Dual-purpose Crop Research Articles

Integrating dual-purpose wheat and canola into high-rainfall livestock systems in south-eastern Australia. 1. Crop forage and grain yield

The development of guidelines for successful dual-purpose (graze and grain) use of wheat and canola in Australia’s high-rainfall zones (HRZ) has mostly emerged from separate wheat- and canola-focused research. Less attention has been placed on the benefits of integrating dual-purpose wheat and canola into pasture-based grazing enterprises. We conducted a farming systems experiment during 2010–11 to evaluate the benefits of integrating wheat and canola as dual-purpose crops into a pasture-based grazing system in Australia’s south-eastern tablelands. We compared forage production and grain yield in three separate crop–livestock systems in which the sheep grazed long-season wheat, winter canola or a combination of these. Initial growth rates were higher in early-autumn-sown canola than wheat in 2010, but were much lower although similar in both crops in 2011. Significant forage was available from both canola (3.1–3.4 t ha–1) and wheat (2.3–2.4 t ha–1) at the onset of grazing, but winter growth rates of wheat were higher than those of canola, leading to increased sheep grazing days (SGD). In the favourable 2010 season, dual-purpose wheat and canola separately provided 2393 and 2095 SGD ha–1, and yielded 5.0 and 1.9 t ha–1 grain, respectively, with an apparent nitrogen limitation in canola. In the drier season of 2011, grazing was reduced to 1455 and 735 SGD ha–1 in wheat and canola, respectively. Wheat yield was reduced from 5.9 to 5.4 t ha–1 grain by grazing, whereas canola yield was unaffected (3.6 t ha–1). In both years, grazing did not affect harvest index or oil content of canola, but harvest index was higher in grazed wheat crops. The yield of wheat and canola crops grazed in sequence did not differ from yield in treatments where animals grazed only a single crop, but the total overall grazing window when crops were grazed sequentially increased by 1054 and 618 SGD ha–1 in wheat, and by 1352 and 1338 SGD ha–1 in canola in 2010 and 2011, respectively. The major benefits of including crops that can be grazed sequentially were the widening of the grazing window and other operational windows (sowing, harvest), along with the rotational benefits for wheat by including canola in the system. Additional benefits to pastures may include eliminating the need to re-sow, because a more productive pasture composition is maintained under lower grazing pressure while stock are on crops, and reduced weed invasion. The commercial availability of new, herbicide-tolerant winter canola varieties provides significant opportunities to underpin the performance of dual-purpose crop sequences on mixed farms in the high-rainfall zone.

Forage canola (Brassica napus): spring-sown winter canola for biennial dual-purpose use in the high-rainfall zone of southern Australia

European winter canola (Brassica napus L.) varieties adapted to the long, cool seasons in high-rainfall areas of southern Australia have recently been adopted as autumn-sown, grain-only and dual-purpose crops. A spring-sown winter canola could be used as a biennial dual-purpose crop, to provide additional forage for summer and autumn grazing before recovery to produce an oilseed crop. We report a series of field experiments demonstrating that European winter canola types have suitable phenological characteristics to allow for their use as biennial, spring-sown crops, providing significant forage (2.5–4 t ha–1) for grazing while remaining vegetative through summer and autumn, and recovering following vernalisation in winter to produce high seed yield (2.5–5.0 t ha–1). Sowing too early (September) in colder inland areas risked exposure of the crop to vernalising temperatures, causing the crop to bolt to flower in summer, whereas all crops sown from mid-October remained vegetative through summer. Crop stands thinned by 20–30% during summer, and this was exacerbated by grazing, but surviving stands of ~30 plants m–2 were sufficient to support high yields. Grazing had no effect on grain yield at one site, but reduced yield by 0.5 t ha–1 at a second site, although this was more than offset by the value of the grazed forage. The spring-sowing approach has potential to replace the existing forage rape–spring cereal sequence, or to add a further option to the existing autumn-sown winter canola in areas such as southern Victoria, where early autumn establishment can be problematic and spring-sown crops can better withstand pests and winter waterlogging, which limit yield of autumn-sown crops. Because these are the first known studies in Australia to investigate the use of spring-sown winter canola, further work is warranted to refine further the crop and grazing strategies to maximise productivity and profitability from this option.

