Sorghum Crop Modeling and Its Utility in Agronomy and Breeding

Crop models are simplified mathematical representations of the interacting biological and environmental components of the dynamic soil–plant–environment system. Sorghum crop modeling has evolved in parallel with crop modeling capability in general, since its origins in the 1960s and 1970s. Here we briefly review the trajectory in sorghum crop modeling leading to the development of advanced models. We then (i) overview the structure and function of the sorghum model in the Agricultural Production System sIMulator (APSIM) to exemplify advanced modeling concepts that suit both agronomic and breeding applications, (ii) review an example of use of sorghum modeling in supporting agronomic management decisions, (iii) review an example of the use of sorghum modeling in plant breeding, and (iv) consider implications for future roles of sorghum crop modeling. Modeling and simulation provide an avenue to explore consequences of crop management decision options in situations confronted with risks associated with seasonal climate uncertainties. Here we consider the possibility of manipulating planting configuration and density in sorghum as a means to manipulate the productivity–risk trade-off. A simulation analysis of decision options is presented and avenues for its use with decision-makers discussed. Modeling and simulation also provide opportunities to improve breeding efficiency by either dissecting complex traits to more amenable targets for genetics and breeding, or by trait evaluation via phenotypic prediction in target production regions to help prioritize effort and assess breeding strategies. Here we consider studies on the stay-green trait in sorghum, which confers yield advantage in water-limited situations, to exemplify both aspects. The possible future roles of sorghum modeling in agronomy and breeding are discussed as are opportunities related to their synergistic interaction. The potential to add significant value to the revolution in plant breeding associated with genomic technologies is identified as the new modeling frontier.

EFFECT OF SORGHUM SEED TREATMENT IN BURKINA FASO VARIES WITH BASELINE CROP PERFORMANCE AND GEOGRAPHICAL LOCATION

Sorghum [ Sorghum bicolor (L.) Moench] is a major subsistence crop throughout the region of Sahel. With the exception of seeds and labour, no agricultural inputs are in general used in sorghum production since the grain is of a relatively low commercial value and the risk of losing the crop to drought, flooding, etc. is substantial. A meta-analysis of 118 field experiments was carried out to identify conditions in which two protective seed treatments could support a yield increase of sorghum in Burkina Faso. The two treatments were: i) treatment with the pesticide Calthio C (thiram and chlorpyrifos) and ii) treatment with an aqueous extract from the plant Eclipta alba . Both treatments were found to produce a yield increase (Medians: Calthio C +199 kg ha-1, P<2x10-9; E. alba +90.5 kg ha-1 P<4x10-4). A strong relative effect of Calthio C on yield (+36%) was found for field experiments with a low baseline yield. A strong relative effect of E. alba extract on yield (+22%) was found for experiments with a low baseline of emergence. ANOVA of the 118 field tests showed that baseline crop performance (yield and emergence) and the effect of seed treatments were strongly linked to geographical location (twelve different villages included). Roots from sorghum in the village showing the strongest effect of both seed treatments (>40% yield increase) were found to carry a comparatively high load of the infectious ascomycetes: Fusarium equiseti , Macrophomina phaseolina and Curvularia lunata .

GENETIC DIVERSITY AMONG SORGHUM LANDRACES OF SOUTHWESTERN HIGHLANDS OF UGANDA

Sorghum ( Sorghum bicolor L. Moench) is an economic and staple crop in sub-Saharan Africa. The genetic diversity in its germplasm is an invaluable aid for its crop improvement. The objective of this study was to assess the existing genetic diversity among sorghum landraces in the southwestern highlands of Uganda. A total of 47 sorghum landraces, collected from southwestern highlands of Uganda, were characterised using 12 qualitative and 13 quantitative traits. The study was conducted at Kachwekano Research Farm in Kabale District, at an altitude of 2,223 m above sea level, during growing season of December 2014 to August 2015. Panicle shape and compactness were the most varied qualitative traits. Grain yield (1.23 to 11.31 t ha-1) and plant height (144.7 to 351.6 cm) were among quantitative traits that showed high variability. Days to 50% flowering (115 to 130 days) showed the least variability. Results of UPGMA cluster analysis generated a dendrogram with three clusters. Panicle weight, leaf width, stem girth, exertion length, peduncle length, panicle shape and compactness, glume colour and threshability were major traits responsible for the observed clustering (P<0.001). Principal Component Analysis revealed the largest variation contributors.

