Platynota Stultana Research Articles

PLATYNOTA STULTANA WALSINGHAM, 1884 (LEPIDOPTERA TORTRICIDAE) FOUND IN ITALY, INVASIVE PEST IN EUROPE

Notes on the presence of the Omnivorous Leafroller, Platynota stultana (Lepidoptera Tortricidae), in Italy and its presence and interception in other European countries are reported. Geographical distributions and principal morphological and biological characters are illustrated. Considering the wide host range of P. stultana, this pest has the potential to damage many cultivated and wild plants in the European and Mediterranean Plant Protection Organization (EPPO) region. Its interception in England, the Netherlands, and Germany and its introduction into Spain and Italy clearly demonstrates that it has the potential to enter and establish itself in the Southern and Mediterranean parts of Europe. Key Words: Platynota stultana, Lepidoptera Tortricidae, Italy, Europe, pest risk.

Role of Lygus hesperus (Hemiptera: Miridae) Adult Feeding on Deformation of Blackberry Fruits

Role of <i>Lygus hesperus</i> (Hemiptera: Miridae) Adult Feeding on Deformation of Blackberry Fruits

Biology and Potential Host Range of Pediobius ni (Hymenoptera: Eulophidae) as a Novel Resident Parasitoid of Light Brown Apple Moth (Lepidoptera: Tortricidae) in California

Abstract Pediobius ni Peck (Hymenoptera: Eulophidae) is a eulophid parasitoid indigenous to North America that was found attacking the invasive light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), in California. We investigated host age suitability, fecundity, and temperature-dependent developmental time for P. ni as a parasitoid of E. postvittana. Parasitoid offspring survival was higher on E. postvittana presented as prepupa or young pupa (&amp;lt;3 d old) than older pupa (&amp;gt;3d old), and P. ni would not attack mature E. postvittana larva. Parasitoid developmental time increased with advanced host age. At 24°C, P. ni parasitized 6.8 ± 0.7 hosts, and produced 119.5 ± 16.8 offspring during a 21.5 2± 3.0 d adult lifetime when provided food and host pupae. The developmental rate of P.ni was a positive linear relationship between 15–28°C, but it failed to develop at constant temperatures &amp;gt;29°C. The estimated lower developmental threshold is 13.0°C, and degree-day requirements (DD) are 278 DD. As a comparison of host species suitability, P.ni was tested with obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae); navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae); omnivorous leafroller, Platynota stultana Walsingham (Lepidoptera: Tortricidae); orange tortrix, Argyrotaenia franciscana (Walsingham) (Lepidoptera: Tortricidae); and peach twig borer, Anarsia lineatella Zeller (Lepidoptera: Gelechiidae). The parasitoid readily attacked all tested host species; percentage parasitism was lower on A. lineatella than on A. transitella, P. sultana, and C. rosaceana, but similar among the other tested species. Clutch size generally increased with host size, but percentage adult emergence and sex ratio was not affected by host species. Exposure of hosts to multiple P.ni increased the numbers of emerged wasps per parasitized host without obvious costs to offspring fitness.

Two New Neotropical Species ofPlatynotawith Comments onPlatynota stultanaWalsingham andPlatynota xylophaea(Meyrick) (Lepidoptera: Tortricidae)

Two new species of Platynota are described and illustrated: P. subtinae, new species, from Venezuela, Bolivia, and Paraguay, and P. meridionalis, new species, from Argentina. Although both have been reared only from cotton (Gossypium sp., Malvaceae), they are suspected to be polyphagous, as are nearly all other species in the genus. Two morphological characters of the male genitalia of the new species, i.e., transtilla densely covered with large thorns and juxta deeply excavated in the middle, are most similar to each other and to Platynota stultana Walsingham, described from northwestern Mexico. The two new species are compared to Platynota stultana and P. xylophaea (Meyrick), the latter native to Argentina, with which the new species are superficially similar.

