Market Garden Crops Research Articles

Suitability of Ten Plant Baits for the Rapid Detection of Pathogenic Pythium Species in Hydroponic Crops

Ten types of plant baits were tested in the laboratory to assess their capacity to detect pathogenic Pythium species. These were orange tree leaves, tomato leaves, pepper leaves, geranium leaves, Bermuda grass leaves, pine needles, immature carnation petals, hemp-seed cotyledons, pepper and cucumber fruits. The Pythium spp. tested were P. aphanidermatum, P. irregulare and Pythium ‘group F’ from hydroponic market garden crops in the Poniente region of Almeria (south-east Spain). The test consisted of observing the velocity at which five baits were colonized and the day of colonization of the first bait. Results indicated that the slowest baits to be infected were immature carnation petals and pine needles. These two, together with Bermuda grass leaves, were also the baits infected in lowest number, such that practically no further infection was produced in the baits after the fifth day of contact with the inoculated water. The other plant baits tested were equally suitable for detection of Pythium spp. over the first two days, although only orange leaves and hemp-seed cotyledons were infected on the first day.

Of cabbages and Kings County: agriculture and the formation of modern Brooklyn

No one today thinks of Brooklyn, New York, as an agricultural center. Yet Kings County enjoyed over two centuries of farming prosperity. Even as late as 1880 it was one of the nation's leading vegetable producers, second only to neighboring Queens County.In Of Cabbages and Kings County, Marc Linder and Lawrence Zacharias reconstruct the history of a lost agricultural community. Their study focuses on rural Kings County, the site of Brooklyn's tremendous expansion during the latter part of the nineteenth century. In particular, they question whether sprawl was a necessary condition of American industrialization: could the agricultural base that preceded and surrounded the city have survived the onrush of residential real estate speculation with a bit of foresight and public policies that the politically outnumbered farmers could not have secured on their own?The first part of the book reviews the county's Dutch American agricultural tradition, in particular its conversion after 1850 from extensive farming (e.g., wheat, corn) to intensive farming of market garden crops. The authors examine the growing competition between local farmers and their southern counterparts for a share of the huge New York City market, comparing farming conditions and factors such as labor and transportation.In the second part of the book, the authors turn their attention to the forces that eventually destroyed Kings County's farming ranging from the political and ideological pressures to modernize the city's rural surroundings to unplanned, market-driven attempts to facilitate transportation for more affluent city dwellers to recreational outlets on Coney Island and, once transportation was at hand, to replace farms with residential housing for the city's congested population.Drawing on a vast range of archival sources, the authors refocus the history of Brooklyn to uncover what was lost with the expansion of the city. For today, as urban planners, ecologists, and agricultural developers reevaluate urban sprawl and the need for greenbelts or agricultural-urban balance, the lost opportunities of the past loom larger.

Contribution to the study of the chemical composition of Verticillium albo-atrum secretions in liquid media.

Verticillium albo-atrum culture filtrates contain numerous metabolites such as enzymes and toxins. Their purification was carried out by high phase liquid chromatography (HPLC). In this study, we set out to look for other lighter metabolites that could be identified by gas chromatography coupled to mass spectrometry (GC-MS). The analyses revealed the presence of many volatile chemical compounds, some of which are of great economic interest such as methyl paraben, propyl paraben tethane and xylene. Verticillium albo-atrum, which is a pathogen of many market-garden and fodder crops, is able to produce substances that can be used in both the agro-food and cosmetic industries.

Irrigation of vegetable crops as a means of recycling wastewater: applied to Hesbaye frost

Since 1991, a food processing plant which freezes a large quantity of locally grown market garden products, has recycled all its wastewater by irrigating 550 hectares of crops located around the factory. Previously, the 700,000 m3 of wastewater was discharged into a nearby stream apparently devoid of aquatic life. By adopting this solution, the processing plant was able to avoid paying a heavy tax introduced in 1991 to penalize the discharge of industrial effluent. The alternative of building an independent wastewater treatment plant would have required investment costs two to three times higher and would not have achieved the same degree of water purification as the soil. Irrigation guarantees a continuous supply of a vital good quality ingredient, since the short life cycle market garden crops are very susceptible to hydric stress. A 110,000 m3 capacity storage tank acts as a buffer between continuous water consumption and seasonal requirements; in addition, by mixing the wastewaters, it stabilizes their physico-chemical characteristics which vary according to the vegetables treated. This processing plant offers the regional agricultural industry hit by European restrictions, a source of diversification; it is perfectly integrated in an environment it not only respects but relies on for the auto-purifying capacity of its biological medium.

