Viticulture and Enology
http://hdl.handle.net/10211.3/5695
2024-03-28T11:18:55ZDetermining the effects of reduced leaf area caused by the grape leaf folder on Thompson Seedless grapevines
http://hdl.handle.net/10211.3/202379
Determining the effects of reduced leaf area caused by the grape leaf folder on Thompson Seedless grapevines
Porter, Gary
With the increased interest in reducing the amount of pesticides applied for insect control, this study was initiated to determine an economic threshold for the grape leaf folder, Desmia funeralis, on Thompson Seedless grapevines in the San Joaquin Valley. Various levels of the insect at 100, 250, 350 and 500 larvae per vine were placed on vines and their damage was compared to artificial defoliation at rates of 16%, 20%, 25%, and 50% used as a reference, measuring the crop yield and quality. The results showed that reduced leaf area by Desmia had no significant effect on total soluble solids, total acid, pH or crop weight attributable to the insect. The data indicate that even at 50% defoliation, control of this insect may not be necessary. Vine vigor and the extensive vegetative growth of the vines accounted for the failure of removal of half the leaves to produce any adverse effects. Time of defoliation in relation to anthesis is the critical factor of leaf removal when considering damage.
1972-01-01T00:00:00ZA cost-analysis study of the grape harvest mechanization
http://hdl.handle.net/10211.3/202282
A cost-analysis study of the grape harvest mechanization
Atkins, Guillermo A.
The economic management of machinery and power in agriculture represents only 5.5 percent of the capital engaged in this type of enterprise, but the cost of operating this equipment represents 36 percent of the annual cost, of production (10). Consequently, the economic study of new machinery is essential in order to develop good management techniques that will help the farmer make sound decisions.
1972-01-01T00:00:00ZThe influence of two cropping regimes on physical properties of a Greenfield soil
http://hdl.handle.net/10211.3/195583
The influence of two cropping regimes on physical properties of a Greenfield soil
Harader, Peter R
Greenfield soil physical properties were compared between permanent pasture and vineyard cropping regimes at four depths. The pasture cropping regime had a higher percentage of moisture at sampling in all four depths. Organic matter, pH, pore space, and volume weights varied with depth. The pasture surface soil (1.2 to 3.8 cm depth) was higher in total pore space, micro-pore space, moisture content at sampling, and hydraulic conductivity than the vineyard surface soil. The pasture soil's moisture equivalence in the 35.5 to 41.1 cm depth was higher, and the vineyard soil had a higher percentage of clay in the 15.2 to 22.8 cm depth.
1971-01-01T00:00:00ZGibberellic acid and grapes: the efects of gibberellic acid on the internal browning of Thompson Seedless Table Grapes
http://hdl.handle.net/10211.3/188781
Gibberellic acid and grapes: the efects of gibberellic acid on the internal browning of Thompson Seedless Table Grapes
Steinhauer, Robert E
In 1968 vines of Thompson Seedless Table Grapes were treated, with different concentrations of gibberellic acid, to determine if this chemical influenced, internal browning, a storage disorder. All treatments were sprayed, at bloom with 10 parts per million. Concentrations of 0, 20, lj.0 and. 100 parts per million gibberellic acid, were applied, at shatter. Fruit was harvested, on two dates and. placed, in cold, storage. A portion of the fruit was separated into maturity classifications and. placed, in. cold, storage. During the storage life of the fruit an average of 1.86$ of the berries inspected, were found, to contain internal browning. The disorder increased, with length of time fruit remained, in storage. The 0 parts per million gibberellic acid, applied, at bloom contained, the highest amount of internal browning with the I4.O part per million post bloom application containing the least amount of the disorder. The 20 to 22 Balling separation was found, to contain, the highest amount of the disorder with 1.92% of its fruit containing internal browning. The fruit of the 18 to 20 Balling separation contained. 0.98% internal browning and. fruit of the 16 to lo Balling separation contained. 0.28% internal browning. Berry weight measurements were not significantly different, between the 40 and 100 part per million gibberellic acid treatments, but a composite Balling sample for the 100 part per million treatment was approximately 1.2 degree Balling lower than the Balling of the UO part per million treatment.
1969-01-01T00:00:00Z