The cultivated plants of the tropics and subtropics: Cultivation, economic value, utilization

The use of natural products to control several phytopathogens is now gaining a great interest because of the environmental risks deriving from the use of synthetic drugs in controlling pathogens. Salvia hispanica L., commonly known as chia, is a traditional food in Central and Southern America. The current research is focusing on the chemical characterization of the essential oil extracted from the aerial parts of chia plant (stem and leaves) using GC–MS analysis, evaluating its antimicrobial effects. The essential oil is constituted mainly of sesquiterpenes, with caryophyllenes as main constituents. Results of antimicrobial tests proved that the essential oil could be potentially utilized in controlling some phytopathogenic fungi and bacteria.

Chemical composition and antimicrobial activity of chia (Salvia hispanica L.) essential oil

Chia (Salvia hispanica L.) is an ancient crop from Central America which has been recently rediscovered as a source of ω-3 and nutraceuticals in seeds. Besides traditional seed consumption, innovative uses of the plant seeds and leaves have been proposed based on the high protein content and the production of mucilage which lends itself to a range of applications. This chapter reviews research on the plant’s genetics and breeding, quality, and uses. Agronomic studies which have only recently started worldwide are also presented along with results from case studies in Basilicata.

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Innovative Crop Productions for Healthy Food: The Case of Chia (Salvia hispanica L.)

Feeding 9 billion by 2050 is one of major challenges for researchers. Use of diversified crops, nonconventional water resources and rehabilitation of marginal lands are alternate options to produce more food to face climate change projections. Adaptation to climate change through climate smart agriculture practices, agroecology activities, and crop-based management packages can help transform the marginal lands from environmental burdens into productive and economic blocks. This review discusses the recent advancements on specialty group of alternate crops (oil seeds, legumes, cereals, medicinal, lignocellulose, and fruit crops) which can adapt in the marginal environments. Availability of alternate water resources (saline water, treated wastewater) for irrigation cannot be omitted. Crop diversification systems involving drought and salt-tolerant crops are likely to be the key to future agricultural and economic growth in the regions where salt-affected soils exist and/or saline aquifers are pumped for irrigation. These systems may tackle three main tasks: sustainable management of land resources and enhancement of per unit productivity; intensification of agroecological practices to increase soil fertility; and improving productivity of marginal lands for diversified climate smart crops. This review explores various aspects of marginal lands and selection of tolerant crop genotypes, crop diversification, and agroecological practices to maximize benefits.

Crop diversification and saline water irrigation as potential strategies to save freshwater resources and reclamation of marginal soils—a review

Salvia hispanica L., commonly known as chia, is an ancient food that provides a balanced amount of nutrients composed of insoluble fiber, high ω-3/-6 fatty acids, proteins with an excellent quality of amino acids, high content of antioxidants, and minerals. In the first instance, chia seed coat contains mucilage that protects all seed nutrients and is involved in water retention in foods. The seed is a valuable source of one of the most important ω-3 fatty acids, α-linoleic. Chia seed storage proteins are composed mainly of globulin, followed by albumin, prolamin, and glutelin fractions containing essential amino acids encrypted in their primary sequences. Rosmarinic, caffeic, and gallic acids are the main phenolic compounds. Nutritionists, researchers, and industry have paid attention to chia for its outstanding benefits. Chia is now recognized as a “seed for the first 21st century” that confers invaluable nutraceutical benefits such as antihypertensive and antioxidant functions. The seed compounds may be improved and modified by genome edition technologies to obtain better nutraceutical attributes for health and food industry. Chia can be crowned as the new golden and super seed with excellent benefits for human health.