Seaweed Aquaculture and Marine Biotechnology

Macroscopic marine algae, typically known as macroalgae or seaweeds, form an important living resource of the oceans, as primary producers. People have collected seaweeds for food, both for humans and animals for millennia. They also have been a source of nutrient rich fertilizers, as well as a source of gelling agents known as phycocolloids. More recently macroalgae are playing significant roles in medicine and biotechnology. Although Biotechnology and in particular marine biotechnology may have different meanings for different people, under the present context we will consider a broader definition. Marine biotechnology consists on the use of biological knowledge and/or the application of biological techniques on marine organisms, for the development of products in some way beneficial for humans. Seaweed aquaculture is, therefore a biotechnology activity. It is also one that can allow for further development of the industry. Today, seaweed cultivation techniques are standardized, routine and economical. Several factors, including understanding the environmental regulation of life histories and asexual propagation of thalli, are responsible for the success of large-scale seaweed cultivation. Presently, seaweed aquaculture represents approximately 23% of the world’s aquaculture production, including fish, crustaceans and other animals. A promising approach for the development of seaweed aquaculture, and aquaculture in general, is the integrated multi-trophic aquaculture (IMTA). In these systems, fed-aquaculture is combined with extractive organisms like bivalves and/or algae. The constraints and advantages of IMTA will be discussed. In particular, land based IMTA systems allow for much greater environmental and input controls. Traceability, security of supply, high-quality standards and safety should be the future of seaweed aquaculture and contribute for the development of marine biotechnology.

Is there a case to be made for a global patent system? The example of plant biotechnology

The assessment of patterns of patentability in plant biotechnology on the basis of existing statistics shows a considerable concentration of patents to a few countries, in particular the United States, Australia, Japan, China, Mexico, Brazil, Germany, Canada, New Zealand, South Korea, India, Spain and Hungary. These patterns suggest that there is a clear relationship between the choice of patent jurisdictions and the biotechnology regulatory framework. This observation of the geographic distribution of biotechnology patents lends credence to maintaining a system of territorial rights that allow for regulatory competition, but continuing the process of substantive patent law harmonization which potentially minimize trade barriers.

Identification of sorghum hybrids with high phenotypic stability using GGE biplot methodology.

The aim of this study was to identify sorghum hybrids that have both high yield and phenotypic stability in Brazilian environments. Seven trials were conducted between February and March 2011. The experimental design was a randomized complete block with 25 treatments and three replicates...

Selectivity and efficiency of herbicides in weed control on sweet sorghum.

A carência de herbicidas registrados para o controle de plantas daninhas, em sorgo sacarino, torna-se fator limitante à produção. Objetivou-se avaliar a seletividade de herbicidas em sorgo sacarino e a eficiência no controle de plantas daninhas. O delineamento experimental foi de blocos ao acaso, com quarto repetições. Os tratamentos incluíram cultivares de sorgo sacarino (BRS 506, BRS 509 e BRS 511) e herbicidas aplicados isoladamente em pré-emergência (atrazine - 1.500 g ha-1; atrazine + s-metolachlor - 1.665 g ha-1 + 1.035 g ha-1; flumioxazin - 50 g ha-1; s-metolachlor - 1.440 g ha-1) e pós-emergência (tembotrione - 100,8 g ha-1) e de forma sequencial em pré e pós-emergência (atrazine + s-metolachlor + tembotrione - 1.665 g ha-1 + 1.035 g ha-1 + 100,8 g ha-1; atrazine + tembotrione - 1.500 g ha-1 + 100,8 g ha-1; flumioxazin + tembotrione - 50 g ha-1 + 100,8 g ha-1), mais duas testemunhas, uma capinada e outra sem capina. A fitotoxicidade ao sorgo foi de 98,0 %, 98,0 % e 100 % de tembotrione; 100 %, 98,7 % e 100 % de flumioxazin + tembotrione; 100 %, 100 % e 100 % de atrazine + s-metolachlor + tembotrione; e 98,7 %, 98,7 % e 99,7 % de atrazine + tembotrione, respectivamente para as cultivares BRS 509, BRS 506 e BRS 511. Tembotrione, flumioxazin + tembotrione, atrazine + s-metolachlor + tembotrione e atrazine + tembotrione apresentaram bom controle de Ipomoea indivisa, Digitaria ciliaris e Urochloa plantaginea, porém, não demonstraram seletividade às cultivares de sorgo. O atrazine, de modo geral, apresentou maior seletividade aos componentes de rendimento das cultivares BRS 509 e BRS 506.

