Genetic diversity and stability of groundnut mini-core collections for early and late leaf spot resistance in Nigeria

Disease epidemics of early and late leaf spots (ELS and LLS, respectively) are affected by weather patterns such as hot and wet conditions, making them prevalent in the Guinea and Sudan Savanna zones of Nigeria. The objective of this research was to determine the genetic diversity and stability of groundnut ( Arachis hypogaea L.) mini-core collections for ELS and LLS in Nigeria. The collections were evaluated at Bayero University Kano (2015, 2016 and 2017) and Minjibir (2017) during the rainy seasons. The data collected were analysed by a mixed model and Cluster analysis was carried out to summarise relationships among the mini-core collections. Significant differences were observed between the lines for kernel yield, ELS and LLS resistance. The highest kernel yield was recorded by ICG 12988 (1225 kg ha-1). The highest yielding check variety was Samnut 24, with a kernel yield of 805 kg ha-1. Lines with low ratings for ELS and LLS were in cluster one but had the lowest mean kernel yield; followed by Cluster 2 with a similar trend. Two lines, ICG 12988 and ICG 12989, were grouped in Cluster 10, which had the highest mean yield (1107 kg ha-1), with ELS and LLS rating of 3 and 4, respectively. Check varieties such as Samnut 22, 24 and 25 were grouped in Cluster 9 and are moderately tolerant to leaf spots; while Samnut 26, which is a more recent improved variety was in Cluster 7 with moderate resistance to leaf spots. There was a significant line 7 environment interaction for kernel yield. ICG 12988 and ICG 12989 were highly unstable; while ICG 2019 was the most stable line followed by ICG 12697, ICG 3312 and ICG 8567. In general, results of the current study show a linkage between kernel yield and leaf spots diseases. Therefore, special breeding techniques such as backcrossing or marker-assisted backcrossing are required to improve lines identified with low yield but high resistance or high yield with low resistance.Les \ue9pid\ue9mies de maladies des taches foliaires pr\ue9coces et tardives (ELS et LLS, respectivement) sont affect\ue9es par des conditions m\ue9t\ue9orologiques telles que des conditions chaudes et humides, ce qui les rend r\ue9pandues dans les zones de savane de la Guin\ue9e et du Soudan au Nigeria. L\u2019objectif de cette recherche \ue9tait de d\ue9terminer la diversit\ue9 g\ue9n\ue9tique et la stabilit\ue9 des collections de mini-noyaux d\u2019arachide ( Arachis hypogaea L.) pour ELS et LLS au Nigeria. Les collections ont \ue9t\ue9 \ue9valu\ue9es \ue0 Bayero University Kano (2015, 2016 et 2017) et Minjibir (2017) pendant les saisons des pluies. Les donn\ue9es recueillies ont \ue9t\ue9 analys\ue9es par un mod\ue8le mixte et une analyse par grappes a \ue9t\ue9 effectu\ue9e pour r\ue9sumer les relations entre les collections mini-core. Des diff\ue9rences significatives ont \ue9t\ue9 observ\ue9es entre les lign\ue9es pour le rendement en grains, la r\ue9sistance ELS et LLS. Le rendement en grains le plus \ue9lev\ue9 a \ue9t\ue9 enregistr\ue9 par ICG 12988 (1225 kg ha-1). La vari\ue9t\ue9 t\ue9moin la plus performante \ue9tait Samnut 24, avec un rendement en grains de 805 kg ha-1. Les lign\ue9es avec de faibles notes pour ELS et LLS \ue9taient dans la grappe un mais avaient le rendement moyen du noyau; suivi du Cluster 2 avec une tendance similaire. Deux lign\ue9es, ICG 12988 et ICG 12989, ont \ue9t\ue9 regroup\ue9es dans le groupe 10, qui avait le rendement moyen le plus \ue9lev\ue9 (1107 kg ha-1), avec une cote ELS et LLS de 3 et 4, respectivement. Les vari\ue9t\ue9s de contr\uf4le telles que Samnut 22, 24 et 25 ont \ue9t\ue9 regroup\ue9es dans le groupe 9 et sont mod\ue9r\ue9ment tol\ue9rantes aux taches foliaires; tandis que Samnut 26, qui est une vari\ue9t\ue9 am\ue9lior\ue9e plus r\ue9cente, appartenait au groupe 7 avec une r\ue9sistance mod\ue9r\ue9e aux taches foliaires. Il y avait une interaction ligne 7 environnement significative pour le rendement du noyau. ICG 12988 et ICG 12989 \ue9taient tr\ue8s instables; tandis que ICG 2019 \ue9tait la lign\ue9e la plus stable, suivie par ICG 12697, ICG 3312 et ICG 8567. En g\ue9n\ue9ral, les r\ue9sultats de la pr\ue9sente \ue9tude montrent un lien entre le rendement des grains et les maladies des taches foliaires. Par cons\ue9quent, des techniques de s\ue9lection sp\ue9ciales telles que le r\ue9trocroisement ou le r\ue9trocroisement assist\ue9 par marqueur sont n\ue9cessaires pour am\ue9liorer les lign\ue9es identifi\ue9es avec un faible rendement mais une r\ue9sistance \ue9lev\ue9e ou un rendement \ue9lev\ue9 avec une faible r\ue9sistance