Evaluating the feasibility of dual-purpose canola in a medium-rainfall zone of south-eastern Australia: a simulation approach

Canola (Brassica napus L.) has recently been adopted as a dual-purpose crop (graze and grain) in the higher rainfall areas (>550 mm) of eastern Australia, but the feasibility in drier inland areas with a shorter growing season is uncertain. We modified the APSIM-Canola model by using observations from an irrigated grazing experiment, with the aim of using a simulation approach to investigate various aspects of dual-purpose canola production. Sowing opportunities, forage production for grazing and grain production were considered in the simulations, and effects of variables such as sowing date, cultivar type, plant density and nitrogen supply were investigated in simulations for 109 years of climate data from Wagga Wagga, NSW. APSIM-Canola predictions of vegetative growth and grain yield for recent varieties were inadequate when using existing parameters, but were improved by increasing the maximum leaf area parameter to reflect those of modern hybrid types. For grazed crops, APSIM-Canola overestimated the initial rate of regrowth, but accurately simulated biomass at flowering. Simulations of a range of management options to generate different pre-grazing biomass predicted that sowing before 15 May, using vigorous (hybrid) cultivars, high plant density (60–80 plants m–2) and adequate soil nitrogen, maximised biomass production. Assuming a rainfall-based sowing opportunity of 25 mm over 3 days and a minimum pre-grazing biomass of 1000 kg ha–1, grazing was possible in 53% of years, with 50% of those years providing grazing opportunities before 7 June at Wagga Wagga. Depending on stocking rate, crops could be grazed until early to mid-July, providing 400–1000 dry sheep equivalent days ha–1 of grazing, and allow regrowth to achieve a target biomass of 5000 kg ha–1 at flowering, which was required to maximise potential yield. The simulation analysis confirms significant opportunities to achieve valuable livestock grazing from canola crops sown in an early window (before May) without compromising potential yield, and the simulation framework developed can be readily applied to other regions.

Forage and grain yield of grazed or defoliated spring and winter cereals in a winter-dominant, low-rainfall environment

In the Mallee region of north-western Victoria, Australia, there is very little grazing of crops that are intended for grain production. The success of dual-purpose crops in other regions in south-eastern Australia with higher and more evenly distributed rainfall has driven interest in assessing the performance of dual-purpose cereals in the region. Five experiments were established in five consecutive years (2009–13) in the southern Mallee to measure the forage production and grain yield and quality response in wheat and barley to grazing by sheep or mechanical defoliation. The first three experiments focused on spring cultivars sown from late April to June, and the last two on winter cultivars planted from late February to early March. Cereal crops provided early and nutritious feed for livestock, with earlier sowing increasing the amount of dry matter available for winter grazing, and barley consistently produced more dry matter at the time of grazing or defoliation than wheat. However, the grain-production response of cereals to grazing or defoliation was variable and unpredictable. Effects on yield varied from –0.7 to +0.6 t/ha, with most site × year × cultivar combinations neutral (23) or negative (14), and few positive (2). Changes in grain protein were generally consistent with yield dilution effects. Defoliation increased the percentage of screenings (grains passing a 2-mm sieve) in three of five experiments. Given the risk of reduced grain yield and quality found in this study, and the importance of grain income in determining farm profitability in the region, it is unlikely that dual-purpose use of current cereal cultivars will become widespread under existing grazing management guidelines for dual-purpose crops (i.e. that cereal crops can be safely grazed once anchored, until Zadoks growth stage Z30, without grain yield penalty). It was demonstrated that early-sown winter wheat cultivars could produce more dry matter for grazing (0.4–0.5 t/ha) than later sown spring wheat and barley cultivars popular in the region (0.03–0.21 t/ha), and development of regionally adapted winter cultivars may facilitate adoption of dual-purpose cereals on mixed farms.

