Sorghum Yield Research Articles

Effects of Major Fungal Pathogens on Growth and Yield of Improved and Local Sorghum Genotypes under Field Trials in Lower Eastern Kenya

Sorghum is a climate resilient cereal that offers food and nutrition security for the arid and semi-arid lands (ASALs). Its production potential is however limited by fungal diseases. A study on the effects of major fungal diseases on sorghum growth and yield and identification of tolerant genotypes is critical for sustainable sorghum production. A total of 14 germplasms were analyzed under a two-seasonal field trial laid out in Randomized Complete Block Design with four replications at two different agro-ecological zones within Kenya’s ASALs. A spreader row technique using a highly susceptible variety and natural infections was used for fungal inoculation. Ten plants randomly sampled and tagged from two inner rows in each plot, were used to asses plant growth, yield, and diseases. Diseases were identified using identification keys, visual symptoms, and signs and effects scored through disease severity (DS) and disease incidence (DI). Identified diseases included anthracnose, leaf blight, rust, gray leaf spot, ladder leaf spot, oval leaf spot, downy mildew, and covered kernel smut. Higher DS (>7.0) and DI (>50%) were recorded in anthracnose, leaf blight, and leaf rust across most genotypes. The significant (P≤0.01) negative correlations between DS and days to 50% flowering, number of green leaves, leaf area and panicle width indicated potential disease inhibition of sorghum growth. Correlations between DS and dry biomass, grain yield and grain weight were also negative but insignificant (P>0.05) implying no disease effects on sorghum yield. Improved genotypes had the least foliar and panicle infections and produced significantly higher grain yield (>2.0 t/ha) compared to local varieties with lower yield (<1.5t/ha) and higher foliar and panicle symptoms. The improved genotypes were thus classified as tolerant to fungal diseases and could be used to support resistance breeding programs as a sustainable management strategy for improved sorghum production in ASALs of Kenya.

Integrated weed management in rabi sorghum (Sorghum bicolor L.) under rainfed conditions

A field experiment was conducted to assess the impact of weed management on growth and yield of grain sorghum at the Regional Agricultural Research Station, Vijayapura during rabi 2022-23. The experiment was laid out in a Randomized Complete Block Design with three replications and comprised eleven treatments. These treatments included five preemergence herbicide treatments (Atrazine @1000 g a.i. ha-1, Metribuzin @ 350 and 700 g a.i. ha-1, Metolachlor @ 750 and 1500 g a.i. ha-1) followed by two intercultivation at 30 & 60 DAS, as well as four post-emergent herbicide treatments (Metribuzin @ 350 and 700 g a.i. ha-1, Mesotrione + Atrazine (RM) @ 550 and 825 g a.i. ha-1) followed by one intercultivation at 60 DAS. These nine herbicide treatments were compared to a weedy check and a weed free check. The experimental results showed that weed free condition recorded minimal weed infestation, better crop growth, higher yield and economical returns. Among the herbicidal treatments, application of Metolachlor 50EC @ 1500 g a.i. ha-1as pre-emergence followed by two intercultivations at 30 and 60 DAS recorded significantly lower weed count (1.67 m-2), weed biomass (4.67 g m-2) and higher weed control efficiency (92%) for total weeds at 60 DAS, with a reduced weed index of 7.21%. Additionally, this treatment led to significantly higher grain yield (1389 kg ha-1), stover yield (3031 kg ha-1), gross returns (`73,759 ha-1), net returns (`40,968 ha-1) and benefit cost ratio (2.25). In contrast, the weedy check treatment resulted in lower grain yield, net returns, and benefit cost ratio.

Attenuating measurement errors in agricultural productivity analysis by combining objective and self-reported survey data

This paper exploits unique survey data from Mali to validate an alternative approach to estimate the relationship between crop yields and inputs. The estimation relies on predicted objective crop yields that stem from a machine learning model trained on a random subsample of surveyed plots, for which crop cutting and self-reported sorghum yield estimates are both available. The analysis demonstrates that it is possible to predict sorghum yields with attenuated non-classical measurement error, resulting in a less-biased assessment of the relationship between yields and agricultural inputs. The external validity of the findings based on the data from a sub-national survey experiment is verified using the data from a nationally representative agricultural survey. The discussion expands on the implications of the findings for the design of future surveys where objective data collection could be limited to a subsample to save costs, with the intention to apply the suggested machine learning approach.

