New Rice For Africa Research Articles

Response of Upland New Rice for Africa (NERICA) to Nitrogen Fertilization in the Guinea Savannah Agro-ecological Zone

Response of Upland New Rice for Africa (NERICA) to Nitrogen Fertilization in the Guinea Savannah Agro-ecological Zone

Effects of Selected Crops on Germination and Growth of Bidens pilosa and other Weeds

A screen house pot study was done at Uganda National Crops Resources Research Institute, Namulonge in Uganda during September-December 2021. Profiled metabolites from 5-donor plants; Mucuna pruriens, L. (Mc), Cymbopogon nardus L. (C), Desmodium uncinatum Jacq. DC. (D), (Zea mays, L. (Mz) and New Rice for Africa 1 (NERICA 1) were Terpenoids and Phenols. NERICA 1 (R) is a cross of Oryza sativa and Oryza glaberrima. C produced 10 terpenoids + 1 ester, R and D each released 6 Terpenoids + 3 Phenols. Mc produced 2 Terpenoids + 4 Phenols and 5 Terpenoids + 4 Phenols were profiled from Mz. Completely randomised block design were adopted with 3 replicates and eight combinations of 3 leaf+stem+root powders namely; Mc+D+C, Mz+Mc+C, RDC, Mc+D+C, Mz+R+Mc, Mz+D+Mc, R+Mc+C and Mz+R+C, mixed with 1.5 kg soil (15, 30 and 45 %, w/w). Controls had no powders. Mixtures were placed in plastic pots and 20 seeds of Biden pilosa L. were sown in each pot. Every 2 days, 200 ml of water was applied to all treatments for 60 days. Mz+Mc controlled B. pilosa and volunteer weeds relative to R+C and C+D. Weed germination and biomass reduced with increased powder doses. Volunteer monocot weeds were more inhibited than dicots. High potential exists for functional allelopathy using allelochemicals in the donor plants to develop bio-herbicides.

Root attributes governing drought stress adaptation and the associated molecular markers in chromosome segment substitution lines in rice (Oryza sativa L.)

The wild relatives of cultivated rice offer crucial resistance genes for combating stresses like drought. Developing rice varieties with drought tolerance is possible through chromosome segment substitution lines (CSSLs), which blend the genetic background of a high-yielding parent with specific chromosome segments from a donor parent. This study aimed to study the effect of drought stress on various root traits of chromosome segment substitution lines (CSSLs) and their relationship with specific molecular markers. Ninety-six genotypes, including 80 chromosome segment substitution lines (Curinga x O. rufipogon and Curinga x O. meridionalis), 9 New Rice for Africa (NERICAs) and 7 controls were grown in Basket and PVC pipe methods for phenotyping different root traits. Under drought stress (DS), MER16, MER20, RUF10, RUF16, RUF44, NERICA1, and NERICA3 showed superior performance for most of the root traits. These evaluations were supplemented with association analysis of 17 root trait-linked simple sequence repeat (SSR) markers with root phenotypic traits. The marker RM201 is strongly associated with multiple root traits, found to be independent of three growth conditions (well-watered “WW” under Basket, WW condition and DS conditions under PVC pipe). The marker RM316 is associated with root volume, and the marker RM7424 and RM1054 show maximum root length. In conclusion, these markers can be used in marker-assisted breeding programs, and the lines carrying them can be used as parental lines in variety-development programs for drought tolerance.