COMMERCIAL POMEGRANATE (PUNICA GRANATUM L.) PRODUCTION IN CALIFORNIA

Commercial pomegranate production in California is found primarily in the southern San Joaquin Valley, a region with Mediterranean type climate. Pome-granates have been grown in California since 1792, spread by Christian missionaries from Spain, and in commercial production since 1896 when shipments of trees arrived from Florida. For decades in the late 1900s the statewide hectarage remained near 1000, but has increased dramatically to 11700 in 2007, most of which is less than four years old. Pomegranates are often grown in conjunction with other permanent crops such as stone fruit and nut crops. Planting systems range from rows 3.6 to 5.8 m and in-row spacing from 1.5 to 5.2 m, with row spacing often determined by equipment preferences for other crops. Training systems are typically free-form multiple trunks, although single trunk and trellised production is being used. Irrigation systems, like crop spacing, are often dictated by companion crops found on individual farms; flood irrigation is found on older trees with newer trees planted with micro irrigation systems. Organic production of pomegranates remains limited due to market acceptance; challenges for organic production are Alternaria alternata and Aspergillus niger, as well as omnivorous leafroller (Platynota stultana) and flat mite (Brevipalpus lewisi). Numerous herbicides are registered for use in conventional pomegranates and weed barriers and hand weeding in organic systems. Both fresh market and juice fruit continue to be commercially harvested by hand but attempts at mechanization for both uses are underway. Common yields for mature pomegranates are as low as 6-10 MT/ha when used exclusively for fresh market consumption, but can be as great as 25-35 MT/ha when grown for juice, with the fresh:juice ratio dependant on both market conditions and autumn weather patterns. Most pomegranates are sold through food retailers in North America, and their current preference for high sugar/high acid, dark red rind color and dark red aril color favors cultivars such as ‘Granada’ and ‘Foothill’ in early season, and ‘Wonderful’ in main season. The United States Depart-ment of Agriculture National Clonal Germplasm Repository in Davis, California, contains selected lines sent from Dr. Levin’s Turkmenistan collection as well as genetic variants found in California production; variation for fruit attributes may influence consumer acceptance to other fruit types already common throughout pomegranate consuming cultures.

Tortricid Moths Reared from the Invasive Weed Mexican Palo Verde,Parkinsonia aculeata, with Comments on their Host Specificity, Biology, Geographic Distribution, and Systematics

As part of efforts to identify native herbivores of Mexican palo verde, Parkinsonia aculeata L. (Leguminosae: Caesalpinioideae), as potential biological control agents against this invasive weed in Australia, ten species of Tortricidae (Lepidoptera) were reared from Guatemala, Mexico, Nicaragua, and Venezuela: Amorbia concavana (Zeller), Platynota rostrana (Walker), Platynota helianthes (Meyrick), Platynota stultana Walsingham (all Tortricinae: Sparganothini), Rudenia leguminana (Busck), Cochylis sp. (both Tortricinae: Cochylini), Ofatulena duodecemstriata (Walsingham), O. luminosa Heinrich, Ofatulena sp. (all Olethreutinae: Grapholitini), and Crocidosema lantana Busck (Olethreutinae: Eucosmini). Significant geographic range extensions are provided for O. duodecemstriata and R. leguminana. These are the first documented records of P. aculeata as a host plant for all but O. luminosa. The four species of Sparganothini are polyphagous; in contrast, the two Cochylini and three Grapholitini likely are specialists on Leguminosae. Ofatulena luminosa is possibly host specific on P. aculeata. Host trials with Rudenia leguminana also provide some evidence of specificity, in contrast to historical rearing records. To examine the possibility that R. leguminana is a complex of species, two data sets of molecular markers were examined: (1) a combined data set of two mitochondrial markers (a 781-basepair region of cytochrome c oxidase I (COI) and a 685-basepair region of cytochrome c oxidase II) and one nuclear marker (a 531-basepair region of the 28S domain 2); and (2) the 650-basepair “barcode” region of COI. Analyses of both data sets strongly suggest that individuals examined in this study belong to more than one species.

Ethyl Formate As a Postharvest Fumigant for Selected Pests of Table Grapes

Ethyl formate (EF) in combination with CO2 was tested for control of arthropods commonly infesting California table grapes. In addition, table grape tolerance to EF exposure was evaluated. LC99 estimates were developed for target pests by using a range of EF concentrations (0.04–4.7% EF). Response to treatments varied greatly between species, as well as life stages within species. Western flower thrips, Frankliniella occidentalis (Pergande), and adult and crawler stages of grape mealybug, Pseudococcus maritimus (Ehrhorn), were most susceptible to EF treatments. Least susceptible were grape mealybug eggs; Pacific spider mite, Tetranychus pacificus McGregor; and omnivorous leafroller, Platynota stultana Walsingham. The LC99 for target pests fell within the range of EF concentrations tolerated by table grapes with the exception of 1-, 3-, and 5-d-old omnivorous leafroller pupae.

