Rainfed agriculture would remain the dominant source of staple food production and the livelihood foundation of the majority of the rural populace in semi-arid West Africa. Prolonged dry spells during the growing season often lead to significant crop yield losses, a situation that is expected to be exacerbated by climate change. In this study, impacts of climate change on the sorghum production system in West Africa semi-arid tropics was analysed using the most accessible process-based crop models (DSSAT, APSIM and Samara) and simulated at six stations under rainfed conditions. The mid-century future climate predictions by 2069 indicate the productivity of grain sorghum would be diversely affected due to the differences in the GCMs projections in terms of temperature and rainfall. On the average, climate change is projected to reduce low photoperiod sensitivity genotype (CSM63E) grain yield to the tune of 13%, and by 7% for both medium photoperiod sensitivity genotype (CSM335) and high photoperiod genotype (IS15401) across the selected sites. Results also indicate that adaptation strategies like longer grain filling period and sowing date reduced the vulnerability on both the medium and high photoperiod sensitivity genotypes (CSM335 and IS15401) compared to low photoperiod sensitivity genotype (CSM63E). As obtained from the study, proper genotypic calibrations and evaluations of crop models could be used to explain the expected outcomes of future climate conditions on the diverse photoperiod sensitivity sorghum genotypes available across semi-arid area. Also, these results would serve as reliable tools towards the understanding of future climate change and adaptation options to be implemented, which could be shared among farmers and development partners interested in food security issues in West Africa semi-arid zone. (Texte integral)
In the tropics, crops sown in the late season are subjected to concurrent stresses of high air and soil temperatures, large saturation vapour pressure deficits and negligible soil water regimes. The responses of three sunflower cultivars to row spacing was analysed in terms of radiation interception and use, plant to plant variability, biomass accumulation and seed set efficiency during the late seasons of 2002 and 2003 on the field in Akure, a rainforest zone of Nigeria. Sunflower cultivars (Functua local, Record and Isaanka) were cropped at 90 x 30, 90 x 60 and 60 x 30 cm row spacing corresponding to 37,037, 18,519 and 55,555 plant.m -2 Increasing density of plant stand appeared to have promoted differences in resource availability per plant during growing season. Row spacing did not significantly affect IPAR while the effects of spacing and cultivar were similar on RUE. Leaf area and dry matter accumulation are suboptimal but RUE appeared to be conservative in circumstances of high saturation vapour pressure deficit and soil moisture stress of the late season. Crops in wide rows intercepted less radiation than their counterparts in narrow rows, and yield response to narrow rows was significant in all cultivars. Seed yield/ha increased as plant density increased although yield of the individual plants and their components were significantly reduced. Among the cultivars, differences in the growth of individual plant at different intensities of inter plant competition were obtained, narrow row spacing enhanced plant-plant variability (inter-plant variation). Under the limiting soil water situation enhanced soil temperatures of the late season EF relates to plant biomass (r 2
Climate change poses significant threats to agriculture, including food security, livelihoods and economic growth. Based on the importance of cocoa, there is a need for sustainable crop production and resilience to anticipated changes in rainfall and temperature in the future. Irrigation is an important climate-smart practice for alleviating abiotic stress and enhancing crop productivity, and irrigation is seldom practiced in the cacao orchards of West Africa. Studies were conducted to examine the effects of dry season gravity drip irrigation on the rootzone moisture, tree water use (evapotranspiration), leaf area index and yield of cacao in a rainforest zone of Nigeria. Irrigation treatments were based on water application at 5- and 10-day intervals and 50, 70 and 100% Pan evaporation, which was applied using point source emitters on drip lines. The soil moisture content, photosynthetic active radiation, leaf area index and extinction coefficient differed among the irrigation treatments. Deficit irrigation (10-day and 50% EPan) enhanced water use efficiency by 25–44% (30 and 50% water savings), while full irrigation enhanced soil moisture, cacao ET, and pod and bean yields. This study established irrigation and water requirements for cacao in the dry season and confirmed the relevance of irrigation for enhanced cacao performance and climate mitigation.
