Australia. The treatments were (1) inorganic fertilizer only (F) as a control; (2) 10tha-1 biochar+F (B+F); (3) 25t compost+F (Com+F)ha-1; (4) 2.5t Bha-1+25t Comha-1 mixed on site+F; and (5) 25tha-1 co-composted biochar-compost+F (COMBI+F). Application of B and COMBI increased seed yield by 23% and 24%, respectively. Biochar, compost and their mixtures significantly improved plant nutrient availability and use, which appeared critical in improving peanut performance. Soil organic carbon (SOC) increased from 0.93% (F only) to 1.25% (B amended), soil water content (SWC) from 18% (F only) to over 23% (B amended) and CEC from 8.9cmol(+)/kg (F only) to over 10.3cmol(+)/kg (organic amended). Peanut yield was significantly positively correlated with leaf chlorophyll content, nodulation number (NN), leaf nutrient concentration, SOC and SWC for the organic amendments. Fluxes of CO2 were highest for the F treatment and lowest for the COMBI treatment, whereas N2O flux was highest for the F treatment and all organic amended plots reduced N2O flux relative to the control. Principal component analysis indicates that 24 out of 30 characters in the first principal component (PRIN1) individually contributed substantial effects to the total variation between the treatments. Our study concludes that applications of B, Com, B+Com or COMBI have strong potential to, over time, improve SOC, SWC, soil nutrient status, peanut yield and abate GHG fluxes on tropical Ferralsols. © 2015 Published by Elsevier B.V. Source

Phan-Thien K.-Y.,University of New South Wales | Phan-Thien K.-Y.,University of Sydney | Wright G.C.,Peanut Company of Australia | Lee N.A.,University of New South Wales
LWT - Food Science and Technology

Five peanut (Arachis hypogaea L.) genotypes with diverse antioxidant capacity were quantitatively profiled for p-coumaric acid, salicylic acid, resveratrol, and daidzein. The co-eluting compounds, caffeic/vanillic acid and ferulic/sinapic acid, were quantified on caffeic acid equivalent and ferulic acid equivalent bases, respectively. The HPLC analysis established significant genotypic differences (P<0.05) in free and total phytochemical composition and also demonstrated the importance of the bound (e.g., conjugated and matrix-embedded) fraction. Specifically, the study suggested that 77-93% of the p-coumaric acid, 44-53% of the ferulic/sinapic acid, 71-89% of the salicylic acid, 59-68% of the resveratrol, and 89-97% of the daidzein in raw peanut kernels were present in bound forms. D147-p8-6F and Sutherland were sister-lines (derived from the same F2 plant) that had high foliar disease tolerance, high antioxidant capacity, and similar phytochemical profiles, which was consistent with associations between phytoalexin production and genetically determined disease resistance made by previous researchers. Principal components analysis linked high antioxidant capacity with a combination of phytochemicals that were not directly correlated in bivariate analysis (e.g., resveratrol was negatively correlated with caffeic/vanillic and p-coumaric acid) and that were not delineated by genotype. © 2013 Elsevier Ltd. Source

Phan-Thien K.-Y.,University of New South Wales | Wright G.C.,Peanut Company of Australia | Lee N.A.,University of New South Wales
Journal of Agricultural and Food Chemistry

The concentrations of 15 essential minerals (B, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Se, and Zn) in kernels of nine diverse peanut genotypes, which were cultivated in five distinct growing environments, were analyzed by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and -mass spectrometry (ICP-MS). The effects of genotype, environment, and genotype-by-environment (G × E) interactions were significant (P > 0.05) for all elements excluding Cr. Genetic control of mineral composition was demonstrated by large (P > 0.05) genotypic differences in Ca, Mo, K, Na, and P contents, and clustering of some genotypes in environment-centered principal components analysis (PCA) along axes comprising both macro (Ca, Mg, P, and K)- and microelements (Co, Cu, Fe, Mn, and Zn). Mo and Na concentrations were strongly influenced (P > 0.05) y the growing environment, with very high levels measured in samples from Bundaberg. The results confirm that that there is breeding potential for several important minerals in peanuts, although significant G × E interactions will complicate the response to selection. From a practical viewpoint, combining genetic improvement with agronomic management may be a useful strategy to consistently achieve desirable mineral concentrations in peanut kernels. © 2010 American Chemical Society. Source

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