Stability of Thai cassava varieties grown in early rainy season

Crop performance under a broad range of environments can be studied to reveal cassava varieties with high yield stability. The objective of this study was to recommend cassava varieties for either a wide range of environments or for specific environments. When the effect of variety x environment interaction was high, cassava variety yielded differently under different environments. Five cassava varieties, namely : Kasetsart 50, Rayong 1, Rayong 60, Rayong 90 and Sriracha 1, were grown in the early rainy season (May 1992) over 9 environments. They were applied with mixed fertilizer 15-15-15 at the rate of 0, 313, 625 and 1,250 kg/ha. Only the data on dry root yield were analyzed. Results of the analysis, the Additive Main effects and Multiplicative Interaction (AMMI), indicated that Sriracha 1 was most stable when compared with the other varieties but yielded very low. Kasetsart 50 was moderately stable and gave high yield in several environments. Rayong 60 performed well at Khon Kaen Field Crops Research Center and Mukdahan Field Crops Experiment Station environments, whereas Rayong 90 performed well only at Maha Sarakham Field Crops Experiment Station environment.