The relationship between population structure and aluminum tolerance in cultivated sorghum.

2011

Association mapping provides insights into the origin and the fine structure of the sorghum aluminum tolerance locus, AltSB.

2014

Sorghum Yield and Zai Holes in Goundi, Burkina Faso

The purpose of this study was to determine if there was a difference in sorghum yield between the Mossi zai hole and the Gourounsi zai hole, specifically examining the effects of manure and soil water conservation. A study field was created with six different treatments: (1) control with traditional management (no zai holes), (2) traditional management with manure, (3) Mossi zai holes with no manure, (4) Mossi zai holes with manure, (5) Gourounsi zai holes with no manure, and (6) Gourounsi zai holes with manure. Soil moisture readings were taken after each rainstorm (about weekly), soil properties were analyzed before planting and after harvest and above ground biomass was weighed at harvest. Manure was the only variable that significantly increased crop yield. This is different from the original hypothesis; zai holes were thought to be the main driver of increased crop yield in Sahelian West Africa. Zai holes did not have a significant effect on soil moisture.

Biotechnology and crop protection in Brazil.

The process of modernization of Brazilian agriculture aimed at increasing the productivity in response to the high demand for agricultural products in the world market and it was based on the intensive use of inputs such as agrochemicals, intense mechanisation and breeding of new varieties. Among these, pesticides were incorporated in almost all production systems. Over reliance on pesticide use has produced many negative effects on both biotic and abiotic components of the environment, generating chemical contamination of soil and water, decrease in biological diversity of agroecosystems, disruption of natural cycles, pest resistance, intoxication of growers, among others. The consumption of pesticides in Brazil was 151.8 thousand tonnes in 1989, and today the country is the fifth world market of these products. The use of pesticides increased from 16 thousand tonnes (a.i.) in 1964 to 60.2 thousand tonnes in 1991, while the area planted to crops grew from 28.4 to 50.0 million ha in the same period. This means an increase of 276.2% in consumption of pesticides compared to an increase of 76% in planted area. Even with this large increase in the use of pesticides, the losses caused by pests have not been significantly reduced, and the net gain in crop productivity has been low. On the other hand, problems with food contamination, environmental degradation of growers have considerably mounted. It is possible to define two classes of crops regarding intense use of pesticides. One is represented by those crops that occupy large areas, and therefore contribute to a large amont of pesticides used for pest control in a country basis. The other class comprises crops that require large amounts of pesticides per unit of area, but not necessarily represent large amounts of pesticides used coutry-wide. Based on the classes proposed, citrus, soybean and sugarcane stand as crops with a nationally great consumption of pesticides, while tomato, potato and citrus are important as intensive users of pesticides. In this paper the biotechnologies in use, the biotechnologies in advanced stages of development, the main constraints to the development and use of biotechnlology and the impact of pesticed on the environment are discussed.

Maturation curves of sweet sorghum genotypes.

O sorgo sacarino [Sorghum bicolor (L.) Moench] se destaca como cultura complementar à cana-de-açúcar Saccharum spp. na produção de etanol, uma vez que este possui colmos suculentos com presença de açúcares diretamente fermentescíveis. Em decorrência deste fato, existe a necessidade de se analisar as propriedades do sorgo, a fim de atender às demandas da agroindústria. No presente trabalho, buscou-se desenvolver e estudar as curvas de maturação de sete cultivares de sorgo sacarino em dez épocas de colheita. Os resultados mostram que houve diferença significativa para cultivares e épocas de colheita para todos os parâmetros (p≤0,01). Quanto aos teores de açúcares, as cultivares BRS508, XBWS80147 e CMSXS629 apresentaram as maiores médias para as variáveis açúcares redutores totais (ART) e açúcares totais recuperáveis (ATR). Em relação à produção de etanol por tonelada de biomassa, as cultivares BRS 508 e a CMSXS629 apresentaram os melhores resultados.

