We evaluated the larvicidal activity of 20 plant essential oils and components from ajowan (Trachyspermum ammi) and Peru balsam (Myroxylon pereira) oils against Aedes aegypti. Of the 20 plant essential oils, ajowan and Peru balsam oils at 0.1 mg/mL exhibited 100% and 97.5% larval mortality, respectively. At this same concentration, the individual constituents, (+)-camphene, benzoic acid, thymol, carvacrol, benzyl benzonate and benzyl trans-cinnamate caused 100% mortality. The toxicity of blends of constituents identified in 2 active oils indicated that thymol and benzyl benzoate were major contributors to the larvicidal activity of the artificial blend. We also tested the acute toxicity of these 2 active oils and their major constituents against the water flea, Daphnia magna. Peru balsam oil and benzyl trans-cinnamate were the most toxic to D. magna. Two days after the treatment, residues of ajowan and Peru balsalm oils in water were 36.2% and 85.1%, respectively. Less than 50% of benzyl trans-cinnamate and thymol were detected in the water at 2 days after treatment. Our results show that the essential oils of ajowan and Peru balsam and some of their constituents have potential as botanical insecticides against Ae. aegypti mosquito larvae.

Plant essential oils from 26 plant species were tested for their insecticidal activities against the Japanese termite, Reticulitermes speratus Kolbe, using a fumigation bioassay. Responses varied with source, exposure time, and concentration. Among the essential oils tested, strong insecticidal activity was observed with the essential oils of ajowan (Trachyspermum ammi), allspice (Pimenta dioica), caraway (Carum carvi), dill (Anethum graveolens), geranium (Pelargonium graveolens), and litsea (Litsea cubeba). The composition of six essential oils was identified by using gas chromatography-mass spectrometry. The compounds thus identified were tested individually for their insecticidal activities against Japanese termites. Responses varied in a dose-dependent manner for each compound. Phenol compounds exhibited the strongest insecticidal activity among the test compounds further, alcohol and aldehyde groups were more toxic than hydrocarbons. The essential oils and compounds described herein merit further study as potential fumigants for termite control.

The potato tuber is known as a rich source of essential nutrients, used throughout the world. Although potatobreeding programs share some priorities, the major objective is to increase the genetic potential for yield through breeding or to eliminate hazards that reduce yield. Glycoalkaloids, which are considered a serious hazard to human health, accumulate naturally in potatoes during growth, harvesting, transportation, and storage. Here, we used the AMMI (additive main effects and multiplicative interaction) and GGE (Genotype main effect and genotype by environment interaction) biplot model, to evaluate tuber yield stability and glycoalkaloid content in six potato cultivars across three locations during 2012/2013. The environment on tuber yield had the greatest effect and accounted for 33.0% of the total sum squares; genotypes accounted for 3.8% and G×E interaction accounted for 11.1% which is the nest highest contribution. Conversely, the genotype on glycoalkaloid had the greatest effect and accounted for 82.4% of the total sum squares), whereas environment and G×E effects on this trait accounted for only 0.4% and 3.7%, respectively. Furthermore, potato genotype ‘Superior’, which covers most of the cultivated area, exhibited high yield performance with stability. ‘Goun’, which showed lower glycoalkaloid content, was the most suitable and desirable genotype. Results showed that, while tuber yield was more affected by the environment, glycoalkaloid content was more dependent on genotype. Further, the use of the AMMI and GGE biplot model generated more interactive visuals, facilitated the identification of superior genotypes, and suggested decisions on a variety of recommendations for specific environments.

Application of genotype by environment (G~;~times~;E ) interaction would be used for identifying optimum test condition of the varietal adaptation in the establishment of breeding purpose. Yield and yield components were used to perform additive main effect and multiplicative interaction (AMMI) analysis. Significant difference for G~;~times~;E interaction were observed for all variable examined. For yield, 0.18 of total sum of squares corresponded to G~;~times~;E interaction. Correlation analysis was carried out between genotypic scores of the first interaction principal component axis (IPCA 1) for agronomic characters. Significant correlations were observed between IPCA 1 for yield and capsule bearing stem length (CBSL), number of capsule per plant (NOC). The biplot of grain yield means for IPCA1 which accounted for 34% of the variation in total treatment sums of squares showed different reaction according to G~;~times~;E interaction, genotypes and environments. Taegu showed relatively lower positive IPCA1 scores, and it also showed smaller coefficient variation of yield mean where it is recommendable as a optimal site for the sesame cultivar adaptation and evaluation trial. In case of variables, Yangbaek and M1 showed relatively lower IPCA1 scores, but the score direction showed opposite each other on the graph. Ansan, Miryang1, Miryang4, and Miryang6 seemed to be similar group in view of yield response against IPCA1 scores. These results will be helpful to select experimental site for sesame in Korea to minimize G~;~times~;E interaction for the selection of promising genotype with higher stability.

Field experiments were conducted to determine the physiological and biochemical basis of the interactive effect of sulphur (S) and nitrogen (N) application on seed and xanthotoxin yield of Ammi majus L. Six treatments were tested (T1 = control-without manure and fertilizers, T2 = manure @ 9 kg plot-1-10~;t~;ha-1,~;T3=A0N50K25P25,~;T4=S40N50K25P25,~;T5=S40N100K25P25~;T6=S20+20N50+50K25P25) ). Nitrate reductase (NR) activity and ATP-sulphurylase activity in the leaves were measured at various phonological stages, as the two enzymes catalyze rate-limiting steps of the assimilatory pathways of nitrate and sulphate, respectively. The activities of these two enzymes were strongly correlated with seed and xanthotoxin yield. The highest nitrate reductase activity, ATP-sulphurylase activity and xanthotoxin yield were achieved with the treatment T4 . Any variation from this treatment decreased the activity of these enzymes, resulting in a reduction of the seed and xanthotoxin yield in Ammi majus L. The higher seed and xanthotoxin yield achieved in Ammi majus L. at treatment T4 could be due to optimization of leaf soluble protein and photosynthetic rate, as these parameters are Influenced by S and N assimilation.

Blast severity data of 39 rice varieties at 11 sites in Korea from 1997 to 1999 were analyzed using AMMI model and pattern analysis. Genotype x Environment (G~times E) interaction sum of squares (SS) accounted for 12 % of the total SS. Eight genotype groups and seven location groups were identified based on blast reaction pattern. The data obtained from over 21 sites with 44 test varieties from 1981 to 1996 were also considered. These were compared with the 1997-1999 data using the G~times E analysis results. Majority of the variability in the Korean Rice Blast Nursery (KRBN) were attributable to variations due to genotypes. Variations of G~times E interaction were maintained though test sites were reduced from 21 to 11 sites. Broadly compatible biological discriminative varieties identified were Nagdongbyeo and Akibare while broadly incompatible biological discriminative varieties identified were Hangangchalbyeo and Seogwangbyeo. Key sites for future evaluation work could be selected from location groups. Each location group should be represented by the site with the strongest interaction pattern. Blast responses in Cheolwon, Gyehwa, Suwon, Iksan, and Icheon showed different patterns from other locations.