Peanut (Arachis hypogaea L.) and maize (Zea mays L.) are essential crops for Ghana’s economy and food security, but weed infestation poses a significant threat to their cultivation. Crop rotations influence weed communities, but little is known about these processes in peanut-cropping systems in West Africa. This study investigated the impact of different crop rotations and input levels on weed communities in Ghana over 3 yr. Results showed that low inputs (absence of herbicide and fertilization) favored species richness, while higher input levels (weed control with herbicides and fertilizer use) reduced it. Diversity and evenness were also affected by inputs, with varying patterns across locations and seasons. Weed population growth rates (λ) varied significantly by location and treatment; all management programs resulted in increasing weed populations. Principal component analysis revealed distinct associations between weed species and crop management. The majority of weed species exhibited a generalist behavior and did not associate with a particular management. However, billygoat weed (Ageratum conyzoides L.) and Benghal dayflower (Commelina benghalensis L.) were positively associated with high-input systems, while purple nutsedge (Cyperus rotundus L.) exhibited strong associations with low and medium inputs. The weed–crop rotation dynamics described here demonstrate how management drives the selection of weed species that are more pervasive and interfere with important food crops in Ghanaian agriculture.

Use of diverse germplasm for generating heterotic hybrids is the foremost requirement in maize. The present study was conducted by using a diverse set of inbred lines and the line × tester method was applied to identify best performing lines and to group QPM inbred lines into different heterotic groups. The test crosses, developed by following line (66) × tester (CML 161 and CML 165) mating design, were evaluated during winter 2013, rainy 2014 and 2015 seasons at Begusarai and Ludhiana, respectively. Based on the specific combining ability, the lines were categorized into two heterotic groups. Out of 66 novel inbreds, 18 lines with significant SCA with CML165 were classified in group A, 16 inbreds with significant SCA with CML161 were classified in group B and 20 inbreds with significant GCA were classified in group (AB). Nine inbred lines were selected based on their positive GCA values and pedigree crosses were developed in rainy season in 2017. Three crosses were made in heterotic group A and four crosses were in group B for synthesizing new inbred lines by using pedigree method. Heterotic grouping based inbred evaluation trial and biochemical analysis were carried out to estimate per se yield potential of developed lines and to estimate tryptophan content. QIL-4-2491 (Group-A) and QIL-4-2401 (Group-B) were the top yielders. A total of 25 crosses were made among the heterotic groups (A and B) by using 22 lines from groups A and B and three best performing hybrids were identified.

The present study generates information related to the molecular divergence between turcicum leaf blight (TLB)-resistant and -susceptible lines. During molecular diversity studies, a total of 212 alleles were detected at 75 marker loci and ranged from two to five with an average of 2.83 alleles per locus. A direct correlation for the number of alleles and polymorphism information content (PIC) values was ascertained. For instance, marker phi123 produced high number of alleles (5) with PIC values of 0.77. Using the DARwin 6.0 programme, the UPGMA dendrogram grouped 40 maize inbreds into two distinct clusters, cluster-I (36 inbreds) and cluster-II (4 inbreds). Cluster-I contained two subclusters; the first subcluster contained 28 inbreds and the second subcluster contained eight inbreds whereas cluster-II contained four inbreds. This major cluster-II was further classified into two subclusters which contained two inbreds each. Most of the inbred lines except V-25 from cluster-II were highly resistant to TLB disease. These inbred lines can be used in crossing programmes to develop TLB-resistant hybrids by using divergent parents. In this study, allelic diversity and PIC values indicated a good efficiency of markers for studying the polymorphism level available in studied inbred lines. High level of diversity among the inbreds detected with simple sequence repeat markers indicated their suitability for the further breeding programme.

The twentieth and twenty-first centuries have witnessed a literary revival in the Indigenous languages of the region known canonically as “Latin America.” Across this varied corpus, a major theme is the cultural significance of maize. This article compares the depiction of maize in four bilingual poems, each written in a different Indigenous language alongside Spanish: Nahuatl (Ethel Xochitiotzin Pérez), Yucatec Maya (María Dolores Dzul Barboza), Central Quechua (César Vargas Arce), and Southern Quechua (Emilio Corrales). Through close textual analysis and by recourse to theoretical perspectives such as “literary cartography,” the “textual continuum,” “deep mapping,” and “trans-indigeneity,” the article argues that each poem communicates culturally specific ways of understanding geography that, when set in dialogue, challenge hegemonic definitions of the Western Hemisphere such as North, South, or Latin “America.” Rather, the poems in combination weave an interconnected yet multiperspectival cartographic tapestry with maize as the common thread.

