Sorghum Production Research Articles

Exploring Genetic Variability, Path Analysis and Divergence in Sorghum (Sorghum bicolor (L.) Moench)

The grain crop known as sorghum [Sorghum bicolor (L.) Moench], which belongs in the Poaceae family, is said to have evolved from Ethiopia or Sudan. This is a crucial crop for food security, especially within the tropical and semi-arid regions in African nations. By terms of long-term domestication and genetic diversity, this crop was native from Ethiopia. showed differences between the crop's cultivated and wild ancestors that gathered within the nation. Due to its enormous diversity of sorghum, which shows innate biological resistant to disease, dryness, and insects in addition to having large lysine content and excellent quality of grain, Ethiopia has become the world's top contributor of germplasm for the sorghum breeding programmes. Ethiopian landraces referred to as "zera zera" sorghum and the generations that sprang of those were used in ICRISAT along with other nations' contemporary sorghum breeding programmes for hybrids creation. Sorghum is at present Ethiopia's second most significant cereal crop after the tef with regard to of its combined area covered and productivity, which means it's used to make injera. Sorghum genotype from Ethiopia is varied and has responded to a variety of rainfall conditions and elevations. Plant breeding starts with the characterisation and recognition of sorghum seeds that offer desired features for improved genetics. When contrast with field trial evaluation, DNA-based molecular markers and PCR-based methods were most effective in characterising and identifying sorghum genotypes which offer desired features since they are unaffected by duration or climate. The most economical method of increasing sorghum production for many applications is genetic enhancement. Gaining more knowledge about sorghum's genetic diversity could be extremely beneficial for improving the crop in terms of quality of food along with other crucial agronomic characteristics. Sorghums from the Ethiopian Centre of Crop Diversity have a vast amount of genetic variety. To effectively gather and conserve this genetic variety before it is overrun and lost, some serious work is required.

The Identification of Kabatiella zeae as a Causal Agent of Northern Anthracnose of Sorghum in China and Estimation of Host Resistance.

Sorghum northern anthracnose is a leaf disease affecting sorghum, which results in plant death and substantial yield loss. This study aimed to effectively understand the disease, clarify its biological characteristics, and evaluate the resistance of germplasm resources. A field sample was collected to isolate and purify the pathogen. The pathogen, identified as Kabatiella zeae Narita et Hiratsuka using both morphological and molecular techniques, was further confirmed as the causative agent of northern anthracnose of sorghum following Robert Koch's principles. The results revealed the optimal culture temperature to be 25 °C, preferred dark culture conditions, and the best growth on potato glucose agar medium with sucrose and L-leucine as the optimal carbon and nitrogen sources, respectively. A total of 138 sorghum germplasm resources were inoculated and evaluated using the isolated pathogen, with 20 lines (14.49%) exhibiting high resistance, 18 lines (13.04%) showing disease resistance, 27 lines (19.57%) demonstrating medium resistance, 37 lines (26.81%) being susceptible, and 36 lines (26.09%) classified as highly susceptible. The indoor fungicide screening was conducted through pathogen medium application, and enilconazole, pyraclostrobin, methylthiophanate, and flusilazole were screened for the best fungicide inhibition with a 100% inhibition rate compared with the control. This study provides reference for field pharmaceutical control in sorghum production.

Farmers' Perception of Calotropis procera on the Soil and Productivity of Off-Season Sorghum (Sorghum durra) in Magoumai, Gawar and Laf, Far North Cameroon

Farmers' Perception of Calotropis procera on the Soil and Productivity of Off-Season Sorghum (Sorghum durra) in Magoumai, Gawar and Laf, Far North Cameroon

A rapid classification method for sorghum seed varieties based on HSI and PCA-SICNN algorithm

