Assessment of Genetic Diversity of Rice in Registered Cultivars and Farmers’ Fields in Burkina Faso

The genetic diversity of cultivated rice in farmers’ fields remains understudied in West Africa despite the importance of rice for food security in this region. In this study, we genotyped rice samples from Burkina Faso using the C6AIR SNP (Single Nucleotide Polymorphism) array (IRRI), including 27 registered cultivars and 50 rice samples collected in rice fields from three geographical zones in western Burkina Faso. Most of the registered cultivars clustered with the indica genetic group, except seven assigned to japonica and one admix. All but one of the rice samples from farmers’ fields belonged to the indica group. The other field sample, which unexpectedly clustered with the Aus genetic group, originated from a rainfed lowland site known to differ in terms of agronomic practices, and which revealed to be highly differentiated from the five other sites. Apart from this peculiar site, the rice grown in irrigated areas did not differ from rice sampled in rainfed lowlands. Finally, obtained genetic data confirmed the high frequency of one cultivar, in congruence with farmers’ interviews. We argue on the importance to document and preserve the high agro-biodiversity observed in rice from Burkina Faso as a prerequisite to face the current challenges of growing rice demand and global change.

Genetic Structure and Diversity of Rice From Certified Cultivars and Farmer’s Fields in Burkina Faso

Background: In West Africa, two rice species are cultivated, the African rice Oryza glaberrima and the Asian rice Oryza sativa, the second one being much more frequent. Despite its importance for food security in West Africa, the genetic diversity of Oryza sativa in farmer’s fields remains understudied in this region. Documenting the dynamics of diversity in the fields between landraces and improved cultivars is of importance to ensure rice cultivation adaptation to global change.In this study, we genotyped 77 rice samples from Burkina Faso using the C6AIR SNP array from IRRI. Among the studied samples, 27 were certified cultivars and 50 were sampled in rice fields from three geographical zones in western Burkina Faso, each zone comprising one irrigated area and a neighboring rainfed lowland. Obtained data were analyzed in the frame of the worldwide rice genetic diversity by using the 3K genomes as reference.Results: Most of the certified cultivars clustered with the indica genetic group, with a minority (26%) assigned to the japonica group. All except one of the rice samples from farmer’s fields belonged to the indica group. The peculiar one unexpectedly clustered with the Aus genetic group and originated from Tengrela (rainfed lowland in Karfiguela zone). This site, already known to differ in terms of agronomic practices, showed the highest genetic diversity compared to the five other sites, as well as highest genetic differentiation. Obtained genetic data confirmed the high global frequency of one cultivar, in accordance with the data from farmer’s interview. However, at the field level, genetic data rarely corresponded to the cultivar’s names obtained from farmer’s interviews.Conclusions: Overall we found a high genetic diversity in the studied samples from Burkina Faso (certified and field’s samples). We argue on the importance to document and preserve this agro-biodiversity as a prerequisite to face the current challenges of growing rice demand and global change. To this purpose, are required further scientific studies to refine our understanding of the dynamics of diversity in farmers’ fields, as well as a better knowledge of rice agro-biodiversity and awareness of its importance by rice farmers themselves.

Determinants of Production and Income Risks of Rainfed Lowland Farming: A Case Study in Maros Regency, Indonesia

Rainfed lowland farming production is generally lower than irrigated lowland rice due to area differentiation regional features. Rainfed lowland rice farming can only produce rice during the rainy season because lowland rice cannot be planted in the dry season. The purposes of this study are (1) to analyze the risk of production and income of rice farming in rainfed lowland farming and (2) to investigate the factors influencing the risk of rice farming in rainfed lowland farming. Data were collected from 100 respondents of rice farmers in four sub-districts in Maros Regency using the multi-stage cluster random sampling technique. The analysis of production and income risks were performed using multiple linear regression with the heteroscedastic method. The results have shown that rice farming in rainfed lowland farming poses a risk to production and income. The variables that significantly influence the rainfed lowland rice farming are land area, the number of seeds, the amount of urea fertilizer and the amount of pesticide. Farmers are required to manage risk by prioritizing the effectiveness and efficiency production factors as needed. Similarly the government is expected to assist farmers in maintaining the level of rice selling prices.

Incidence and relative abundance of rice stem borers in three selected rice fields in Lagos and Ogun States, Nigeria

This study was conducted to investigate the incidence of rice stem borer infestations and the species composition present in the selected rice fields. Data were collected between April 2017 and November 2018 across three locations, which include the upland rice field in Agbajege, Ogun state, rainfed lowland in Itoikin and Mangrove swamp in Igbogun, Lagos state, respectively. The incidence of rice stem borers was indicated by dead heart and white heads symptoms, while tillers were excised for rice stem borer identification and population. Results showed a high and low incidence of rice stem borers with no significant difference(p>0.05) at p= 0.29 and 0.37 between the early and late planting seasons in the rainfed lowland and upland rice fields respectively. Planting seasons were significant in the incidence of rice stem borers in mangrove swamp rice fields at p<0.05, p=0.01). This study showed that the predominant species of rice stem borers present in the three study sites were Chilo zacconius and Sesamia calamistis. C. zacconius was the most abundant species at 89% while S. calamistis was 11%. Rice stem borer populations were significantly higher at (p<0.05, p=0.000) in flooded zones while the highest rice stem borer populations were observed at the reproductive phase of the rice plants. Thisstudy showed that the planting seasons coincided with the peak period of the development of rice stem borers. Hence, conservation of natural enemies, monitoring and surveillance should be adopted in insect pest management in rice agroecosystems

