Tree crops

Also, EPRI is iavestigatiag whole-tree bum power plants that will dry and bum SRWC fuel without requiring tree trimming, wood chipping, or other fuel preparation. The concept iavolves the combustion of tree crops from farms distributed within a 40-km radius of a given plant. 

This author recommends a minimum plot size of 4 rows x 200 ft for each treated plot. Foliar sampling would occur on the middle two rows with a 10-ft buffer on each end. Soil sampling would occur on each side of the middle two rows with a 10-ft buffer on each end. The 180-ft rows should be divided into 60-ft replicates designated as A, B, and C. The untreated plot should be 2 rows x 50 ft. For tree crops, 3 rows x 14 trees should be treated. The middle row should be sampled excluding the first and last trees. 

For tree crops, the EPA recommends the Iwata approach. In this approach, 40 punches are collected for each sample at various heights and at 45° intervals around the circumference of each sampled tree. The sampling design and technique are described below. 

Faust, R.H. (2000) The use of Hair Sheep in Organic/Poly-Culture Tree Crop Weed Management. Proceedings of the 13th International IFOAM Scientific Conference, Basel, Switzerland, p. 425. 

Hydrogen cyanide is an important raw material used in the production of methyl methacrylate and is widely used for Lucite, Plexiglas molding, and extrusion powders as well as coating resins. It is used widely in the agricultural sector to fumigate orchards and tree crops. 

In the Far East, on the whole, the most troublesome hevea rubber diseases are root decays. It is commonly realized (4, 11, 35, 36, 40, 42, 43, 45) that, left unchecked, rubber root rots would have very soon destroyed commercial production of plantation rubber in the Orient. There is no tree crop that has had its many root rot diseases given such thorough study as has rubber. E. W. Brandes, R. D. Rands. Theodore J. Grant, E. P. Imle, and John B. Carpenter agreed that these troubles have been of practically no concern in tropical America. Langford (19) found little root rot trouble in his considerable observations specifically on rubber in the Western Hemisphere. 

In many crops where weed killers are used, applications must be made with care or the crop being weeded may suffer. This takes some attention. Coffee showed characteristic injuries (22, 51) from applications of the weed killers 2,4-D, TCA, and CMU [3-(p-chlorophenyl)-l,l-dimethylurea]. On the other hand, as in other tree crops, further work on coffee proved that, if properly handled, weed sprays did not result in important permanent harm to the trees. Some of the most recent work has shown (22) that amine salts and butoxyethanol esters of 2,4-D caused less... 

This problem of natural balance is, of course, less noticeable in annual crops of short season than in perennial tree crops, where the results of an unfortunate application may show up 9 months to a year later. Sometimes also this business of... 

The time-honored method of controlling insect-borne virus diseases is by breeding resistant varieties. This has been practical in annual crops, but is hopelessly slow in tree crops, where it may take 20 years or more to test a new variety. What is needed desperately is some sort of treatment which will control the virus, probably a systemic treatment, as the virus works within the plant cells. This is not a new idea and work has been done along this line by many workers. A sense of urgency is inevitable, however, when 500 to 600 acres of citrus can be wiped out completely in 3 to 5 years time, followed by an expensive replanting job and a wait of 5 to 6 years to get back into production. This is the outstanding problem at the present time and may need years to answer. 

Examples 3 and 4 illustrate a potential application of allelo-pathic chemicals in today s agricultural practices, as illustrated in Figure 3 to plant allelopathlc plants as a cover crop in the field, especially for tree crops such as peach and citrus. Such plants produce allelopathlc chemicals to control soil pests such as nematodes. This approach will be appreciated today, because there is no effective agent to control soil pests on a field scale and, as has been noted, there is no economic incentive for a chemical company to develop a minor-crop pesticide. 

Acid deposition or, acid rain, occurs when SO2 and oxides of nitrogen (NOx) react with water, oxygen, and oxidants to form acidic compounds. It is deposited in dry form (gas, particles) or wet form (rain, snow, fog), and can be carried by wind hundreds of miles across state and national borders. Acid rain harms lakes and streams, damages trees, crops, historic buildings, and monuments. 