Accurate classification of sorghum varieties is crucial to the production and processing of liquor with sorghum as raw materials. Hyperspectral imaging (HSI) has the potential to achieve this goal quickly and nondestructively. This study proposes a novel algorithm, an improved Principal Component Analysis combined with Spectrum-Image-Convolutional Neural Network (PCA-SICNN), which can combine spectral features and image features of HSI data, to enhance the accuracy of variety identification of sorghum seeds. To verify the effect of this algorithm, hyperspectral imaging data (939–1700 nm) of 13,200 sorghum seeds from 6 varieties were collected. The principal component analysis (PCA) was employed to select 20-dimension images from the origin hyperspectral imaging data. Spectrum-Image-Convolutional Neural Network (SICNN) extracts the spectral and image features of sorghum in the network and then fuses the features. By fully learning the HSI data features of sorghum, it achieves the classification of sorghum varieties. The results demonstrate that PCA-SICNN achieves an accuracy on the training set and on the test set reaches 98.67 % and 98.64 %, respectively. Compared with other control methods, the prediction accuracy of the PCA-SICNN model increased by at least 1.10 %. These results suggest the potential for the method to be widely applied in the production and processing of sorghum.

The stepwise regression analysis method for estimating sorghum production in Karangmojo

Abstract Sorghum is a multifunctional crop that can be utilized as a source of food, feed, and bioenergy. Sorghum is a plant that can adapt to land with optimal conditions, dry land with minimal nutrients and tolerant to pests and diseases. Sorghum has been widely cultivated in Indonesia, one in Gunungkidul, Yogyakarta. Sorghum production is influenced by several agronomic characteristics. The purpose of the study was to determine agronomic variables that affect sorghum production. The research was conducted in Karangmojo, Gunungkidul, Special Region of Yogyakarta, from October 2022 to March 2023. Sorghum varieties were local varieties as well as national superior varieties which are usually planted by local farmers. A total of 10 variables were analysed for their significance level on sorghum yield. The collected data were then processed using a multiple linear regression model (stepwise) using SPSS 16.0. The results showed that of the 10 agronomic variables observed, two variables contributed to the sorghum production, namely panicle weight and days to harvesting. The regression model from stepwise results is y = 8.884 + 0.036x3 – 0.062x10, with R2 = 0.754. This result indicates that the two independent variables are the main variables in determining sorghum production in Karangmojo.

Effect of different nutrient management practices on productivity, profitability and nutrient dynamics in forage-based cropping systems under mid-hill conditions of north-western Himalayas

A field experiment was conducted at the research farm of Fodder Section, CSKHPKV, Palampur, from Kharif 2018 to Rabi 2019-20 to study the effect of different nutrient management practices in forage-based cropping systems. Ten nutrient management practices in two cropping systems were tested in randomized block design with three replications. Integrated nutrient management, i.e., 50% recommended N + 10 t/ha FYM + 10% Jeevamrit and 50% recommended N+ 10 t/ha FYM + 5% Jeevamrit and recommended NPK behaving alike resulted in higher oat green fodder equivalent yield, nutrient uptake (N, P and K) and system productivity of sorghum + pearl millet - oat + sarson/wheat cropping systems. An increase in soil organic carbon content was observed with integrated nutrient management (50% recommended N + 10 t/ha FYM + Jeevamrit) and organic nutrient management (10 t/ha FYM + Jeevamrit) over the initial status at the end of sorghum + pearl millet - oat + sarson/wheat cropping systems. Integrated nutrient management improved available soil nitrogen, phosphorus and potassium contents over the initial values. Significantly higher available soil nitrogen, phosphorus and potassium contents were recorded with integrated nutrient management as well as with recommended NPK through inorganic sources over other treatments comprised of organic and natural farming systems of nutrition in both the cropping systems. Recommended NPK proved most profitable with the highest net returns and benefit-cost ratio in sorghum + pearl millet - oat + sarson/wheat cropping systems. Sorghum + pearl millet - oat + sarson cropping system comprised of all fodder crops resulted in higher productivity and profitability but did not increase soil available nutrient status as compared to sorghum + pearl millet - wheat cropping system comprised of fodder as well as grain crops.