Response of lowland rice varieties to integrated nutrient management in a derived Savannah agro-ecology

In the inland valley (FADAMA) of the Directorate of University Farms (DUFARMS) of the Federal University of Agriculture, Abeokuta (FUNAAB) in Nigeria, an experiment was conducted successfully. The objective was to see how integrated nutrient sources influenced the performance of two lowland varieties of rice. A split-plot two-factorial experiment was used in the study, and it was replicated three times in a randomized complete block design. Rice seedlings were transplanted 12 days after being planted in the nursery to a depth of 3 cm and a spacing of 20 cm × 20 cm, one seedling per hill. Two varieties and six nutrient sources were used for the research. Rice yield and growth data were collected. ANOVA (Analysis of Variance) was used on data, and the significant means were separated using Tukey HSD (Honestly Significant Difference) at a probability level of 5%. ARICA 3 grew taller than NERICA L-34 as a result of the research. ARICA (Advanced Rice Varieties for Africa) 3 exceeded NERICA (The New Rice for Africa) L-34 in terms of shoot dry weight (4 WAP (Weeks After Planting) (1.53) and 6 WAP (1.53 g), respectively (5.60 g). Rice cultivars produced the highest grain when 25 kg N ha-1 (NPK 20:10:10) and 75 kg N/ha (Poultry manure) were applied.

Assessing combined effects of biochar concentrations and different fertilizer applications on physicochemical properties of a sandy loamy soil

Biochar application in the soil is a major strategy for modifying or improving its physicochemical properties, while soil fertility can be boosted by fertilizer application. The process of soil amendment was explored to investigate the impact of combined biochar and fertilizer treatments on soil properties and yield of New Rice for Africa (NERICA 2) upland rice variety. A Randomized Complete Block Design experiment was conducted using three different fertilizer types, three different biochar concentrations, and two sets of control each, with zero biochar and zero fertilizer. The biochar levels were 0 t/ha, 5 t/ha, 10 t/ha, and 15 t/ha, while the fertilizer types were zero fertilizer, liquid organic fertilizer (LOF), solid fertilizer (NPK), and farmyard poultry manure (PM). A drip irrigation system with the completed layout captured the entire set-up, while soil properties were measured before soil treatment, post-season 1, and post-season 2. A significant increase in particle density from 3 3 3 3 2.51 g/cm3 to 2.56 g/cm3 was recorded while bulk density decreased from 1.42 g/cm3 to 1.41 g/cm3 , and soil textural classification remained relatively unchanged. Organic carbon, organic matter, nitrogen, phosphorus, potassium, cation exchange capacity, and base saturation increased from their respective pre-treatment values. Also, soil pH improved significantly from 6.38 to 6.37. There was a better improvement in soil properties, which resulted in increased paddy rice yield with an average value of 6.36 t/ha obtained using NPK with a biochar concentration of 15 t/ha (NPKB15) treatment. This is an equivalent of approximately 400% increase in yield compared to the zero fertilizer and zero biochar (FOBO) treatment yield of 1.14 t/ha. NPK fertilizer at a biochar concentration of 15 t/ha, gave the best result in the soil's physical and chemical properties and is recommended for rice production.

Effects of water use efficiency on plant dry matter in NERICA and Japanese rice cultivars under drought conditions

NERICA (New Rice for Africa) was produced by crossing Asian rice (Oryza sativa L.) and African rice (Oryza glaberrima Steud.) and recorded to be drought tolerance. This study aimed to examine the transpiration and water use efficiency affected plant aboveground dry matter in total 29 cultivars including 23 NERICA, 1 indica-type and 5 japonica-type cultivars. Seedlings were transplanted 2 plants per pot (1/5000 a Wagner pot) on June 14, 2021. When the flag leaf appeared, three water treatments with three replications were imposed for 14 days. The control plot (C) was watered daily to maintain the water content per pot at field capacity (SW). The water content of medium dry pots (MD) and hard dry pots (HD) were maintained at 40% and 10% of SW, respectively. Surface of the pots was covered to eliminate the evaporation. Samples for dry matter measurement were collected on the same day starting and ending water treatment. Water use efficiency (WUE) was significantly different among cultivars when soil moisture treatments were included, and the same observation on soil moisture treatments when included cultivars. NERICA 4 showed the lowest WUE while NERICA 9 and Hokuriku 193 had the highest WUE. Cultivars with higher transpiration rate (Tr) had higher dry matter production (ΔDW). Under high vapor pressure deficit, ΔDW was more correlated with transpiration corrected by vapor pressure deficit (Tr/VD) than with WUE.