Irrigation of vegetable crops as a means of recycling wastewater: Applied to hesbaye frost

Since 1991, a food processing plant which freezes a large quantity of locally grown market garden products, has recycled all its wastewater by irrigating 550 hectares of crops located around the factory. Previously, the 700,000 m3 of wastewater was discharged into a nearby stream apparently devoid of aquatic life. By adopting this solution, the processing plant was able to avoid paying a heavy tax introduced in 1991 to penalize the discharge of industrial effluent. The alternative of building an independent wastewater treatment plant would have required investment costs two to three times higher and would not have achieved the same degree of water purification as the soil. Irrigation guarantees a continuous supply of a vital good quality ingredient, since the short life cycle market garden crops are very susceptible to hydric stress. A 110,000 m3 capacity storage tank acts as a buffer between continuous water consumption and seasonal requirements; in addition, by mixing the wastewaters, it stabilizes their physico-chemical characteristics which vary according to the vegetables treated. This processing plant offers the regional agricultural industry hit by European restrictions, a source of diversification; it is perfectly integrated in an environment it not only respects but relies on for the auto-purifying capacity of its biological medium.

Agricultural problems of small states, with special reference to commonwealth Caribbean countries

For purposes of this paper, states are grouped by total population size, those with less than five million inhabitants being classified as small. Small states do not necessarily have smaller farms. However, external economies of scale in research, extension, training, procurement and distribution of inputs, and the transportation and marketing of output may be missed. Product specialisation and regional co-operation offer some scope for alleviating these problems. Foreign trade is important for the development of small economies; and for those well-endowed with natural resources, may be based on primary production. For those less well-endowed, increasing dependence on industry and other sectors is necessary, and agriculture must undergo adjustment. The plantation system, common in the Caribbean and other island economies, imposes a rigid structure and obstructs the change to family farming, food production and more intensive methods of cropping, appropriate to the development process. For those small countries with high man:land ratios, land reform is crucial. This highlights the need for sector planning and sector-based development finance. Island small states can often encourage tourism in place of manufacturing which is limited by market size constraints. Tourism increases the demand for food and agriculture must adjust to meet this demand and prevent over rapid emigration to the tourist sector. The location of small countries can influence agricultural development prospects, adversely in the case of remote islands and favourably when near to large industrialised countries with markets for high value market garden crops.

Halotydeus destructor . [Distribution map

Abstract A new distribution map is provided for Halotydeus destructor (Tucker) (Acarina, Penthaleidae) (Red-legged Earth Mite (Australia), Black Sand Mite (South Africa)) Hosts: Pasture plants (notably clover) cereal and other field and market-garden crops. Information is given on the geographical distribution in AFRICA, Southern Rhodesia, Union of South Africa, AUSTRALASIA, Australia, New Zealand.

Conserving Supplies of Potash Alkalis

WITH the object of ensuring that the reduced supplies of potash compounds shall be used to the best advantage the Ministry of Supply has made an Order under which purchases by consumers of caustic potash and carbonate of potash may be made only under licence. Licences will not be granted except in cases where substitution of potash by soda is impossible, but for the present, lots not exceeding half a ton a month are exempt from the Order. Compared with the vast quantities of potassium compounds used as fertilizers the amount used in the manufacture of medicinal salts is small; at a rough estimate it is probable that it does not exceed 5 per cent of the total consumption of potash; but it is desirable, nevertheless, that medical practitioners should prescribe sodium or ammonium compounds instead of potassium compounds whenever this substitution can be made without prejudice to patients. For example, sodium or ammonium bromide should be used instead of potassium bromide and sodium iodide in place of potassium iodide; and so the list might be extended. In the aggregate, the quantity of potash saved for potatoes and other market garden crops and sugar beet, for example, would not be inconsiderable.

Investigations on Trichogramma lutea, Gir., as a Parasite of the Cotton Bollworm, Heliothis obsoleta, Fabr.

