California Agriculture, February 1976

Volume 30, Number 2

research articles

Outdoor education for California's migrant children
by Edward J. Johnson , Augustine Perez
pp4-6, doi#10.3733/ca.v030n02p4
Abstract
UC Cooperative Extension has been working for four years with regional offices of the Bureau of Migrant Education and the California Mini-Corps to develop outdoor education programs for the children of migrant farm workers. Inquiry techniques and learn-by-doing activities were used to teach oral language with science as the vehicle.
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Influencing growth of dwarf eugenia
by T. Mock , T. Furuta , A. Leiser
pp7, doi#10.3733/ca.v030n02p7
Abstract
Experiments showed that growth of the dwarf Eugenia plants was influenced by the soil mixture and that the use of GA3 was actually detrimental, considering the type of growth obtained. Whenever these plants are propagated and cultivated, a highly organic soil mixture should be used.
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Drip and furrow irrigation of fresh market tomatoes on a slowly permeable soil: Part 1. production
by V. H. Schweers , D. W. Grimes
pp8-10, doi#10.3733/ca.v030n02p8
Abstract
Growers of fresh market tomatoes frequently attribute an increase in small fruit during the growing season to poor water relations. In studies on a Vista sandy loam soil, greater numbers of small fruit were produced by drought-stressed plants. A high frequency of furrow irrigation caused the soil surface to "seal" greatly restricting water penetration and lowering the production of large tomatoes. Production was best when water was added through a drip hose placed at the base of plants in the row or by less frequent furrow irrigation.
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Drip and furrow irrigation of fresh market tomatoes on a slowly permeable soil: Tomatoes: Part 2. water relations
by D. W. Grimes , V. H. Schweers , P. L. Wiley
pp11-13, doi#10.3733/ca.v030n02p11
Abstract
Frequent furrow irrigation of fresh market tomatoes, on a sandy loam soil, caused the soil surface to seal, greatly restricting water penetration into the plant root zone. Water penetration in furrows was adequate throughout the season if the frequency of irrigation was lowered. A drip irrigation system maintains not only a desirable soil moisture distribution, but also the cultural advantage of a dry surface area for foot traffic of harvesters that improves their efficiency and reduces soil compaction.
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Control of biting and annoying gnats with fertilizer
by E.F. Legner , R.D. Sjogren , G.S. Olton , L. Moore
pp14-17, doi#10.3733/ca.v030n02p14
Abstract
Naturally breeding field populations of Hippelates eye gnats and Leptoconops biting gnats were reduced with granular and spray applications of urea to the soil. Control ranged from 10 to 96 percent depending on the dosage and application method (disced or surface-applied). Possible modes of action are mechanical abrasion of gnat larvae, and the favoring of fungal infections. The use of urea as a substance harmless to natural enemies may be beneficial in the integrated control of pestiferous soil arthropods.
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Preventive medication for feedlot replacement calves
by D.G. Addis , G.P. Lofgreen , J.G. Clark , J.R. Dunbar , C. Adams , F. D. Cress
pp18-20, doi#10.3733/ca.v030n02p18
Abstract
In three preventive medication experiments at the UC Imperial Valley Field Station, oxytetracycline was administered orally and intramuscularly to calves with varying success in reducing cost per pound of gain. The presence of OTC in feed rations and water can reduce feed intake; intramuscular injections are costly but do not affect weight gain negatively.
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Sugarbeet powdery mildew in imperial valley
by A.O. Paulus , D.G. Kontaxis , J.A. Nelson
pp21, doi#10.3733/ca.v030n02p21
Abstract
Not available – first paragraph follows: Powdery mildew of sugarbeet, caused by Erysiphe polygoni DC., was first reported in California in 1934 but did not become prevalent statewide until the 1974 season. Observations in Imperial County show wide differences in intensity of powdery mildew in various fields. In some sugarbeet fields many plants were completely covered with mildew while others had medium to light infestation of leaves. A question was raised as to whether it was necessary o treat every field in the valley for control of powdery mildew. To help answer this question a sulfur-dust airplane trial was initiated in the 1974-75 growing season.
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Rind necrosis in watermelon cultivars
by Demetrios G. Kontaxis
pp22, doi#10.3733/ca.v030n02p22
Abstract
Rind necrosis is a perennial disorder of watermelon fruit in the Imperial Valley, California, which, on the average, causes about $100,000 loss each year. The disorder has also been reported in Hawaii, Texas and Florida. Bacteria have often been implicated as causal agents for rind necrosis. In this study, all cultivars were susceptible to rind necrosis.
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editorial, news, letters & science briefs

EDITORIAL: Accentuating the positive
by J. B. Kendrick
pp2, doi#10.3733/ca.v030n02p2
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Researchers crack blue egg claims
Editors
pp3, doi#10.3733/ca.v030n02p3a
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Removing competition boosts tree growth
Editors
pp3, doi#10.3733/ca.v030n02p3b
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Fungi improve yields
Editors
pp3, doi#10.3733/ca.v030n02p3c
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Breakthrough in study of living cells
Editors
pp3, doi#10.3733/ca.v030n02p3d
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