Effect of date of sowing and weather factors on infestation of Atherigona soccata (Rondani) and yield parameters of forage sorghum

Ecofriendly strategies for the management of sorghum shoot fly, helps in addressing the Atherigona soccataissues related to insecticides load on forage crop. The present study was carried out to know the suitable date of sowing on damage indices of sorghum shoot fly and green fodder yield in sorghum. The staggered sowing technique at a different time intervals was used, starting from 2 fortnight of March (12 SMW) to 1 fortnight of ndthstJuly (27 SMW). Oviposition in terms of eggs per 10 plants and dead heart percentage was recorded to be low thin 18 SMW (1 fortnight of May) sown crop (eggs: 6.66 and dead heart: 25.46%), but it was found to be highest thstin 1 fortnight of July (27 SMW) sown crop (eggs: 21.95 and dead heart: 65.45%). The correlation of shoot fly stthinfestation in relation to weather parameters revealed that egg load and dead hearts were negatively correlated with maximum temperature and positively correlated with minimum temperature, relative humidity and rain fall. Green fodder yield was recorded to be highest and lowest for the crop sown on 18 SMW (409 q/ha) and 27 ththSMW (302 q/ha), respectively. The study indicated that 1 fortnight of May was the best time to escape from the stsorghum shoot fly attack.

Phenology, phyllochron and productivity of sorghum in response to varying growing environments and nitrogen levels in the semiarid irrigated condition

Climate change is likely to affect agricultural production in many parts of the world. Sorghum is the stable food crop in semiarid areas, and climate change has significant adverse effects on sorghum yields. The optimum time of sowing is one of the important technologies that allow the crop to better utilise natural resources by the crop to maximise productivity. For optimizing the sowing time, the field investigation was carried out in Tamil Nadu Agricultural University, Coimbatore, under summer irrigated conditions in 2022. The experiment was laid out in a split-plot design with three replications. The main plot consists of five dates of sowing and the subplot includes different nitrogen levels. The results revealed that advanced sowing (first fortnight of April) reduced the yield by 13.73% and delayed sowing (second fortnight of May) recorded the maximum yield (4230.3kg ha-1) with higher phyllochron values. GDD manifested a significant negative relationship with a high correlation coefficient (r) value of -0.98** (p = 0.01) for days to anthesis, -0.98** (p = 0.01) for days to physiological maturity and -0.88* (p = 0.05) for phyllochron. Average temperature exhibited a significant negative correlation with days to anthesis (-0.75*), physiological maturity (-0.97**) and phyllochron (-0.89*). The best-fit regression model showed that a GDD-based model could better predict the phenology of sorghum compared to an average temperature-based model. The study indicated that understanding sorghum's phenological response and productivity level under varied dates of sowing and the nitrogen levels in semiarid environments can help determine the appropriate sowing time and optimum nitrogen level for achieving better yield in summer-irrigated sorghum.

Less negative impacts of climate change on crop yields in West Africa in the new CMIP6 climate simulations ensemble

Food insecurity is among one of the greatest risks posed by climate change in Africa, where 90 to 95% of African food production is rainfed and a large proportion of the population already faces chronic hunger and malnutrition. Although, several studies have found robust evidence of future crop yield losses under climate change scenarios, there is wide variation among crops and regions as well as large modeling uncertainties. A large part of this uncertainty stems from climate projections, as climate models may differ in simulating future changes in precipitation and temperature, which could lead to different future crop production scenarios. This work examines the impacts of climate change on crop yields of maize, millet and sorghum in West Africa using climate change projections from the Coupled Model Intercomparison Project 5th Phase (CMIP5) and from the new generation of climate models from the Coupled Model Intercomparison Project 6th Phase (CMIP6). We use the SIMPLACE crop modeling framework to simulate historical and future crop yields, and bootstrap techniques to evaluate projected changes in crop productivity between the CMIP5 and CMIP6 ensembles. Using the new generation of climate models CMIP6, we find that the negative crop yield projections shown by CMIP5 simulations are largely reduced, with even large increases in crop yields when the effect of atmospheric CO2 concentration is considered in the crop model. These differences in crop yield impacts between the CMIP5 and CMIP6 simulations are mainly due to different climate projections of temperature and precipitation in West Africa; CMIP6 projections being significantly wetter and cooler by mid-century and to a lesser extent by the end of the century. Such results highlight the large uncertainties that remain in assessing the impacts of climate change in the region and the consequent difficulty for end-users to anticipate adaptation strategies.