Ethyl Formate As a Postharvest Fumigant for Selected Pests of Table Grapes

Ethyl formate (EF) in combination with CO2 was tested for control of arthropods commonly infesting California table grapes. In addition, table grape tolerance to EF exposure was evaluated. LC99 estimates were developed for target pests by using a range of EF concentrations (0.04-4.7% EF). Response to treatments varied greatly between species, as well as life stages within species. Western flower thrips, Frankliniella occidentalis (Pergande), and adult and crawler stages of grape mealybug, Pseudococcus maritimus (Ehrhorn), were most susceptible to EF treatments. Least susceptible were grape mealybug eggs; Pacific spider mite, Tetranychus pacificus McGregor; and omnivorous leafroller, Platynota stultana Walsingham. The LC99 for target pests fell within the range of EF concentrations tolerated by table grapes with the exception of 1-, 3-, and 5-d-old omnivorous leafroller pupae.

Pheromone mating disruption offers selective management options for key pests

The direct management of insect pests using pheromones for mating disruption, or “attract and kill” approaches, can provide excellent suppression of key lepidopteran pests in agriculture. Important successes to date include codling moth in pome fruit, oriental fruit moth in peaches and nectarines, tomato pinworm in vegetables, pink bollworm in cotton and omnivorous leafroller in vineyards. Large-scale implementation projects have yielded significant reductions in pesticide use while maintaining acceptably low crop-damage levels. Because of some difficulties with high populations of pests, these programs should not be viewed as stand-alone strategies but rather as one tactic within a suite of integrated pest management options.

Efficacy of Silwet L-77 Against Several Arthropod Pests of Table Grape

Silwet L-77, an organosilicone surfactant, was applied to several arthropod pests of California table grapes. Eggs of grape mealybug, Pseudococcus maritimus (Ehrhorn), and omnivorous leafroller, Platynota stultana Walsingham, were tolerant to 0.1, 0.25, and 0.5% treatment solutions; however, eggs of Pacific spider mite, Tetranychus pacificus McGregor, were highly susceptible with mortality >99.4% (0.1% Silwet L-77). Mortality of immature and adult stages of cotton aphid (Aphis gossypii Glover), Western flower thrips (Frankliniella occidentalis Pergande), and Pacific spider mite (Tetranychus pacificus McGregor) was ≥93.8, ≥98.5, and ≥99.4% for 0.1, 0.25, and 0.5% Silwet L-77, respectively. Grape mealybug crawlers had 100% mortality when treated with 0.5 and 1.0% Silwet L-77 solutions; however, mortality was only 6.7% when 0.1% Silwet L-77 was applied. ‘Thompson Seedless’ table grapes were not damaged when treated with up to 1% Silwet L-77; however, grapes treated with the 0.5 and 1.0% solutions appeared wet after removal from cold storage because of the effect of the surfactant spreading the water condensation. Grapes dried with the normal bloom on the berries when they reached room temperature.

Efficacy of Silwet L-77 against several arthropod pests of table grape.

Silwet L-77, an organosilicone surfactant, was applied to several arthropod pests of California table grapes. Eggs of grape mealybug, Pseudococcus maritimus (Ehrhorn), and omnivorous leafroller, Platynota stultana Walsingham, were tolerant to 0.1, 0.25, and 0.5% treatment solutions; however, eggs of Pacific spider mite, Tetranychus pacificus McGregor, were highly susceptible with mortality >99.4% (0.1% Silwet L-77). Mortality of immature and adult stages of cotton aphid (Aphis gossypii Glover), Western flower thrips (Frankliniella occidentalis Pergande), and Pacific spider mite (Tetranychus pacificus McGregor) was > or = 93.8, > or = 98.5, and > or = 99.4% for 0.1, 0.25, and 0.5% Silwet L-77, respectively. Grape mealybug crawlers had 100% mortality when treated with 0.5 and 1.0% Silwet L-77 solutions; however, mortality was only 6.7% when 0.1% Silwet L-77 was applied. 'Thompson Seedless' table grapes were not damaged when treated with up to 1% Silwet L-77; however, grapes treated with the 0.5 and 1.0% solutions appeared wet after removal from cold storage because of the effect of the surfactant spreading the water condensation. Grapes dried with the normal bloom on the berries when they reached room temperature.

