At maturity, the fruit of two early maturing orange cultivars, Hamlin and Pineapple (Citrus sinensis [L.] Osbeck), contained more ethylene and abscisic acid than the late maturing Valencia and Lamb Summer (C. sinensis [L.] Osbeck) cultivars. Ethylene (up to 95 nl/l in internal atmosphere) and abscisic (50 mug/kg dry weight flavedo) increased most rapidly in Pineapple, leading to increased cellu...

in recent years, anthracnose disease of citrus has caused and contiunes to cause heavy losses to some citrus commercial tree varieties in mazandaran province. this disease is deeply spread out in the citrus orchards of the province. in order to isolate and identify the causal agent or agents of the disease, random sampling was done from infected trees during 2004-2005. in lab, samples were cult...

Since citrus flowering is a key process in citriculture and its evaluation is often difficult due to the canopy structure and field sampling, the aim of this research was to give some directions regarding the evaluation of flowering in field-grown sweet orange plants. This study was conducted in a citrus orchard of sweet orange plants cv. ‘Valencia’ [Citrus sinensis (L.) Osbeck] grafted on ‘Cle...

Most of the plant regeneration processes in citrus, through tissue culture, involve indirect somatic embryogenesis. The optimization of these processes is important for the development of in vitro plant improvement and micropropagation studies. Studies to evaluate the effect of different carbohydrates in somatic embryogenesis were conducted using calli from ‘Ponkan’ mandarin (Citrus reticulata,...

Cellulase activity increased in separation-zone tissues 1 day after "Valencia" orange (Citrus sinensis [L.] Osbeck) was treated with 20 micrograms per milliliter cycloheximide. Exocellulase was detected only in the separation zones of treated fruit, whereas endocellulase was present in zones from both treated and control fruit. Endocellulase activity in separation-zone tissue of treated fruit w...

Shade and sun leaves of Valencia orange [Citrus sinensis (L.) Osbeck] were collected to evaluate comparative effects of their leaf chlorophyll concentration, water content, thickness, and mesophyll volume of air on visible light reflectance, specifically the 0.45-, 0.55-, and 0.65-#m wavelength (WLs). The reflectance at the 0.45-, 0.55-, and 0.65-/~m WLs of sun leaves but not shade leaves was n...

The relationship between carotenoid accumulation and the expression of carotenoid biosynthetic genes during fruit maturation was investigated in three citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Valencia orange (Citrus sinensis Osbeck), and Lisbon lemon (Citrus limon Burm.f.). We cloned the cDNAs for phytoene synthase (CitPSY), phytoene desaturase (CitPDS), zeta-carotene (car) des...

Florida citrus production has declined by more than 70% because of Huanglongbing (HLB), and a major cause tree decline is nutrient uptake limitations caused HLB. This study was conducted on 6–9-year-old “Valencia” sweet orange [Citrus sinensis (L.) Osbeck] Swingle rootstock in the central southwest to evaluate effects macronutrient fertilization foliar application Mn Fe growth yield HLB-affecte...

A trial was conducted in a 7-year old citrus orchard of the National Horticultural Research Institute, Nigeria, to investigate the effect of different levels of organo-mineral fertilizers as it affect the economic returns of sweet orange (Citrus sinensis L. Osbeck var. Agege 1). The treatments consisted of: (1). 10 tha Poultry 1 manure (PM), (2). 15 t ha PM, (3) 20 t ha-1 PM, (4). 0.45 t ha NPK...