No abstract

Banana aphid Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae) is widely known as the main vector of Banana bunchy top virus (BBTV). It had been reported that banana aphid could live on alternative hosts belong to Family Araceae, and become important issue since Araceous plants are commonly found surrounding banana cultivations. Research had been conducted to study the morphometrics and biological characteristics of banana aphids living on various species of Araceous plants. The results showed that Araceous plant species could influence the morphometric and biological characteristic of banana aphids, indicated by the significant difference in some biological characteristics such as life cycle, life span, reproductive period, and fecundity. The average life span of banana aphids living on Araceous plants ranged from 22.80 to 47.90 days, it was shorter than the one that of lived on a banana plants. P. nigronervosa was able to develop a bigger colony when the aphid lived on Araceous plants, especially when they were transferred to Bogor taro where their fecundity reached 63 nymphs per female. Araceous plants also affected the morphometric of P. nigronervosa indicated by smaller size of the aphids, compared to those living on banana plant. The ability of banana aphid to live and reproduce in various Araceous plants would be beneficial to the development of control strategies of BBTV.

Planting resistant varieties is the most effective control method and is recommended because it is safe for the environment. The problem to be raised in this study was the use of the same variety of maize in every growing season by farmers. The use of one of these varieties could cause a decrease in yield due to the resistance of the variety to certain pests and diseases.  This study aimed to provide information in the form of the use of sweet maize varieties resistant to leaf blight and potential to be planted in the swampy lowland of South Sumatra. The varieties used in this study were Bonanza F1, MB-01 Sweet and Love Sweet varieties. Based on the results of the study, as a whole the use of several varieties had a significant effect on the severity of leaf blight. The results of this study showed that there were differences in the response to resistance of each variety to leaf blight caused by the fungus Exserohilum turcicum. The observation of disease severity was carried out only in the vegetative phase. The highest disease severity was found in the Bonanza, Love Sweet, and MB-01 Sweet varieties at 16.90%, 9.99% and 7.07% respectively. The production data showed that there was no significant effect on the leaf blight. The MB-01 Sweet variety had the potential to be planted on swampy soil because it had resistance to blight and had a high production rate.