Access and Use of Information for Enhanced Adoption of Climate Smart Agricultural Practices among Smallholder Farmers in Lake Victoria Basin, Kenya

The value of information in agricultural production cannot be overemphasized given the challenges caused by the impact of climate change. This study evaluated the importance of accessing and using information for enhanced adoption of climate-smart agriculture (CSA) practices in sorghum production among smallholder farmers in Lake Victoria Basin, Kenya. The study used a quantitative research method with a correlation design, collecting data from 382 farmers through a questionnaire. A pilot study was conducted with a 10% sample size to assess reliability and validity achieving a CVI value of 0.877445696 and Cronbach’s alpha (α) value of 0.809. Descriptive statistics were used to determine information access and use, while correlation analysis examined associations between age and education and information access and use. The findings showed that farmers obtained information primarily from television, radio, extension workers, and neighbors and friends. The accessibility and use of this information were influenced by age and level of education. The findings are significant since they can help agricultural stakeholders identify and use appropriate channel and context-specific information to disseminate information that would enhance the adoption of CSA practices for improved sorghum yield. This may increase farmers' resilience to climate variability and improve their farming knowledge and skills, potentially leading to better livelihoods for the farming communities in the region. By advocating the provision of easily accessible and relevant information in the appropriate format and media, the findings may aid in policy formulation by providing policymakers with insights when formulating agricultural policies and legislation.

Genome-wide screening and characterization of phospholipase A (PLA)-like genes in sorghum (Sorghum bicolor L.).

The characterisation of PLA genes in the sorghum genome using in-silico methods revealed their essential roles in cellular processes, providing a foundation for further detailed studies. Sorghum bicolor (L.) Moench is the fifth most cultivated crop worldwide, and it is used in many ways, but it has always gained less popularity due to the yield, pest, and environmental constraints. Improving genetic background and developing better varieties is crucial for better sorghum production in semi-arid tropical regions. This study focuses on the phospholipase A (PLA) family within sorghum, comprehensively characterising PLA genes and their expression across different tissues. The investigation identified 32 PLA genes in the sorghum genome, offering insights into their chromosomal localization, molecular weight, isoelectric point, and subcellular distribution through bioinformatics tools. PLA-like family genes are classified into three groups, namely patatin-related phospholipase A (pPLA), phospholipase A1 (PLA1), and phospholipase A2 (PLA2). In-silico chromosome localization studies revealed that these genes are unevenly distributed in the sorghum genome. Cis-motif analysis revealed the presence of several developmental, tissue and hormone-specific elements in the promoter regions of the PLA genes. Expression studies in different tissues such as leaf, root, seedling, mature seed, immature seed, anther, and pollen showed differential expression patterns. Taken together, genome-wide analysis studies of PLA genes provide a better understanding and critical role of this gene family considering the metabolic processes involved in plant growth, defence and stress response.

Unconventional Strategies for Aphid Management in Sorghum.

Since the invasion of the sorghum aphid Melanaphis sorghi (Theobald), farmers in the sorghum (Sorghum bicolor L. Moench) production region in the Great Plains of the U.S. have faced significant crop damage and reduced yields. One widely used practice to aid in managing sorghum aphids is pest monitoring, which often results in field-level insecticide applications when an economic threshold is reached. However, relying on this traditional management practice includes the application of insecticides to non-infested plants. To reduce insecticide usage in sorghum, we proposed spraying individual plants when aphids are present or absent compared to traditional spraying based on a standard economic threshold using field replicate plots over two summer seasons. The experimental results of this study indicated fewer aphids in plots managed with an economic threshold, followed by randomly sprayed and plant-specific treatments compared with the untreated control treatment. Therefore, compared with traditional management, those treatments can be alternative strategies for managing aphids on sorghum within our field plot study.

Optimizing bioenergy sorghum productivity and nutrient removal in Illinois: Impact of nitrogen fertilization under diverse marginal conditions