Applications of Olefin Cross Metathesis to Commercial Products

In this paper, we will demonstrate the value of olefin cross metathesis as an effective synthetic tool for applications in the agrochemical and pharmaceut- ical industries. First, we will demonstrate the useful- ness of cross metathesis reactions in the efficient synthesis of the major component of the Peach Twig Borer pheromone and the of Omnivorous Leafroller pheromone, insect pheromones are environmentally friendly pest-controlling agents. Second, we will demonstrate highly efficient cross metathesis routes into novel ,-unsaturated carbonyl intermediates. These novel ,-unsaturated carbonyl intermediates can be further functionalized into pharmaceutical compounds that are difficult to prepare by the traditional synthetic methodologies. This paper high- lights key catalyst-substrate reactivity variations with different ruthenium olefin metathesis catalysts, high- lights cross metathesis reactions and techniques and highlights an efficient ruthenium catalyst removal technique.

Pest response in packed table grapes to low temperature storage combined with slow-release sulfur dioxide pads in basic and large-scale tests.

The effect of low temperature storage combined with slow release sulfur dioxide pads was determined in basic laboratory and large-scale commercial tests on western flower thrips, Frankliniella occidentalis Pergande; grape mealybug, Pseudococcus maritimus (Ehrhorn); Pacific spider mite, Tetranychus pacificus McGregor; twospotted spider mite, Tetranychus urticae Koch; and omnivorous leafroller, Platynota stultana Walshingham. Temperatures within the foam containers among the packed clusters decreased from ambient to 2 degrees C within approximately 1 d and ranged from 0.4 to 1.7 degrees C in all tests. Sulfur dioxide concentrations in the foam containers ranged between 0.2 and 1.6 ppm during the 1- to 6-wk storage period in basic tests and 0.5-1.1 ppm during the 1- to 8-wk storage period in the large-scale test. Western flower thrips was completely controlled by a > or =1-wk exposure. Grape mealybug mortality was > or =93% after 2-5 wk exposures and 100% after a 6-wk exposure in basic tests. Pacific spider mite and twospotted spider mite mortality was 98.0 and 99.6%, respectively, after a 6-wk exposure. Mortality of grape mealybug and twospotted spider mite increased significantly at > or =3-wk exposures and Pacific spider mite mortality increased significantly at > or =4-wk exposures. Mortality of the spider mites in general was directly related to the duration of exposure. An 8-wk exposure to low temperature storage combined with slow release sulfur dioxide pads in the large-scale test resulted in 100% mortality of western flower thrips, twospotted spider mite, and omnivorous leafroller. The treatment resulted in <8% survival of grape mealybug and <1% survival of Pacific spider mite in the large-scale test. The combination treatment offers an economical method to attain quarantine control of certain insects and mites.

Metabolic response of Platynota stultana pupae during and after extended exposure to elevated CO 2 and reduced O 2 atmospheres

The metabolic response of Platynota stultana pupae to elevated CO 2 and reduced O 2 atmospheres was measured using microcalorimetry. Initial measurements at 20°C immediately upon placement in controlled atmosphere indicated a decrease in metabolic heat rate (MHR) of 27, 45, 56, 56, and 72% in an atmosphere of 5, 10, 20, 40, and 79% CO 2, respectively, and a decrease of 20, 50, 66 and 100% under 6, 2, 1, and 0% O 2. With extended exposure to controlled atmospheres, MHR increased under 5, 10, and 20% CO 2 and 6 and 2% O 2; however, the increase was greater and occurred more rapidly with lower CO 2 and higher O 2 concentration. The MHR at 40 and 79% CO 2 remained at the initial reduced level for 8 and 6 days, respectively, then decreased with longer exposure. The MHR of pupae held under 1 and 0% O 2 remained at the initial reduced level for 22 days. Upon transfer to air, the MHR of pupae increased from the reduced levels and then decreased. When the MHR decreased by no more than 30%, as a result of controlled atmosphere treatment, the pupae still developed into adults. However, when the MHR decreased by more than 50%, the energy supply was insufficient and the pupae died. Pupa mortality was comparable between 5% CO 2 and 6% O 2, and 10% CO 2 and 2% O 2. The MHR was reduced less under 20% CO 2 than under 2 or 1% O 2; however, the pupae were more susceptible to 20% CO 2 than 2 or 1% O 2. These and other data indicate an increased toxicity of high CO 2 over low O 2 atmospheres that may be related to an increase in membrane permeability as a result of CO 2 treatment.