Optimising grain yield and grazing potential of crops across Australia’s high-rainfall zone: a simulation analysis. 1. Wheat

Interest is growing in the potential to expand cropping into Australia’s high-rainfall zone (HRZ). Dual-purpose crops are suited to the longer growing seasons in these environments to provide both early grazing for livestock and later regrow to produce grain. Grain yield and grazing potential of wheats of four different maturity types were simulated over 50 years at 13 locations across Australia’s HRZ, and sowing date, nitrogen (N) availability and crop density effects were explored. Potential grazing days on wheat were obtained by simulating sheep grazing crops to Zadoks growth stage Z30 at 25 dry sheep equivalents (DSE)/ha. Optimal sowing dates for each maturity type at each location were matched to the flowering window during which risk of frost and heat stress was lowest. Overall, we found significant national potential for dual-purpose use of winter wheat cultivars across Australia’s HRZ, with opportunities identified in all regions. Simulated mean wheat yields exceeded 6 t/ha at most locations, with highest mean grain yields (8–10 t/ha) in southern Victoria, and lower yields (5–7 t/ha) in the south-west of Western Australia (WA) and central and northern New South Wales (NSW). Highest grazing days were from winter cultivars sown early (March–mid-April), which could provide 1700–3000 DSE-days/ha of grazing across HRZ locations; this was 2–3 times higher than could be obtained from grazing spring cultivars (200–800 DSE-days/ha). Sowing date was critical to maximise both grazing and grain yield potential from winter cultivars; each 1-week delay in sowing after 8 March reduced grazing by 200–250 DSE-days/ha and grain yield by 0.45 t/ha. However, in Mediterranean climates, a lower frequency of early sowing opportunities before mid-April (<30% of years) is likely to limit the potential to use winter cultivars. Prospects to graze shorter season spring cultivars that fit later sowing windows require further examination in south-west WA, the slopes of NSW and southern Queensland.

Effect of defoliation by grazing or shoot removal on the root growth of field-grown wheat (Triticum aestivum L.)

Dual-purpose crops for grazing and grain production can be highly profitable, provided grazing does not cause significant loss of grain yield. In many plants, defoliation causes a transient reduction in the allocation of resources to stem and root growth and remobilisation of soluble resources to re-establish leaf area rapidly. In Australia, the usual autumn and winter period of defoliation for grazed crops, May–July, coincides with a phase of near-linear root depth penetration in ungrazed crops, and the crop recovery period after grazing occurs during stem elongation, when grain number and yield potential are determined. However, few studies have investigated the potential impact of crop defoliation through grazing on root growth of wheat in the field. We investigated the effect of defoliation by grazing or shoot removal on the root growth of wheat crops in four field experiments in south-eastern Australia in which the timing, frequency and intensity of defoliation varied. Despite significant impacts of defoliation on aboveground biomass (50–90% reduction) and grain yield (10–43% reduction) in all experiments, we found little evidence of effects on the rate of root penetration or final rooting depth. A notable exception was observed in one experiment when defoliation commenced very early (four-leaf stage, Zadoks growth stage Z14) in a repeatedly defoliated crop, reducing rooting depth from 1.65 to 1.35 m. The only other measured impact on roots was in an early-sown winter wheat crop grazed by sheep for 3 months (6 June–3 September), in which root length density was reduced by ~50% in surface layers above 1.0 m depth, but there was no impact on maximum root depth or root length density at 1.0–2.0 m depth. Our results suggest that grazing has little impact on the rooting depth of wheat unless it occurs very early and repeatedly, when plants are allocating significant resources to establish the primary roots. However, there may be some reduction in the density of roots in surface layers during recovery after long-term grazing, presumably associated with reduced proliferation of the nodal root system. We conclude that most significant yield penalties due to grazing relate to impacts on the assimilation of aboveground resources, rather than to reduced water or nutrient acquisition by roots.

Winter Wheat Cultivars with Temperature-Sensitive Resistance to Wheat streak mosaic virus Do Not Recover from Early-Season Infections.