Chia—The New Golden Seed for the 21st Century: Nutraceutical Properties and Technological Uses

﻿A 2-year field experiment was conducted in 2012 and 2013 at the research fields of CSIR-Crops Research Institute to determine the best agronomic practices for the field establishment and cultivation of Chia (Salvia hispanica) and determine insect pests and diseases associated with the plant. The study also determined the nutritional composition of the plant under Ghanaian environment. A split-plot field trial with 2 planting methods (direct planting with seed; planting from seedling) as main plot and 3 planting density (10,000 plants/ha; 20,000 plantst/ha; 40,000 plantst/ha) as subplot were used for the agronomic evaluation of the plant. A sweep net was used to sweep diagonally across the field under two separate regimes to collect insects on the crop for the entomological investigations. Major insects collected were coreid bugs, lagria sp., Zonocerus variegatus and Diopsis thoracica. The method used for the pathological investigations were the moist blotter test and culture of pathogens on Potato Dextrose Agar. The results of the study in both years show high biomass and seed yield of chia when the crop was planted directly in the field. Narrow-row spacing of 0.5m x 0.5m consistently produced the highest biomass and seed yield in both years of the study. The results indicated that interaction between planting method and planting density positively influenced most of the growth and yield parameters of Chia plants. Nutritional profile analysis from the Chia seeds shows medium to high proximate and mineral composition. Disease evaluation revealed evidence of Fusarium wilt infection on Salvia hispanica in the field. The study recommends the adoption of direct planting method and narrow-row spacing (0.5m x 0.5m) (SP3) as the best option for the production of Chia plants in Ghana.

Influence of Planting Methods and Density on Performance of Chia (Salvia hispanica) and its Suitability as an Oilseed Plant

Fusarium wilt is a major constraint in amaranth production in Africa; the disease can lead to total crop failure. However, few studies have identified Fusarium species associated with amaranth diseases in Ghana. The study was conducted to identify Fusarium species causing wilt in amaranth in the Semi-deciduous and Guinea Savannah 
Agro-ecological zones of Ghana and determine variations in isolates. Using standard laboratory procedures, fungal pathogens were isolated and culture characteristics studied. Variations in virulence were determined using root dip method. Sequence analysis of the internal transcribed spacer region of isolates was carried out for species identfication. Based on morphological features complemented by sequence analysis; Fusarium equiseti, F. oxysporum, F. solani and F. proliferatum were identified. Fusarium equiseti was the dominant species appearing in 82% of isolates. All the isolates were pathogenic. Based on virulence level, 9% of the isolates were classified as very highly virulent whilst 56% were weakly virulent. Genetically, isolates clustered into four groups irrespective of origin. The work identified and classified Fusarium species causing amaranth wilt in Ghana.

Identification and Characterization of Fusarium Species Associated With Amaranth (Amaranthus Species) Wilt Disease in the Semi-deciduous and Guinea Savannah Agro-ecological Zones of Ghana

Forty common bean accessions of multiple genetic background trait attribution regarding drought tolerance were selected based on mean yield performance from an earlier field test evaluation conducted using augmented RCBD. The various bean genotypes were further evaluated with phosphorus and water treatment interactions at two different levels for each factor. The experiment was conducted in a 2 × 2 × 40 factorial using RCBD with three replications under screen-house conditions at the CSIR-Crops Research Institute, Kumasi-Ghana. The objective was to select drought- and low phosphorus-tolerant common bean genotypes; which are suitable for tropical climatic conditions. The results showed that common bean with drought and heat trait tolerance survived, developed flowers and podded with seeds to physiological maturity, whilst genotypes with no heat trait tolerance had impaired reproductive structural development and growth disruption; thus, flowers could not develop into pods with seeds. This reproductive developmental anomaly was due to prevailing average daytime and nighttime high temperatures of 35.45 °C and 29.95 °C, respectively, recorded during the growth period, which reduced pollen fertility. Among the 478 experimental bean plants (two plants were missing) analyzed, 141 (29.5%) did not flower, 168 (35.18%) had their pods dropped whilst 99 (20.7%) podded with seeds to achieve physiological maturity. The podded-seed bean genotypes were of the SEF-line pedigrees, which were shown to be heat and drought-tolerant. Meanwhile, bean accessions with SMC, SMN and SMR code prefixes did not pod into seed despite possessing drought-tolerant traits. The effects of interactions between phosphorus and water treatments on the root characteristics of drought-tolerant common bean were as follows: root length, root surface area, average root diameter and root volume growth extensions doubled dimensionally under optimum conditions (P2W2) compared to stressed conditions (P1W1). The results from the present study identified four SEF-bean genotypes, namely, SEF15, SEF 47, SEF 60 and SEF 62, as superior yield performers, even under low soil phosphorus and in extreme high temperature conditions. Therefore, breeding for the selection of drought- and low-P-tolerant common bean for tropical agro-ecological environments must also consider concomitant heat stress tolerance.