Quality protein maize (QPM) has protein quality of opaque 2 (>0.074% tryptopan) with endosperm modifiers which turn its kernels vitreous that is similar to normal maize. Use of QPM as a cereal can significantly improve daily intake of lysine and tryptophan for humans and livestock. However QPM cultivars have lower yields due to trait compensation. Therefore, a breeding programme was carried out to convert parental lines of Shalimar maize hybrid 5 (SMH-5) viz. IML-187 and BML-6 into QPM versions. Marker polymorphism was worked out in donors and recipients. IML-187 was crossed with DQL-2029-1 and BML-6 was crossed with DQL-779-2-9. The first and second backcross generations involving IML-187 as recurrent parent were marked as BC1F1 (A) and BC2F1 (A) respectively, whereas those involving BML-6 were designated as BC1F1 (B) and BC2F1 (B) respectively. The BC2F2 lines derived from two generation of backcrossing coupled with SSR marker and phenotypic background and foreground selection were advanced to BC2F3. Approximately 80–90% of RPG similarity was observed in BC2F2 lines. Eight lines namely IML-187 × DQL-2029-1- BC2F3:06, 07 and 23: BML-6 × DQl-779-2-9: 02,04,09,20 and 13 were identified from BC2F3 to have tryptophan higher than 0.075% and <25% opaqueness. These lines were used for trait fixing and crosses were made to produce QPM version of SMH-5. Six improved versions of SMH-5 were selected for higher grain yield and tryptophan content and are to be employed in further testing and varietal release in Northern Hill Zone (NHZ) in India.

Smallholders in Southern Africa continue to grapple with low maize productivity despite this being the staple food crop. This study sought to analyze and isolate the relative contribution of agronomic practices to maize yields obtained by smallholders in Malawi and Mozambique using data generated from on-farm trials testing the performance of conservation agriculture cropping systems. The trials were implemented in two communities, namely Kasungu district in Malawi and Sussundenga district in Mozambique, and ran for seven consecutive growing seasons starting in 2010–2011. Maize yield was measured annually in the on-farm trials, which included a ‘control treatment’ representing an improved farm practice, and in neighboring fields managed by the same farmers on their own, hence representing a ‘true farm practice’. Results indicated that maize yield increased linearly with increasing plant population at harvest at both sites. On average, an increase in plant population at harvest by 1000 plants ha–1 resulted in an increase in maize yield of 90 and 63 kg ha–1 at Kasungu and Sussundenga, respectively. The greatest maize yields were obtained when plant population at harvest exceeded 40 000 plants ha–1. Yet, the plant population at harvest was below the generally recommended optimum for most of the cropping systems studied and in most growing seasons. Furthermore, the use of agronomic practices alone without conservation agriculture (i.e., improved varieties, fertilizer management, and timely weed control) resulted in maize yield gains of as much as 54% and 43% relative to the ‘true farm practice’ at Kasungu and Sussundenga, respectively. Overall, the proportion of these yield increases relative to the ‘true farm practice’ accounted for by agronomic practices amounted to 53–70% and 57–85% at Kasungu and Sussundenga for the highest to the lowest-yielding cropping system. Although conservation agriculture significantly improved maize yield at both sites, such increases were smaller in magnitude compared to the yield gains derived from improved agronomic practices. The study suggests that considerable strides toward narrowing maize yield gaps in Southern Africa can be achieved through improvement of current crop management practices, let alone adhering to the conservation agriculture principles of minimum tillage, residue retention, and crop diversification.

The transition to maize agriculture frames important cultural shifts in the Eastern Woodlands. However, the tempo and mode of this transition are unclear, particularly when analytical techniques are not standard across the region. In this article, we present evidence of directly dated maize macrobotanical fragments from the Turpin site in southwest Ohio that date between cal AD 552–649 and 684–994. These dates add to current dialogues on the spread of maize in the American Midcontinent and help further situate the Middle Ohio Valley as a cultural crossroads through which people and ideas flowed. We echo suggestions that, to refine our understanding of the introduction of maize into the region, we must develop pan-regional analytical standards and create multiple working hypotheses at a variety of scales.