Wheat streak mosaic virus (WSMV), Triticum mosaic virus, and Wheat mosaic virus, all vectored by the wheat curl mite Aceria tosichella Keifer, frequently cause devastating losses to winter wheat production throughout the central and western Great Plains. Resistant 'Mace' and 'RonL are commercially available and contain the wsm1 and wsm2 genes, respectively, for resistance to WSMV. However, the resistance in these cultivars is temperature sensitive, ineffective above 27°C, and does not protect against the other common wheat viruses. The majority of winter wheat in the Southern Great Plains is planted in early fall as a dual-purpose crop for both grazing and grain production. Early planting exposes wheat plants to warmer temperatures above the threshold for effective resistance. Studies were conducted to determine whether the resistance found in these cultivars would give infected plants the ability to recover as temperatures cooled to a range conducive to effective genetic resistance. RonL, Mace, 'TAM 111', 'TAM 112', and 'Karl 92' wheat were infested with WSMV viruliferous mites at temperatures above the resistance threshold. After the initial 4-week infection period, plants were subjected to progressively cooler temperatures during the winter months, well below the resistance threshold. Throughout the study, plant samples were taken to quantify virus titer and mite populations. Resistant RonL and Mace, which became severely infected during the initial infection period, were not able to recover even when temperatures dropped below the resistance threshold. However, TAM 112 showed resistance to WSMV but, more importantly, it also showed resistance to the wheat curl mite, because the mite population in this cultivar was significantly lower than on all other cultivars. The results of this study are significant in that they represent the first evidence of quantitative resistance to both WSMV and the wheat curl mite in a single wheat cultivar. Resistance to the wheat curl mite has potential to reduce losses to all mite-vectored virus diseases of wheat and not just WSMV.

Using dual-purpose crops in sheep-grazing systems

The utilisation of dual-purpose crops, especially wheat and canola grown for forage and grain production in sheep-grazing systems, is reviewed. When sown early and grazed in winter before stem elongation, later-maturing wheat and canola crops can be grazed with little impact on grain yield. Recent research has sought to develop crop- and grazing-management strategies for dual-purpose crops. Aspects examined have been grazing effects on crop growth, recovery and yield development along with an understanding of the grazing value of the crop fodder, its implications for animal nutrition and grazing management to maximise live-weight gain. By alleviating the winter 'feed gap', the increase in winter stocking rate afforded by grazing crops allows crop and livestock production to be increased simultaneously on the same farm. Integration of dual-purpose wheat with canola on mixed farms provides further systems advantages related to widened operational windows, weed and disease control and risk management. Dual-purpose crops are an innovation that has potential to assist in addressing the global food-security challenge.

Utilization of Annual Warm-Season Grasses as a Biofuel Source and Feedstock By-Product

Annual warm-season grasses such as forage sorghum, sorghum × sudangrass hybrid and sundangrass are highly productive and valuable feed crops (rotational crop and silage). In addition, sugar in the stems of these warm-season grasses can be extracted and fermented, while the cellulose in the bagasse (pressed stalk) can be used for feedstock or cellulosic ethanol, making them versatile to both the forage and biofuel industry. Twelve annual warm-season grasses including forage sorghums, sudangrass, sorghum × sudangrass hybrid, and pearl millet were planted in 1.82 m × 3.35 m plots, harvested and treated as silage and hay before and after sap removal. Dry matter (DM) yield from a single harvest in 2011 and 2012 were collected and analyzed. Further analysis from the varieties includes evaluation for sap production, OBrix, crude protein (CP), Neutral Detergent Fiber (NDF), and Acid Detergent Fiber (ADF). Forage quality in silage was negatively affected by removing the sap before ensiling, producing quality similar to that of the hay samples. Sugar yields (SY) were not comparable to sweet sorghum yields reported in the literature, but when considering SY along with bagasse yield a few varieties may offer the potential as a dual purpose crop.

Modelling the effect on stocking rate and lamb production of allowing ewes to graze a dual-purpose wheat crop in southern New South Wales

Slow pasture growth rates during winter limit the potential gross margins from autumn and early winter lambing in southern New South Wales (NSW) by limiting stocking rates and/or increasing supplementary feed requirements. Dual-purpose crops can reduce the winter feed gap in mixed-farming systems by increasing the available feed in winter. The simulation software AusFarm was used to model a mixed-farming system at Wagga Wagga with Merino ewes joined to terminal sires and grazing lucerne-subterranean clover pasture over a 41-year period. A paddock of dual-purpose wheat was then added to the system, and ewes were allowed to graze the wheat crop when feed on offer reached 850 kg DM/ha and before GS31. Weaned lambs were sold after late August if lamb growth rates fell below 20 g/head.day, mean lamb weight reached 45 kg or production feeding of lambs was required. Lambing in June resulted in the highest median gross margin whether or not ewes were able to graze the wheat crop during winter. Grazing of a dual-purpose wheat crop resulted in greater proportional increases in gross margins as stocking rate was increased, increased lamb production and reduced supplementary feeding costs, and reduced interannual variability in gross margin returns.