Two experiments were conducted to examine the effects of watering regime and mycorrhizal inoculation on growth, development and drought tolerant traits of seedlings of five cocoa varieties ( Theobroma cacao ) obtained from the Cocoa research Institute Nigeria (CRIN), Ibadan, Nigeria. For each experiment, treatments were 5 x 3 x 2 factorial scheme consisting of cocoa hybrids/varieties, watering regimes in addition to mycorrhizal inoculation or without. Treatments were arranged using Completely Randomized Design with five replications. In experiment one, cocoa hybrids: CRIN: (TC1, TC2, TC3, TC4 and TC5) were subjected to watering regimes (100, 60 and 40% field capacity (FC) equivalent to 1.5 0.9 and 0.6 litres of water per pot) and were applied twice per week. Treatment effects were significant (P ≤ 0.05) for the measured growth variables of cocoa such as plant height, stem girth, root length, root and shoot weight were enhanced by 100 and 60% FC watering regime. Variety TC2 that were watered at 100 and 60% FC were taller in height and produced higher number of leaves and stem girth compared to those watered at 40% FC. Among varieties, increasing orders of water use by seedlings were TC1, TC2, TC5, TC3 and TC4. The 100 and 60% FC TC1 and TC2 had taller plants and produced higher number of leaves and stem girth compared to those watered at 40% FC. The response of cocoa varieties to mycorrhizal inoculation varied, inoculated seedlings of TC1, TC2 and TC3 had enhance vigor than the non-inoculated. Across varieties, both inoculated and non-inoculated seedlings that were subjected to 100% FC and 60% FC watering regimes enhanced growth and development. Cocoa variety TC3 showed best response to 100% FC and 60% FC watering and AMF inoculation. Watering regime and AMF Inoculation affected the concentration of chlorophyll and water soluble carbohydrate and water use efficiency of cocoa varieties. In experiment two, the elite varieties: T65/7 x N38, T65/7 x T57/22, T82/27 x T12/11, PA150 x T60/887 and T82/27 x T16/17 were subjected to watering regimes (4-, 8- and 14- day watering intervals). Cocoa seedling water use, plant height, stem girth, plant biomass and number of leaves and branches were enhanced by the 4- and 8- day watering intervals and with or without mycorrhizal inoculation compared with 14- day watering. Varieties T82/27 x T12/11 and PA150 x T60/887 watered at 4- and 8- day intervals was consistently taller in height, had enhanced biomass and produced higher number of leaves and branches compared with those watered at 14- day intervals. The variety PA150 x T60/887 consumed more water and had wider stem girth. The inoculated seedlings of varieties T82/27 x T12/11 and T65/7 x N38 were taller than the non-inoculated seedlings. The interaction effects of watering regime and variety enhanced the growth parameters of varieties T82/27 x T12/11 and PA150 x T60/887 that were watered at 4- and 8- day intervals. Mycorrhizal inoculation enhanced vigour of growth and survival of seedlings of tested cacao varieties that were subjected to the evaluated watering regimes in the nursery in the dry season.
The patterns of nutrients (N, P, K, Ca, Mg) and organic matter release, leaching losses from applied organic materials (poultry manure and wood ash) and a compound NPK mineral fertilizer and the growth response of amaranthus (Amaranthus cruentus) were investigated in drainage lysimeter tanks. The soil at the site of the experiment is sandy clay loam (Alfisol, clayey skeletal oxic paleustalf). Subsurface drain water (leachates) recovered from the lysimeters was analysed for concentrations of nutrients, and from the time course of nutrient analyses, contrasting patterns of nutrient concentrations were obtained for the different treatments. The application rate of N 150 kg ha -1 from NPK fertilizer and 10 t ha -1 of wood ash resulted in the highest nutrient concentrations in subsurface drain water in comparison with application of poultry manure at 10 t ha -1 . However, significantly lower nutrient concentrations in subsurface drainage water was obtained in the treatment where neither mineral fertilizer nor manures were applied. Nitrogen recoveries in the leachates were reduced over time regardless of the sources of nutrients, however, a significantly higher rate of N depletion was obtained under wood ash application. The recovery of N in plant tissues and in leachates as a percentage of N added from the tested materials in increasing order of magnitude was wood ash (9%), poultry manure (14%) and NPK fertilizer (23%). Significantly higher values of fresh and dry weights of root and shoot biomass were produced by vegetable amaranthus grown in lysimeters in which NPK, poultry manure, or wood ash was applied than in unfertilized treatment. Application of poultry manure to lysimeters resulted in higher shoot biomass yield over treatments involving application of wood ash and NPK fertilizer. The nutrient release characteristics of poultry manure matched the nutrient requirements of amaranthus more closely than the inorganic fertilizer and wood ash. Wood ash and mineral fertilizer were more susceptible to leaching losses of nutrients during the establishment of amaranthus. The use of poultry manure did not result in significant effects on the quality of amaranthus. Poultry manure and unfertilized control had considerably lower 2-year average NO 3 -N concentration in subsurface drainage water in comparison with lysimeters treated with NPK or wood ash. Lower N recoveries in plant tissues and in leachates were obtained from lysimeters in which poultry manure was applied compared to NPK fertilized lysimeters. A higher proportion of the N present in poultry manure appeared to be resistant to microbial degradation and was thus unavailable for plant uptake.
