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Mechanical Conditioning Of Tomato Seedlings Improves Transplant Quality Without Deleterious Effects On Field Performance, Lauren C. Garner, Thomas Björkman Sep 1999

Mechanical Conditioning Of Tomato Seedlings Improves Transplant Quality Without Deleterious Effects On Field Performance, Lauren C. Garner, Thomas Björkman

Horticulture and Crop Science

Excessive stem elongation reduces plant survival in the field and hinders mechanical transplanting. Mechanical conditioning is an effective method for reducing stem elongation during transplant production. This investigation examined the consequences of mechanical conditioning, using brushing and impedance, on subsequent field performance of tomatoes (Lycopersicon esculentum Mill.). Mechanically conditioned transplants of processing tomatoes resumed growth after transplant shock as quickly as did untreated plants, and subsequent canopy development was also equal. In 4 years of field trials, yield was not reduced by mechanical conditioning. Transplants for fresh-market tomatoes may be more sensitive to injury than those for processing tomatoes because …


Development And Reproduction Of A Population Of Eretmocerus Eremicus (Hymenoptera: Aphelinidae) On Bemisia Argentifolii (Homoptera: Aleyrodidae), David H. Headrick, Thomas S. Bellows, Jr., Thomas M. Perring Apr 1999

Development And Reproduction Of A Population Of Eretmocerus Eremicus (Hymenoptera: Aphelinidae) On Bemisia Argentifolii (Homoptera: Aleyrodidae), David H. Headrick, Thomas S. Bellows, Jr., Thomas M. Perring

Horticulture and Crop Science

Although the aphelinid parasitoid Eretmocerus eremicus Rose & Zolnerowich is the most abundant naturally occurring parasitoid of Bemisia argentifolii Bellows & Perring in the U.S. desert southwest, its effectiveness in different cropping systems varies. Development and reproduction of a population of this parasitoid attacking B. argentifolii infesting cotton, Gossypium hirsutum L., and sweet potato, Ipomoea batatas L., were quantified and compared. Females potato; there were no significant differences of these parameters between host plant species. A preoviposition period of 0.61 d was recorded, and a maximum number of eggs laid in a day was 69 on cotton and 13 on …


Reproductive Biology And Search Behavior Of Amitus Bennetti (Hymenoptera: Platygasteridae), A Parasitoid Of Bemisia Argentifolii (Homoptera: Aleyrodidae), Andrea L. Joyce, Thomas S. Bellows, Jr., David H. Headrick Jan 1999

Reproductive Biology And Search Behavior Of Amitus Bennetti (Hymenoptera: Platygasteridae), A Parasitoid Of Bemisia Argentifolii (Homoptera: Aleyrodidae), Andrea L. Joyce, Thomas S. Bellows, Jr., David H. Headrick

Horticulture and Crop Science

No abstract provided.


Abundance Of Spiders And Insect Predators On Grapes In Central California, Michael J. Costello, Kent M. Daane Jan 1999

Abundance Of Spiders And Insect Predators On Grapes In Central California, Michael J. Costello, Kent M. Daane

Horticulture and Crop Science

We compared the abundance of spiders and predaceous insects in five central California vineyards. Spiders constituted 98.1% of all predators collected. More than 90% of all spiders collected were from eight species of spiders, representing six families. Two theridiids (Theridion dilutum and T. melanurum) were the most abundant, followed by a miturgid (Cheiracanthium inclusum) and an agelinid (Hololena nedra). Predaceous insects comprised 1.6% of all predators collected, and were represented by six genera in five families. Nabis americoferis (Heteroptera, Nabidae) was the most common predaceous insect, with its densities highest late in the growing …


Nitrogen Utilization Efficiency Of Creeping Bentgrass Genotypes, Y. Kuo, David J. Wehner, T. W. Fermanian, John M. Swiader Jan 1999

Nitrogen Utilization Efficiency Of Creeping Bentgrass Genotypes, Y. Kuo, David J. Wehner, T. W. Fermanian, John M. Swiader

Office of the Dean (CAFES) Scholarship

A greenhouse study was conducted in a hydroponic system to determine the nitrogen (N) utilization efficiency (NUE) of 14 creeping bentgrass cultivars. There were significant differences among cultivars in plant tissue dry weight, tissue N content, root absorption efficiency (RAE), and NUE. Considering all plant tissue (whole plant), 'Penncross' accumulated the highest N accompanied with the highest whole plant dry weight (WPDW), while 'Allure' accumulated the lowest total Nand WPDW than all the other cultivars. The proportion of WPDW and total N partitioned to shoots was higher than partitioned to roots in each cultivar. On a whole plant basis, 'Regent' …


Nitrogen Utilization In Creeping Bentgrass, Y. Kuo, T. W. Fermanian, David J. Wehner Jan 1999

Nitrogen Utilization In Creeping Bentgrass, Y. Kuo, T. W. Fermanian, David J. Wehner

Office of the Dean (CAFES) Scholarship

N utilization, including plant dry weight (DW) production, total N and nitrate N (NO3-N) content accumulation, N utilization efficiency (NUE), root absorption efficiency (RAE), reduced N accumulation, and nitrate assimilation capacity (NAC) were determined for creeping bentgrass cultivars grown in hydroponic culture. Possible mechanisms affecting N utilization including nitrate reductase activity (NRA) and root morphology were also examined. Four cultivars, selected from an initial screening of creeping bentgrasses were grown under both low and high levels of N in a flowing solution culture system. The relationship between NUE and plant growth for two different creeping bentgrass cultivars was …