Response of Growth, Yield and Quality of Sorghum (Sorghum bicolor L. Moench) to Kinetin Foliar Spraying

Field experiments were carried out during the spring and autumn seasons of 2019 in the research station of the College of Agriculture - University of Anbar in the Al-Hamidiyah region - Al-Ramadi district - Al-Anbar Governorate, to study the response of growth, yield and grain quality of sorghum (Inkath cv.) to spraying with kinetin at different growth stages. The experiments were conducted using a randomized complete block design (RCBD) according to split plots arrangement at three replications, the main plots included foliar spraying of four concentrations of kinetin (0, 15, 30 and 45 mg L−1), while the sub-plots included three stages of spraying {(spraying at the five leaves stage, spraying at the end of the vegetative growth stage (beginning of flag leaf appearance) and spraying at the 25% flowering stage}. The results showed that the spraying of kinetin at a concentrations of 45 mg L−1 was significantly superior in the most of the studied traits, such as leaf area, 1000 grain weight, grain yield (3.548 and 5.110 ton ha−1) and grain protein content (11.04 and 11.56%) in the two seasons respectively. However, the spraying of kinetin at a high concentration (45 mg L−1) at the 25% flowering stage had a highest value of grain protein content in the autumn season.

Effect of Potassium Silicate Spray and Water Stress on Yield and Yield Components of Sorghum

A field experiment was carried out for the year 2021-2022 at Al Buaitha Research Station of the College of Agriculture - Anbar University, to study the effect of potassium silicate and water stress on the growth and yield of sorghum. The experiment was carried out using a Split-Plot arrangement according to the Randomized Complete Block Design (RCBD) with three replications. The main plots included irrigation intervals (I1, irrigated every 4 days; I2, irrigated every 8 days; and I3, irrigated every 12 days), while the concentrations of potassium silicate fertilizer (250 S1, 500 S2, and 750 S3 ml liter−1 of distilled water), in addition to the control treatment S0, which was sprayed with distilled water only, allocated to the sub-plots. The results showed a significant effect of water stress treatments I1 and I2 on the average traits of head length, number of seeds per head, grain yield, and biological yield (26.20, 1920, 6.34, and 15.30 respectively). while, the treatments of potassium silicate fertilization S2 and S3 had a significant effect on the head length, number of seeds per head, grain yield, and biological yield (26.56, 1968, 6.12, and 14.63 respectively). The results also showed a significant interaction effect between the two study factors of I2S2, I1S2, I2S0, and I1S0 on the same traits (27.17, 2052, 6.52, and 16.32 respectively).

Effect of Cutting Stages and Cytokinin Spray on Growth and Yield and Quality of Green Forage of Different Varieties of Sorghum (Sorghum bicolor L.)

The experiment was conducted at field crops department field, college of agriculture, Tikrit university. during the autumn season 2017 to investigate the effect of cytokinein and stage of cutting in the growth characteristics and forage yield of sorghum. The experiment design was (R.C.B.D) with three replicutions arranged in split-split-plot. concentrations of cytokinein (0,100,200,300ppm) were used as the main plots while the varieties (alkaer, enqad, rabih, abu-sabaen, and giza 113) were used as the sub-plots. the cutting stage (after 45 days of planting, after 50 days of the first stage and after 50 days the second stage) were used as the sub-sub-plots. plant height, number of leaves. Plant, steam diameter, leaf area and green forage yield were studed. the results the following showed the abu-sabaen gave highest values in plant height and forage yield (141.41cm and 66.23 t.ha −1) . the rabih variety gave highest valust in steam diameter and leaf area (20.80 mm and 1499.57 cm 2). the spraying 300 ppm gave lowest value of forage yield (45.42 t.ha −1) . the third stage of cutting gave highest value, plant height, number of leaves. plant−1, leaf area and forage yield (135.86 cm, 10.72 leaf.plant −1, 1524.36 cm2 and 66.56 t.ha −1) interaction between abusabaen third stage cutting gave highest value of forage yield (85.73 t.ha−1).