The oil palm (Elaeis guineensis Jacq), is a crop of tremendous food, nutrition and economic importance in the tropics. Weather variability and extremes profoundly impact the establishment, survival and productivity of oil palm on the field. Alleys of palm trees in plantation are cropped with arables during early years following field establishment. Studies were conducted at the Nigerian Institute for Oil Palm Research, Benin City, Nigeria. Oil palm seedlings responded to shading, irrigation and AMF inoculation via enhanced water use efficiency, growth vigor and reduced seedling mortality in the nursery during dry season. Age of oil palm and intercrops of Cassava, Maize and Pepper affected mixture productivity and competitive functions in alleys of 2 to 6 years old oil palm fields. Fertilizers (inorganic/organic) promoted agronomic and physiological efficiencies of N use by alley species. Sole crops had higher N use efficiency compared with the intercrops across the fertilizers.
Monitoring Nigeria climate extremes is essential for building resilience, reducing vulnerabilities, and ensuring sustainable development in the face of Nigerian changing climate. ClimPACT2 software is used in this research to quantify climate extreme indices rate of change in the three Nigerian climate zones. The weather inputs were daily precipitation, minimum and maximum air temperatures secondary data obtained from ERA5 from 1979 to 2021. The peaks of the maximum day and night temperatures were observed to be on significant increase in all the regions. WSDI is significantly increasing per year in the Savannah by about 1.19 and 1.14, 1.10 in monsoon and 0.50 in Sahel regions. CDD is significantly increasing per year by about 0.33 in Akure, 0.44 in Lokoja, 0.12 in Port Harcourt and insignificantly by about 0.46 in Katsina while CWD is observed to be decreasing in all the regions. The number of wet and very wet days were observed to be decreasing over the years indicating drying days. SPEI drought index on time scales of 3, 6, 12 and 24 revealed significant increase in short time scale drought magnitudes of about 0.001 in Sahel while no significant change was observed in monsoon region. The analysis has shown significant warming trends in the Nigerian climate zones with significant implication on our climate, agriculture and overall environment leading to ecosystem disruptions. It is crucial for policymakers and stakeholders to take note of these trends and consider implementing measures to mitigate its impacts
The growth and yield of late-season tomato was studied at Akure, Nigeria, from 1995 to 1998. In each year, treatments were 0 (bare ground) or 12 kg/ha grass mulch applied to tomatoes at densities of 1·9, 2·8, 3·7 and 5·6 plants/m 2 in a factorial combination. Increase in plant density and mulching reduced soil temperature at 5 cm depth while only the latter enhanced soil moisture at 10 cm depth throughout tomato growth. The improved soil hydrothermal regime resulted in earlier onset of flowering, 50% flowering date and date of first harvest respectively and shorter fruit harvest duration in tomato grown on either bare ground or at increased plant density. Although increased plant density reduced shoot dry weight per plant at final harvest, both root length per plant and root dry weight per plant were enhanced. Fruit yield/ha increased as plant density increased although yield of the individual plants and their components were significantly reduced. Because of compensation at higher plant population densities, it is economical to grow late-season tomato at 5·6 plants/m 2 . Mulching enhanced growth and yield of tomato compared to bare ground and the result emphasizes the need for early and rapid growth of late-season tomato before the onset of terminal drought.