The influence of dual-purpose production on triticale grain quality

Triticale is a high yielding cereal grain which performs well as a dual-purpose crop (both mid-season biomass and end-season grain harvests), however, is usually inferior to wheat under the requirements of a high-value milling grain market. There is potential to increase the profitability of dual-purpose triticale by improving grain quality for food products. Currently the ash content of triticale grain is above acceptable limits and protein content is usually below the requirement for a milling market. This research compared the yield, test weight, ash and protein content of four winter triticale genotypes in replicated grain only and dual-purpose treatments over five year-site environments, based on a previously reported hypothesis that removal of triticale biomass reduces grain ash content. Cutting had a highly variable influence on yield and protein content between genotypes. Ash content was either unaffected or increased by cutting, again depending on the genotype. Ash content was negatively correlated with both stage of plant development when cut (explaining 82% of the variation) and amount of dry matter removed (explaining 65% of the variation). The results suggest that ash content in dual-purpose triticale grain may be reduced by combining suitable cultivars with later cutting; however, this may also decrease the grain protein content. It is unlikely that grazing or cutting is a suitable strategy to reduce ash content in triticale to the level required by wheat milling markets.

Interactive Effect of GA3, N and P Ameliorate Growth, Seed and Fibre Yield by Enhancing Photosynthetic Capacity and Carbonic Anhydrase Activity of Linseed: A Dual Purpose Crop

Linseed (Linum usitatissimum L.) is an important dual-purpose, industrial crop. Its seeds are used for the extraction of oil and stem for fibres. However, the production of linseed is not going parallel with the increasing demand of its products. The present work was carried out with an aim to find out whether exogenous application of gibberellic acid (GA3) with or without graded levels of nitrogen (N) and phosphorus (P) could improve the performance of three linseed genotypes Parvati, Shekhar and Shubhra together with minimizing the costly fertilizer input and losses. Four combinations of N and P, viz., 0 mg N+0 mg P kg−1 soil (N0P0), N13.4P4.46, N26.8P8.94 and N40.2P13.4 were constituted. Half dose of each combination was applied basally at the time of sowing and remaining half dose was given at 40 d after sowing (DAS) as foliar spray along with 10−6 mol L−1 GA3. Prior to sowing, the seeds of each linseed genotype were grouped in to two, one group of seeds was soaked in 0 mol L−1 GA3 (control) and the other group was soaked in 10−6 M GA3 solution, each for 8 hours. Treatments were comprised of (i) 0 mol L−1 GA3+N0P0 (T0, control), (ii) 10−6 mol L−1 GA3 + N134P446 (T1), (iii) 10−6 mol L−1 GA3+N26.8P8.94 (T2) and (iv) 10−6 mol L−1 GA3+N40.2P13.4 (T3). The crop performance was assessed in terms of growth, physiological and biochemical parameters at 60 and 75 DAS and yield attributes at harvest (175 DAS). The results showed a parallel increase in most of the parameters with increasing levels of N and P. However, application of 10−6 mol L−1 GA3 in association with N26.8P8.94 proved best, it enhanced seed yield, oil yield and fibre yield by 83.3, 97.3 and 78.7%, respectively accompanied with increase in net photosynthetic rate, carbonic anhydrase activity and dry matter accumulation. Among the genotypes tested, Shubhra performed best, while Parvati the least for most of the parameters studied. Thus, combined application of 10−6 mol L−1 GA3 plus N26.8P8.94 proved best and can be recommended to exploit the linseed as a dual-purpose crop for good yield of seed and fibre.

Genetic characterization of a core collection of flax (Linum usitatissimum L.) suitable for association mapping studies and evidence of divergent selection between fiber and linseed types

