Physiological mechanisms underpinning tolerance to high temperature stress during reproductive phase in mungbean (Vigna radiata (L.) Wilczek)

This study investigated the physiological factors underlying genotypic variation in response to high temperature and the role of acclimation prior to high temperature stress, in mungbean genotypes, selected based on their sensitivity to high temperature. The genotypes were subjected to three temperature regimes during the reproductive phase, i.e. normal (28 °C/24 °C, CON), acclimation temperature (35 °C/28 °C, Ac-HT) before transferring to high temperature (45 °C/30 °C), and direct exposure of non-acclimated plants to high temperature (45 °C/30 °C, NAc-HT). Environmentally controlled growth chambers were used to provide the required temperature regimes. The plants were maintained at fully watered conditions throughout the growing cycle. The average shoot biomass (including root) was reduced by 9% and 41%, and the grain yield by 31% and 50%, in the acclimated (Ac-HT) and non-acclimated (NAc-HT) treatments, respectively, compared to CON. The mean root weight in the NAc-HT treatment was reduced by 32%, while the mean root weight in Ac-HT treatment was comparable to CON, although there was genotypic variation with in the treatments. The mean root weight in the tolerant group was 48%, 180% and 130% greater than susceptible group, in CON, Ac-HT and NAc-HT treatments, respectively. There was significant variation among genotypes for root weight. A positive relationship (r = 0.54**) between root and shoot weight indicated that plants with larger root weight also produced higher shoot biomass. The high temperature tolerant genotypes responded to acclimation treatment by promoting root growth while such enhanced root growth was not observed in susceptible genotypes. The study suggested that acclimation treatment followed by high temperature could be used as a technique to identify genotypes with ability to adapt to high temperature stress conditions

Formal planning and the reshaping of public sector professional work

This paper deals with the ‘managerialization’ of public sector professional work. Specifically, it will focus on the role of formal planning practices (as expressed in strategic planning, project management and budgeting practices) in changing public sector professional work. Planning and accounting are at the heart of public sector reforms, responding to a logic of having public service professionals transparent on what they do, on how they pursue their goals, and accountable on the use of resources and on results. Thus planning and accounting practices have been transferred from private sector management models to public, professional organizations. Yet public sector professional organizations can be conceived as a pluralistic setting characterized by diffuse power, fragmented objectives and knowledgebased and are deeply embedded in public administration regulatory logics: how can management models deriving from private, hierarchical firms be applied to the specificities and complexities of public, pluralistic settings? What is the specific meaning of formal planning practices in such complex contexts? Based on a qualitative, single case study design, this paper will show how the planning system (in its manifestation of strategic planning, project management and budgeting) applied in a public hospital apparently ‘fails’ when its deliberate role of serving as a tool for decisions is considered. Yet it is widely in use and widely accepted by professionals as well. Conclusions on the value of formal planning when other emergent roles are taken into account will be discussed

Can partial reduction of shoot biomass during early vegetative phase of chickpea save subsoil water for reproductive and pod filling?

The present study investigated if partial reduction of shoot dry matter during early vegetative growth phase of chickpea crop (cv. PBA Seamer) saves sub-soil water for reproductive growth and grain filling of the crop grown at 9 diverse environments. The environments were created by a combination of 3 sites (Emerald, Hermitage and Kingaroy), 3 planting windows (environments 1, 2, 3 at each site) with and without supplementary irrigation. The effects of environments on canopy management (partial reduction in shoot dry matter vs control) and irrigation treatments on the water uptake by roots, crop growth and yield performance and yield components were investigated. Crops in the planting windows (EN 1, 2, 3) experienced variable environments at each site. Days to 50% flowering and crop maturity reduced progressively from EN 1 to EN 3 at the three sites. The environment had significant effect on shoot biomass, yield and HI at the three sites (P  0.5 in EN 2 at Emerald. There was a trend for an increase in HI from EN 1 to EN 3 at all sites. The response to Irr, computed as the difference in peak shoot biomass and yield between the Irr and RF treatments, was the highest at Hermitage and the least at Emerald site. Vapour pressure deficit during reproductive phase accounted for the majority of variation in shoot biomass response to irrigation (r2 =0.66, P < 0.001) for total dry matter and (r2 =0.46, P < 0.01) for yield. The environments had a significant effect on radiation use efficiency and water use efficiency and the yield components including hundred seed weight

Defining agro-ecological regions for field crops in variable target production environments: A case study on mungbean in the northern grains region of Australia

The northern grains region (NGR) of Australia, which includes the state of Queensland and the northern half of the New South Wales, has highly variable climate leading to heightened production risk for all rainfed crops. Characterisation of the production environment of this region can assist in exploration of potential opportunities for reducing this risk. In this case study on mungbean (Vigna radiata L. Wilczek.) we demonstrate how this region could be characterised using the Agricultural Production Systems sIMulator (APSIM) model. The model was first evaluated for variety Crystal grown widely in the region, and then applied to simulate a water stress index (the daily supply and demand ratio) and yield from 1889 to 2012 at 28 locations. The model was run using location specific as well as three generic soils of 136, 166 and 204. mm plant available water holding capacities (PAWC). Two complementary characterisations were performed using the simulated output, one based on clustering of supply demand ratio averaged for every 100. °Cd to and from flowering, and another on clustering of percentile rankings of seasonal yield variation at different locations. Clustering of supply demand ratio revealed four drought patterns (i.e., target production environments) which commenced at different times from flowering. Seasonal frequencies of these drought patterns, which differed due to major location effects and relatively smaller soil effects, accounted for significant (~84%) variation in simulated yield. Clustering of percentile ranks corresponding to simulated yield in different seasons identified seven meaningful yield clusters. Location memberships of these yield clusters were geographically contiguous and were only slightly influenced for the lowest PAWC generic soil. All locations within these yield clusters showed a tendency to have similar seasonal drought patterns and their frequencies. Locations within different yield clusters could therefore be considered as part of distinct agro-ecoregions. These model defined agro-ecoregions could be used as selection environments for their dominant target production environment(s) to develop new genotypes and their agronomy for better adaptation and yield under variable climatic conditions

