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California Agriculture, Vol. 23, No.8

Cover:  Test plots for chemical “mowing” of turfgrass with fluorine compounds ut U.C. Davis.
August 1969
Volume 23, Number 8

Research articles

Influence of weather on the harvesting of high elevation christmas trees
by Arthur Scarlett, Dewayne Gilbert, Charles Wagener, Ed Gilden
| Full text HTML  | PDF  
Summary Not Available – First paragraph follows: OVER FOUR MILLION FAMILIES in California enjoy fresh evergreen trees in their homes every Christmas. Few people realize what efforts have gone into producing a tree that will maintain a vigorous, healthy appearance over the long Christmas holidays. Thousands of acres of trees are thinned, pruned, sheared and fertilized before harvest. Approximately a million of these trees are thinned annually from the high elevation forests of California. Large timber companies and other forest landowners have given long-term management and harvesting leases to Christmas tree operators to insure an annual income from their forest lands. Many forest landowners also manage and harvest trees from their lands on a sustained yield basis. The success of the Christmas tree industry and its $20 million payroll depends on the high quality of properly harvested trees. The date a Christmas tree operator selects to start harvesting, plays an important role in determining freshness.
Abstract Not Available – First paragraph follows: OVER FOUR MILLION FAMILIES in California enjoy fresh evergreen trees in their homes every Christmas. Few people realize what efforts have gone into producing a tree that will maintain a vigorous, healthy appearance over the long Christmas holidays. Thousands of acres of trees are thinned, pruned, sheared and fertilized before harvest. Approximately a million of these trees are thinned annually from the high elevation forests of California. Large timber companies and other forest landowners have given long-term management and harvesting leases to Christmas tree operators to insure an annual income from their forest lands. Many forest landowners also manage and harvest trees from their lands on a sustained yield basis. The success of the Christmas tree industry and its $20 million payroll depends on the high quality of properly harvested trees. The date a Christmas tree operator selects to start harvesting, plays an important role in determining freshness.
Resistance to sun blotch virus in seed source trees of Duke avocado
by R. M. Burns, R. J. Drake, J. M. Wallace, G. A. Zentmyer
| Full text HTML  | PDF  
Summary Not Available – First paragraph follows: Of 12 Duke avocado trees tested, 10 were found to be free of sun blotch virus infection. However, two trees without sun blotch symptoms were infected and apparently both are symptomless carriers. These transmit the virus through seeds to their seedling progeny and can cause infection of the scion tops that are worked on them when used as rootstocks. These studies demonstrate that it is necessary to test all Duke seed-source trees before using them as rootstock parents.
Of 12 Duke avocado trees tested, 10 were found to be free of sun blotch virus infection. However, two trees without sun blotch symptoms were infected and apparently both are symptomless carriers. These transmit the virus through seeds to their seedling progeny and can cause infection of the scion tops that are worked on them when used as rootstocks. These studies demonstrate that it is necessary to test all Duke seed-source trees before using them as rootstock parents.
Testing fluorine compounds for chemical mowing of turfgrass
by John H. Madison, James M. Johnson, William B. Davis, Roy M. Sachs
| Full text HTML  | PDF  
Summary Not Available – First paragraph follows: On the basis of present evidence, morphactins, used at low rates, appear to have some regulatory effects on turfgrass growth—stimulating seed yield and flowering, and affecting tillering and degree of culm elongation. However, reductions in leaf growth from morphactins, do not indicate specific growth regulation but appear to be caused by phytotoxicity. Such poisoning generally leads to lowered vigor and reduced ability to recover from wear, insect, and disease attacks, and may increase susceptibility to disease and insects; therefore, the continuing recommendation is for replacement of hybrid bermudagrasses when used for purposes to which they are not suited. When a brown color is not objectionable, a considerable reduction of thatch and clippings can be obtained by withholding irrigation and fertilizer.
On the basis of present evidence, morphactins, used at low rates, appear to have some regulatory effects on turfgrass growth—stimulating seed yield and flowering, and affecting tillering and degree of culm elongation. However, reductions in leaf growth from morphactins, do not indicate specific growth regulation but appear to be caused by phytotoxicity. Such poisoning generally leads to lowered vigor and reduced ability to recover from wear, insect, and disease attacks, and may increase susceptibility to disease and insects; therefore, the continuing recommendation is for replacement of hybrid bermudagrasses when used for purposes to which they are not suited. When a brown color is not objectionable, a considerable reduction of thatch and clippings can be obtained by withholding irrigation and fertilizer.
Preplant soil fumigation increases head weights in California lettuce
by J. D. Radewald, P. G. Mowbray, A. O. Paulus, Fujio Shibuya, J. M. Rible
| Full text HTML  | PDF  
Summary Not Available – First paragraph follows: Preplant bed fumigation of lettuce soils significantly increased lettuce head weights in three Palo Verde field trials with DD and Telone. Treatments also produced trends toward more uniform and earlier crop maturity (although differences were not statistically significant). The reasons for the beneficial responses are not completely understood, but the responses were at least partly accounted for by the control of two nematodes, Tylenchorhynchus clarus and Meloidognye hapla.
Preplant bed fumigation of lettuce soils significantly increased lettuce head weights in three Palo Verde field trials with DD and Telone. Treatments also produced trends toward more uniform and earlier crop maturity (although differences were not statistically significant). The reasons for the beneficial responses are not completely understood, but the responses were at least partly accounted for by the control of two nematodes, Tylenchorhynchus clarus and Meloidognye hapla.
Mechanical aids to sweet potato harvest
by M. Zahara, R. W. Scheuerman
| Full text HTML  | PDF  
Summary Not Available – First paragraph follows: APPROXIMATELY 9,000 acres of sweet potatoes are grown annually in California, with Merced County accounting for more than 60 per cent of this total acreage. Fresno, Stanislaus, San Joaquin, and Kern counties grow the remaining 40 per cent of the acreage. The average yield of marketable roots is low—from 4.5 to 5.0 tons per acre. In the past, the farm family grew the crop with members of the family providing the necessary labor to produce and harvest. Individual growers are now increasing their sweet potato acreage, thereby replacing a number of the farm family units. The development of mechanical harvest aids has contributed to the change to larger acreages. This tractor-drawn mechanical harvester digs and conveys the roots past four or five people on the trailer unit who snap the roots from the stems and place them in boxes. The stems, cull roots, and trash drop back onto the ground at the rear of the harvest-aid machines. Space is provided on this aid for several pallets, on which empty and full boxes can be stacked.
Abstract Not Available – First paragraph follows: APPROXIMATELY 9,000 acres of sweet potatoes are grown annually in California, with Merced County accounting for more than 60 per cent of this total acreage. Fresno, Stanislaus, San Joaquin, and Kern counties grow the remaining 40 per cent of the acreage. The average yield of marketable roots is low—from 4.5 to 5.0 tons per acre. In the past, the farm family grew the crop with members of the family providing the necessary labor to produce and harvest. Individual growers are now increasing their sweet potato acreage, thereby replacing a number of the farm family units. The development of mechanical harvest aids has contributed to the change to larger acreages. This tractor-drawn mechanical harvester digs and conveys the roots past four or five people on the trailer unit who snap the roots from the stems and place them in boxes. The stems, cull roots, and trash drop back onto the ground at the rear of the harvest-aid machines. Space is provided on this aid for several pallets, on which empty and full boxes can be stacked.