Yield of Sorghum bicolor (L.) Moenh Genotypes in A Plastic Mulch Planting System in Gunungkidul

Sorghum is a strategic commodity with good nutritional and high antioxidant content that can be used as a source of food, feed, and industrial raw materials. Sorghum is a relatively low and less intensive crop than other staple food crops. Sorghum yield can be increased by establishing plant population through a mulching planting system. The purpose of this study was to determine the yield power of several sorghum genotypes, namely three new superior varieties (Bioguma, Kawali, and Samurai) and three local varieties (Plonco, Hitam Wareng, and Ketan Merah), planted with a plastic mulch planting system. The research was conducted on farmers' land in Karangmojo, Gunungkidul, Daerah Istimewa Yogyakarta, which is a dryland soil type. The experimental design used a randomized complete block design (RCBD) with 5 replications. Observation parameters included growth components and sorghum production. The results showed that sorghum planting with a mulching planting system was able to provide yields for the Bioguma variety of 7.70 tons/ha, Plonco variety of 8.41 tons/ha, Samurai variety of 5.38 tons/ha, Kawali variety of 8.21 tons/ha, Hitam Wareng variety of 3.91 tons/ha, and Ketan Merah variety of 4.00 tons/ha. Based on the results of the study, it was found that the genotypes of local varieties were able to compete with new superior varieties and had the best growth response and yield power in the rainy season planting.

Co-Expression Network Analysis of the Transcriptome Identified Hub Genes and Pathways Responding to Saline–Alkaline Stress in Sorghum bicolor L.

Soil salinization, an intractable problem, is becoming increasingly serious and threatening fragile natural ecosystems and even the security of human food supplies. Sorghum (Sorghum bicolor L.) is one of the main crops growing in salinized soil. However, the tolerance mechanisms of sorghum to saline–alkaline soil are still ambiguous. In this study, RNA sequencing was carried out to explore the gene expression profiles of sorghum treated with sodium bicarbonate (150 mM, pH = 8.0, treated for 0, 6, 12 and 24 h). The results show that 6045, 5122, 6804, 7978, 8080 and 12,899 differentially expressed genes (DEGs) were detected in shoots and roots after 6, 12 and 24 h treatments, respectively. GO, KEGG and weighted gene co-expression analyses indicate that the DEGs generated by saline–alkaline stress were primarily enriched in plant hormone signal transduction, the MAPK signaling pathway, starch and sucrose metabolism, glutathione metabolism and phenylpropanoid biosynthesis. Key pathway and hub genes (TPP1, WRKY61, YSL1 and NHX7) are mainly related to intracellular ion transport and lignin synthesis. The molecular and physiological regulation processes of saline–alkali-tolerant sorghum are shown by these results, which also provide useful knowledge for improving sorghum yield and quality under saline–alkaline conditions.

Grain sorghum and late-emerging Palmer amaranth response to sorghum planting density and nitrogen rate in an irrigated environment

Palmer amaranth germination and emergence occur throughout the growing season; however, little is known about the impact of late-emerging Palmer amaranth on sorghum, a major crop in Kansas. Field trials were conducted in 2016 and 2017 to measure grain sorghum and late-emerging Palmer amaranth’s response to sorghum planting density and nitrogen rate. Trials were comprised of weed-free and weedy sorghum as main plots, three sorghum planting densities as sub-plots, and three nitrogen rates as sub-sub-plot treatments laid in a randomized complete block design with a split–split-plot arrangement. Weedy sorghum was infested with late-emerging Palmer amaranth only. Weed-free sorghum outyielded its weedy counterpart by 42.2%. At the high sorghum planting density (296 400 plants ha−1), applying 112 kg N ha−1 did not improve grain yield or decrease Palmer amaranth’s number, height, and biomass, but increased sorghum head number and height. Altogether, our findings suggest that increasing sorghum planting density and nitrogen rate in an irrigated environment did not facilitate Palmer amaranth control. Strategies for long-season Palmer amaranth control are needed to protect sorghum yield from weed competition.