Primed Seeds of NERICA 4 Stored for Long Periods under High Temperature and Humidity Conditions Maintain Germination Rates

Agriculture depends on the ability of seeds to survive until the next planting season under ambient conditions that may be averse to seed quality even when the seed is in a quiescent state. Seed priming invigorates seeds, but the impact on the longevity of seeds has limited its adoption. This study investigated the effect of the storage of primed rice seed on seed viability, vigor, and longevity. Three seed priming methods were employed on the rice cultivar New Rice for Africa (NERICA 4) seeds. Subsequently, the seeds were stored for 120 days at 25 °C and 65% relative humidity, simulating the ambient seed storage conditions of the tropics and sub-tropics. The primed seed recorded increased vigor compared to the non-primed seed until 90 days of storage. However, seed storage for 120 days reduced seed vigor and viability for all the seeds. The results indicated a significant reduction in seed vigor, increased solute leakage, generation of hydrogen peroxide, and accumulation of malondialdehyde after storage. Priming enhances cell membrane integrity and maintains seed vigor in storage at near ambient conditions long enough before reversal of its performance by the storage conditions. This assures that primed seed can either be stored until the following planting season or remain viable in the soil during delayed germination.

The Contribution of New Rice for Africa (NERICA) Farming to Livelihood Security of Smallholder Households in Migori, Kenya

Improved people's livelihoods have a great potential to solve food insecurity issues. The uptake and use of enhanced agricultural technologies have been identified as one of the best ways to improve yields of smallholder rural farmers leading to improved livelihoods and stable socio-economic growth. This adoption has been attributed to higher incomes, better nutritional conditions, access to food stability and prices, more employment opportunities, and improved payments for the rural poor. NERICA rice was one such agricultural technology introduced in many countries across Africa to enable smallholder farmers to achieve food security. Previous studies on NERICA adoption in Africa show mixed findings on its effect on rural livelihoods. The main objective of this study was to examine the influence of NERICA rice agricultural technology on the livelihoods of smallholder households in Migori. The study on agricultural technology adoption and livelihood is of great concern to many stakeholders in Kenya because previous studies report low adoption of agricultural technologies in rural households of smallholders whose livelihoods depend on farming and are food insecure. The study was carried out in Migori County. Multistage sampling was used by combining purposive and simple random sampling. Data was collected from 262 NERICA rice farmers selected using a simple random sample, 22 key informants were purposively selected and interviewed, and eight focus group discussions were conducted from purposively selected NERICA rice-farming villages. Quantitative data was analyzed using SPSS computer software. Qualitative data were analyzed using thematic analysis, and the integrated data was triangulated and used to write this report. The findings revealed that the adoption of NERICA contributed to the livelihoods of smallholder farmers by increasing their incomes, creating food security and enhancing their social capital.

Interspecific Hybridization Is an Important Driving Force for Origin and Diversification of Asian Cultivated Rice Oryza sativa L.