'/%3e%3cpath id='l' d='M-26.25 0h52.5v-12h-40.5v-16h33v-12h-33v-11H25v-12h-51.25z'/%3e%3cpath id='k' d='M-31.5 0h12v-48l14 48h11l14-48V0h12v-70H14L0-22l-14-48h-17.5z'/%3e%3cpath id='b' fill-rule='evenodd' d='M0 0a31.5 35 0 0 0 0-70A31.5 35 0 0 0 0 0m0-13a18.5 22 0 0 0 0-44 18.5 22 0 0 0 0 44'/%3e%3cpath id='d' fill-rule='evenodd' d='M-31.5 0h13v-26h28a22 22 0 0 0 0-44h-40zm13-39h27a9 9 0 0 0 0-18h-27z'/%3e%3cpath id='n' d='M-15.75-22C-15.75-15-9-11.5 1-11.5s14.74-3.25 14.75-7.75c0-14.25-46.75-5.25-46.5-30.25C-30.5-71-6-70 3-70s26 4 25.75 21.25H13.5c0-7.5-7-10.25-15-10.25-7.75 0-13.25 1.25-13.25 8.5-.25 11.75 46.25 4 46.25 28.75C31.5-3.5 13.5 0 0 0c-11.5 0-31.55-4.5-31.5-22z'/%3e%3cuse xlink:href='%23a' id='o' transform='scale(31.5)'/%3e%3cuse xlink:href='%23a' id='p' transform='scale(26.25)'/%3e%3cuse xlink:href='%23a' id='r' transform='scale(21)'/%3e%3cuse xlink:href='%23a' id='q' transform='scale(15)'/%3e%3cuse xlink:href='%23a' id='s' transform='scale(10.5)'/%3e%3cg id='m'%3e%3cclipPath id='c'%3e%3cpath d='M-31.5 0v-70h63V0zM0-47v12h31.5v-12z'/%3e%3c/clipPath%3e%3cuse xlink:href='%23b' clip-path='url(%23c)'/%3e%3cpath d='M5-35h26.5v10H5z'/%3e%3cpath d='M21.5-35h10V0h-10z'/%3e%3c/g%3e%3cg id='h'%3e%3cuse xlink:href='%23d'/%3e%3cpath d='M28 0c0-10 0-32-15-32H-6c22 0 22 22 22 32'/%3e%3c/g%3e%3cg id='a' fill='%23fff'%3e%3cg id='f'%3e%3cpath id='e' d='M0-1v1h.5' transform='rotate(18 0 -1)'/%3e%3cuse xlink:href='%23e' transform='scale(-1 1)'/%3e%3c/g%3e%3cuse xlink:href='%23f' transform='rotate(72)'/%3e%3cuse xlink:href='%23f' transform='rotate(-72)'/%3e%3cuse xlink:href='%23f' transform='rotate(144)'/%3e%3cuse xlink:href='%23f' transform='rotate(216)'/%3e%3c/g%3e%3c/defs%3e%3crect width='100%25' height='100%25' x='-50%25' y='-50%25' fill='%23009b3a'/%3e%3cpath fill='%23fedf00' d='M-1743 0 0 1113 1743 0 0-1113z'/%3e%3ccircle r='735' fill='%23002776'/%3e%3cclipPath id='g'%3e%3ccircle r='735'/%3e%3c/clipPath%3e%3cpath fill='%23fff' d='M-2205 1470a1785 1785 0 0 1 3570 0h-105a1680 1680 0 1 0-3360 0z' clip-path='url(%23g)'/%3e%3cg fill='%23009b3a' transform='translate(-420 1470)'%3e%3cuse xlink:href='%23b' y='-1697.5' transform='rotate(-7)'/%3e%3cuse xlink:href='%23h' y='-1697.5' transform='rotate(-4)'/%3e%3cuse xlink:href='%23i' y='-1697.5' transform='rotate(-1)'/%3e%3cuse xlink:href='%23j' y='-1697.5' transform='rotate(2)'/%3e%3cuse xlink:href='%23k' y='-1697.5' transform='rotate(5)'/%3e%3cuse xlink:href='%23l' y='-1697.5' transform='rotate(9.75)'/%3e%3cuse