Context or problemBioenergy sorghum (Sorghum bicolor L. Moench) is a promising crop for contributing to the United States bioenergy supply. However, the varying limitations of the marginal lands targeted for its cultivation present a management challenge. ObjectiveThis two-year study aimed to investigate how the limitations associated with marginal cropland impact the effects of nitrogen fertilization on the yield of bioenergy sorghum and the uptake of 11 macro- (N, P, K, Ca, Mg, and S) and micronutrients (Fe, Mn, Zn, Cu, and B). MethodsThe study contrasted prime cropland in central Illinois (Urbana) with three marginal cropland sites in southern (Ewing) and central Illinois (Fairbury and Pesotum). These marginal cropland sites are characterized by varying limitations, including low soil fertility (P and K limitations), leaching and erosion, and flooding, respectively. Four nitrogen rates (0, 56, 112, and 168 kg N ha−1) were tested under eight environments. ResultsThe average yields and ranges of sorghum biomass were 20.2 (17.0–23.2) Mg ha−1 in Urbana, 18.1 (13.1–19.8) Mg ha−1 in Ewing, 13.8 (9.0–17.3) Mg ha−1 in Fairbury, and 23.3 (14.6–33.0) Mg ha−1 in Pesotum. Optimal N rates were 56 N in Pesotum and 112 N in Urbana, Ewing, and Fairbury. Tissue macronutrient contents in Urbana were generally higher than in the marginal croplands, while micronutrient contents did not show discernible trends. Increasing N rate generally correlated with the macronutrient removal except in Ewing. ConclusionComparable sorghum biomass yields were observed between prime and marginal croplands (averaging 18.3 Mg ha−1), but optimal N rates varied between 56 N and 112 N. This suggests that yield gaps can be narrowed by applying the optimal N rates for the respective locations. However, increased removals of macronutrients, especially P and K, with increasing yields indicate the need to revise fertilizer recommendations, particularly for soils deficient in these nutrients. Implications or significanceOur study suggests that while sorghum production on marginal cropland is feasible, N management needs to be adapted to the unique limitations associated with various types of marginal cropland.

TECHNOLOGICAL GAP AMONG THE FARMERS REGARDING RECOMMENDED SORGHUM PRODUCTION TECHNOLOGY

In India and other Asian and African countries, millets commonly include sorghum, pearl millet, and a range of small millets (Vetriventhan et al., 2020). India is the sixth largest producer of sorghum globally (www.smartfood.org). Sorghum is mainly used for food, fodder, alcoholic beverages and production of bio fuels. Sorghum is also known as "Global Grain" due to its multipurpose uses being a 4F (food, feed, fodder and fuel) crop. Despite of its multiple uses, the area under sorghum in India has declined from 18.61 m. ha in 1969-70 to 4.96 m. ha in 2017-18. There is wide gap between national productivity and yield potential of the improved sorghum technologies developed from the research institutes. Productivity of the crop can be enhanced by adopting the improved practices. The extent of technological gap in different production components of the technology contributes differently to the yield gap. Keeping in view the afore mentioned facts, the study on Technological Gap among the farmers regarding recommended sorghum production technology was undertaken the middle of Gujarat. A sample of 300 sorghum growers were selected from all 14 villages of Vadodara district by using proportionate random sampling. Ex-post-facto research design was used. The results of the study show that higher (87.64 per cent) technological gap in use of plant protection measures, 75.30 per cent technological gap in use of seed treatment, 63.18 per cent technological gap in weed management and 61.93 per cent technological gap in use of FYM were found in adoption of recommended sorghum production technology as majority of the sorghum growers faced constraints of high cost of farm inputs ( pesticide, insecticide, FYM), non availability of seed, good quality of FYM & fungicides at proper time, inadequate knowledge about sorghum production technology, non-availability of labor at proper time for weeding & harvesting during adoption of recommended sorghum production technology. Hence, more emphasis should be given to supply inputs in time, sufficient in quantity at affordable price to farmers.

Optimizing Soil Health and Sorghum Productivity through Crop Rotation with Quinoa.

Crop rotation has been considered a potential solution to mitigate the negative effects of the continuous cropping of sorghum, including soil quality issues, inadequate plant development, and diminished yield and quality. A two-year field experiment was conducted to compare the effects of sorghum-sorghum continuous cropping and quinoa-sorghum rotation on soil properties and sorghum yield. The treatments were arranged in a randomized complete block design with three replicates. Sorghum seeds (Jinza 22) and quinoa seeds ('Jiaqi 1' variety) were used. Soil samples were collected before and during the experiment for the analysis of physicochemical properties. The yield traits of sorghum were measured at maturity. The results showed that soil nutrients and organic matter were higher in the top 0-20 cm soil depth compared to 20-40 cm depth, with significant differences observed between cropping systems. Sorghum-quinoa cropping increased soil total N and organic matter, particularly at the jointing and maturity stages of sorghum. However, the available phosphorus was higher under continuous cropping at all growth stages. Crop rotation significantly improved sorghum yield traits, including spike fresh weight, spike dry weight, grain weight per spike, and grain yield per hectare. A correlation analysis revealed positive relationships between soil total N, organic matter, and sorghum yield. Overall, sorghum-quinoa rotation demonstrated potential for improving soil fertility and enhancing crop productivity compared to continuous cropping, although further studies are needed to explore the long-term effects and optimize management practices.