As one of the most important crops, Asian cultivated rice has evolved into a complex group including several subgroups adapting various eco-climate-systems around the globe. Here, we pictured a comprehensive view of its original domestication, divergences, and the origin of different subgroups by integrating agriculture, archeology, genetics, nuclear, and cytoplasm genome results. Then, it was highlighted that interspecific hybridization-introgression has played important role in improving the genetic diversity and adaptation of Oryza sativa during its evolution process. Natural hybridization-introgression led to the origin of indica, aus, and basmatic subgroups, which adapted to changing cultivated environments, and produced feral weedy rice coexisting and competing with cultivars under production management. Artificial interspecific hybridization-introgression gained several breakthroughs in rice breeding, such as developing three-line hybrid rice, new rice for Africa (NERICA), and some important pest and disease resistance genes in rice genetic improvement, contributing to the stable increase of rice production to meet the expanding human population. We proposed a series to exploit the virtues of hybridization-introgression in the genetic improvement of Asian cultivated rice. But some key issues such as reproductive barriers especially hybrid sterility should be investigated further, which are conducive to gene exchange between cultivated rice and its relatives, and even is beneficial to exploiting interspecific hybrid vigor. New technologies help introduce favorable genes from distant wild species to Asian cultivated rice, such as transgenic and genome editing systems. Rising introgression lines in a wider range with multi-donor benefits allele mining, understanding genetic network of rice growth and development, yield formation, and environmental adaptation. Then, integration of new tools and interspecific hybridization can be a future direction to develop more usable breeding populations which can make Asian cultivated rice more resilient to the changing climate and world.

Impact of Different Nitrogen Amount and Seeding Rates on Growth and Yield of NERICA 4 Rice Varieties in Upland Conditions

With the recent breakthrough in the development of the New Rice for Africa (NERICA) for the upland production system and the high demand for rice, farmers’ interest in growing upland rice has increased. A field experiment was conducted at Tsukuba International center, Japan from May to October 2019 to evaluate the response of rice to seed rate and nitrogen fertilizer application and also determine economically optimum seed rate and nitrogen level for NERICA-4 upland variety. The experiment contained factorial combination of four levels of nitrogen (0, 30, 60, 90 kg ha -1 and two seed rates (60& 80 Kg ha -1 ). The experiment was laid out in randomized complete block design plot arrangement with three replications. The results from this study indicated that seed rate showed no significant effect on total dry matter weight, plant length, SPAD value, Leaf area index, panicle number, spikelet number, ripening ratio and grain yield while the total number of tillers was significant. However, nitrogen fertilizer rates significantly (p < 0.05) affected in plant length, tiller number, SPAD value, dry matter and Leaf area index. Except 1000grain, all the yield and yield component parameters have also shown a significant increase up to the rate of 90 kg N ha−1. The highest grain yield (3340 kg∙ha−1) was recorded using 90 kg N ha −1 followed by 60 kg N ha −1 (3200 kg ha −1) and the lowest yield (2100 kg ha −1 ) was recorded from control . Marginal rate of return analysis is also showed that the treatment with N fertilizer rate of 90 kg N ha −1 and seed rate 60 kg ha −1 gave the highest Marginal rate of return 1217 % followed by the treatment with N fertilizer rate of 60 kg N ha−1 and seed rate 60 kg ha−1.The general trend of the data indicated that the fertilizer rate has a greatest impact on grain yield compared to the seed rate of rice crop. Based on this study using 60 kg/ha seed rate and application of 90 kg N ha −1 gives high grain yield for rice crop production at experimental site. Keywords: Economic profit, Seed rate, N fertilizer rate, Optimum grain yield, Marginal rate of return DOI: 10.7176/JBAH/12-9-04 Publication date: May 31 st 2022

English

Climate change and inefficient water utilization have led to marked fluctuations of the mean rice crop production in sub-Sahara Africa. In order to improve food security and households’ income, adaptation strategies to climate change such as the adoption of new rice varieties are inevitable. This study examined the farmers’ perception and adoption of climate change friendly New Rice for Africa in Mwea West Sub-county. The study applied the descriptive survey design with questionnaires being administered to a sample of 376 farmers. Key informants included four officers from Mwea Irrigation Agricultural Development and the Ministry of Agriculture. Quantitative data were analysed using Statistical Package for Social Sciences whereas qualitative data were analysed through establishing the categories and themes, relationships/patterns, and conclusions drawn in line with the study objectives. Results indicated a highly significant difference in adoption between farmers affiliated to Mwea Irrigation Scheme and the out-growers (X2= 18.5, df =2, p= 1.67×10-6). The study concluded that the adoption of New Rice for Africa varieties in the Mwea West Sub-county is low and slow. This is mainly caused by inadequate information among the farmers as well as low market demand for the rice varieties. There is a need to enhance these rice varieties by intensifying efforts to sensitize farmers.   Key words: Climate change, new rice for Africa, adaptation strategies.