xlink:href='%23d' y='-1697.5' transform='rotate(14.5)'/%3e%3cuse xlink:href='%23h' y='-1697.5' transform='rotate(17.5)'/%3e%3cuse xlink:href='%23b' y='-1697.5' transform='rotate(20.5)'/%3e%3cuse xlink:href='%23m' y='-1697.5' transform='rotate(23.5)'/%3e%3cuse xlink:href='%23h' y='-1697.5' transform='rotate(26.5)'/%3e%3cuse xlink:href='%23j' y='-1697.5' transform='rotate(29.5)'/%3e%3cuse xlink:href='%23n' y='-1697.5' transform='rotate(32.5)'/%3e%3cuse xlink:href='%23n' y='-1697.5' transform='rotate(35.5)'/%3e%3cuse xlink:href='%23b' y='-1697.5' transform='rotate(38.5)'/%3e%3c/g%3e%3cuse xlink:href='%23o' x='-600' y='-132'/%3e%3cuse xlink:href='%23o' x='-535' y='177'/%3e%3cuse xlink:href='%23p' x='-625' y='243'/%3e%3cuse xlink:href='%23q' x='-463' y='132'/%3e%3cuse xlink:href='%23p' x='-382' y='250'/%3e%3cuse xlink:href='%23r' x='-404' y='323'/%3e%3cuse xlink:href='%23o' x='228' y='-228'/%3e%3cuse xlink:href='%23o' x='515' y='258'/%3e%3cuse xlink:href='%23r' x='617' y='265'/%3e%3cuse xlink:href='%23p' x='545' y='323'/%3e%3cuse xlink:href='%23p' x='368' y='477'/%3e%3cuse xlink:href='%23r' x='367' y='551'/%3e%3cuse xlink:href='%23r' x='441' y='419'/%3e%3cuse xlink:href='%23p' x='500' y='382'/%3e%3cuse xlink:href='%23r' x='365' y='405'/%3e%3cuse xlink:href='%23p' x='-280' y='30'/%3e%3cuse xlink:href='%23r' x='200' y='-37'/%3e%3cuse xlink:href='%23o' y='330'/%3e%3cuse xlink:href='%23p' x='85' y='184'/%3e%3cuse xlink:href='%23p' y='118'/%3e%3cuse xlink:href='%23r' x='-74' y='184'/%3e%3cuse xlink:href='%23q' x='-37' y='235'/%3e%3cuse xlink:href='%23p' x='220' y='495'/%3e%3cuse xlink:href='%23r' x='283' y='430'/%3e%3cuse xlink:href='%23r' x='162' y='412'/%3e%3cuse xlink:href='%23o' x='-295' y='390'/%3e%3cuse xlink:href='%23s' y='575'/%3e%3c/svg%3e)
'%3e%3cpath fill='%23001489' d='M0 0v6h9V0z'/%3e%3cpath fill='%23e03c31' d='M0 0v3h9V0z'/%3e%3cg stroke='%23fff' stroke-width='2'%3e%3cpath id='d' d='m0 0 4.5 3L0 6m4.5-3H9'/%3e%3cuse xlink:href='%23b' stroke='%23ffb81c' clip-path='url(%23c)'/%3e%3c/g%3e%3cuse xlink:href='%23d' fill='none' stroke='%23007749' stroke-width='1.2'/%3e%3c/g%3e%3c/svg%3e)
'%3e%3cg id='b'%3e%3cpath id='a' d='M0-95V0h50' transform='rotate(18 0 -95)'/%3e%3cuse xlink:href='%23a' transform='scale(-1 1)'/%3e%3c/g%3e%3cuse xlink:href='%23b' transform='rotate(72)'/%3e%3cuse xlink:href='%23b' transform='rotate(144)'/%3e%3cuse xlink:href='%23b' transform='rotate(216)'/%3e%3cuse xlink:href='%23b' transform='rotate(288)'/%3e%3c/g%3e%3c/svg%3e)