Capacitance sensor for nondestructive determination of total oil content in peanut kernels

In this work, attempts were made to estimate the total oil content (TOC) in single peanut kernels, using the CI meter (Chari's Impedance meter, described below). Mature peanut kernels of selected varieties with a range of oil contents from 47% to 61% were placed one at a time, between the parallel-plate electrodes of the CI meter, and the impedance (Z) and phase angle (θ) of the system were measured, and capacitance, C was computed at 1, 5 and 9 MHz. After the measurements, the TOC of each kernel was determined by Soxhlet method. Using the known TOC values, and the corresponding C, Z and 0 values, initially on a calibration group of kernels, calibration equations were developed. Using the model coefficients from the calibration, the TOCs of kernel samples of 31 diverse peanut genotypes grown in different environments in Australia were determined. The method predicted the TOC values of peanut kernels of 31 peanut genotypes, within 2% of the Soxhlet values, with an R of 0.87 (

Peanut: a friend or a foe?

About 36 million tons of peanuts are produced annually worldwide. Penut kernels are utilized as a major source of cooking oil in developing countries and are used in snack food industries in developed countries. Although the use of peanut kernels as a confectionary snack is increasing rapidly due to growing trends of vegetarianism and a demand for healthy foods, aflatoxin and allergenic proteins have become major public health issues globally. The aim of Chapter 1 is to introduce the reader to "positives (bioactives)" and "negatives (allergens)" in peanuts and to provide a comprehensive and up-to-date review of both beneficial and allergenic compounds present in peanut kernels including current information about bioengineering and allergen management

Integrated weed management using row arrangements and herbicides in pigeonpea (Cajanus cajan) in Australia

In Australia, efforts are under way to revive the pigeonpea (Cajanus cajan (L.) Millsp.) industry, which has high export potential because of an increased demand in the international market. However, weeds are a major constraint to achieve high yield in pigeonpea. This study was designed to assess the effect of row arrangement and herbicide treatment on weed suppression and pigeonpea grain yield. Row arrangements included row spacing (narrow, 25 cm wide, 50 cm) and paired rows (rows 25 cm apart within a pair, each pair separated from the next by 75 cm). Herbicide treatments were: untreated control pre-emergent pendimethalin at 910 g a.i. ha post-emergent imazapic at 84 g a.i. ha and pre-emergent pendimethalin followed by post-emergent imazapic (rates as above). In the first year, Trianthema portulacastrum was the dominant weed, and infestation was 100% in the non-treated control plots. In the second year, other weeds (Setaria viridis, Eragrostis cilianensis and Chloris virgata) comprised 30% of the weed population. Averaged over row arrangements, grain yield varied from 2088 to 2689 kg ha in 2017 and from 835 to 2145 kg ha in 2018, and was lowest in the untreated control and highest in the plots treated with the sequential application of pendimethalin and imazapic. Averaged over years and herbicide treatments, yield was lower in paired rows (1850 kg ha) than in narrow (2225 kg ha) and wide (2165 kg ha) row spacings. In the first year, all herbicide treatments provided >50% control of T. portulacastrum in the narrow and wide row spacings and increased yield by >22% over the untreated control. In the second year, the single application of imazapic proved inferior for controlling weeds, resulting in a 21% reduction in grain yield compared with sequential application of pendimethalin and imazapic. In both years, grain yield was similar for the single application of pendimethalin and sequential application of pendimethalin and imazapic. Despite the complex weed flora in 2018, the single application of imazapic provided acceptable weed control only when the crop was planted at 25 cm row spacing. Our results suggest that the single application of pendimethalin was effective on T. portulacastrum. However, in a complex weed flora situation, the sequential application of pendimethalin and imazapic provided effective weed control and resulted in improved yield

Characterization of maize growing environments in eastern and southern Africa using the APSIM model

Maize grown in eastern and southern Africa experiences random occurrences of drought. This uncertainty creates difficulty in developing superior varieties and their agronomy. Characterisation of drought types and their frequencies could help in better defining selection environments for improving resistance to drought. We used the well tested APSIM maize model to characterise major drought stress patterns and their frequencies across six countries of the region including Ethiopia, Kenya, Tanzania, Malawi, Mozambique and Zimbabwe. The database thus generated covered 35 sites, 17 to 86 years of daily climate records, 3 varieties and 3 planting densities from a total of 11,174 simulations. The analysis identified four major drought environment types including those characterised by low-stress which occurred in 42% of the years, mid-season drought occurring in 15% of the years, late-terminal stress which occurred in 22% of the years and early-terminal drought occurring in 21% of the years. These frequencies varied in relation to sites, genotypes and management. The simulations showed that early terminal stress could result in a yield reduction of 70% compared with low-stress environmental types. The study presents the importance of environmental characterization in contributing to maize improvement in eastern and southern Africa