https://www.mdpi.com/2223-7747/11/18/2352/pdf?version=1662704627

Heat Stress Tolerance: A Prerequisite for the Selection of Drought- and Low Phosphorus-Tolerant Common Beans for Equatorial Tropical Regions Such as Ghana

Maize (Zea mays L) is a major cereal crop for both plant and animal nutrition worldwide. The production and consumption of maize are adversely affected by aflatoxin contamination resulting in reduced grain quality with high health risk to consumers. Unsafe aflatoxin levels above 20 ppb have been reported in maize from farmers’ fields in Ghana. A study was undertaken to evaluate the yield and aflatoxin contamination resistance stabilities of selected hybrids being developed in Ghana. Eighteen maize genotypes (14 hybrids with the following code names: GH01, GH02, GH03, GH04, GH05, GH06, GH07, GH08, GH09, GH10, GH11, GH12, GH13, and GH14 and four local checks: Etubi, Obotantim, Tintim, and Mamaba) were evaluated across six environments in two seasons. Artificial inoculation was done randomly using the side needle injection method 14 days after midsilk at a concentration of 9 × 107 conidia/ml. After the harvest levels of aflatoxin in the harvested grains were determined using high-performance liquid chromatography (HPLC). Data analysis showed that genotypic effects and environmental effects on some traits were consistently significant across environments, which mean that there was useful variation among the genotypes that could be utilized for the development of hybrids. Non-significant genotype by environment interaction effects for grain yield suggests that a promising genotype selected in one of these locations will also be suitable for production in the other locations in the same agroecological zone. GGE biplot analyses provided clear bases for determining stability and performance of the hybrids. Two hybrids have the potential for production in Ejura, Fumesua, Ohawu, Akumadan, and Kpeve and similar agroecological zones. GH04, GH10, and GH01 were lowest yielding, but GH10 was most stable. GH05 was identified as the most promising for production in Ejura, Ohawu, and Akumadan. Again, GH08 was the Vertex genotype for Wenchi environment. Ejura, located in the transition zone, was identified as the ideal testing environment for the hybrids. Most of the hybrids showed low levels of aflatoxin accumulation below 20 ppb despite artificial inoculation. The study revealed GH01, GH05, and GH08 as the most stable among the top yielding hybrids with aflatoxin levels of 11.9, 14.3, and 3.8 ppb, respectively, after artificial inoculation, which can be considered for cultivation as varieties to help mitigate aflatoxin contamination in maize in Ghana and beyond.

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Z. Appiah-Kubi

Papers

Influence of Planting Methods and Density on Performance of Chia (Salvia hispanica) and its Suitability as an Oilseed Plant

Identification and Characterization of Fusarium Species Associated With Amaranth (Amaranthus Species) Wilt Disease in the Semi-deciduous and Guinea Savannah Agro-ecological Zones of Ghana

Heat Stress Tolerance: A Prerequisite for the Selection of Drought- and Low Phosphorus-Tolerant Common Beans for Equatorial Tropical Regions Such as Ghana

Mitigating aflatoxin contamination in maize: Breeding for stable resistant cultivars