Grain yield and leaf gas exchange in upland NERICA rice under repeated cycles of water deficit at reproductive growth stage

New Rice for Africa (NERICA) was reported to have higher exudation and transpiration rates, above ground dry matter at heading than Japanese cultivars. Information on the expression of their gas exchange attributes and water balance under repeated cycles of water deficit at reproductive stage is unknown. This investigation tested the hypothesis that variation in leaf gas exchange and energy attributes of NERICA rice under repeated cycles of water deficit at reproductive stage would affect their performance under field conditions. Repeated cycles of water regimes (irrigation and water deficit) at reproductive stage were imposed on eight NERICA rice (NERICA 1–8) and checks (CG14, WAB56–104 and IR64). Water regimes were assigned to main plots and rice cultivars to sub-plots using randomised complete block design with three replicates. Drought-tolerant NERICA 4 and 7 had significantly higher relative water content, stomatal conductance, leaf photosynthetic rates with the least canopy temperature than others. A converse pattern was observed in the drought-susceptible IR 64. Grain yield of NERICA 4 and 7 was significantly higher than that of IR 64. These results suggested that improved water and energy status observed in NERICA 4 and 7 could have been responsible for its better performance than IR 64.

Adoption Rates of NERICA Innovation among Rice Farmers in Northern Ghana

Adoption rates of the New Rice for Africa (NERICA) have been generally low across Africa, indicating that the innovation has not been well accepted on the African continent, including Ghana. The adoption rates of the innovation were determined in Northern Ghana to ascertain the extent to which farmers have accepted to grow the ‘magic’ crop in curbing food insecurity, poverty, unemployment, and rice importation. However, the adoption rates so determined were too low, due to incomplete diffusion. The current paper aimed at determining the rates of adoption of NERICA in Northern Ghana from 2015 to 2018, to verify the findings and predictions of previous researchers. Simple random sampling technique was accordingly used to obtain quantitative and qualitative data from 346 rice farmers. The data were analyzed qualitatively and quantitatively using logistic regression as well as descriptive statistics. The study revealed a low average adoption rate of 25% with a high standard deviation of 44.03%, indicating an uneven spread out of the adoption rates over the period under study. However, the specific adoption rates of the innovation were 91.04%, 3.18%, 2.89% and 2.89% for 2015, 2016, 2017 and 2018 farming seasons respectively, confirming that the rates rose to 91% but fell drastically in subsequent years as predicted by previous researchers. Farmers' educational level, perception of NERICA, family size and rice farming significantly affected adoption of NERICA. The persistent low adoption rates showed that the innovation was unsuccessful in the study area. The Ministry of Food and Agriculture should therefore intensify her innovation dissemination/diffusion campaigns in the study area to revamp its adoption; by providing ready jobs to the youth and market for the commodity through the flagship programs, Planting for Food and Jobs, and the National Food Buffer Stock Company.

Effects of multi-growth stage water deficit and orthosilicic acid fertiliser on lodging resistance of rice cultivars

