A New Concept in Assessing Adaptability Index for Superior Potential Cropping Intensity in Early-Maturing Rice Provisionally Accepted

Muhammad F. Anshori^1* Yunus Musa¹ Muh Farid¹ Muh Jayadi² Abd H. Bahrun¹ Amir Yassi¹ Andi A. Sulaiman³ Yi C. Huang⁴ Madonna Casimero⁵ Lizzida Llorca⁵ Willy B. Suwarno⁶ Muh M. Putra⁷ Hasil Sembiring⁸ Bambang S. Purwoko⁶ Daniel O. Wasonga⁹ Dr. Mahmoud F. Seleiman¹⁰

• ¹Department of Agronomy, Faculty of Agriculture, Hasanuddin University, Indonesia
• ²Department of Soil Science, Faculty of Agriculture, Hasanuddin University, Makassar, 90245, Indonesia, Indonesia
• ³Department of Agribusiness, Faculty of Agriculture, Hasanuddin University, Makassar, 90245, Indonesia, Indonesia
• ⁴Taiwan International Cooperation and Development Fund (TaiwanICDF), Taipei, 111047, Taiwan, Taiwan
• ⁵International Rice Research Institute (IRRI), Philippines
• ⁶Department of Agronomy and Horticulture, IPB University, Indonesia
• ⁷Agrotechnology study program, University of West Sulawesi, Majene, 91412, Indonesia, Indonesia
• ⁸National Research and Innovation Agency (BRIN), Indonesia
• ⁹University of Illinois at Urbana-Champaign, United States
• ¹⁰Department of Plant Production, College of Food and Agriculture Sciences, King Saud University, P.O. Box 2460, Riyadh 11451, Saudi Arabia, Saudi Arabia

Implementing a cropping intensity program with rice cultivation four times a year (CI 400) can be done by using early maturing varieties. However, this development needs to pay attention to the adaptability of the varieties planted. The adaptability approach is a combination of assessing stability and productivity potential. This concept has been developed in several studies, including on rice. However, this approach is considered less comprehensive because it is non-parametric and only focuses on one stability analysis. Therefore, a systematic integration of various stability analyses, including index methods, is needed to comprehensively assess adaptability. It is especially for earlymaturing rice in South Sulawesi a dynamic climate zone and the top four highest rice producers in Indonesia. Meanwhile, this study aims to develop a comprehensive adaptability index and select the best early-maturing rice varieties, especially in South Sulawesi. The investigation was conducted in Bone, Soppeng, and Gowa over two seasons using a nested randomized complete block design, with organized replications in each environment (location-season). Additionally, there was a significant focus on the application of five early maturing and two check rice varieties, with each factor repeated three times at each location, totaling 126 experimental units. The results showed that the adaptability index, by the combination of stability rank accumulation with yield min max standardization, was effective at assessing the yield potential and stability of early-maturing rice varieties in supporting CI 400. Inpari 13 had the best index value at 0.55, followed by Cakrabuana at 0.31, hence both were recommended as adaptive early-maturing rice varieties, especially in South Sulawesi.