Productivity, water- and nitrogen-use efficiency, and profitability of pearl millet (Pennisetum glaucum) under different nitrogen applications in semiarid region of Nigeria

An experiment was conducted to examine the performance of pearl millet under different nitrogen (N) fertilizer rates in two locations in the semiarid zone of Nigeria. The objective was to evaluate the effects of different N rates on pearl millet yields, water- and nitrogen-use efficiency, and profitability. Grain yield increased by 23, 26, 32, 32, and 27% and by 38, 41, 54, 58, and 56% compared to unfertilized plots when applying 20, 40, 60, 80, and 100 kg Nha−1 in Minjibir and Gambawa, respectively. Similarly, stalk yield increased by 4, 3, 9, 9, and 9% and by 16, 24, 36, 40, and 37% compared to unfertilized plot when applying 20, 40, 60, 80, and 100 kg Nha−1 in Minjibir and Gambawa, respectively. The variations in GY that could be explained by TWU and NUE were 28% and 26% in Minjibir and 46% and 41%, respectively, in Gambawa. There was a strong and positive correlation (R = 0.81 and R = 0.95) between WUE and GY across N-fertilizer rates and pearl millet varieties in both locations. An increase in N-fertilizer levels increased WUE, confirming the optimal application of 60 kg Nha−1 in Minjibir and of 80 kg Nha−1 in Gambawa. Similarly, the highest net economic return (NER) of US$610 ha−1 was obtained at 60 kg Nha−1 in Minjibir and the highest NER of US$223 ha−1 was obtained at an application rate of 80 kg Nha−1 in Gambawa. Break-even yield was above 1000 kg ha−1, signifying that average farmer with a mean yield of less than 1000 kg ha−1 produces millet at a loss

Establishing optimal planting windows for contrasting sorghum cultivars across diverse agro-ecologies of north-eastern Nigeria: a modelling approach

Open Access Journal; Published online: 28 Feb 2023In the context of climate change, the sowing date and cultivar choice can influence the productivity of sorghum, especially where production is constrained by low soil fertility and early terminal drought across the challenging agro-ecologies of north-eastern Nigeria. Planting within an optimal sowing window to fit the cultivar’s maturity length is critical for maximizing/increasing the crop yield following the appropriate climate-smart management practices. In this study, the APSIM crop model was calibrated and validated to simulate the growth and yield of sorghum cultivars with differing maturing periods sown within varying planting time windows under improved agricultural practices. The model was run to simulate long-term crop performance from 1985 to 2010 to determine the optimal planting windows (PWs) and most suitable cultivars across different agro-ecological zones (AEZs). The performance of the model, validated with the observed farm-level grain yield, was satisfactory across all planting dates and cropping systems. The model predicted a lower mean bias error (MBE), either positive or negative, under the sole cropping system in the July sowing month compared to in the June and August sowing months. The seasonal climate simulations across sites and AEZs suggested increased yields when using adapted sorghum cultivars based on the average grain yield threshold of ≥1500 kgha−1 against the national average of 1160 kgha−1. In the Sudan Savanna (SS), the predicted optimum PWs ranged from 25 May to 30 June for CSR01 and Samsorg-44, while the PWs could be extended to 10 July for ICSV400 and Improved Deko. In the Northern Guinea Savanna (NGS) and Southern Guinea Savanna (SGS), the optimal PWs ranged from 25 May to 10 July for all cultivars except for SK5912, for which predicted optimal PWs ranged from 25 May to 30 June. In the NGS zone, all cultivars were found to be suitable for cultivation with exception of SK5912. Meanwhile, in the SGS zone, the simulated yield below the threshold (1500 kgha−1) could be explained by the sandy soil and the very low soil fertility observed there. It was concluded that farm decisions to plant within the predicted optimal PWs alongside the use of adapted sorghum cultivars would serve as key adaptation strategies for increasing the sorghum productivity in the three AEZs