Lodging and water deficit (WD) are both yield limiting factors for rice production in Africa. A number of New Rice for Africa (NERICA) cultivars with drought adaptive and high yielding ability have been released but the extent of their lodging susceptibility due to water deficit is unclear. Application of orthosilicic acid (OSA) fertiliser can reduce lodging due to water deficit. An experiment was therefore conducted involving six cultivars (NERICAs 1, 4, 6, 7, 8 and Moroberekan), subjected to five multi-growth stage WD treatments: non-stressed (Nst), 10-day stress at each of any two stages of vegetative (Veg), reproductive (Rep) and grain filling (Grain) stages viz (Veg10 + Rep10), (Veg10 + Grain10), (Rep10 + Grain10), and 7-day stress at each stage (Veg7 + Rep7 + Grain7) and with/without 500 mL ha−1 of OSA fertiliser. Lodging traits (LTs) such as lumen diameter, bending moment, panicle weight (PW) and grain yield (GY) were increased by OSA fertiliser. Under Veg7 + Rep7 + Grain7 stress, OSA fertiliser increased rice vigour through increases in internode length, lumen diameters and cross-section modulus by 7%, 18% and 18%, respectively, while under Veg10 + Rep10 stress, culm wall thickness was increased by 20%. Veg10 + Rep10 stress caused the most significant reduction in all LTs but with lowest lodging index (LI, 0.32) attributed to reduced PW and GY. Among the cultivars, Moroberekan combined higher GY with average LI (0.40) across the stress conditions while NERICA 1 had the lowest LI (0.34) attributed mainly to its short height. Although water deficit caused a reduction in lodging resistant traits, resistance to lodging under Veg10 + Rep10 and Veg7 + Rep7 + Grain7 stresses can be enhanced with OSA fertiliser.

Određivanje reoloških osobina pojedinih varijatiteta nove sorte pirinča (NERICA) relevantnih za preradu

The pasting properties of some NERICA (New Rice for Africa) varieties were determined using the rapid visco-analytical machine (RVA). The studied varieties include FARO 44, FARO 52, FARO 57, FARO 60, and FARO 61. The parameters assessed include the pasting temperature, peak time, peak or maximum viscosity, hot paste viscosity or trough, cold paste or final viscosity, breakdown, and setback. Results obtained indicated that the pasting characteristics of NERICA varieties studied exhibited good pasting behavior. Results showed that peak viscosity, final viscosity, hot paste viscosity, breakdown, and setback ranged from 30.83 to 85.17 RVU; 62.21 to 167.13 RVU; 25.83 to 76.88 RVU; and 5.01 to 8.29 RVU; and 31.38 to 81.96 RVU, respectively. There were significant effects of moisture content and temperature (p < 0.05) on all parameters studied. These generated results of the pasting characteristics of NERICA will be extremely useful in determining their suitability in food and other relevant industries.

Integrated Research for Development Approach to Upgrade the Whole Rice Value-chain in Sub-Saharan Africa: Contribution of Africa Rice Center after NERICA (New Rice for Africa)

Integrated Research for Development Approach to Upgrade the Whole Rice Value-chain in Sub-Saharan Africa: Contribution of Africa Rice Center after NERICA (New Rice for Africa)

PHYSIOLOGICAL RESPONSES OF UPLAND RICE; WATER AND NITROGEN UPTAKES AND WATER USE EFFICIENCY UNDER WET AND PARTIAL DRYING SOIL CONDITIONS

Rice is an important cereal and staple food crop in Tanzania, the rice production has not met the demand, mainly due to water shortage. Dissemination of New Rice for Africa (NERICA) has been in progress to improve production in upland rice ecosystem. A pot experiment was conducted in a split plot design at university farm to elucidate water uptake, water use efficiency and nitrogen uptakes for two NERICA cultivars (NERICA1 and 2) and two Japanese rice cultivars ( and ). Amount of transpired water was recorded every day until maturity. Nitrogen uptake at booting and maturity growth stage were compared between these cultivars. The results indicated that amount of water transpired was greater for NERICA cultivars in the period from booting to maturity, in particular, under the dry soil condition. All the cultivars showed similar slope of regression lines between amount of transpired water and dry matter production (Water use efficiency), Nitrogen concentration per unit weight was higher in NERICA rice than in Japanese rice during grain filling stage. These results indicate that NERICA’s rice cultivars have high productivity due to higher water and Nitrogen uptake during grain filling stage compared with the Japanese rice cultivars tested.

