Course Managers and greenkeepers are well aware of the deleterious aspects of excess thatch: Increased disease and insect problems, localised dry spots, chlorosis of the turf, proneness to scalping, foot printing, decreased heat, cold and drought hardiness, restricted rooting, nitrogen immobilization, reduced effectiveness of pesticides, a soft, spongy surface in wet weather, and the potential ...

Hawaiian plants exposed to volcanic sulfur dioxide showed interspecific differences in leaf injury that are related to sulfur dioxide-induced changes in stomatal condutance. Species with leaves that did not close stomata developed either chlorosis or necrosis, whereas leaves of Metrosideros collina closed stomata and showed no visual symptoms of sulfur dioxide stress.

In order to study the mechanisms behind the infection process of the necrotrophic fungus Botrytis cinerea, the subcellular distribution of hydrogen peroxide (H₂O₂) was monitored over a time frame of 96 h post inoculation (hpi) in Arabidopsis thaliana Col-0 leaves at the inoculation site (IS) and the area around the IS which was defined as area adjacent to the inoculation site (AIS). H₂O₂ accumu...

Normal leaves of gardenia are glossy and dark green in color. Immature leaves may be a lighter green, but they are glossy and quite green even as they open from the bud. During the winters of 1934-35 and 1935-36 a chlorotic condition of the leaves of gardenia growing under glass caused serious concern to Massachusetts growers. The malady in its early stages is characterized by a gradual decreas...

The impact of the leaf-chlorosis-eliciting Russian wheat aphid, Diuraphis noxia (Mordvilko), and the nonchlorosis-eliciting bird cherry-oat aphid, Rhopalosiphum padi (L.), feeding on D. noxia-susceptible and -resistant cereals was examined during the period (i.e., 3, 6, and 9 d after aphid infestation) that leaf chlorosis developed. After aphid number, leaf rolling and chlorosis ratings, and fr...

Xylary fluid pH and reduction potentials were measured on silver maple (Acer saccharinum L.) grown under Fe and pH stress. Although pH and reduction potential (millivolt/59.2) varied significantly in the nutrient solution, xylary pH and reduction potential remained constant. It was concluded that changes in the pH and reduction potential in the xylary fluid of silver maple are not responsible f...

BACKGROUND AND AIMS This work evaluates the regulation of iron uptake responses in Citrus leaves and their involvement in the Fe paradox effect. METHODS Experiments were performed in field-grown 'Navelina' trees grafted onto two Cleopatra mandarin × Poncirus trifoliata (L.) Raf. hybrids with different Fe-chlorosis symptoms: 030146 (non-chlorotic) and 030122 (chlorotic). RESULTS Chlorotic le...

To study the effect of Zn and B as foliar spray on growth and yield of sweet orange, cv. Blood red at Dargai, Malakand Agency, Pakistan during 2006 and 2007. The micronutrients zinc (Zn) in the form of zinc sulphate (ZnSo4.7H2O) as zinc source at the rate of 0.5 % and 1.0 % and boron (B) in the form of boric acid (H3BO3) at the rate of 0.02 % and 0.04 % were applied as foliar spray at three dif...

Among chlorosis-inducing herbicides that interfere with carotenoid synthesis two groups o f different potency can be discriminated (group 1; aminotriazole amd haloxidine; group 2 with more extensive photodestructions: pyridazinone herbicides and difunon). After application of herbicides o f group 2 colored carotenoids were completely absent and preexisting chlorophyll was degraded by photochemi...