Cowpea-Cereal Intercrop Producitivity in the Sudan Savanna Zone of Nigeria as Affected by Planting Pattern, Crop Variety and Pest Management

Cowpea [ Vigna unguiculata (L.) Walp.] productivity in the West African sub-region is low due to attacks from insect pests, inefficient cropping system and low yield potential of local varieties. Therefore, to increase productivity, it is necessary to develop suitable agronomic practices and planting arrangement that will maximize the productivity of the improved varieties available from research institutes. A trial comprising ten cowpea-cereals cropping patterns, two cowpea varieties and two spray treatments was conducted in the Sudan Savanna of Nigeria in 1999 and 2000. The cropping patterns involved different row-to-row combinations of cowpea with millet ( Pennisetum glaucum L. R. Br.) or sorghum ( Sorghum bicolor ). Insecticide spraying increased cowpea grain yield, threshing percentage, harvest index, gross monetary returns significantly under all planting patterns and varieties, but had no significant effect on growth parameters. Sole cowpea produced significantly higher gross monetary returns than other treatments. Cowpea-sorghum systems had higher productivity than cowpea-millet systems. Gross returns on total produce from sole crop cowpea with insecticide spray were almost doubled of the returns from sole cereals. Overall, 2 rows of sorghum: 4 rows of cowpea (2S:4C) system using improved cowpea with insecticide spray, was identified the most promising considering the socio-economic conditions of the resource poor farmers

Germplasm enhancement for increasing groundnut productivity and production in West and Central Africa

West and Central Africa (WCA) account for almost 70% of groundnut production in Africa playing and important role to farmers' livelihood and significantly contributes to the export sector of the countries in the region..

Evaluation of multiple stress tolerant groundnut genotypes for productivity and nutritional quality in Nigeria

Groundnut plays a very important economic role for smallholder farmers in the semi-arid tropics as a major cash crop for many households; a nutritious and safe food thereby contributing to improved health of the rural population. It is rich in protein, oil and micronutrients such as iron and zinc. High iron and zinc contents are especially beneficial for women and children at risk of anemia and have proven to be genetically malleable. High oleic acid and low linoleic acid make groundnut oil ideal for storage and better human health. Evaluation of 541 advanced breeding lines along with local landraces and improved varieties for their reaction to drought, rosette and foliar diseases besides productivity parameters over two locations during 2014 main season resulted in identification of 45 promising lines with significantly superior pod yield (1304-2796 kg/ha) compared to check entries (189-1005 kg/ha). Further, these superior genotypes were evaluated for nutritional quality and in trials during 2014/15 dry season to confirm their superiority. Nutritional quality (oil, 0/L ratio, protein, Fe and Zn content) analyses lead to the identification of nutritionally dense genotypes. Genotypes ICGV IS 11060, Samnut 23, ICGV 00064, ICGV O 1276, ICGV IS 07827 and Kampala had high oil content (53-54%); while ICGV 07813 had high 0 /L ratio of 6.1 followed by ICGV IS 09992, ICGV SM 05593 and ICGV SM 06722 with 3.0 0/L ratio. Genotypes ICGV IS 07833, ICGV IS 3980, ICGV SM 08553 and ICG 589 I had high protein (30-32%), Zn (46-51 ppm) and Fe (23-34 ppm) content. These serve as ideal genetic resources to develop agronomically superior and nutritionally enhanced groundnut cultivars with multiple resistances to biotic and abiotic stresses