Lignins are irregular phenylpropane polymers that represent approximately 20-30% by weight of the available polymeric content of hardwood tree stems (1-3). This material offers, therefore, a valuable resource that must be utilized as fully as possible if the full value of harvested tree crops is to be attained. 

Within North America and a few other countries, most triazine-resistant weed biotypes have been reported after repeated use of atrazine in com and sorghum. In some areas of Western Europe and other countries, triazine-resistant weeds have been reported after repeated use of simazine in orchards and along roadsides. A few triazine-resistant weeds (e.g., kochia, cheatgrass, and common groundsel) have biotypes with triazine resistance in nurseries and perennial tree crops, as well as along railways and roadsides. 

Triazine herbicides are particularly well suited for conservation tillage because they provide foliar and residual control of a broad spectrum of weeds. Atrazine, simazine, and metribuzin are used in com, atrazine and propazine in sorghum, metribuzin in soybean, and simazine reduces tillage required for weed control in many perennial and tree crops. Atrazine is also used extensively in chemical fallow cropping systems in rotations involving corn, sorghum, and wheat. Cyanazine was also used extensively in corn and cotton until 2002. 

Paraquat, a bipyridyl quaternary ammonium salt, was introduced by ICI in 1965 (Fig. 3). It is a non-selective, contact herbicide on plant foliage, but is immediately inactivated when applied to soil. It is used in minimum tillage programs and as a postemergence directed spray in sugarcane and in fruit tree crops. 

The control s iderat ion. two or three desired. Fo or three mon conditions, tree crops, may be desir characteris t and through must tailor the period o... 

Luckwill, L.C. Physiology of Tree Crops 237-253 Academic Press, London and New York (1970). 

Tree crop mainly based on the production of permanent crops, e.g. cocoa, coffee, oil palm or rubber. In the establishing phase, before shade impedes annual crop growth, food crops are interplanted and grown mainly for subsistence. 

Root crop the area in West Africa where this farming system is mainly practiced is sandwiched between the "tree crop" and "forest based" systems in the South and the "cereal-root crop mixed" system in the North. A similar strip exists south of Central Africa. 

Uses herbicide, pastures, sugarcane, forestry, tree crops... 

Jorgensen, J. R., and C. G. Wells. 1986. Tree nutrition and fast-growing plantations in developing countries. International Tree Crops Journal 3 225-244,... 

Sanchez, P. A., C. A. Palm, C. B. Davey, L. T. Szott, and E. C. Russell. 1985. Tree crops as soQ improvers in the humid tropics In Attributes of trees as crop plants, eds. M.G.R. Cannell, and J.E. Jackson (Institute of Terrestrial Ecology, Natural Environmental Research Council, Abbots Ripton, Huntingdon, England), pp. 327-350. 

Some commodity oils and fats such as palm, palm kernel, coconut, and olive are tree crops. Once the trees mature, they continue to produce fruit for many years and production levels cannot be greatly changed from season to season. 

Laurie Oils There are two major lauric oils—coconut oil and palm-kernel oil. Both are tropical oils, and both are tree crops. They differ from all other commodity oils in their higher level of medium chain acids, especially lauric, and slightly from one another as shown in Table 2(b). They find limited use in food products and are used extensively in the production of surface-active compounds. For more information, see Sections 5.3 and 5.10. 

Ecological concern exists about transmission of pollen from some types of plant, such as the Brassicas and tree crops, either into weedy relatives or into crops grown at some distance. This problem is not limited to transgenic plants. Canola, a rape-seed cultivar bred to produce low glucosinolates and low erucic acid, must be planted in isolation from industrial rapeseed, as each crop will result in seed with altered composition from the ideal that is, excessive erucic acid in the canola and less erucic acid in the industrial rapeseed. Because the products of industrial crops are not intended for consumption, and may even be noxious, risk management and containment, including the prevention of intercrop cross-pollination, is... 

The consequences may be serious because the fertile topsoil supports the tree crops, which are the major local food resource. The replacement of the soil with topsoil from elsewhere would be an enormous undertaking which is likely to be prohibitively expensive. The content of natural radionuclides in any continental soil used as replacement soil would most probably exceed that of the present soil. 

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