BackgroundFlax is valued for its fiber, seed oil and nutraceuticals. Recently, the fiber industry has invested in the development of products made from linseed stems, making it a dual purpose crop. Simultaneous targeting of genomic regions controlling stem fiber and seed quality traits could enable the development of dual purpose cultivars. However, the genetic diversity, population structure and linkage disequilibrium (LD) patterns necessary for association mapping (AM) have not yet been assessed in flax because genomic resources have only recently been developed. We characterized 407 globally distributed flax accessions using 448 microsatellite markers. The data was analyzed to assess the suitability of this core collection for AM. Genomic scans to identify candidate genes selected during the divergent breeding process of fiber flax and linseed were conducted using the whole genome shotgun sequence of flax.ResultsCombined genetic structure analysis assigned all accessions to two major groups with six sub-groups. Population differentiation was weak between the major groups (FST = 0.094) and for most of the pairwise comparisons among sub-groups. The molecular coancestry analysis indicated weak relatedness (mean = 0.287) for most individual pairs. Abundant genetic diversity was observed in the total panel (5.32 alleles per locus), and some sub-groups showed a high proportion of private alleles. The average genome-wide LD (r2) was 0.036, with a relatively fast decay of 1.5 cM. Genomic scans between fiber flax and linseed identified candidate genes involved in cell-wall biogenesis/modification, xylem identity and fatty acid biosynthesis congruent with genes previously identified in flax and other plant species.ConclusionsBased on the abundant genetic diversity, weak population structure and relatedness and relatively fast LD decay, we concluded that this core collection is suitable for AM studies targeting multiple agronomic and quality traits aiming at the improvement of flax as a true dual purpose crop. Our genomic scans provide the first insights into candidate regions affected by divergent selection in flax. In combination with AM, genomic scans have the ability to increase the power to detect loci influencing complex traits.

The potential of C4 grasses for cellulosic biofuel production.

With the advent of biorefinery technologies enabling plant biomass to be processed into biofuel, many researchers set out to study and improve candidate biomass crops. Many of these candidates are C4 grasses, characterized by a high productivity and resource use efficiency. In this review the potential of five C4 grasses as lignocellulosic feedstock for biofuel production is discussed. These include three important field crops—maize, sugarcane and sorghum—and two undomesticated perennial energy grasses—miscanthus and switchgrass. Although all these grasses are high yielding, they produce different products. While miscanthus and switchgrass are exploited exclusively for lignocellulosic biomass, maize, sorghum, and sugarcane are dual-purpose crops. It is unlikely that all the prerequisites for the sustainable and economic production of biomass for a global cellulosic biofuel industry will be fulfilled by a single crop. High and stable yields of lignocellulose are required in diverse environments worldwide, to sustain a year-round production of biofuel. A high resource use efficiency is indispensable to allow cultivation with minimal inputs of nutrients and water and the exploitation of marginal soils for biomass production. Finally, the lignocellulose composition of the feedstock should be optimized to allow its efficient conversion into biofuel and other by-products. Breeding for these objectives should encompass diverse crops, to meet the demands of local biorefineries and provide adaptability to different environments. Collectively, these C4 grasses are likely to play a central role in the supply of lignocellulose for the cellulosic ethanol industry. Moreover, as these species are evolutionary closely related, advances in each of these crops will expedite improvements in the other crops. This review aims to provide an overview of their potential, prospects and research needs as lignocellulose feedstocks for the commercial production of biofuel.

Impact of forage clipping treatments on performance of winter wheat

Farmers in northern parts of Pakistan face severe shortage of green forage for their livestock during the harsh winter season. Winter wheat has the potential to be used as a dual-purpose crop for forage plus grain production in these areas. Ten elite winter wheat lines from Oklahoma State University were evaluated at Hazara Research Station Abbottabad under unclipped and clipped treatment level during 2005-06. The material was planted in a randomized complete block design with three replications, with a row length of four meters and a row to row space of 25 cm. Data were recorded on green forage yield, plant height, spike length, spikelets/spike, days to maturity, spike weight, biological weight, and grain yield. Analysis of variance indicated significant differences among genotypes for all traits except spike length. Similarly all traits except spikelets/spike exhibited significant differences between unclipped and clipped treatment levels. Genotype x clipping interaction was non-significant for all traits except grain yield. Overall, winter wheat lines OK98G508W and OK00611W performed better for important traits such as early maturity, biological yield and grain yield, although over-environment testing is needed before recommendations can be made to the farmers.