Editorial, News, Letters and Science Briefs

Agricultural field stations —laboratories of the university
by James L. Myler
Full text HTML  | PDF  

General Information

Extension laboratory, U.C., Davis
by Editors
Full text HTML  | PDF  
Webmaster Email: wsuckow@ucanr.edu

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California Agriculture, Vol. 23, No.8

Cover:  Test plots for chemical “mowing” of turfgrass with fluorine compounds ut U.C. Davis.
August 1969
Volume 23, Number 8

Research articles

Influence of weather on the harvesting of high elevation christmas trees
by Arthur Scarlett, Dewayne Gilbert, Charles Wagener, Ed Gilden
| Full text HTML  | PDF  
Summary Not Available – First paragraph follows: OVER FOUR MILLION FAMILIES in California enjoy fresh evergreen trees in their homes every Christmas. Few people realize what efforts have gone into producing a tree that will maintain a vigorous, healthy appearance over the long Christmas holidays. Thousands of acres of trees are thinned, pruned, sheared and fertilized before harvest. Approximately a million of these trees are thinned annually from the high elevation forests of California. Large timber companies and other forest landowners have given long-term management and harvesting leases to Christmas tree operators to insure an annual income from their forest lands. Many forest landowners also manage and harvest trees from their lands on a sustained yield basis. The success of the Christmas tree industry and its $20 million payroll depends on the high quality of properly harvested trees. The date a Christmas tree operator selects to start harvesting, plays an important role in determining freshness.
Abstract Not Available – First paragraph follows: OVER FOUR MILLION FAMILIES in California enjoy fresh evergreen trees in their homes every Christmas. Few people realize what efforts have gone into producing a tree that will maintain a vigorous, healthy appearance over the long Christmas holidays. Thousands of acres of trees are thinned, pruned, sheared and fertilized before harvest. Approximately a million of these trees are thinned annually from the high elevation forests of California. Large timber companies and other forest landowners have given long-term management and harvesting leases to Christmas tree operators to insure an annual income from their forest lands. Many forest landowners also manage and harvest trees from their lands on a sustained yield basis. The success of the Christmas tree industry and its $20 million payroll depends on the high quality of properly harvested trees. The date a Christmas tree operator selects to start harvesting, plays an important role in determining freshness.
Resistance to sun blotch virus in seed source trees of Duke avocado
by R. M. Burns, R. J. Drake, J. M. Wallace, G. A. Zentmyer
| Full text HTML  | PDF  
Summary Not Available – First paragraph follows: Of 12 Duke avocado trees tested, 10 were found to be free of sun blotch virus infection. However, two trees without sun blotch symptoms were infected and apparently both are symptomless carriers. These transmit the virus through seeds to their seedling progeny and can cause infection of the scion tops that are worked on them when used as rootstocks. These studies demonstrate that it is necessary to test all Duke seed-source trees before using them as rootstock parents.
Of 12 Duke avocado trees tested, 10 were found to be free of sun blotch virus infection. However, two trees without sun blotch symptoms were infected and apparently both are symptomless carriers. These transmit the virus through seeds to their seedling progeny and can cause infection of the scion tops that are worked on them when used as rootstocks. These studies demonstrate that it is necessary to test all Duke seed-source trees before using them as rootstock parents.
Testing fluorine compounds for chemical mowing of turfgrass
by John H. Madison, James M. Johnson, William B. Davis, Roy M. Sachs
| Full text HTML  | PDF  
Summary Not Available – First paragraph follows: On the basis of present evidence, morphactins, used at low rates, appear to have some regulatory effects on turfgrass growth—stimulating seed yield and flowering, and affecting tillering and degree of culm elongation. However, reductions in leaf growth from morphactins, do not indicate specific growth regulation but appear to be caused by phytotoxicity. Such poisoning generally leads to lowered vigor and reduced ability to recover from wear, insect, and disease attacks, and may increase susceptibility to disease and insects; therefore, the continuing recommendation is for replacement of hybrid bermudagrasses when used for purposes to which they are not suited. When a brown color is not objectionable, a considerable reduction of thatch and clippings can be obtained by withholding irrigation and fertilizer.