First Report of Bacterial Leaf Blight caused by Enterobacter asburiae on Sorghum in Jiangsu Province, China.

Sorghum (Sorghum bicolor [L.] Moench) is a major cereal crop in China, with a planting area of more than 674666 ha in 2021. In August 2022, bacterial leaf blight symptoms were observed on sorghum plants grown in a field in Huai'an (119.30437 ºE, 33.999644 ºN), in Jiangsu Province (Fig. 1). To determine the causal agent, four symptomatic leaves from different plants were surface sterilized with 75% (v/v) ethanol for 1 min and washed three times with ddH2O. The surface-sterilized plant tissues were cut into small pieces (4 × 4 mm in size) and cultured on Nutrient Agar (NA) plates at 28ºC for 24 h. To obtain pure cultures, these colonies were transferred to fresh NA plates by using the conventional streak plate method. The purified bacterial cells were rod-shaped, from 1.14 to 1.66 μm long, and from 0.61 to 0.86 μm wide (number of observations = 31) (Fig. 2). Three isolates were used for further characterization. The Gram stain test indicated that the three isolates were Gram negative. 16S rRNA (27F/1492R primers) and gyrB (UP1/Up2r) genes were amplified and sequenced (Marchesi et al. 1998; Yamamoto and Harayama 1995). The obtained 16S rRNA (0R143361-0R143363) and gyrB sequences (0R146993-0R146995) were submitted to GenBank. The 16S rRNA sequences of the three isolated strains showed over 98% identity (1447/1462, 1438/1462 and 1443/1460 bp) to the E. asburiae reference strains ENIPBJ CG1, CAV1043 and 1808 013 (CP014993.1, CP011591.1 and AP019632.1, respectively). Similarly, the gyrB sequences of the three strains showed 98% identity (1103/1129, 1105/1129 and 1108/1129 bp) to the same E. asburiae reference strains. Four-week-old sorghum plants were used in the pathogenicity tests. A phylogenetic tree was constructed with reference strains (Hoffmann et al., 2005). The healthy leaves were inoculated with bacterial suspensions of the three bacterial isolates (OD600 = 0.6~1.0) using the leaf cutting method (Kauffman et al. 1973). For the control group, sterilized ddH2O was used. Each isolate was inoculated in three healthy plants. Inoculated plants were incubated at 28ºC and 75% humidity with alternating 12-h light and 12-h dark cycles with a photon flux density of 200 mmol/m2/s. After 10 days, bacterial leaf blight symptoms were observed in all the inoculated leaves. The inoculated leaves showed severe browning near the inoculation site (1-2 cm), and advanced yellowing from 2 to 7 cm from the inoculation site, while no symptoms were found in control group. The pathogen was recovered from the infected leaves, and its identity was confirmed by 16S rRNA/gyrB sequencing and morphological analysis, fulfilling Koch's postulates (Fig 2). To our knowledge, this is the first report of E. asburiae causing bacterial leaf blight on sorghum worldwide. This species is a well-known pathogen of humans that can cause nosocomial infections (Markovska et al. 2019; Zhu et al. 2017). Recently, E. asburiae was identified as the causal agent of bacterial blight on rice and tuber rot on radish (Wang et al. 2023; Yu et al. 2021). The emergence E. asburiae as a plant pathogen may be produced by the numerous resistant strains reported during recent years. Pantoea ananatis has been reported as a common companion pathogen of E. asburiae (Xue et al. 2021). This report will help to better understand the host promiscuity of E. asburiae and reveals a new pathogen that affects sorghum production in China. This study also serves as a basis for future studies to develop management strategies and cultivation for the disease to prevent sorghum yield loss. As far as we know, no control method for the management of this new plant pathogen was reported to date, which highlights the potential hazard of this discovery. Reference Hoffmann, H., et al. 2005. Syst. Appl. Microbiol. 28:196. Kauffman, H. E., et al. 1973. Plant Dis. Rep. 57:537. Marchesi, J. R., et al. 1998. Appl. Environ. Microbiol. 64:795. Markovska, R., et al. 2019. Infect. Dis. 51:627. Wang, R., et al. 2023. Plant Dis. in press. https://doi.org/10.1094/PDIS-11-22-2650-PDN Xue, Y., et al. 2021. Plant Dis. 105:2078. Yamamoto, S., et al. 1995. Appl. Environ. Microbiol. 61:1104. Yu, L., et al. 2021. Plant Dis. 106:310. Zhu, B., et al. 2017. J. Glob. Antimicrob. Resist. 8:104.

