Penetration, leaf

Figure 2. Advanced stage of barley leaf penetration by C. sativus. The pathogen has penetrated the anticlinal cell wall junction between two host epidermal cells (e). The fungal appressorium (a) is visible above the cell comer. The host cell comer matrix has been displaced by an enlarged hyphal element (h) situated between the thin cell walls of the host epidermal cells. The host epidermal cell walls have been densely labeled with the cellulase-gold probe. An intercellullar hyphal element (ih) is present within the penetrated host cell. Bar = 1 pM.

Applications. Some of the very low molecular weight sulphonates (such as sodium diiso-propylnaphthalene sulphonates) are used as dispersants/coupling agents in agrochemical formulations and they are also used to improve wetting and leaf penetration. 

With a pKa of about 3.8 (vinylogous acid), the dione area is well suited for propesticide formation with the aim to increase leaf penetration. Various analogs were synthesized, sulfonates and pivaloates in particular were found to be ideal regarding increased herbicidal activity. The combination of all key elements ultimately led to the discovery of pinoxaden [7]. 

Oils, such as crop oil and crop oil concentrates, or solvents such as Al-alkyl pyrrolidones, can have a significant impact on pesticide nptake. The oils can aid in solubilizing the leaf cuticle as an aid to penetration, and also aid the solnbilization of the AI and distribution into plant leaf waxes. The polar alkyl pyrrolidone-based solvents often act as solvents for the pesticide, thus aiding leaf penetration as do the paraffinic and vegetable oils and the methylated seed oils. Mixtures of these solvents with surfactants and vinylpyrroUdone copolymers can act as wetters, stickers, and penetration-enhancers, increasing the rate of penetration of the pesticide as well as limiting wash off of the pesticide by dew or rain [38]. 

Figure 1. Leaf penetration and transfer of phloem-mobile xenobiotics.

As explained just before, the studied compounds had to be analyzed on three grounds leaf penetration, stability inside living plant material, selective efficiency on cuticle biosynthesis. 

The leaf penetration of the fatty acid analogues studied here has been measured with the use of labelled compounds. Under our conditions, 29% 1% to 31% 1% of the deposited amounts were shown to have penetrated into Vida faba leaves 60 hours after droplet deposition. 

Figure 8. Leaf penetration and metabolisation rate of the Cl2-tr and Cfg-tr inhibitors (labelled on the first carbon).

Precoat Procedure Precoat filtration tests are run in exactly the same manner as bottom-feed tests except that the leaf must first be precoated with a bed of diatomaceous earth, perhte, or other shave-able inert sohds. Some trial and error is involved in selecting a grade of precoat material which will retain the filtered solids to be removed on the surface of the bed without any significant penetration. During this selection process, relatively thin precoat beds of I to 2 cm are satisfactory. After a grade has been selected, bench-scale tests should be... 

Typical pore size distributions result in mean pore diameters of around 15 //m. Even long and intensive efforts did not succeed in decreasing this value decisively in order to enable production of micropo-rous pocketing material resistant to penetration [65, 66], In practice PVC separators prove themselves in starter batteries in climatically warmer areas, where the battery life is however noticeably reduced because of increased corrosion rates at elevated temperature and vibration due to the road condition. The failure modes are similar for all leaf separator versions shedding of positive active mass fills the mud room at the bottom of the container and leads to bottom shorts there, unless — which is the normal case — the grids of the positive electrodes are totally corroded beforehand. 

Figure 1. Transverse section of barley leaf epidermal cells taken perpendicular to the long axis of the cells and anticlinal to the leaf surface. The section has been labeled by the EMSIL technique (see Methods) utilizing purified C. sativus endopolygalacturonase and monoclonal antibody EPG-4, which is specific for this enzyme, in order to localize the substrate of the enzyme at the typical site penetrated by the fungal pathogen. Bar = 1 pm. Inset Comparable cell wall region as in Fig. 1 but labeled with monoclonal antibody JIM 5 to localize non-esterified pectin. Bar = 1 pm. Note the identical labeling patterns obtained with either method.

A low-fertility soil improver such as leaf mold can be incorporated as the bed is dug initially. This deep cultivation is useful where the soil is compacted. It results in a deep, fertile zone with an open, free-draining structure into which roots can easily penetrate. Medium- to high-fertility materials, if required, should only be mixed into the top 6-8 in (15-20 cm). Increases in yield are noticeable and plants cope better in drought. Make the edging at least 6 in (15 cm) high as the soil level will rise considerably. 

Soil. Residual activity in soil is limited to approximately 3-4 months (Hartley and Kidd, 1987). Plant. The penetration, translocation, and metabolism of radiolabeled MCPA in a cornland weed Galium aparine) was studied by Leafe (1962). Carbon dioxide was identified as a metabolite but this could only account for 7% of the applied MCPA. Though no additional compounds were identified, it was postulated that MCPA was detoxified in the weed via loss of both carbon atoms of the side chain. 

M. E. Barker, USP 2558726 (1951) CA 45, 9864 (1951) describes an incendiary device consisting of a mass of NC in the form of a disc, or leaf, with a hollow center filled with white P and sealed with a material such as gelled Na silicate. The disc is stored under water, or in atmosphere of saturated steam. When exposed to air the coating of silicate loses its water of gellation thus making it porous. Air then penetrates through the pores and causes... 

Fox 9) attempted to determine whether oils penetrated the eggs of the leaf roller Archips argyrospila. Eggs were immersed in petroleum oils saturated with Sudan III... 

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