Legume breeding and seed systems for improved livelihoods and impact

The Tropical Legumes III project aims to reduce food insecurity in drought-prone areas of Sub Saharan Africa (SSA) and South Asia (SA), through improved productivity and production of four major grain legumes – chickpea, common bean, cowpea and groundnut. This is being sone by conducting research under three complementary research and delivery pillars: support for the development and release of farmer-preferred varieties; strengthening of the legume breeding capacity of partner CGIAR centers (ICRISAT, IITA and CIAT), and national partners Burkina Faso, Ghana, Mali, Nigeria, Ethiopia, Tanzania and Uganda; and establishment of sustainable seed delivery systems that service the needs of small-holderfarmers. Significant achievements have been recorded. Breeding program assessments have been completed in all countries and improvement plans developed for execution. New seed varieties (163) have been released and are fast replacing the old ruling seed varieties in all target countries. Thirty seven national partners were trained at MSc and PhD levels. As a result of the enhanced skills and knowledge of seed value chain actors, seed production significantly increased by 221% (from 139,048 to 446,359 tons) in seven years. Since 2007, improved varieties have been adopted on at least 2 million hectares and more than $448 million has been generated from the project funding and nearly$976 million from the project and investment partners. For each dollar invested, the project generated $9 with direct project investment or$20 with partnership’s investment, and again $20 when using adoption rate based estimate. These achievements and implementation challenges will be discussed

Eficiência de utilização de água e nutrientes em plantas de feijão-de-corda irrigadas com água salina em diferentes estádios de desenvolvimento Water and nutrient use efficiency in cowpea irrigated with saline water at different growth stages

O objetivo deste trabalho foi investigar os efeitos do uso de água salina em diferentes estádios de desenvolvimento de plantas de feijão-de-corda sobre a eficiência de utilização de água e de nutrientes. O experimento foi conduzido no campo e obedeceu ao delineamento em blocos ao acaso, com cinco tratamentos e cinco repetições. Os tratamentos empregados foram: T1 - água de poço com condutividade elétrica (CEa) de 0,8 dS m-1 durante todo o ciclo; T2 - água salina (CEa de 5,0 dS m-1) durante todo o ciclo; T3, T4 e T5 - água salina de 0 a 22 dias após o plantio (DAP), de 23 a 42 DAP e de 43 a 62 DAP, respectivamente. As plantas dos tratamentos T3, T4 e T5 foram irrigadas com água de poço nas demais fases do ciclo. Aos 8; 23; 43 e 63 DAP, as plantas foram colhidas e determinaram-se a matéria seca total e de grãos, a eficiência no uso da água, considerando a produção de matéria seca total (EUA P) e a produção de grãos (EUA GR), e a eficiência de utilização de nutrientes (K, Ca, N, P, Fe, Cu, Zn e Mn). A aplicação de água salina durante todo o ciclo (T2) reduziu a EUA P e a EUA GR, enquanto a aplicação de água na fase inicial do ciclo (T3) reduziu a EUA GR e a eficiência de utilização da maioria dos nutrientes. Por outro lado, a irrigação com água salina dos 23 aos 42 DAP (T4) e dos 43 aos 62 DAP (T5) não afetou as eficiências nos usos de água e de nutrientes.<br>The objective of this paper was to evaluate the effect of the saline water applied at different development stages of cowpea plants, on water and nutrient use efficiency. The experiment was set up in the field, during the dry season. A completely randomized block design, with five treatments and five repetitions was adopted. The treatments studied were: T1 - (groundwater with electrical conductivity (ECw) of 0.8 dS m-1) during the whole crop cycle; T2 - saline water (ECw = 5.0 dS m-1) during the whole crop cycle; T3, T4 and T5 - saline water from 0 to 22 days after sowing (DAS), from 23 to 42 DAS and from 43 to 62 DAS, respectively. The plants of T3, T4 and T5 were irrigated with groundwater in the remaining stages of the crop cycle. At 8, 23, 43 and 63 DAS the plants were harvested and the total dry mass and grain yield were measured. The water use efficiency was estimated by using total dry mass production (WUE P) and grain yield (WUE GR), as well as the nutrients use efficiency - NUE, (K, Ca, N, P, Fe, Cu, Zn and Mn). The application of saline water during whole the crop cycle (T2) reduced WUE P and WUE GR, while the use of saline water during the germination and initial plant development (T3) caused reduction in WUE GR and in the NUE for most of the analyzed nutrients. Irrigation with saline water from 23 to 42 DAS (T4) and from 43 to 62 DAS (T5) did not affect water and nutrient use efficiencies