Effect of Nitrogen Application Timing and Cutting Treatments on Phenology and Leaf Area of Three Brassica Cultivars

Brassica has potential as a grain and grazing option for mixed farming operations. The objectives of this experiment were to determine suitable nitrogen (N) application timing and Brassica cultivar for use as a dual-purpose crop. The field experiment was conducted at the Agricultural Research Farm of the Agricultural University, Peshawar, Pakistan, during winter 2009–2010 in a randomized complete block design with split-plot arrangement. The experiment consisted of three cultivars, three N application timings, and cutting treatments. Plant height and leaf area were greater at two and three split N applications. Likewise, leaf area was greater for N when applied in two split applications. Brassica cultivar Abasin-95 quickly emerged and attained more leaf area and leaf area index when compared to NIFA Raya and Dure-e-NIFA. Abasin-95 and Dure-e-NIFA took fewer days to mature when compared to NIFA Raya. NIFA Raya produced taller plants. Cutting significantly affected all parameters except days to maturity. Early flowering, taller plants, and greater leaf number, area, and leaf area index were noted for no-cut plots when compared to cut plots.

Fumonisin B1 contamination in kharik grain sorghum in India

Sorghum [Sorghum bicolor (L.) Moench] is the fifth most important cereal crop in the world after rice, wheat, maize and barley. It constitutes the main grain food for over 750 million people who live in the semi-arid tropics of Africa, Asia and Latin America. Sorghum is grown in kharif (rainy), rabi (post rainy) and summer seasons in India. Sorghum is a truly dual-purpose crop; both grain and stover are highly valued outputs. Sorghum is the preferred staple food in states of Maharashtra, Karnataka and Andhra Pradesh in India. Grain moulds cause significant losses in both grain yield and its nutritional quality (Ratnavathi & Sashidhar, 2003). Mycotoxins are a group of chemically diverse secondary metabolites of fungi that have a wide range of toxic effects on humans and animals. Among numerous mycotoxins, aflatoxins (AFs), fumonisins and ochratoxin A (OTA) are of high priority for control because of their frequent and worldwide distribution in agricultural products. According to the CODEX Committee (2011), worldwide occurrence of mycotoxins in grain sorghum was reported in twelve different countries, of which Fumonisins were reported in Brazil, Ethiopia, India and the USA. These mycotoxins, discovered in 1988 in South Africa, have been shown to exhibit unique toxicological properties that differed with different animal species (Marasas, 1996). Fumonisins may contribute to liver and kidney damage and cause esophageal cancer in human beings. Natural contamination of food grains is greatly influenced by environmental factors such as type of storage structure, temperature, rainfall, pH, moisture etc. The present study was carried out to estimate the fumonisin B1 contamination in kharif grain sorghum collected from different geographical regions of India over a period of three years and also to determine the safety of sorghum as food and feed (Das, Kumar, Ratnavathi, Komala, Annapurna & Seetharama, 2010) A total of 835 kharif grain sorghum samples were collected over a period of three years. In the years 2006–07 368 sorghum samples, in the years 2007–08 255 sorghum samples, and in the years 2008–09 212 sorghum samples were collected for assessment of Fumonisin B1 contamination. These samples were grown in different locations Parbhani, Akola (Maharashtra), Hyderabad, Palem (Andhra Pradesh), Dharwad (Karnataka), Udaipur (Rajasthan) and Coimbatore (Tamilnadu). Sorghum is consumed as human food, animal feed and as an industrial raw material in these states. The detection of FB1 from sorghum grains was estimated by deploying the method of indirect competitive ELISA (Devi, Mayo, Reddy, Emmanuel, Larondelle, & Reddy, 2001). Fumonisin B1 content varied over locations. The highest fumonisin B1 percent contamination was recorded during 2008 and the lowest in 2006. The study conducted for three years showed that natural contamination of Fumonisin B1 was at a minimum. 74.97% (626) of total number of samples were positive for toxin as compared to highly susceptible crops like rice, maize and groundnut. However, 7.30% (61) samples contained fumonisin above the safety limit (200 μg/kg). From this study it is observed that, contamination of fumonisins in sorghum is low to medium in kharif produce and grain is mostly safe for consumption.

EFFECT OF SOIL MOISTURE STRESS ON THE EMERGENCE, ESTABLISHMENT AND PRODUCTIVITY OF AMARANTHUS (AMARANTHUS CRUENTUS L.)

