Information on spatial distribution and peak occurrence is important for site and time specific pest management. So, we investigated seasonal occurrence and edge distribution of major soybean pests by visual count in six commercial fields located in Andong from July 16 to October 23 in 2015. We found a total of 19 species in 10 families. The major pest during vegetative stage was Medythia nigrobilineata (Motschulsky) while Riptortus pedestris (Fabricius) and Halyomorpha halys (Stal) showed peak occurrence during reproductive stage of soybean. Aphis glycines Matsumura was found throughout the season. Seasonal density of M. nigrobilineata was 0.20 and 0.38/plant in edge and interior without significance, respectively. The infestation of A. glycine was also found similar between edge and interior. Immatures of R. pedestris and H. halys distributed more in edge (0.21 and 0.36/plant) than interior (0.12 and 0.12/plant), respectively. The application of these informations on spatial distribution pattern of soybean pest was discussed.

A mycoinsecticide, Beauveria bassiana (strain GHA) marketed as BotaniGard® ES, was evaluated as a biological control agent against Riptortus pedestris (Fabricius) (Hemiptera: Alydidae) a major soybean pest. It was tested on commercial soybean fields with one time spray of both high (1×109) and medium (1×108spore/ml) concentration and double spray of the medium concentration. Nymph population decreased in all treated fields regardless of dose and frequency of spray. But, adult and egg populations were not affected. Alive nymphs collected from the fields and kept in laboratory showed infection rate ranging 35-68% in treated plots while 0% in control plots. It also reduced damage on soybean pods and seeds by 17.7-21.2 and 18.0-22.5% compare to control, respectively. Additionally, B. bassiana reduced other pests found in soybean fields including brown marmorated stink bug Halyomorpha halys (Stål) and two striped leaf beetle Medythia nigrobilineata Motschulsky. Also there was no negative effect on the parasitism of released non-viable eggs of R. pedestris. These results suggest that, in field condition, one time spraying of B. bassiana in the concentration of 1×108spore/ml can help reducing crop damage as well as R. pedestris nymph population.

This study was conducted to investigate the effects of bacterial inoculation (Lactobacillus plantarum) and cutting height on the chemical composition, fermentation characteristics and in vitro dry matter digestibility (IVDMD) in whole crop barley silage. Barley forage (Youngyang hybrid) was harvested at about 27% of dry matter (DM) level at two different cutting height (5 vs. 15 cm). And it was chopped to 5 cm length and treated with or without L. plantarum. Four replicates of each treatment were ensiled into 10 L mini silo (3 kg) for 100 days. After 100 days, bacterial inoculation decreased (p=0.001) DM content, while increased cutting height increased (p=0.002) DM in uninoculated silage. Crude protein (CP) concentration was decreased by increasing height in uninoculated silage (8.84 vs. 8.16) but increased in inoculated silage (8.19 vs. 8.99). Both neutral detergent fiber (NDF) (p<0.011) and acid detergent fiber (ADF) (p<0.004) were decreased by increasing cutting height of forage at harvest. The IVDMD and ammonia-N was increased (p=0.001) by increasing cutting height and inoculation, respectively. Lactic acid bacteria (LAB) was increased (p=0.002) in inoculated silage, but yeast count was decreased (p=0.026) in uninoculated silages. It is concluded that increased cutting height of forage at harvest could be useful to make a fibrous portion with increase of dry matter digestibility of silages.

Drought is one of the most important types of abiotic stress that affects stability and amount of yield. This study was conducted to screen for drought tolerance at early seedling stages for 318 ecogeographically diverse wild barley (HordeumvulgareL.spp.spontaneum) diversity collection (WBDC). Considerable variation was observed for all the seedling characters examined. Seedling growth was significantly reduced by 17% polyethyleneglycol -induced osmotic stress with significant variation among accessions. Comparison of mean performance under normal and osmotic stress conditions indicated that shoot length was the most sensitive trait, followed by seedling length, seminal root number, root-shoot length ratio and root length. The mean of root-shoot length ratio, however, increased under osmotic stress. Correlation studies indicated that the root length was the most important trait, followed by shoot length and root-shoot length ratio. The accessions from the Fertile Crescent and North Africa showed more drought tolerance than those from the other geographical regions. The accessions WBDC009 (Jordan), WBDC075 (Libya), WBDC181 (Jordan), WBDC242 (Jordan) and WBDC280 (Israel) exhibited the lowest stress susceptibility index ‘S’ values. Consequently, these accessions showed tolerance to drought at the early seedling stage and are considered to be good sources of drought tolerance for cultivated barley improvement. This work was supported by a grant from Regional Subgenebank Support Program of Rural Development Administration, Republic of Korea .