Young, budded Valencia orange trees were grown for several years in outdoor sand cultures with three levels each of nitrogen, potassium, and magnesium in factorial combinations. Total growth and fruitfulness were greatly dependent on the nitrogen level but relatively independent of the two base elements over a very wide range of supply. These responses and those pertaining to fruit quality were...

Count data for the number of citrus rust mites per cm 2 on fruit across a 4-ha (10acre) area of orange trees followed the negative binomial probability distribution 79% of the time based on chi-square tests. A correlation of r = 0.993 was found between observed counts and counts projected based on the distribution. A common k of 0.149 was computed but generally appeared more suitable for mean d...

‘Aliza’ is a new pomelo × mandarin hybrid (Citrus maxima, cv. Red Chandler Citrus reticulata, Ora) developed by the Israeli citrus breeding program at Volcani Institute. Here, we aimed to characterize quality and flavor of fruit as compared other commercial fruit, specifically (C. maxima), grapefruit paradisi), orange sinensis) reticulata). fruits have similar size grapefruits, but thinner peel...

The role of alpha-naphthaleneacetic acid (NAA) in the control of abscission in Citrus (Citrus sinensis L. Osbeck) leaf explants and its conjugation were studied in non-aged and 24-hour-aged explants. Dipping non-aged explants in 1.5 micromolar NAA for 15 minutes immediately after excision did not delay abscission whereas 150 micromolar NAA effectively delayed it. As incubation time was prolonge...

Effects of cyclic lipopeptides (CLPs) obtained from Bacillus subtilis ABS-S14 on eliciting defense-related gene transcription and activity of defense-related enzymes; glucanase (GLU), chitinase (CHI), peroxidase (POX) and lipoxygenase (LOX) in Citrus sinensis cv. Valencia fruit were determined. The maximum level of GLU transcripts induced in fruit treated with fengycin was significantly greates...

BACKGROUND Huanglongbing (HLB) or citrus greening is a bacterial disease vectored by the Asian citrus psyllid (ACP) causing tree decline, and yield loss. Vector control and foliar nutrition are used in Florida to slow the spread of HLB and mitigate debilitating effects of the disease. A four year replicated field study was initiated February 2008 in a 5.2-ha commercial block of young 'Valencia'...

Sustained cyclic oscillations in stomatal conductance, leaf water potential, and sap flow were observed in young orange trees growing under natural conditions. The oscillations had an average period of approximately 70 min. Water uptake by the roots and loss by the leaves was characterized by large time lags which led to imbalances between water supply and demand in the leaves. The bulk of the ...

The bacterium Xylella fastidiosa is the causal agent of citrus variegated chlorosis (CVC) and has been associated with important losses in commercial orchards of all sweet orange [Citrus sinensis (L.)] cultivars. The development of this disease depends on the environmental conditions, including the endophytic microbial community associated with the host plant. Previous studies have shown that X...

Throughout the history of citrus production in Florida one of the diseases with a major impact has been the Asian form of citrus greening (HLB), which was first detected in 2005. As a response to this introduction, new survey and detection methods had to be developed utilizing field observations directed not only to corroborate symptoms already reported in the literature, but to describe any va...

A 2-yr study was conducted in a citrus orchard (Citrus sinensis L. Osbeck cultivar Valencia) todetermine the inßuenceofplantwater stresson thepopulationdynamicsofglassy-winged sharpshooter,Homalodisca vitripennis (Germar). Experimental treatments included irrigation at 100% of the crop evapotranspiration rate (ETc) and continuous deÞcit-irrigation regimens at 80 and 60% ETc. Microclimate and pl...