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Asian Journal of Agriculture and Development (AJAD) - Call for papers!

Selection Criteria for Soybeans under Varying Cropping Systems and Environments

(Thailand), Doctor of Philosophy in Agronomy (University of the Philippines Los Baños)

Dissertation Abstract:

 

Twenty-four soybean varieties were planted under five growing conditions, namely, lowland mulched following rice dry season, upland open wet season, upland shaded wet season, upland open dry season and upland shaded dry season, to determine the responses and adaptability of these varieties to changes in growing conditions, to study the genotypic correlations between yield and certain characters, and to establish some criteria in selecting for maximum been yield under various growing conditions.

Results showed that variations in characters and yield were largely due to the main effects of varieties and growing conditions, and the interaction between variety and growing conditions.

Average bean yield of all varieties was highest in the open wet season and lowest in the shaded dry season. Among the varieties, UPL-SY 2 gave the highest bean yield, followed by Kaohsiung No. 3 and Williams. On the other hand, Hill and Lincoln produced the lowest yields.

None of the 24 varieties could be identified as an ideal variety possessing general adaptability and maximum phenotypic stability. On the other hand, Wayne, L-114 and No. 29 shoed high phenotypic stability but produced low yields.

Correlations between yield and other characters were not consistent from one environment to another, suggesting that selection criteria for different environments need not to be the same. However, further analysis indicated closely similar performance between shaded and open environments but substantial deviations under lowland conditions. These results suggest that a separate performance test, both in the preliminary and advanced trials, be conducted for developing varieties to be planted after lowland rice. On the other hand, a common preliminary trial can probably serve both upland open and upland shaded conditions.