The North-Eastern region (NER) of India falls under the Eastern Himalayan region and it is a bio-diversity hub. Diverse maize landraces with wide adaptability to extreme climatic and soil scenario like heavy rainfall, drought and acidic soil conditions have been grown in NER since time immemorial. However, maize diversity in NER region has drastically reduced due to introduction of high yielding varieties and hybrids. Modern maize breeding programmes are focused on high yield but other unique traits like stay green trait, prolificacy (more than one fertile ear per plant), self-fertilizing ability are also important and the local germplasm of the NER region can contribute with these unique traits. Prior to the selection of any lines in several breeding programmes, assessment of genetic diversity and population structure are basic requirements. Hence, in the present study assessment of genetic diversity and population structure study in 30 maize inbreds developed from different germplasm of NER was undertaken using SSR markers, selected for their broad distribution throughout the genome, in order to assess the extent of allelic diversity among the lines and whether any population structure could be established. In addition to assessing molecular diversity, the study aims to evaluate the potential for yield and other beneficial and unique alleles that have high potential to contribute in the genetic enhancement programme of maize.

Archaeologists working in eastern North America typically refer to precontact and early postcontact Native American maize-based agriculture as shifting or swidden. Based on a comparison with European agriculture, it is generally posited that the lack of plows, draft animals, and animal manure fertilization resulted in the rapid depletion of soil nitrogen. This required Indigenous farmers to move their fields frequently. In Northern Iroquoia, depletion of soil fertility is frequently cited as one reason why villages were moved to new locations every 20 to 40 years. Recent analysis of δ15N ratios of maize macrobotanical remains from Northern Iroquoia, however, suggests that Iroquoian farmers were able to maintain soil nitrogen in their maize fields. An expanded analysis of maize kernel δ15N ratios from three ancestral Mohawk villages indicates that farmers from those villages maintained soil nitrogen throughout the occupational spans of their villages. It further suggests that precontact Iroquoian agronomy was consistent with contemporary conservation agriculture practices.

We present macrobotanical, starch, and phytolith data from artifacts and sediments from Middle Formative La Blanca (1000–600 cal BC) and Late Formative El Ujuxte (600 cal BC–cal AD 115 ) in the Soconusco region in Guatemala. Potential economic plants identified included palm (cf. Arecaceae), two varieties of maize (Zea mays), guava (Psidium guajava), bean (Phaseolus), chili peppers (Capsicum), squash (Cucurbitaceae), custard apple (Annonaceae), coco plum (Chrysobalanaceae), lerén (Calathea), arrowroot (Maranta), and bird-of-paradise (Heliconia). The results suggest that control of food production and consumption was critical for the transition from complex chiefdoms during the Middle Formative to the archaic state in the Late Formative. The arrival of a more productive South American variety of maize at El Ujuxte (about 2549 BP) allowed elites to exploit an already existing broad-based economic system and to use the maize-based religious system to increase control over maize agricultural practices and maintain power through ideology and disciplinary power. These data suggest that the arrival of fully domesticated South American maize likely influenced the overall development of Mesoamerican state-level societies.

To explore trait variation, assess relative performance and establish association among yield and its associated traits in maize under organic system, 373 maize genotypes that consisted of landraces, open-pollinated varieties and single-cross hybrids were tested under organic management in Sikkim midhills. Data of 8 years (2009–2015 and 2019) for 12 agronomic traits viz., plant height, days to 50% tasselling, days to 50% silking, days to 75% dry husk, grain yield per ha, anthesis–silking interval, cob length, cob diameter, kernel rows per cob, kernels per row, number of cobs per plot and test weight were taken for analysis. Conventionally bred maize hybrids yielded 95.36% higher than the landraces and 58.60% higher than the open-pollinated varieties. Landraces displayed highest mean anthesis–silking interval of 7.18 days. In open-pollinated varieties, test weight showed a positive association with grain yield (0.37) while plant height (0.33) and kernels per row (0.34) were positively correlated to grain yield in case of landraces. Number of cobs per plot showed a very strong association with grain yield in hybrids (1.0). Kernels per cob and test weight contributed 24% to the variation in grain yield in open-pollinated varieties while anthesis–silking interval, days to maturity, number of cobs/plot, test weight and kernel per row accounted for 97% of the variation in grain yield in landraces. Grain yield in single-cross hybrids is contributed maximum (97%) by days to tasselling, silking, anthesis–silking interval, plant height and number of cobs per plot. The study indicates attaining high number of cobs per unit area along with emphasis on traits such as kernels per row, cob length and diameter for achieving higher yields in single-cross hybrids, selection of high test weight genotypes for open-pollinated varieties and emphasis on cob length, kernels per row and plant height for yield improvement in landraces.