On the basis of present evidence, morphactins, used at low rates, appear to have some regulatory effects on turfgrass growth—stimulating seed yield and flowering, and affecting tillering and degree of culm elongation. However, reductions in leaf growth from morphactins, do not indicate specific growth regulation but appear to be caused by phytotoxicity. Such poisoning generally leads to lowered vigor and reduced ability to recover from wear, insect, and disease attacks, and may increase susceptibility to disease and insects; therefore, the continuing recommendation is for replacement of hybrid bermudagrasses when used for purposes to which they are not suited. When a brown color is not objectionable, a considerable reduction of thatch and clippings can be obtained by withholding irrigation and fertilizer.
Preplant soil fumigation increases head weights in California lettuce
by J. D. Radewald, P. G. Mowbray, A. O. Paulus, Fujio Shibuya, J. M. Rible
| Full text HTML  | PDF  
Summary Not Available – First paragraph follows: Preplant bed fumigation of lettuce soils significantly increased lettuce head weights in three Palo Verde field trials with DD and Telone. Treatments also produced trends toward more uniform and earlier crop maturity (although differences were not statistically significant). The reasons for the beneficial responses are not completely understood, but the responses were at least partly accounted for by the control of two nematodes, Tylenchorhynchus clarus and Meloidognye hapla.
Preplant bed fumigation of lettuce soils significantly increased lettuce head weights in three Palo Verde field trials with DD and Telone. Treatments also produced trends toward more uniform and earlier crop maturity (although differences were not statistically significant). The reasons for the beneficial responses are not completely understood, but the responses were at least partly accounted for by the control of two nematodes, Tylenchorhynchus clarus and Meloidognye hapla.
Mechanical aids to sweet potato harvest
by M. Zahara, R. W. Scheuerman
| Full text HTML  | PDF  
Summary Not Available – First paragraph follows: APPROXIMATELY 9,000 acres of sweet potatoes are grown annually in California, with Merced County accounting for more than 60 per cent of this total acreage. Fresno, Stanislaus, San Joaquin, and Kern counties grow the remaining 40 per cent of the acreage. The average yield of marketable roots is low—from 4.5 to 5.0 tons per acre. In the past, the farm family grew the crop with members of the family providing the necessary labor to produce and harvest. Individual growers are now increasing their sweet potato acreage, thereby replacing a number of the farm family units. The development of mechanical harvest aids has contributed to the change to larger acreages. This tractor-drawn mechanical harvester digs and conveys the roots past four or five people on the trailer unit who snap the roots from the stems and place them in boxes. The stems, cull roots, and trash drop back onto the ground at the rear of the harvest-aid machines. Space is provided on this aid for several pallets, on which empty and full boxes can be stacked.
Abstract Not Available – First paragraph follows: APPROXIMATELY 9,000 acres of sweet potatoes are grown annually in California, with Merced County accounting for more than 60 per cent of this total acreage. Fresno, Stanislaus, San Joaquin, and Kern counties grow the remaining 40 per cent of the acreage. The average yield of marketable roots is low—from 4.5 to 5.0 tons per acre. In the past, the farm family grew the crop with members of the family providing the necessary labor to produce and harvest. Individual growers are now increasing their sweet potato acreage, thereby replacing a number of the farm family units. The development of mechanical harvest aids has contributed to the change to larger acreages. This tractor-drawn mechanical harvester digs and conveys the roots past four or five people on the trailer unit who snap the roots from the stems and place them in boxes. The stems, cull roots, and trash drop back onto the ground at the rear of the harvest-aid machines. Space is provided on this aid for several pallets, on which empty and full boxes can be stacked.

Editorial, News, Letters and Science Briefs

Agricultural field stations —laboratories of the university
by James L. Myler
Full text HTML  | PDF  

General Information

Extension laboratory, U.C., Davis
by Editors
Full text HTML  | PDF  

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