Improving the Genetics of Tuber Yield and Resistance to Mite to Avoid Mite Incident and to Increase the Productivity of Cassava (Manihot esculenta Crantz)

Abstract

Mite (Tetranychus urticae) that attacks the cassava plants during dry season can reduce the yield up to 53%, depending on plant age and duration of attacks. The objective of the trial was to evaluate the cassava promising clones for tuber root yield and mite resistance. The field trial was done in Malang, East Java, Indonesia, in 2018 with fifteen clones using a randomized complete block design, with three replications. The glass house experiment for mite evaluation was done in Malang in 2018. A total of fifteen clones were used in this glass house trial. Infestation of mite (imago) was done 1 month after plating with 15 mites/pot on the lower part of the fourth or fifth leaf. Results of the field experiment showed that there was a genetic variability in the clones tested. The fresh tuber yield in 10 months ranged 30.33–55.67 t/ha with mean 41.34 t/ha. The fresh tuber yield of clone OMM 0915-11 was the highest of 55.67 t/ha. The tuber result of clone UJ5d50-207-3 similar to OMM 0915-11 and significantly higher than check variety UJ5. Response of clones to mite attack were as follows: two clones were resistant, ten clones were moderately resistant, and the other clones were susceptible. Based on the green house trial, the response of clones to mite attack was as follows: one clone was highly resistant, two clones were resistant, ten clones were moderately resistant, and the other clones were susceptible. Clone OMM 0915-11 was resistant variety or high resistant variety based on the green house and field experiments, while clone UJ5d50-207-3 was moderately resistant based on both glass house and field experiments.

Cassava (Manihot esculenta Crantz) Selection under Medium Altitude Tropics in Preliminary Yield Trial

“…[17] reported that tuber yield of 24 clones in 2018 ranged from 22.4 to 51.5 t.ha -1 (average 34.6 t.ha -1 ), and in the 2019 tuber yield ranged from 24.1 t.ha -1 to 54.6 t.ha -1 (average 38.6 t.ha -1 ). While [18] reported that the fresh tuber yield of 15 genotypes in 10 months ranged 30.33-55.67 t.ha -1 with mean 41.34 t.ha -1 . It can be seen that the average tuber yield in this experiment was not significantly different from that of [17], but lower than that reported by [18] because this study has entered the multi-location test stage.…”

“…While [18] reported that the fresh tuber yield of 15 genotypes in 10 months ranged 30.33-55.67 t.ha -1 with mean 41.34 t.ha -1 . It can be seen that the average tuber yield in this experiment was not significantly different from that of [17], but lower than that reported by [18] because this study has entered the multi-location test stage. Harvest index had a range between 0.32 to 0.63 with an average of 0.51.…”

Variance analysis and heritability estimation of growth and yield parameter of sweet cassava promising clones in two environments

“…The implication was a good clone on Entisol soil would generally be good in Alfisol soil. However, another experiment showed interaction between genotype and environment for tuber yield [16,17,18,19,20]. The genotype factor was significantly difference for the fresh tuber yield (Table 5).…”

“…This clone has the potential to be released as a new variety. However, this clone needed to be evaluated in a minimal eight environments before releasing this clone because the fresh tuber yield is affected by interaction between genotype and environment [16,17]. Farmers consider the fresh tuber yield in selecting the variety.…”

Geostatistical techniques to account for the heterogeneity ofFusariumwilt inoculum distribution in upland cotton field screening studies

“…For example, in maize yield trials, high‐producing commercial varieties are used for controls when analyzing new hybrids’ abiotic stress tolerance and provide a direct comparison of the performance of possible new varieties compared to what is currently commercially grown (Setimela et al., 2017). The use of checks is a widespread practice in agriculture variety development, including in programs for maize, wheat, sweet potato, soy, and cassava (Gasura et al., 2021; Mondal et al., 2016; Setimela et al., 2017; Sholihin et al., 2022; Webster et al., 2021); however, these checks only provide direct comparisons to adjacent plots, and their relevance diminishes the further a trial plot is located from the check.…”