Incorporating the dominant male sterile gene, Ms44, in new maize varieties results in 50% non-pollen producing (FNP) varieties. This makes the varieties more nitrogen efficient and increases yield directly by an average of 200 kg ha−1 across yield levels. However, as half of the plants do not shed pollen, the presence of Ms44 in an FNP variety is clearly visible. This technology can improve food production and security in the African maize-based agri-food systems, but only if accepted by farmers. Farmers were therefore invited to 11 on-farm, researcher managed trial sites of FNP varieties in Kenya over 2 years. They were asked to identify the traits they find important in evaluating maize varieties and to score the FNP varieties, as well as their conventional counterparts, on these criteria (including yield, resistance to pests, and cob size) and overall, using a five-point hedonic scale. In total, 2,697 farmers participated, of which 62% were women. Farmers mentioned many traits they find important, especially yield and related traits, early maturity, and drought resistance, but also tassel and pollen formation. In 2017, mid-season, participants scored FNP varieties lower than conventional varieties on tassel and pollen formation, indicating that farmers could distinguish the trait. FNP varieties still received higher scores for yield and overall evaluation. In mid-season 2018, participants no longer scored FNP varieties lower for pollen formation as they now understood the technology. In both years, at the end-season evaluation, scores for tassel formation were not different, but participants scored FNP varieties higher for yield and overall. We conclude that farmers recognized the FNP trait but did not mind it as they clearly favored its yield advantage. The FNP technology, therefore, has high potential not only to increase maize yields, food production, and food security in the agricultural systems of Africa but also to increase varietal turnover and the adoption of new, high-yielding, climate-smart maize hybrids.

Weed control in corn is a major challenge due to increasing problems with highly dominant weed species and herbicide resistance evolution. Common lambsquarters and johnsongrass constitute up to 80% to 90% of the weed population in many spring crops, such as soybean [Glycine max (L.) Merr.], sunflower (Helianthus annuus L.), and corn, in Serbia. Currently, acetolactate synthase–inhibiting herbicides, such as the systemic selective sulfonylurea nicosulfuron, are most commonly used for chemical weed control of those species. A better understanding of the impact of nozzle type and adjuvant use on nicosulfuron efficacy can help to improve control of common lambsquarters and johnsongrass and minimize herbicide resistance development. Field trials were conducted in Serbia from 2020 to 2022 to evaluate the impact of two adjuvants (a non-ionic surfactant [NIS] and a mineral fertilizer ammonium sulfate [AMS]) and two nozzle types (drift-reducing nozzles and flat-fan nozzles) on common lambsquarters and johnsongrass control using nicosulfuron. Satisfactory biomass reduction of common lambsquarters (83% to 87%) and johnsongrass (83% to 97%) was achieved after nicosulfuron application. Adding a NIS adjuvant increased the biomass reduction for common lambsquarters (94% to 98%) and johnsongrass (90% to 100%) independently of the nozzle type used. Selection of nozzle type did not show consistent effects on common lambsquarters and johnsongrass control. Nicosulfuron efficacy was increased with NIS adjuvant for both nozzle types compared to nicosulfuron solo for both species, and Extended Range (XR) TeeJet® nozzles on average resulted in a higher efficacy for common lambsquarters compared to Turbo TeeJet® induction. Adding a mineral AMS adjuvant resulted in lower biomass reduction for both nozzle types and weed species (65% to 78% and 61% to 91% for common lambsquarters and johnsongrass, respectively). Corn grain yield was predominantly influenced by annual meteorological conditions and adjuvant type added to nicosulfuron. This research suggests that addition of the non-ionic adjuvant is an essential factor for successful control of common lambsquarters and johnsongrass in corn and enables use of drift-reducing nozzles.

Auxin is a key regulator of root morphogenesis across angiosperms. To better understand auxin-regulated networks underlying maize root development, we have characterized auxin-responsive transcription across two time points (30 and 120 min) and four regions of the primary root: the meristematic zone, elongation zone, cortex and stele. Hundreds of auxin-regulated genes involved in diverse biological processes were quantified in these different root regions. In general, most auxin-regulated genes are region unique and are predominantly observed in differentiated tissues compared with the root meristem. Auxin gene regulatory networks were reconstructed with these data to identify key transcription factors that may underlie auxin responses in maize roots. Additionally, Auxin-Response Factor subnetworks were generated to identify target genes that exhibit tissue or temporal specificity in response to auxin. These networks describe novel molecular connections underlying maize root development and provide a foundation for functional genomic studies in a key crop.