Sorghum biomass yield and allocation as affected by the combination of photoperiod sensitivity, sweet-stalk and brown midrib traits

Context or problemTraits like photoperiod sensitivity, sweet-stalk and brown midrib (bmr) have been introgressed to increase the biomass yield and quality of sorghum (Sorghum bicolor (L.) Moench) towards bioenergy yield improvement. The effects of combined traits on sorghum performance are far from clear. ObjectivesThe objectives were to investigate the effects of different combinations of photoperiod sensitivity, sweet-stalk and bmr traits on sorghum biomass yield and allocation, and to discuss the implications of such effects on bioenergy production. MethodsData from our own as well as publicly available field trials were analyzed. A corpus of 51 hybrids grown in 49 environments were classified based on photoperiod sensitivity trait (PS or PI for photoperiod sensitive or insensitive), sweet-stalk trait (sweet- and sweet+), and bmr trait (bmr- and bmr+), and differences in the yields of shoot biomass and biomass fractions were determined. Biomass allocation was further evaluated in terms of allometric analysis. ResultsSignificant triple interaction of the effects of the traits on shoot biomass and plant fractions yields were found. In PS-sorghum, bmr decreased shoot biomass only in sweet- genotypes. In PI-sorghum, sweet-stalk trait increased shoot biomass only in bmr- genotypes. In both PS and PI-sorghum, sweet–stalk and bmr traits drove changes in plants’ stem to leaves biomass ratio. In PI-sorghum they also promoted an increase of stem biomass at the expense of panicle biomass. Allometric analysis allowed us to capture different effects of traits on biomass allocation when the yield of biomass shoot changed. ConclusionsInteraction among the effect of traits on shoot biomass yield help to explain discrepancies of biomass yield responses to traits found in the literature. Sweet-stalk and bmr traits produced changes in biomass distribution that depended on plant size, and that ultimately would impact on bioenergy production. Implications or significanceUnraveling the mechanisms underlying biomass and quality changes in response to increasing biomass yield is essential to simultaneously improve bioconversion efficiency and biomass yield. This work provides a starting point for studying the mechanisms behind the effects of combined traits of agronomic interest on biomass yield and allocation of sorghum as an energy crop.

Herbicide Program to Control Parthenium hysterophorus in Grain Sorghum in an Arid Environment

Parthenium weed (Parthenium hysterophorus L.) is an emerging production constraint in many summer crops including sorghum (Sorghum bicolor L. Moench), but limited control options are available. In this field study, the efficacy of sole and sequential applications of a pre-emergence (pendimethalin) and a post-emergence (bromoxynil) herbicide was evaluated for parthenium weed control in grain sorghum over two years. Pendimethalin or bromoxynil alone could only provide 54% and 63% control, whereas their sequential application provided 86% control of parthenium weed over the weedy treatment. The sorghum plants in pendimethalin followed by bromoxynil treatment had the highest leaf fresh weight per plant, plant dry biomass, plant height, and the number of heads among the herbicide treatments. Sorghum fresh forage yield, dry fodder yield, 1000-grain weight, and grain yield were highest in the weed-free treatment followed by the pendimethalin followed by (fb) bromoxynil treatment. Overall, the herbicide treatment performance was in an order of pendimethalin fb bromoxynil > bromoxynil > pendimethalin for weed control and sorghum yield improvement. These results suggest that pendimethalin followed by bromoxynil may provide acceptable control (>85%) of parthenium weed and may improve sorghum grain yield (up to 23%).