Exploring genotypic diversity in sorghum breeding lines for water‐saving traits to enhance drought adaptation during the post‐rainy season

AbstractSorghum [Sorghum bicolor (L.) Moench], a crucial staple crop in South Asia and sub‐Saharan Africa, faces challenges amid increasing climate variability. Post‐rainy sorghum serves as a dominant food and fodder crop in India. Aligned with International Crops Research Institute for the Semi‐Arid Tropics's post‐rainy sorghum product profile, this research extensively characterizes sorghum lines, emphasizing the traits vital for post‐rainy drought adaptation in hybrid parents. We examined genotypic differences and trait correlations in 25 sorghum hybrid parents and varieties (B line for seed parent, R line for restorer, and check for varieties) through atmospheric and soil drought experiments. Results from atmospheric drought experiments revealed significant variation in transpiration rate (TR) under high vapor pressure deficit (VPD), with certain lines showing limited TR (BTX623 and ICSR 21002), while others exhibited high TR. In soil drought experiments, transpiration decline occurred at fractions of transpirable soil water ranging between 0.38 (ICSR 174) and 0.65 (40162 and ICSR 21005). R lines consistently displayed superior plant growth, water use, and biomass compared to B lines. Transpiration efficiency (TE) and total biomass showed positive correlations (r2 = 0.69) in well‐watered and (r2 = 0.45) in water‐stressed conditions. Most R lines displayed higher biomass and TE. Genotypes exhibiting enhanced vigor and limited TR in high VPD conditions and high TE hold potential for enhancing drought adaptation in post‐rainy sorghum. Notably, genotypes with higher biomass, lower TR, and increased TE within both R and B line groups represent valuable genetic resources for enhancing sorghum crops, post‐rainy sorghum adaptation to water deficit.

Brown midrib (BMR) and plant age impact fall armyworm (Spodoptera frugiperda) growth and development in sorghum-sudangrass (Sorghum x drummondii)

Economic losses from insect herbivory in agroecosystems has driven the development of integrated pest management strategies that reduce pest incidence and damage; however, traditional chemicals-based control is either being complemented or substituted with sustainable and integrated methods. Major sustainable pest management strategies revolve around improving host plant resistance, and one of these traits of interest is Brown midrib (BMR). Originally developed to increase nutritional value and ease of digestion for animal agriculture, BMR is a recessive plant gene usually found in annual grasses, including sorghum and sorghum-sudangrass hybrids. In sorghum-sudangrass, BMR expressed plants have lower amounts of lignin, which produces a less fibrous, more digestible crop, with possible implications for plant defense against herbivores- an area currently unexplored. Fall Armyworm (FAW; Spodoptera frugiperda) is a ruinous pest posing immense threat for sorghum producers by severely defoliating crops and being present in every plant stage. Using FAW, we tested the effect of seed treatment, BMR, and plant age on FAW growth, development, and plant defense responses in sorghum-sudangrass. Our results show that seed treatment did not affect growth or development, or herbivory. However, presence of BMR significantly reduced pupal mass relative to its non-BMR counterpart, alongside a significant reduction in adult mass. We also found that plant age was a major factor as FAW gained significantly less mass, had longer pupation times, and had lower pupal mass on the oldest plant stage explored, 60-days, compared to younger plants. These findings collectively show that pest management strategies should consider plant age, and that the effects of BMR on plant defenses should also be studied.