Estadio de Quillota (EDQ) is the largest known pre-Columbian cemetery site within the Aconcagua Valley of Central Chile. Despite its importance, existing chronological data for EDQ are limited and questions remain regarding the prehistory of the Valley, particularly around the adoption and intensification of maize agriculture, as well as the timing of Inka influence reaching the region. Seventeen new AMS radiocarbon dates presented here indicate two distinct phases of use at EDQ: An earlier phase (339–196 cal BC to cal AD 128–339), and a later phase (cal AD 1280–1387 to cal AD 1413–1458). Accompanying stable isotope (δ13C and δ15N) analyses of human bone collagen (n=22) demonstrate diachronic dietary changes corresponding to these phases, with a reliance on terrestrial C3 resources during the earlier period, followed by a heavy dependence on C4-based (maize) resources during the later use. Bayesian modeling of the dates from Late Period contexts suggests Inka influence arrived in Central Chile by ca. cal AD 1400, decades before the date cited in traditional chronologies, AD 1471. Inka expansion likely occurred here with an initial phase of interaction and exchange preceding a later phase of integration. This finding supports growing evidence that the traditional chronology of the Inka Empire requires reconsideration.

The history of maize in Central America and surrounding areas has implications for the slow transition from hunting and gathering to agriculture. The spread of early forms of domesticated maize from southern Mexico across Mesoamerica and into South America has been dated to about 8,700–6,500 years ago on the basis of a handful of studies relying primarily on the analysis of pollen, phytoliths, or starch grains. Recent genomic data from southern Belize have been used to identify Archaic period south-to-north population movements from lower Central America, suggesting this migration pattern as a mechanism that introduced genetically improved maize races from South America. Gradually, maize productivity increased to the point that it was suitable for use as a staple crop. Here we present a summary of paleoecological data that support the late and uneven entry of maize into the Maya area relative to other regions of Central America and identify the Pacific coastal margin as the probable route by which maize spread southward into Panama and South America. We consider some implications of the early appearance of maize for Late Archaic populations in these areas; for example, with respect to the establishment of sedentary village life.

‘Sikkim Primitive’ (SP) maize locally known as ‘murali makkai’ in Sikkim is a unique genetic resource exhibiting prolificacy and excellent popping capacity. Status of SP has reached extinction level due to its very small population size and neglected conservation efforts in-situ. In an initial effort to conserve and revive this landrace, characterization and documentation was carried out with 31 morphologically assayed traits recorded at different growth stages along with molecular characterization with simple-sequence repeat (SSR) markers. Plants exhibited prolificacy (5–6 cobs/plant) and excellent popping capacity along with other distinct traits. Plants were tall with thin stem, loose drooping tassel with anthocyanin coloration present at the base of glumes and in brace roots. Cobs were medium sized carrying small seeds with low test weight (87.90 g). A total of 22 SSR markers show amplification in murali makkai with markers bnlg1083, umc1353, umc1128, bnlg1017, bnlg2077, umc2298 and umc2373 amplified unique amplicons ranging from 100 to 800 bp. The characterized set of traits and molecular characterization for murali makkai will facilitate in utilization for genetic improvement and maintenance of genetic purity.

Artifacts, including ceramics, ground stone, and soil samples, as well as dental calculus, recovered from sites in the eastern North American central Plains were submitted to multiple laboratories for analysis of microbotanical remains. Direct accelerator mass spectrometer (AMS) dates of 361–197 cal BC provide evidence for the earliest use of maize (Zea mays ssp. mays) in this region. Squash (Cucurbita sp.), wild rice (cf. Zizania spp.), and palm (Arecaceae sp.) microremains were also found. This research adds to the growing evidence of the importance of microbotanical analysis in documenting plant use and in the identification of early maize. The combined data on early maize from the eastern Plains adds to our understanding of the timing and dispersal of this crop out of the American Southwest. Alternative explanations for the adoption and early use of maize by eastern central Plains communities include its value as a secondary resource, as an addition to an existing farming strategy, or as a component of Middle Woodland rituals.