Metabolic response of Platynota stultana pupae to controlled atmospheres and its relation to insect mortality response

The metabolic responses of Platynota stultana pupae to reduced O 2, elevated CO 2, and their combinations were investigated using microcalorimetry, and mortality of pupae under elevated CO 2 atmospheres was correlated with metabolic responses. The metabolic heat rate decreased slightly with decreasing O 2 concentration until a critical O 2 concentration ( P c) below which the heat rate decreased rapidly. The P c increased with temperature. The percentage decreases of metabolic heat rate were comparable to the percentage decreases of O 2 consumption rate ( RO 2) at 10, 8, 6, and 4% O 2, but were smaller at 2 and 1% O 2. The metabolic heat rate decreased rapidly at 20% CO 2 relative to 0% CO 2, with little to no further decrease between 20 and 79% CO 2. The percentage decreases of RO 2 under 20 and 79% CO 2 at 20°C were comparable to the percentage decreases of metabolic heat rates. The additive effects of subatmospheric O 2 and elevated CO 2 levels on reducing metabolic heat rate were generally fully realized at combinations of ≤5% CO 2 and ≥4% O 2, but became increasingly overlapped as the O 2 concentration decreased and the CO 2 concentration increased. The high susceptibility of pupae to elevated CO 2 at high temperature was correlated with high metabolic heat rate. The metabolic responses of pupae to reduced O 2 concentrations included metabolic arrest and anaerobic metabolism. The net effect of elevated CO 2 on the pupal respiratory metabolism was similar to that of reduced O 2; however, mechanisms other than the decrease of metabolism were also contributing to the toxicity of CO 2.

Response of omnivorous leafroller (Lepidoptera: Tortricidae) and onion thrips (Thysanoptera: Thripidae) to low-temperature storage.

Eggs and first-fifth instars of omnivorous leafroller, Platynota stultana Walshingham, had a mean percentage survival to the adult stage of 60.7-95.2% for nonexposed immatures and 14.5-54.3% for immatures exposed to 1 wk at 0-1 degree C. Exposures of 2-5 wk resulted in 0-6.7% survival, and a 6-wk exposure resulted in < 1% survival of all stages tested. A significant reduction in survival of all larval stages occurred between exposures of 0 and 1 wk and between 1 wk and 2-6 wk. Survival of eggs after exposures of 0 and 1 wk was significantly different than survival after exposures of 2-6 wk. The second instar was the stage least susceptible to low-temperature storage. Adults that were exposed to low temperature for 1 wk in the third through fifth instars laid a mean of 120-289 eggs per female, and the mean percentage viability of the eggs ranged from 56.2 to 71.4%. Mean percentage survival of adults and nymphs of onion thrips, Thrips tabaci Lindeman, was inversely related to the duration of exposure from 1 through 3-6 wk at 0-1 and 5 degrees C and was lower at 0-1 (0.2-52.5%) than at 5 degrees C (17.6-66.6%). Exposure to 0-1 degree C for 4 wk attained 91.2% control, which increased to 99.8% after 6 wk. Low-temperature storage has potential to control omnivorous leafroller in table grapes, Vitis vinifera L., and onion thrips in onions, Allium cepa L.

Host status of fresh prunes by potential quarantine pests in laboratory tests and evaluation of packinghouse culls.

