Joseph Connell

Followers

Following

Co-authors

Public Views

Interests

Uploads

Papers by Joseph Connell

Alternative Practices for Almond

Hortscience, Aug 1, 1996

Download

Relative Hardiness of Blossoms and Small Nuts of Nine Almond Cultivars

Hortscience, Jun 1, 1992

Download

Navel Orangeworm Control in Almond with Bacillus Thuringiensis

II International Symposium on Pistachios and Almonds, 1998

Pollination of Almonds: Practices and Problems

Batsch] are self-incompatible requiring cross-pollination to produce a commercial crop. Within se... more Batsch] are self-incompatible requiring cross-pollination to produce a commercial crop. Within seven known pollen groups, they also display cross-incompatibility. Coincidence of bloom between compatible cultivars is essential for cross-pollination. Since almonds are pollinated primarily by honeybees [Apis mellifera L.], arranging pollinizers in close proximity to one another promotes maximum pollen transfer. Almonds are frequently subject to inclement weather during their February bloom period. Strong honeybee colonies are better able to forage during marginal weather conditions than are weak colonies. Honeybee management can encourage pollen foraging and placement of colonies can affect flight activity and ultimately nut-set. Weather permitting vigorous honeybee flight activity is the most important factor for setting a good crop. Temperature also affects anther dehiscence, pollen germination, and pollen tube growth. The sooner an almond flower is cross-pollinated after opening, the greater the chance of fertilization and nut-set. Optimizing all of these pollination factors is therefore essential to achieve maximum production in almond orchards.

Download

Leading Edge of Plant Protection for Almond

ADDITIONAL INDEX WORDS. Prunus dulcis, Prunus amygdalus, pests, diseases, orchard floor managemen... more ADDITIONAL INDEX WORDS. Prunus dulcis, Prunus amygdalus, pests, diseases, orchard floor management, IPM, integrated pest management SUMMARY. Almond, [Prunus dulcis (synonym Prunus amygdalus)] planted on approximately 595,000 acres (240,797 ha), is California's largest acreage tree crop. California's Central Valley accounts for nearly 100% of the U.S. domestic production of almonds. Integrated pest management (IPM) programs that integrate cultural practices and pest and disease monitoring with selective controls have improved plant protection in almond. Methods of orchard floor management and their effects must also be taken into account. Minimizing dust reduces mites while harvesting earlier and the destruction of overwintering refugia are cultural practices that reduce worm damage. Improved methods for field sampling and monitoring have reduced the need for pesticide applications while improving timing and effectiveness of needed crop protection sprays. Selective controls have further reduced the impact on nontarget species. Augmentative parasite releases have also helped manage navel orangeworm (Ameylois transitella). Effective use of new selective fungicides will require precise application timing and greater knowledge of diseases and resistance management. A better understanding of disease life cycles leading to improved monitoring of the fungal diseases, shothole (Wilsonomyces carpophilus), almond scab (Cladosporium carpophilum), and anthracnose (Colletotrichum acutatum) have reduced fungicide applications. Future challenges include the potential loss of effective pest control products, the need to continually develop improved utilization strategies, and maintaining economic sustainability.

Download

Tolerance of Peach Twig Borer, Anarsia Lineatella Zeller, to Organophosphate and Pyrethroid Insecticides

Acta Horticulturae, 2002

... Frank G. Zalom 1 , Douglas B. Walsh 2 , William Krueger 3 and Joseph Connell 4 ... Walter Ben... more

Management and Etiology of Replant Disorder on Almond and Peach

Pre-plant fumigation with methyl bromide has been used to prevent Prunus replant disorder (PRD) i... more Pre-plant fumigation with methyl bromide has been used to prevent Prunus replant disorder (PRD) in California. The disorder commonly occurs when the tree crops are planted without precautions at sites previously devoted to closely related Prunus species. The symptoms include poor growth, delayed crop production, and, in severe cases, tree death. Some known causal agents of decline and death of replanted almond and peach trees include parasitic nematodes, oak root fungus, and Phytophthora species. Additional, but presently unknown, biological cause(s) of PRD apparently exist, however, because it occurs in absence of the known pests, and several diverse fumigants can prevent it or reduce its severity. Root systems of trees affected by the unknown cause(s) of PRD are stunted and typically possess diseased or relatively few feeder roots. We report here on alternatives to methyl bromide for management of PRD on almond and peach and on determinations of unknown causes for the disorder. Al...

