Leaf spot disease of rough lemon and brown spot disease of tangerines caused by distinct pathotypes of Alternaria alternata, and postharvest fruit black rot disease caused by A. citri, are the three major fungal diseases of citrus. The pathogenicity and specificity for the pathogens of Alternaria leaf spot and brown spot diseases are associated with the production of different host-specific tox...

Citruses are the worlds’ second fruit crops by volume next to banana. It is one of the most important commodity in tropical Africa as source of foreign currency, raw material for agro-industries and source of employment. The production and productivity of citrus in tropical Africa including Ethiopia are critically threatened by a number of diseases. Among others, pseudocercospora leaf and fruit...

22 23 2 SUMMARY 23 Citrus exocortis viroid (CEVd) populations are composed by closely related 24 haplotypes whose frequencies in the population result from the equilibrium 25 between mutation, selection and genetic drift. The genetic diversity of CEVd 26 populations infecting different citrus hosts was studied by comparing 27 populations recovered from infected trifoliate orange and sour orange...

Volatiles from crushed and intact guava leaves (Psidium guajava L.) were collected using static headspace SPME and determined using GC-PFPD, pulsed flame photometric detection, and GC-MS. Leaf volatiles from four common citrus culitvars were examined similarly to determine the potential component(s) responsible for guava's protective effect against the Asian citrus psyllid (Diaphorina citri Kuw...

Studies on some bacterial diseases of fruit plants from Aurangabad district was carried out during 2003-2009. They are: Leaf necrosis of Custard apple caused by Xanthomonas annonae; Citrus canker caused by Xanthomonas campestris pv. citri; Bacterial canker of Mango caused by Xanthomonas campestris pv. mangiferaeindicae; Leaf necrosis of Guava caused by Xanthomonas psidae; and leaf spot of Badam...

In recent years, Huanglongbing (HLB) also known as citrus greening has greatly affected citrus orchards in Florida. This disease has caused significant economic and production losses costing about $750/acre for HLB management. Early and accurate detection of HLB is a critical management step to control the spread of this disease. This work focuses on the application of mid-infrared spectroscopy...

The genus Phyllosticta occurs worldwide, and contains numerous plant pathogenic, endophytic and saprobic species. Phyllosticta citricarpa is the causal agent of Citrus Black Spot disease (CBS), affecting fruits and leaves of several citrus hosts (Rutaceae), and can also be isolated from asymptomatic citrus tissues. Citrus Black Spot occurs in citrus-growing regions with warm summer rainfall cli...

It is well known that citrus plants that have been infected by Xylella fastidiosa display nutritional deficiencies, probably caused by production of extracellular polymers by the bacteria that block normal nutrient flow through the xylem. The aim of this work was to study the mineral composition of specific foliar areas in different stages of infection in citrus. Thus, the concentrations of mac...

The long juvenile period of citrus trees (often more than 6 years) has hindered genetic improvement by traditional breeding methods and genetic studies. In this work, we have developed a biotechnology tool to promote transition from the vegetative to the reproductive phase in juvenile citrus plants by expression of the Arabidopsis thaliana or citrus FLOWERING LOCUS T (FT) genes using a Citrus l...