The status of fresh prunes, Prunus domestica L., as a host for codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae); peach twig borer, Anarsia lineatella Zeller (Lepidoptera: Gelechiidae); omnivorous leafroller, Platynota stultana Walshingham (Lepidoptera: Tortricidae); oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae); navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae); and walnut husk fly, Rhagoletis completa Cresson (Diptera: Tephritidae), was investigated in laboratory tests and by examination of packinghouse culls. In laboratory no-choice tests, the mean number of adults reared per fruit was 0.01 for codling moth, 0.08 for omnivorous leafroller, 0 for oriental fruit moth, and 1.6 for navel orangeworm. In choice tests the mean number of adults reared per apple or fresh prune was for codling moth, 0.78 and 0.02 (significantly different); for omnivorous leafroller, 0.05 and 0.02; and for oriental fruit moth, 2.07 and 0 (significantly different), respectively. Walnut husk fly oviposited in fresh prunes in no-choice tests but pupae did not develop from the fruit. In choice tests, walnut husk fly did not oviposit in fresh prunes when caged with its normal host, green walnuts, in which large numbers of pupae developed. Inspection of packinghouse culls for immature insects showed that fresh prunes with possible larval feeding sites in the form of frass or fruit gum extrusions were lighter in weight, significantly less firm, similar in color, and had significantly higher soluble solids than noninfested fruit. Based on packinghouse cull samples, 1 fresh prune per 133 harvested fruit would be expected to show possible insect damage. Eleven peach twig borer larvae were found in fresh prune cull samples (213.9 kg) removed from a 16,744.5-kg harvest. The calculated level of infestation was 1 infested fruit per 8,501.8 fruit harvested or per 21.7 cartons of medium-sized packed fruit. Based on our results, the risk of infestation of fresh prunes by the insects in this study would be minimal in fruit exported from the San Joaquin Valley of California.

Low Temperature Storage Combined with Sulfur Dioxide Slow Release Pads for Quarantine Control of Omnivorous Leafroller Platynota stultana (Lepidoptera: Tortricidae)

Low temperature storage combined with sulfur dioxide slow release pads caused 100% mortality of omnivorous leafroller, Platynota stultana Walshingham, 2nd instar (the least susceptible stage to low temperature storage) after 3 wk of exposure in table grapes, Vitis vinifera L. Temperatures in packed grape clusters decreased from ambient to 2 degrees C within approximately equal to 2 d after placement in storage. Sulfur dioxide concentrations in the grape clusters ranged between 0.2 and 1.0 ppm during the 1-to 6-wk storage period. The combination treatment incorporates existing packinghouse facilities and has potential to be used as an alternative to chemical fumigants such as methyl bromide to control pests of regulatory concern in exported table grapes.

Controlled Atmospheres for Quarantine Control of Three Pests of Table Grape

Two controlled atmosphere treatments (45% CO 2 + 0.5% O 2 and 45% CO 2 + air [11.5% O 2 ]) significantly increased mortality of Platynota stultana Walsingham; Pacific spider mites, Tetranychus pacificus McGregor; and western flower thrips, Frankliniella occidentalis Pergande. The small difference in response of arthropods to the 2 controlled atmosphere treatments indicated greater response to 45% CO 2 + 11.5% O 2 . Temperature (0 and 5°C) had a significant effect on arthropod mortality (i.e., arthropods treated at 0°C showed greater mortality). We detected no effects of exposure to the controlled atmosphere treatments for 10 or 15 d at 0°C on the table grapes. Treatment with 45% CO 2 + 11.5% O 2 at 0°C appeared to be the best method for disinfestation of table grapes of these 3 pests.

AN ORGANIC VERSUS A CONVENTIONAL FARMING SYSTEM IN KIWIFRUIT

To determine the feasibility of growing kiwifruit organically, a kiwifruit vineyard converted to an organic farm was compared to a conventionally farmed vineyard from 1990 through 1992. January or March applications of composted chicken manure (organic system) or NH4NO3 plus CaNH 4(NO3)3 through micro sprinklers during the growing season (conventional system) were applied to give nearly equal rates of 168 kg N ha. Soil analysis showed a trend toward a higher pH and organic matter over time for the organic system. In 1992, there was a trend for the organic system to have higher NH4-N and lower NO3-N concentration in the soil. Leaf nitrogen levels from the organic system were consistently lower than those from the conventional system but were not deficient. Leaf concentrations of sodium and chloride increased over the three-year period in the organic system but not to phytotoxic levels. Leaf zinc levels were adequate and increased over time in both systems. Organically grown fruit was as firm as or firmer than conventionally grown fruit at harvest and four months after harvest. No differences were seen in percent soluble solids content. Damage from latania scale and omnivorous leaf roller was small in both systems except scale damage in the organic system in 1992. An economic analysis of the cultural practices showed that the organic system cost almost $720 per ha more then the conventional system. The grower reported fewer repack losses for organically grown fruit in 1992. We conclude that growing kiwifruit organically is feasible if an economic premium is received.