Effects of Silicon Alone and Combined with Organic Matter and Trichoderma harzianum on Sorghum Yield, Ions Accumulation and Soil Properties under Saline Irrigation

The action of silicon as a salt stress mitigator has been investigated in isolation, and its combined efficacy with other salt stress mitigators needs to be addressed. This work verified whether silicon, in combination with organic matter and Trichoderma harzianum, enhances the production of forage sorghum under saline irrigation and its effects on soil properties. The field experiment was conducted in Parnamirim (PE), a semiarid region of Brazil. Forage sorghum (Sorghum sudanense (Piper) Stapf) was irrigated with saline water (3.12 dS m−1) and subjected to the application of non-silicon, silicon alone, and silicon combined with Trichoderma and organic matter over three consecutive cuts (every three months after germination). Silicon applied in combination significantly increased the content of nutrient ions K+, P, Ca2+, and Mg2+ in sorghum leaves, stems, and panicles and increased P content in the soil by 170, 288, and 92% for the first, second, and third cuts, respectively. When silicon was applied in combination, sorghum’s dry and fresh matter (total yield for the three cuts) increased to 62.53 and 182.43 t ha−1, respectively. In summary, applying silicon (Si) combined with Trichoderma and organic matter promotes higher nutrient ion contents in soil and sorghum plants and a higher forage sorghum yield.

Tartaric acid coupled with gibberellin improves remediation efficiency and ensures safe production of crops: A new strategy for phytoremediation

Phytoremediation is the direct use of living green plants and it is an effective, inexpensive, non-invasive, and environmentally friendly technique used to transfer or stabilize all the toxic metals and environmental pollutants in polluted soil or ground water. To study the effect of tartaric acid, gibberellin, and tartaric acid coupled with gibberellin on rape-kenaf or rape-sweet sorghum rotation, a field experiment was carried out on a farmland combined polluted with Cd and Pb in eastern Hunan Province, China. The results showed that these two rotation systems coupled with superposition measure has potential to enhance yield and biomass of rape (Brassica napus L.), kenaf (Hibiscus cannabinus) and sweet sorghum (Sorghum dochna (F.) Snowden), as well as to increase Cd and Pb uptake of the three crops, thus accelerating phytoextraction. The Cd and Pb annual removal by rape-kenaf rotation in one year under different treatments were 269–438 and 112–149 g·hm−2, respectively. And the Cd and Pb annual removal by rape-sweet sorghum rotation in one year under different treatments were 68.0–111 and 43.8–92.3 g·hm−2, respectively. Under the two rotation systems, these integrated management measures can remove Cd and Pb up to 438 g·hm−2·year−1 and 149 g·hm−2·year−1, respectively. The Cd and Pb content in rape seeds or sweet sorghum stems and leaves were lower than the food or forage standard, indicating that we can use this rotation system for both remediation and safety production. Furthermore, the two rotation systems also generated considerable economic value. These results showed that the combination of phytoremediation and agricultural production is a feasible technical mode in the field of Cd and Pb co-contamination, and also provides useful information for further study of the interaction mechanism between rotation crops and enhancement measures. In subsequent experiments we can set concentration gradients for tartaric acid and gibberellin, and we can also select other crops for rotation, with a view to finding the optimal auxiliary measure and crop rotation modern.

Sustainable intensification of sorghum-based cropping systems in semi-arid sub-Saharan Africa: The role of improved varieties, mineral fertilizer, and legume integration

ProblemSustainable intensification of cereal cropping systems can contribute to reducing food insecurity while mitigating biodiversity losses thanks to land sparing. Yet, intensifying crop production with more nutrient inputs often increases sensitivity to climate hazards and yields inter-annual variability. How different options for sustainable intensification interact and how they could help achieve greater and less variable yields is not well known for key cereal cropping systems of sub-Saharan Africa. ObjectiveHere, we aim to assess the impact on productivity and its interannual variation of three contrasted strategies of crop intensification, namely i) the integration of cowpea intercropped with sorghum or as sole crop, ii) improved varieties with high harvest index and greater nitrogen use efficiency, and iii) the use of more mineral fertilizer. MethodsWe did this assessment using a calibrated soil-crop model for a case study of sorghum-based cropping systems of semi-arid southern Mali, using a historical weather series from 1980 to 2010. ResultsWe found that the incremental combinations of two or three strategies helped increase productivity in terms of energy and protein. However, greater productivity went hand in hand with greater inter-annual variability. Intercropping sorghum with cowpea helped to reduce the inter-annual variability of productivity, but only when mineral fertilizer was not added. With mineral fertilizer input, sorghum contributed the largest share of the intercrop productivity, and sorghum yield was more variable from a year to another than cowpea yield. The overall productivity of intercropping sorghum with cowpea was always greater than having the two sole crops on separate plots. This was possible thanks to the facilitation of light, water and N acquisition by the two crops in the intercropping, regardless of the specificities of the growing season with regard to water and nitrogen stress. However, the variability of productivity was smaller for the cultivation of the two sole crops on separate plots, regardless of fertilizer input. ConclusionThe often-claimed benefit of intercropping on reducing the inter-annual variability of production does not hold when the three strategies are combined. ImplicationsOur results suggest that the integration of legumes does not help cushion farmers against the risk related to the intensification of cropping systems with more nutrients and improved seeds. Careful gross margin analysis that accounts for price variability and uncertainty would be required to refine this risk assessment for specific farm contexts. We discuss the implication of these findings in light of the current research agenda for the sustainable intensification of cropping systems in sub-Saharan Africa.

