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Soybean (Glycine max [L.] Merrill) planted in rainfed land during dry season often experiences crop failure due to drought. The objective of this study was to estimate the tolerant level and genetic advance values of 36 soybean genotypes on agronomic traits tested in drought and optimal irrigated conditions. The field research was conducted in Malang, East Java, Indonesia during late dry season of 2016. The soybean genotypes were tested in two environments, namely optimal condition (irrigation was applied until pods ripening) and drought condition (irrigation was applied until flowering). Results of the study showed that based on the genetic advance value, the number of branches per plant and the number of fertile pods per plant could be used as soybean selection criteria in normal irrigation and drought condition, respectively. In general, the mean of all traits in drought condition were lower than those in normal irrigation condition. Seed yield (t/ha) showed the lowest drought stress tolerant index (STI) (0.72). Based on the drought STI, four soybean lines (TGm-161-25-10, AB-142-40-21, AB-157-41-22, and ARG/GCP) had STI values of 1.0 and above 1.0 which are equivalent to the check drought tolerance variety Dering 1. These soybean lines could be grown in drought-stressed conditions. [ABSTRACT FROM AUTHOR]

Soybean in Indonesia mostly planted during late dry season after rice harvested in rainfed land resulting in crop failure due to drought. The effect of drought in some areas becomes more severe due to climate change. This paper discusses the breeding and development of soybean varieties tolerant to drought to anticipate the effect of climate change in Indonesia. Breeding program at ILETRI has released three drought tolerant soybean varieties during the reproductive phase. Dering 1 variety was derived from a promising line DV/2984-330 which was cross between Davros variety and MLG 2984; Dering 2 variety was derived from a promising line AB-157-41-22 which was a single cross between Baluran variety with Arg/GCP-335 line; and Dering 3 variety was derived from a promising line DM-122-357-17 which a single cross between Dering 1 and Malabar varieties. Dering 1, Dering 2, and Dering 3 varieties showed average grain yield of 2.12, 2.49, and 2.42 t / ha, respectively which was 1.9 - 19.7%, higher than Grobogan variety. These three varieties having a tolerant response to drought could be developed in drought prone areas for sustainable soybean production in Indonesia. [ABSTRACT FROM AUTHOR]

The breeding of cassava superior varieties requires the collection of germplasm support that accommodates various gene sources and has a wide variety of characters. This research was conducted to analyze morpho-agronomic characters of 100 cassava accessions, to examine its relationship to tuber yield, and to identify accessions with early maturity and high yield potential. The field experiment was carried out at the Muneng Experimental Station of ILETRI in 2019. The characters observed included 31 characters of leaves, stems, yields, and tuber yield components at 7 and 10 MAP. The results showed that most of the characters varied widely, except for petiole length, central leaf lobe length, stem diameter, distance between leaf scar, and number of marketable tuber at 7 MAP, and weight of marketable, unmarketable, and average tuber at 7 and 10 MAP. Path analysis showed that the number of total tubers per plant and the average tuber weight at 7 MAP had a large direct effect and a positive equal effect on the total. Meanwhile, the other 11 characters had less direct effect than the indirect effect through these two important characters. Tuber yield of 100 accessions harvested at 7 MAP was equivalent to 6.8–50.6 t/ha, with average of 28.8 t/ha. Meanwhile, it was between 8.0–68.4 t/ha at 10 MAP, with average of 38.1 t/ha. With K-mean cluster analysis, eight accessions were obtained having fresh tuber yield ranged of 39.6–50.6 t/ha and 46.20–67.20 t/ha at 7 and 10 MAP, respectively. The eight selected accessions were MLG 10361, MLG 10328, MLG 10292, MLG 10371, MLG 10353, MLG 10352, MLG 10360, and MLG 10308. Accessions identified with early maturity or high yield potential need further evaluation with repeated trials and evaluation of various other advantages. [ABSTRACT FROM AUTHOR]