Evaluating effects of selected water conservation techniques and manure on sorghum yields and rainwater use efficiency in dry region of Zimbabwe

Sorghum production in semi-arid areas of Zimbabwe is constrained by low and erratic rainfall, low fertility and soil moisture stress. Sorghum grain yields ranges from 0.2 to 0.4 t ha−1 in sandy-to-sandy loam soils respectively. The objective of the study was to assess cattle manure and rainwater harvesting techniques in improving sorghum grain yield in a semi-arid region of Zimbabwe. The experiment used a randomised complete block design with rainwater harvesting technique as a main treatment factor at three levels. Sub-plot factor was cattle manure at five levels (0, 2.5, 5, 10 and 15 t ha−1) and two sorghum varieties (Macia and SV1) as sub-sub plot factor. Sorghum grain yields were improved significantly (p < 0.05) for both varieties using tied contours. Increasing application rates of cattle manure, showed significant increase (p < 0.05) in sorghum grain yield over the control (0 t ha−1). Tied contour had higher grain yield (1.15 t ha−1) with the use of Macia variety. Stover yield was highly influenced by rainwater harvesting method of tied contour (p < 0.05) compared with infiltration pit and standard contour. Increase in application levels of cattle manure show significant (p < 0.05) increase in stover yields. Tied contour had the highest (3.11 kg ha−1 mm−1) rainwater use efficiency which show significant differences (p < 0.05) from infiltration pits and standard contour. Interaction of tied contour and different rates of cattle manure showed significant increments in rainwater use efficiency with increases in manure application rates. Tied contours, 15 t ha−1 cattle manure and Macia variety are potential strategy to achieve climate smart agriculture and improve food security in semi-arid areas. Sorghum production in marginalised areas can be productive with adoption of tested techniques.

Diversity of Pest Types and Natural Enemies in Plantations Sorghum (Sorghum bicolor L)

The types of pests that attack sorghum plants are very diverse, ranging from the germination phase to harvest. This is the main obstacle in efforts to increase sorghum production. These pests have different behaviors, morphologies, and ecobiologies. The aim of this research is to identify all types of pests and natural enemies that disturb sorghum plants. This research was conducted on sorghum farming land in Pantai Gemi village, Stabat subdistrict, Langkat district, Medan, from March to July 2022. Morphological identification was carried out using the sweeping net method, yellow sticky traps, and pitfall traps. The results of the research showed that there were 126 weaver ants. (Oecophlla Smaragdina ), 83 black ants ( Dolichoderus thoracicus ), and some of the pests that were caught and the least were 14 seed flies ( Atrigona soccata ) and 12 dragonflies ( Trithemis arteriosa). is the type of pest that most often attacks sorghum plants. By identifying pests and natural enemies, it is hoped that we can control pests effectively and integratedly in sorghum cultivation.

Performance of sorghum varieties with various fertilizer doses in peatlands of West Aceh Regency

West Aceh Regency is one of the regions in Indonesia with quite extensive peatlands, but the diversity of food crop commodities is still very low. To enhance food diversification programs of rice, sorghum production is important. The purpose of this research was to test several varieties of sorghum in the peatlands of West Aceh Regency. This research was carried out from July to November 2023. Several new varieties of sorghum released by the Indonesian Cereals Research Institute (ICERI) were evaluated in the peatland of West Aceh. The research method used a randomized complete block design (RCBD) with two factors and three replications. The first factor was different varieties of sorghum, and the second factor was various doses of fertilizers. The varieties used were Soper 7 Agritan, Bioguma 1, and Suri 3. The doses used Control (no treatment), Dose I (75 kg Urea ha-1 + 50 kg SP-36 ha-1 + 50 kg KCl ha-1), Dose II (150 kg Urea ha-1 + 100 kg SP-36 ha-1 + 100 kg KCl ha-1), and Dose III (225 kg Urea ha-1 + 150 kg SP-36 ha-1 + 150 kg KCl ha-1). The results showed that the Bioguma 1 variety adapted better than the other varieties, where the plant height was 187.97 cm, the number of leaves was 15.08, the panicle diameter was 35.92 mm, and the panicle weight was 79.52 g. Meanwhile, fertilizer dose II is better on the character of the number of leaves and panicle length. The interaction effect between the two factors only showed a significant influence on panicle length. Therefore, the Bioguma 1 sorghum variety can be a recommended variety for planting in the shallow peatlands of West Aceh. Keywords: Acidic soil; alternative food; food diversification

What is the potential of sugarcane borer in reducing sorghum fitness and grain production?