Some of the problems involved in the estimation of parasitism in populations of Heliothis eggs are discussed:—(a) Effective parasitism of the “active fraction” of eggs as laid in situ is denned.(b) The habits of the egg-laying moth in point of the duration of oviposition on individual crops and diversion of moth activity from one host to another are discussed in relation to releases of Trichogramma lutea. Data are given on the distribution of bollworm eggs in a crop and associated factors.(c) Investigations on the dispersion of liberated parasites are described. Dispersion was found to be rapid and widespread; concerted activity by large numbers in given areas did not apply.Investigations in rain-grown crops are described and results are quoted from a typical experiment in maize, wherein the percentages of parasitism recorded in a large number of equal sections of the crop are regressed on proportionate larval survival. Although the egg parasitism ranged from 21·2 per cent, to 82·3 per cent., differences in larval populations were inappreciable. An explanation for this is offered in an analysis of the effect of various mortality factors.The parasite was relatively ineffective in cotton crops. The low degrees of parasitism found are assigned to the growth-habit of the plant, the scattered manner of egg deposition thereon and the impediment offered to the insect by the dense hair processes of the plant at many sites where eggs are commonly placed.Investigations on irrigated (cool season) market-garden crops and citrus orchards are described. These form the principal breeding sources of summer bollworm. Oviposition is extensive and sustained for three to four months on these crops, thereby affording opportunity for continuous parasite activity and the cumulative participation of progeny bred in the field. In nature Trichogramma lutea does not, however, appear until the latter end of the egg-laying by Heliothis and the authors were unable to establish laboratory-bred representatives at an earlier period.Another egg parasite, Phanurus ullyetti, is prevalent before Trichogramma appears and accomplishes much that was hoped for from the attempted earlier introduction of Trichogramma. In effect, the latter, as seen from diagrams furnished with the paper, becomes substituted for Phanurus toward the close of the winter season. It is probable that temperature is a determining factor in the biology of both parasites, although other causes for the observed relations are suggested.Further investigations are needed on the subject of exploiting T. lutea in the cool season.

Garden Allotments

UNTIL the beginning of this century, allotments were chiefly to be found in rural districts; but at the present time, largely owing to the stimulus given to the movement during the Great War, nearly four times the number are situated in urban, as compared with rural, areas. Advice on their management is frequently required, particularly by residents in towns and cities, and the publication by the Ministry of Agriculture of an illustrated bulletin (No. 90. “Allotments”. London: H.M. Stationery Office, Is.) should prove of immense practical value to all holding or contemplating holding an allotment. The scope of the bulletin is wide, and only an indication of its range can be given here. Questions of soils and their treatment, manures and manuring, with a special section on lime, are dealt with in some detail. Full directions follow for the cultivation of all the ordinary market garden crops, such as potatoes, the cabbage group, peas, beans and root vegetables and to a lesser extent fruit and flowers. Advice is also given on simple methods for purposes of protection and forcing. Only a small section is devoted to pests and diseases, as the reader is referred to the more detailed publications on the subject already issued by the Ministry. At the end of the bulletin a summary of work appropriate for each month of the year will be found, together with useful hints for those intending to exhibit their vegetables at shows. Further, the business side of allotment holding is not overlooked, and a part of the bulletin is devoted to questions of rules for allotment associations, tenancy agreements, choice, planning and layout of sites and the methods by which an individual can, where practicable, acquire an allotment.

Developments in Market Gardening

THE report of the recent conference on “Recent Developments in Market Gardening” held at Rotham-sted contains a great deal of information which is not readily available in a collected form. Two of the classical market garden areas, the Bedfordshire early potato and brussels sprouts district and the equally well-known spring cabbage, brussels sprouts and fruit area of Evesham are treated in detail from the point of view of the practical grower, and the subject is also considered from the point of view of the canner, whose part in the industry is becoming increasingly important. In recent years market gardeners have found their province invaded by large-scale farmers, who have in part substituted vegetable growing for the less profitable crops of their ordinary rotation. These men, whose methods form the subject of one of the papers, have several advantages not possessed by the smaller cultivators; plentiful animal manures, large-scale mechanical methods, and a possibility of converting unsaleable surplus into live stock products. The reply of the genuine market gardener has been to move towards greater intensification, and to retire into districts as yet inaccessible to large-scale methods. The conference as a whole leaves the impression that abundant production of market garden crops is relatively easy to secure. It can in fact be an embarrassment, and every additional outlet whether by preservation, more economical distribution, or the education of the public taste, needs careful investigation. Copies of the report, price 2s., can be obtained from the Secretary, Rothamsted Experimental Station, Harpenden, Herts.

(1) The Manuring of Market Garden Crops (2) The Chemistry of Cattle Feeding and Dairying (3) Garden Farming

(1) The Manuring of Market Garden Crops (2) The Chemistry of Cattle Feeding and Dairying (3) Garden Farming

The Manuring of Market-Garden Crops

The Manuring of Market-Garden Crops