Dietary intake of vegetables is low in Sub-Sahara Africa (SSA) compared to the world's average. This situation is worsened by low water availability for vegetable production especially in the dry season. However, amaranth which can be grown in the different agro-ecologies of Nigeria is a dual purpose crop with edible leaves and seeds rich in essential nutrients, minerals and proteins. The crop is also a drought tolerant C4 plant which has the ability to survive under minimum soil moisture condition, hence the reason for its use in the study. This investigation was therefore conducted to discover the optimum water requirements in a screen house, and evaluation of different moisture stress based on the derived optima in two subsequent field trials. In the screen house and field, water stress treatments varied from: -6.0, -1.2 to -0.3 bar (the control). Results in the screen house study showed that optimum soil water potential for amaranth was reached at -1.2 bar, and that variety NH84/493 performed better than the others, in all growth and yield parameters measured. In field trials, bringing the moisture content from dry (-6.0 bar) to -1.5 bar optimum soil water potential favored seedling emergence better than all other treatment combinations. However, treatment combination -0.3, -1.5 bar when the soil was initially wet (-0.3 bar) then bringing it to the optimum (-1.5 bar) gave the best seedling establishment and productivity. Variety NH84/493 grown at -0.3, -1.5 bar performed better than all other interactions. We therefore recommend -1.5 bar and variety NH84/493 amaranth for the SSA vegetable industry, especially for improving dry season productivity.

English

Biomass production in plant is directly related to the amount of intercepted solar radiation by the canopy and available water to the plant. Growth and development of leaves, especially under drought condition, is therefore major determinant of crop productivity. Xyloglucan endotransglucosylase (XET) plays important role in growth and development of plants. XETs are a family of enzymes that mediate construction and restructuring of xyloglucan cross-links, thereby controlling the mechanical properties of cell wall. We cloned complete cDNA of an XET from pearl millet (Pennisetum glaucum L.) and characterized it using in silico comparative genomics and activity assays. The cloned cDNA was 1266 bp in length, encoding a protein with 291 amino acids having signal peptide targeting it to the cell wall. The protein showed xyloglucan endotransglucosylase activity but no hydrolytic activity, therefore, named as PgXET1 as per the convention. The comparative genomics revealed that the functional sites of the enzyme (XET) were highly conserved. Evolutionary studies using phylogenetic tree indicated its grouping with XETs from maize (with >95% bootstrap support), barley, rice, etc. This is the first report on cloning and characterization of an XET (PgXET1) from pearl millet, an important dual-purpose crop.   Key words:    Xyloglucan endotransglucosylase, Pennisetum glaucum, pearl millet, primary cell wall, cell expansion, drought tolerance.

Gibberellic acid mediated co-ordination of calcium and magnesium ameliorate physiological activities, seed yield and fibre yield of Linum usitatissimum L.—a dual-purpose crop

Commercial cultivation of linseed for both seed and fibre is not keeping pace with increasing demand for linseed products. Although, different strategies are being adopted to produce a dual-purpose linseed crop with good yield of seed and fibre, little progress has been achieved. The present study was carried out to investigate whether application of gibberellic acid (GA3) along with CaCl2 and/or MgSO4 could ameliorate the seed yield in three linseed genotypes 'Parvati', 'Shekhar' and 'Shubhra' without compromising the fibre production. Before sowing the seeds of linseed genotypes were soaked for 8h in 10(-6)M GA3. Forty days after sowing (DAS), the plants were sprayed with 10(-6)M GA3 along with 2kg Ca/ha (Ca2) and/or 0.5kgMg/ha (Mg0.5). Treatments comprised of (1) 10(-6)M GA3 + Ca0Mg0 (control, T0); (2) 10(-6)M GA3 + Ca2Mg0 (T1); (3) 10(-6)M GA3 + Ca0Mg0.5 (T2) and (4) 10(-6)M GA3 + Ca2Mg0.5 (T3). Performance of the crop was assessed in terms of growth characteristics, physiological and biochemical parameters at 60 and 75 DAS and yield and quality attributes at harvest. Treatment T3 proved best, it enhanced dry weight per plant by 38.2 and 20.6%, P N by 20.7 and 19.1% and gs by 18.2 and 8.8% at 60 and 75 DAS, respectively and seed yield by 39.6%, oil yield by 46.9% and fibre yield by 36.9% at harvest. Further, a decrease in lodging by 13.9% was recorded. Of the three genotypes tested, all exhibited significant difference for all the parameters studied, except for leaf-N content, biological yield and iodine value which showed no difference. However, 'Shubhra' performed better than 'Parvati'.