AfricaRice trials ignite farmer curiosity on ratoon rice in Madagascar.

Photo 1: Ratoon rice from AfricaRice agronomic experimental fields in Madagascar (Credit: AfricaRice).

Madagascar is the largest rice producer in East Africa, where transplanting is the most predominant method for rice cultivation. Depending on the location, farmers grow rice once, twice, or even three times annually. Growing multiple seasons, however, usually comes with heavy workload, because it requires ploughing the fields and transplanting seedlings after each harvest.

Ratoon rice, instead of transplanting, consists of allowing the rice plants to regrow after the harvest of the main crop to produce a second crop from the stubbles. While this technique has existed in Madagascar for decades, it is not yet widely adopted. Currently, ratoon rice is mainly practiced in a localized small area of the highland region. Adoption of this technique depends on numerous factors such as water availability, suitable rice varieties, soil fertility, farmer awareness and social perception of the practice.

Multiple Harvest Rice for Africa Project

In late 2023, AfricaRice launched the Multiple Harvest Rice for Africa (MHRA) project with the aims of identifying elite lines and varieties with high ratooning ability and developing management recommendations for increased yields, grain quality, and reduced production costs for multiple harvest rice system across seven African countries, including Madagascar. The project is funded by Gates Foundation. It is led by AfricaRice in partnerships with National Agricultural Research Institutes of project countries, IRRI and Alliance Bioversity CIAT.

Since July 2024, experiments have been conducted in the southwest of Madagascar, in Ankilizato, Menabe. The trials include different i) cropping systems: Rice-Rice per year, Rice-ratoon-ratoon per year and Rice-ratoon-Rice-ratoon per year; ii) cutting heights: 10cm, 15cm, 30cm and 45cm; iii) water management: continuous flooding (CF), alternate wetting and drying (AWD), mid-season drainage (MIDA) and early drainage followed by AWD and mid-season drainage (ED_MIDA); and iv) fertilizer management strategies with the aim to assess their effects on the main and ratoon crop yields, nutrient use efficiency and profitability. The varieties being tested included: perennial rice variety (PR107), a local check variety (Sebota70), and two recommended varieties (FyVary32 and FOFIFA190). Although ratoon rice is relatively new to the farmers in this area, the site was chosen because of the water availability and favorable temperatures with a monthly average temperature ranging from 22.5 to 28.5°C, creating ideal conditions for ratoon rice experiments.

Preliminary results from the agronomy trials

The cropping system experiment showed no significant interaction between cropping system and variety on the cumulative yield. However, significant differences were observed among cropping systems. The cumulative grain yield was 5.46 and 0.91 t/ha higher in the Rice-ratoon-Rice-ratoon and Rice-ratoon-ratoon systems, respectively than in the Rice-Rice cropping system. Varietal performance within each cropping system is presented in Figure 1. FyVary32 and Sebota70 had the highest average cumulative grain yield among the varieties.

Results from the cutting height experiment showed no significant interaction between cutting height and variety on the cumulative grain yield. Independent significant effect of the cutting height indicates that higher cutting heights (45 cm) and very low cutting height (10 cm) were associated with lower cumulative yields. Significant varietal differences were observed in the main and ratoon seasons. FyVary32 and Sebota70 achieved significantly higher total yields compared to PR107 and Fofifa190 (Figure 2).

Figure 1. Comparison of the cumulative grain yield of rice varieties in Rice-Rice, Rice-ratoon-Rice-ratoon and Rice-ratoon-ratoon cropping systems. S1 to S4 indicate the number of cropping seasons. In the Rice-Rice system, S1 to S2 corresponds to transplanted rice twice a year. In the Rice-ratoon-Rice-ratoon system, S1 to S4 corresponds to one transplanting (S1) and one ratoon (S2) followed by a second transplanting (S3) and one ratoon (S4) in a year. In the Rice-ratoon-ratoon system, S1 to S3 corresponds to one transplanted rice (S1) and two ratoons (S2 and S3) in a year. Means with different lower-case letters between the varieties in each cropping system in a site are significantly different at p≤0.05.

Figure 2. Effect of cutting height on the cumulative grain yield of four rice varieties in the rice-ratoon-ratoon cropping system in Madagascar. Means with different lower-case letters between the varieties in treatment are significantly different at p≤0.05. 

 Farmer interest and on-farm experimentation

Based on these results, the field trials generated considerable curiosity among local farmers. Many visited the fields to ask about varieties and cultivation techniques. During the second ratoon crop, some were amazed that rice could still regrow and produce yield even after the first ratoon harvest. After witnessing the first ratoon harvest, about ten farmers surrounding the experimental plots even tried ratoon rice in their own fields.

One such farmer is RAZANAMANANTSOA Fanilo Christine, a female rice grower from Ankilizato. With 12 years of rice farming experience, she reported that it was her first time cultivating ratoon rice, inspired by the AfricaRice research plots near her field. She used a local variety named Fitarikandro and obtained about 27% of the main crop yield from the ratoon season. Notably, she only weeded the ratoon plot once and did not apply any fertilizer. She acknowledged that with improved crop management practices, the ratoon yield could be further enhanced. According to her, ratoon rice is highly attractive because it requires lower expenses while providing a rapid additional harvest. She emphasized potential benefits such as reduced seed costs (no need for replanting), time and labor savings in land preparation, and the opportunity to secure a second harvest potentially contributing to food security during lean periods. Importantly, she expressed strong willingness to continue cultivating ratoon rice and to learn better techniques for its management.

In summary, ratoon rice represents a promising innovation in Madagascar. Field experiments demonstrated that ratoon rice systems (rice-ratoon) can achieve higher yields than two seasons of transplanted rice systems (rice-rice) within a calendar year. However, further economic analysis are needed to determine their profitability and the suitable regions for ratoon rice cultivation. Farmers experimenting with ratoon rice in their own field indicate that local farmers are open to agricultural innovations. Nevertheless, additional research and fine-tuning are required to ensure its wide-scale adoption.

Photo 2: Surrounding farmers testing ratoon rice inspired from the AfricaRice field trials in Madagascar (Credit: AfricaRice)

Authors: Andrialalao Sophie Raharimalala, Elliott Ronald Dossou-Yovo, Kalimuthu Senthilkumar