Trading off consumer preferences induced by cultural and colonial heritage: Lessons from New Rice for Africa (NERICA) in Casamance, Senegal

Abstract Breeders face the challenging task of tailoring crop varieties to complex consumer preferences shaped through culture and history. The Casamance rice sector in Senegal is an interesting case; while the region is endowed with a 3,000-year-old cultural heritage of African rice domestication, it has also been exposed to century-long colonial import substitution policies, leading to massive influx of cheap, broken Asian rice. Markets have responded to the amalgam of consumer preferences that have emerged as a result of cultural and colonial heritage by offering three standard grades of rice: 100 per cent broken, semi-broken (35–60 per cent broken), and unbroken. To disentangle the trade-off between indigenous and ‘imported’ traits and inform breeding priorities, we conducted framed field experiments with urban women in the Casamance. We assessed consumers’ revealed price premiums for replacing imported, broken Asian rice with three locally produced New Rice for Africa (NERICA) hybrids between African and Asian rice: (i) broken, fragrant NERICA 1; (ii) broken NERICA 4; and (iii) unbroken NERICA 6 featuring medium/bold grain shape. Consumers with genealogical lineages tracing back to the original domesticators of African rice put significantly higher value on locally produced NERICAs relative to immigrants from the north and northeast, who put premiums on ‘imported’ traits such as rice fragrance. Driven by preferences for both broken and unbroken rice, NERICA 6 outcompeted all other varieties as it mimics the grain shape of semi-broken rice while being unbroken. The latter exemplifies how breeders can strike an optimal compromise in the trade-off between cultural and colonial heritage-induced preferences.

English

Soil nutrient management is an important factor in plant growth for increased crop production and productivity in Sub-Saharan Africa whose food demand is over the threshold. Rice production in Uganda is still very low with current yield less than 2.5 ton ha-1. The impressive production increase is mainly on to farmer area expansion. A fertilizer trial was established to determine a New Rice for Africa (NERICA) 4 variety response to the nitrogen and phosphorus application. At Tsukuba International Center, Japan, 2014 an experiment with objective to obtain the minimum fertilizer recommendation amount of nitrogen and phosphorus application dose was established during rice growing season May to September. The nitrogen (N) fertilizer rates were 0, 40 and 80 kg ha-1 while phosphorus (P) 0 and 70 kg ha-1 fertilizer quantities applied. Several data were obtained and indicated tiller number, panicle number m-2, plant dry matter were significantly (P 0.05) different on application of different nitrogen doses. However, in P conditions, both nitrogen doses (40 and 80 kg ha-1) did not vary in ripened grains and number of spikelets/ m2. A significant amount of N was utilized when 40 kg N ha-1 was applied compared to 80 kg N ha-1 in similar P condition through growth stages. Applying N and P fertilizers at 80 and 70 kg ha-1 respectively, as well as applying N fertilizer 80 kg ha-1 alone increased growth parameters and yield compared to other rates of N and P fertilizers applied. Key words: Fertilizer rate, upland rice, New Rice for Africa (NERICA), N use efficiency

DETERMINATION OF THE OPTIMUM MATURITY OF NEW RICE FOR AFRICA USING ARTIFICIAL NEURAL NETWORK

The New Rice for Africa (NERICA) is a child birth of research to improve upon the production of rice in sub-Sahara Africa due to challenges of shortages in agricultural food production. Two major varieties were obtained, for low lands and uplands. NERICA-4 is commonly suited for uplands and has delicious taste as compared to the other upland varieties. However, the problem of loss of grains at harvest which translates to low productivity amongst other factors needs to be addressed. In this paper, about 750m2 farm land was cultivated with NERICA-4 rice variety and 60 images at different maturity period with ten features extracted, preprocessed and processed using MATLAB2018Ra software. The processed images were classified using Artificial Neural Network to determine the optimum maturity period based on visual properties. 93.30% classification accuracy was obtained. This shows that when made operational, the loss of grains can be drastically reduced and productivity increased