Effects of tillage practices and planting techniques on crop yield and soil properties in northwestern lowlands of Ethiopia

Vertisols are crucial for improving and sustaining food production in Ethiopia. However, due to conventional tillage and waterlogging, the great potential of Vertisols in the study area has been underutilized. Different tillage practices combined with planting techniques play a significant positive role in improving crop yield in high-rainfall areas. This study was conducted to evaluate the effects of tillage practices and planting techniques on the productivity of sesame and sorghum in Metema experimental site, in northwestern lowlands of Ethiopia. The experiment was conducted with three replications and six treatments described as: permanent raised bed with minimum tillage (PRB + MT), permanent raised bed with minimum tillage, and mulch (PRB + MT + M), broad bed furrow (BBF), flatbed with minimum tillage and mulch (Flat + MT + M), flatbed with minimum tillage (Flat + MT) and control. The results indicated that the soil moisture content was significantly higher in control (40.77–43.56 %) and flatbeds compared with BBF (39.30–40.39 %) and PRB + MT + M treatments. The bulk density of the soil and organic carbon levels showed significant variations between treatments. The highest bulk density was observed in the control (1.29 Mg m−3) than in PRB + MT (1.12 Mg m−3). In this regard, the highest seed yield of sesame (1138.52 kg ha−1) and grain yield of sorghum (5456.90 kg ha−1) were obtained from BBF and PRB + MT + M respectively. Inversely, the lowest seed yield of sesame (778.77 kg ha−1) and grain yield of sorghum (4052.7 kg ha−1) were obtained from the control plot. Therefore, to improve the productivity of sesame and sorghum, the preparation of BBF and PRB + MT + M should be taken into account.

The effects of heat stress on male reproduction and tillering in Sorghum bicolor

AbstractDue to global climate change, heat stress is increasingly harming the growth, development, overall biomass, and grain yield of numerous crops. Heat stress impairs pollen development and thus reduces seed set in Sorghum bicolor (L.) Moench; however, the effects of heat stress on anther development at specific stages and tiller formation remain incompletely understood. Here we report that exposure to heat stress [42°C/32°C (day/night)] at pollen mother cell (PMC) and booting stages profoundly disrupts tapetum and pollen development, resulting in a significant decrease in grain yield in sorghum. Sorghum plants subjected to 9 days or less of heat stress at the PMC stage exhibited normal pollen viability, but 12 days of heat stress caused almost complete loss of grain yield and the formation of nonviable pollen grains. Similarly, sorghum plants that were heat‐stressed for 3 days at the booting stage produced few seeds. Further analysis revealed that aberrant tapetum and pollen development contributed to the sterility of pollen in these heat‐stressed plants. Notably, in addition to inhibiting plant height, a 12‐day heat stress at the PMC stage promoted the formation of basal tillers, whereas a 3‐day heat stress at the booting stage stimulated the formation of apical tillers, which helped salvage seed yield under heat stress conditions. Moreover, the application of exogenous auxin promoted the formation of apical tillers and leaf numbers per apical tiller. Collectively, our findings suggest that sorghum is susceptible to heat stress during both early and late anther development, and auxin might be involved in governing the formation of apical tillers.