Population fluctuation of Fruit Flies and Effect of The Weather Factors on Their Activity and Infestation rates on guava fruits of summer and winter at fayoum governorate.

Abstract

This study was contributed for monitoring the population fluctuations and estimation of infestation rates of the peach fruit fly, Bactrocera zonata and the Mediterranean fruit fly, Ceratitis capitata on both summer and winter seasons of guava fruits at Fayoum governorate. The present investigation was conducted from 1 st week of August until end of March throughout the two successive seasons; 2014/2015 and 2015/2016. B. zonata was the most frequent and dominant species associated with guava at the experimental site during summer and winter seasons, while, C. capitata relatively appeared during the second season in summer (2015) and winter (2015/2016). The captured flies/trap/day (FTD) of B. zonata ranged between 0.59-5.57 and 0.16-7.81, in summer during the two seasons 2014 and 2015, respectively, while, C. capitata ranged between 0.17-8.97 flies/trap/day in summer during the second season (2015). Concerning in winter, FTD of B.zonata ranged between 0.03-0.86 and 0.01-3.10 flies/trap/day, for the two seasons 2014/2015 and 2015/2016, respectively, while, C. capitata ranged 0.26-4.94 flies/trap/day during the second season(2015).In summer, maximum temperature was the variable weather factor significantly effect on the population of B. zonata during the first season, while the other weather factors correlated insignificantly effects. On the other hand, C. capitata, correlated with weather factors insignificantly during the two successive seasons. In winter, both of maximum and minimum temperatures effect significantly and positively on the population of B. zonata, while, the relative humidity had insignificantly positive effect during 2014/2015 season. During the second season (2015/2016), minimum temperature only had high-significantly in positive effect. Respecting C. capitata, during the first season (2014/2015), both of maximum and minimum temperatures effected insignificantly positive on the population, while, the relative humidity effected insignificantly and negatively on C. capitata population. While, in the second season, maximum and minimum temperature significantly effect in positive, whereas the relative humidity had high significantly negative correlation.In two summer periods during seasons (2014 and 2015), the highest infestation percentage (22.14 and 27.64%, respectively) were recorded on first week of October, while, in the winter periods during the two seasons, fruits were free from fruit flies infestation. Forcing guava trees for fruiting during winter season during periods of relatively low fruit fly activity through some cultural practices like irrigation preventing and hand defoliation can be effectively employed to manage fruit fly infestations.

The Effectiveness of Calcium Citrate for Improving the Quality and Extending the Shelf-Life of Winter Guava Fruits during Ambient Storage

“…Under Egyptian conditions, guava tree flower in mid-April and the principal yield appears in markets in summer, However, this yield is low in price, quality and has a very short marketability as the fruits are exposed to high heat and direct solar radiation, which causes browning, rot and short shelf life (El-Baz et al, 2011 andAtawia et al, 2017). Therefore, farmers using some agriculture practices to obtained winter crop, by prevent partially of irrigation for four months, and in this case the crop is given in January and February (El-Shobaky 2007 &Amin andSaafan 2016). The importance of winter guava is due to the fact that most of the production is exported abroad, so there is need to some postharvest application for keeping overall quality and extension shelf life.…”