Rainfed Rice Farming Production Constrains and Prospects, the Kenyan Situation

Kenya experiences huge production-consumption deficit in relation to rice. This is due to changing eating habits that has adopted more rice in the menu and rapidly rising population. Rice production has remained low being unable to meet consumption. Rice ecosystems in Kenya include irrigated, rainfed lowland and rainfed upland. Irrigated ecosystem has over the years been given more emphasis despite rainfed rice farming having double the potential over irrigation system. Ecologically rice grows well in abundant water supply, warm to high temperatures and in Clay sandy to loamy soils with slightly acidic to neutral pH. Rice varieties grown in Kenya are mainly traditional, introduced improved, hybrids and landraces. Rainfed rice farming faces constraint’s key among them being; drought and erratic rainfall, weeds, pest and diseases, cheap imports, land ownership and poor infrastructure. Mitigating against drought and erratic rainfall, improving farm inputs and equipment, increasing germplasm production and distribution, credit support and marketing to farmers, improving farmers skills through technological transfers and infrastructural development are prospects that if adopted could increase rainfed rice productivity. More attention towards improvement of rainfed rice farming could greatly contribute to bridging the production-consumption deficit that is bridged through imports. It is with this, that this review updates our understanding of rain fed rice farming in Kenya in terms of ecological conditions, ecological systems, varieties, constraints and prospects.

Agronomic and yield selection of doubled haploid lines of rainfed lowland rice in advanced yield trials

Akbar MR, Purwoko BS, Dewi IS, Suwarno WB, Sugiyanta, Anshori MF. 2021. Agronomic and yield selection of doubled haploid lines of rainfed lowland rice in advanced yield trials. Biodiversitas 22: 3006-3012. Selection process is important step to obtain high yielding variety. This study aimed to obtain information on agronomic performance of doubled haploid lines of rainfed rice in advanced yield trials and select the best lines for multi-location yield trials. Two experiments were conducted in Bogor and Subang using a randomized complete block design for each location and consisted of 35 doubled haploid lines and two check varieties namely Ciherang and Inpari 18 as a treatment. The result revealed that interaction between genotype and environment (G x E) significantly affected all agronomic characters, except on the panicle length. Characters with high heritability value were all agronomic characters except number of productive tillers and productivity. Genotypic correlation analysis showed that number of productive tillers and weight of 1000 grains had significant and positive correlation with productivity. The selection used weighted selection index based on multivariate analysis. Fourteen lines were selected for multi-location yield trials. These lines had characteristics as follows: number of productive tillers (14.0-17.7 tillers), weight of 1000 grains (24.7-32.5 g), and productivity (5.0-6.2 ton ha-1). The selected lines can be evaluated further to obtain superior lines in multi-location trials.

Performance of New Superior Variety of Rice and its Feasibility in Rainfed Rice Lowland of South Sumatra

Rainfed lowland has great potential to produce rice in South Sumatra Province. Rice cultivation in such marginal lowland needs technological innovation for sustainable use. This study aimed to analyze the crop performance and farming feasibility of a New Superior Variety (VUB) in rainfed rice cultivation. The study was carried out on 2019/2020 in Tugu Jaya Village, Lempuing District, OKI Regency. It was implemented in a demonstration plot of rice cultivation covering 2 hectares, using Inpari 30 and 43 varieties. The plant spacing was in accordance with 2:1 “jajar legowo” planting system. This was compared to the tile planting system outside the demonstration plot using IR 42 variety, which was planted by the local farmers. The results of observations of plants’ performance one day before harvest showed that the tallest plant was IR 42 (109.1 cm), the most tillers were from Inpari 43 (19.7 tillers), the longest panicle was of IR 42 (25.1 cm) and the highest harvested crop grain production was from Inpari 30 (6.8 tonnes/ha). In terms of business feasibility, judging from the resulting production and financial indicators, all three varieties were suitable for planting in rainfed lowland. Furthermore, of the three varieties, Inpari 30 on MH 2019/2020 was the most feasible, with a break-even price (BEPr) of Rp. 3,983 per kg; break-even production (BEP) of 1,568 kg per hectare; revenue cost ratio (R/C) of 2.39 and Marginal Benefit-Cost Ratio (MBCR) of 6.96.

Pemetaan Status pH Tanah dan C-Organik Tanah Sawah Tadah Hujan di Kecamatan Panai Tengah Kabupaten Labuhanbatu

<p>The production center for lowland rice in Labuhanbatu Regency in the last three years, precisely in Panai Tengah District, North Sumatra Province, has decreased production since 2018. One of the causes is a decrease in production because the nutrient content in the soil has decreased and added by fertilizer application by farmers. Lowland rice is still common due to limited data on land resources. This study aims to evaluate the land through the identification of classes, distribution and status of soil pH and C-Organic nutrients as well as organic matter in agricultural land in Central Panai District, and to determine the level of soil damage in each Land Mapping Unit. This research was carried out in Central Panai District with elevation. place 11 meters above sea level. Soil analysis was carried out in the integrated science laboratory of the Faculty of Science and Technology, Labuhanbatu University from January 2021 to March 2021, while the method in this study was a semi-detailed grid survey with the density of observation of 1 sample per 250 meters. Soil pH measurements used the pH-H₂O and C-organic methods of soil using the Walkley and Black method. Furthermore, the results of the analysis of nutrient rainfed lowland soils are interpreted into a nutrient status map. The results showed that the pH content of rainfed lowland soil in Panai Tengah District, Labuhanbatu Regency was classified as very acidic and slightly acidic, while based on the soil nutrient status, namely C-organic and organic matter in the low category, so as to increase the productivity of rainfed lowland soil with soil organic matter content.up to 3% required organic fertilizer in the Central Panai District, Labuhanbatu Regency.</p>