Iron deficiency chlorosis is a worldwide problem that mainly affects fruit crops such as citrus, deciduous fruit trees, and grapevine [ Vitis vinifera ( Mengel et al., 2001 )] that are grown in calcareous soils ( Marschner, 1995 ; Mengel et al
cultivar has a number of characteristics, which present challenges for the commercial grower ( Rosenberger et al., 2001 , 2004 ). One of the challenges to growing ‘Honeycrisp’ is the development of zonal chlorosis that resembles potato leafhopper damage
Franksred red maple (Acer rubrum `Franksred') trees were sampled from nursery fields in 2003 and 2004 to determine the cause of a common foliar chlorosis. Plots in 21 and 39 different nurseries were identified in 2003 and 2004, respectively. A single plot from each nursery was sampled in June of each year, whereas two to four plots per nursery were sampled in September. Each plot consisted of 20 consecutive trees in a single row. From each plot, a foliar tissue sample was analyzed for the complete range of essential nutrients. Plant height, stem diameter, leaf chlorophyll content, and a subjective plant quality rating were also recorded. From each plot, a soil sample was collected and analyzed for pH, EC, organic matter, and a range of essential nutrients. The foliar chlorosis was determined to be incited by manganese (Mn) deficiency. Tissue Mn was highly correlated with soil pH. Chlorotic plants were smaller with less stem diameter than nonchlorotic plants. Sufficiency ranges for tissue and soil tests were determined and are provided for red maple nursery production.
equally to this work. This work was supported in part by New York Apple Research and Development Program and Hatch funds. The authors thank Dr. Jim Schupp for helpful discussions on zonal chlorosis of `Honeycrisp' leaves, Drs. Anil Ranwala and Bill Miller
extension publication that guided her production strategy ( Smith, 2001 ). On 23 Jan., Maria noticed subtle chlorosis appearing on about a third of her dicentra crop. It tended to be interveinal and did not quite reach the leaf margins. In general, it was
Lilies and gladioli are among the most important cut flowers grown throughout the world. However, leaf chlorosis is a major postharvest disorder that can limit their vase life. The chlorosis starts on lower leaves and proceeds upward, reducing stem
Chlorophyll extraction (TCHL) and spectrophotometric (CM45) techniques were compared with a visual (VISINDX) method of indexing chlorosis on spinach (Spinacea oferacea L.) leaves that show various degrees of white rust (Albugo occidentalis G.W. Wils.) infection. The CM45 method gave a good fit (R2 = 0.91) when its readings were regressed against MSINDX ratings. Both regression and cluster analyses indicated that the CM45 method was more efficient than the TCHL method in separating leaves into unique chlorosis severity classes.
significant effects of ABA (Tukey–Kramer test, P < 0.05). DAM = days after maturity. Leaf chlorophyll index in the control decreased gradually during the experiment ( Fig. 3 ). In ‘Florida 91’, leaf chlorosis, as indicated by reductions in chlorophyll index
, develop chlorosis on sites with high pH soils, and “brown out” in periods of extended or severe drought ( Arnold, 2002 ). Arnold (2002) defines ecotypic variation as “a distinct morphological or physiological form, or population, resulting from
Leaf yellowing of excised Easter lily leaves was significantly delayed by application of gibberellic acids ≥250 mg·liter-1 or benzyladenine ≥50 mg·liter-1. Rapid development of foliar chlorosis following cold storage was delayed significantly by applying 500 mg·liter-1 of GA3 or BA before storage. Poststorage treatments were less effective. Development of chlorosis was associated with rapid loss of fresh weight and was not related to the aperture of the stomates (diffusive resistance). Respiration rates of leaves treated with growth regulators were significantly lower than those of the controls.'