AbstractPest attack is an important biotic threat to sorghum productivity, and one of the main insect pests of grain sorghum is sugarcane borer (SCB) Diatraea saccharalis. Despite the importance of this insect species, little is known about the relationship between SCB infestation and reduction in sorghum grain yield, as well as on the gain threshold and economic injury level for decision making of pest control. This study evaluated the influence of SCB infestation on plant performance and grain production in three commercial grain sorghum hybrids. Hybrids AG1090, BRS 373, and DKB 590 were planted in three crop seasons in Sete Lagoas, Brazil, and six treatments were assessed in the experiments, consisting of three grain sorghum hybrids with and without the insecticide chlorantraniliprole at 52.5 g a.i. ha−1 under SCB natural infestation. The parameters evaluated on sorghum plants were the length of tunnels, plant height, length and weight of panicles, stem borer injury, and grain yield. The infestation of SCB was higher when sorghum plants were not treated with insecticide, resulting in lower productivity. The use of insecticide increased plant height, reduced tunnel length, and increased panicle length and weight. Hybrids only affected panicle weight. The hybrid that presented the highest panicle weight when using the insecticide was AG 1090. Hybrids AG 1090 and DKB 590 showed reduced grain production with increasing gallery length, whereas BRS 373 did not show a significant correlation, which may suggest a certain level of tolerance to SCB attack. This is the first study that determines the gain threshold and economic injury level and that effectively shows how much grain yield is lost by SCB attack in grain sorghum hybrids.

Response of Intercropping Sorghum (Sorghum bicolor L. Moench) with Cowpea and Nitrogen Application on Growth and Yield of Sorghum

Sorghum grain yields have remained low despite the emergence of higher yield varieties, due to inadequate soil fertility, unsuitable cropping patterns, and restricted nitrogen fertilizer application (N). Cowpea integration and N utilization in sorghum-based cropping systems are likely to boost yield. However, knowledge of the impacts of sorghum-cowpea intercropping, nitrogen usage, and their interactions on companion crop performance is lacking. The effect of sorghum-cowpea intercropping and three N rates on the growth and yield of two sorghum varieties (ETS 2752 and ETS 4946) and two cowpea varieties (Keti and Bole) was investigated in RCBD with a split-plot arrangement, replicated three times. Sorghum grain yield was positively correlated with harvest index, fertile tiller m-2, leaf area index, panicle weight, and CGR. Sorghum/cowpea intercropping was more productive than sole (LER&gt;1). ETS 2752 was superior to ETS 4946 in terms of growth and yield, hence it is recommended to farmers for commercial production. Therefore, the sole cropping system and N addition were effective in enhancing growth and grain yield of sorghum and cowpea, hence recommended for commercial production of ETS 2752. Intercropping is only recommended for sorghum production to improve household food security since it improves land productivity (LER&gt;1).

The genotypic variation in the positive response of sorghum to higher sowing density is linked to an increase in water use efficiency

In semi-arid tropical areas, sorghum is sown at very low planting densities. Hence, increasing plant density represents an opportunity to improve productivity. However, assessing the expected increase in water needs is critical prior to testing higher densities under rainfed conditions. This was tested with a panel of elite cultivars in field and lysimiter experiments, and testing the effects of two density treatment, high (HD, 22 plants.m-²) and low (LD, 11 plants.m-²), on grain and biomass yield and on water use and water use efficiency (WUE). Doubling the conventional sowing density significantly increased biomass and grain yield, with a genotypic variability in the biomass response. No link was found between the response to density and the maintenance of the tillering capacity, whereas the response to density was somewhat explained by a differential increase in the leaf area index under high density (r=0.43 P<0.05). Lysimeter experiments showed that, compared with the conventional density, the high-density treatment had 62% increase in biomass vs a 38% increase in water use, resulting in a 17% higher WUE on average of the genotypes tested. There was an appreciable genotypic variability in this degree of WUE increase under high density. The most striking result was the very tight positive link between the biomass response to density and the differential increase in WUE in the dry season (r=0.91 P<0.0001), whereas in the wet season this link was negative (r=-0.48 P<0.02). This work shows that intensifying sorghum production by increasing sowing density is possible, in the short term using cultivars that show the largest WUE increase under high density, in the longer term by breeding high-density adapted cultivars, targeting plant traits that explain the tight link between higher WUE and higher yield under high density.