Comparing pollination control bag types for sorghum seed harvest.

Efficacy of pollination bags made of new nonwoven fabrics was compared with the traditional paper bags in sorghum during 2015 using three cultivars comprising BR007B (red seeded), SC283 (white seeded) and 1167048 hybrid with tannin (brown seeded). The five pollination bag treatments were: no bagging, traditional paper bag, paper bag plus plastic screen bag for extra bird protection, duraweb®SG2 polypropylene bag and duraweb®SG1 polyester bag. There was no bird damage on tannin hybrid but birds damaged bags to access grains of the other two varieties. Varieties and bag types differed significantly, and also showed significant interactions for panicle weight (at P<0.06), seed weight and average seed weight per panicle. The tannin hybrid was consistently a better performer for all traits regardless of bag type. The paper bags were the worst for bird damage. Duraweb® SG1 was the best performer for all traits including bird damage followed by duraweb®SG2. The joint regression analysis showed that BR007B performed consistently under all bag types with average response. On the other hand, SC283 improved its response with the increasing quality of bag type at an above average rate for panicle weight and seed traits. It was concluded that new nonwoven fabric bags could replace paper bags in providing better seed production potential and greater protection against bird damage.

Characterization of biomass sorghum cultivars aiming to generate energy for the north region of Mato Grosso, Brazil.

O sorgo biomassa possui elevada produção de biomassa lignocelulósica, surgindo como alternativa de cultivo visando produção de energia renovável. O objetivo deste trabalho foi caracterizar cultivares de sorgo biomassa visando a geração de energia para região Norte de MT. Para tal, implantou-se em 04/12/2014, em Sinop-MT, um experimento no delineamento em blocos casualizados, com três repetições, composto por 36 genótipos de sorgo (34 biomassas e 2 forrageiros). As características avaliadas foram: florescimento, altura de plantas, acamamento, população de plantas, produção de massa verde, produção de massa seca, porcentagem de massa seca e umidade. Os dados foram submetidos a análise de variância e as médias dos genótipos foram agrupadas pelo teste de Scott-Knott. Os materiais forrageiros floresceram, em média, aos 77 dias, enquanto que os genótipos de biomassa floresceram dos 101 aos 130 dias. Enquanto o melhor genótipo forrageiro (Volumax) produziu 11,6 t de massa seca ha -1, 15 genótipos de sorgo biomassa produziram, em média, 24 t. Demonstrando estes serem os de maior interesse de cultivo na região de estudo. A matéria seca produzida pelos genótipos de sorgo biomassa associado a seu poder calorífico demonstram potencial da cultura para produção de energia renovável.

Influência da temperatura na germinação de sementes de Digitaria insularis, Leptochloa virgata, Pennisetum setosum e Sorghum halepense

Objetivou-se com este trabalho avaliar a influência de temperaturas constantes na germinação de sementes de espécies de plantas daninhas da família Poaceae que apresentam ocorrência em áreas de pastagem, para isto, foram analisadas as sementes de Digitaria insularis, Leptochloa virgata, Pennisetum setosum e Sorghum halepense coletadas manualmente de diversas plantas em áreas de pastagem. As sementes foram dispostas em caixas gerbox sobre folha dupla de papel "germitest", umedecido com água destilada equivalente a 2,5 vezes a massa do papel seco. As caixas foram incubadas em três germinadores verticais tipo MANGELSDORF com as temperaturas de 25ºC, 30ºC e 35ºC e fotoperíodo de 12 horas. As avaliações foram realizadas, efetuando-se a contagem diária das ocorrências germinativas, a partir da protrusão da radícula, durante 28 dias após o início do estudo. Os parâmetros avaliados foram porcentagem e índice de velocidade de germinação (IVG), efetuando-se a análise estatística pela análise de variância com comparação de médias pelo teste de Tukey a 5% de probabilidade e transformação dos resultados de porcentagem de germinação. As temperaturas que proporcionam os melhores resultados de porcentagem e velocidade de germinação são 30 e 35°C, para as espécies de D. insularis, L. virgata e S. halepense, por outro lado, a espécie de P. setosum não apresenta germinação em nenhuma das temperaturas avaliadas (25º 30º e 35ºC) não são adequadas para a sua germinação.