Validation of Phenology Models for Predicting Development of the Navel Orangeworm Ameylois Transitella (Walker) in California Almond Orchards

II International Symposium on Pistachios and Almonds, 1998

Wade (1961), Gal (1978), and Engle and Barnes (1983) measured development of A. transitella in th... more

Comparison of olive fruit fly ( Bactrocera oleae (Gmelin)) (Diptera: Tephritidae) captures in several commercial traps in California

International Journal of Pest Management, 2008

Download

Almond Replant Disease and Its Management with Alternative Pre-Plant Soil Fumigation Treatments and Rootstocks

Plant Disease, 2006

. Almond replant disease and its management with alternative pre-plant soil fumigation treatments... more . Almond replant disease and its management with alternative pre-plant soil fumigation treatments and rootstocks. Plant Dis. 90:869-876. Trials were conducted in orchards near Chico, CA and microplots near Parlier, CA to examine symptoms and control measures for a replant disease (RD) on almond (Prunus dulcis). In the orchard trials, areas with a recent history of severe RD were cleared, given soil fumigation treatments in the fall, and replanted with almond trees on various rootstocks the following winter. The replants in nonfumigated soil developed severe RD (stunting, wilting, chlorosis, defoliation) by the following summer, while those in most fumigated treatments remained healthy. Trees in nonfumigated soil developed smaller trunk diameters and fewer healthy roots ≤1 mm diameter, compared with the healthy trees. Almond developed RD on all rootstocks evaluated (Marianna 2624, Lovell, and Nemaguard), but the trees on Marianna 2624 were the most severely affected. Pre-plant tree-site (spot) fumigation treatments with methyl bromide (MB), chloropicrin (CP), 1,3-dichloropropene (1,3-D), 1,3-D + CP, iodomethane, and iodomethane + CP all prevented severe RD. Broadcast soil fumigation with CP also was effective, but broadcast MB and 1,3-D were ineffective. In microplots filled with RD-conducive soil, CP was more potent than MB for prevention of RD on Nemaguard peach. There was no association between nematodes and RD in orchard or microplot trials. The RD apparently was mediated by a biological agent(s) other than nematodes and can be prevented by appropriate fumigation with CP or other MB alternatives.

Download

First Report of Fruit Rot and Associated Branch Dieback of Almond in California Caused by a Phomopsis Species Tentatively Identified as P. amygdali

Plant Disease, 1999

A fruit rot of almond (Prunus dulcis (Mill.) D. Webb.) was observed in an orchard in Durham, CA (... more

Etiology and Management of a Mandarin Rind Disorder in California

ABSTRACT

The Bee Informed Partnership: Using Beekeeper's Real-World Experience to Solve Beekeepers' Real-World Problems

by Joseph Connell and Marla Spivak

Download

The Bee Informed Partnership: Using Beekeeper's Real-World Experience to Solve Beekeepers' Real-World Problems

by Joseph Connell and James Wilkes

American Entomologist, 2012

Download

Olive Fruit Fly Management Guidelines for 2006

by Joseph Connell and Alexandra K Devarenne

Foliar Boron Application Improves Flower Fertility and Fruit Set of Olive

Hortscience, 2001

A 2-year field study was conducted to determine if foliar B applications prior to flowering incre... more A 2-year field study was conducted to determine if foliar B applications prior to flowering increased fruit set in olive (Olea europaea L.) cv. Manzanillo. Boron solutions were applied (935 L·ha -1 ) at four concentrations (0, 246, 491, and 737 mg·L -1 ) to trees exhibiting no vegetative symptoms of B deficiency. Foliar B application increased both the percentage of perfect flowers and fruit set, but no effect on pollen germination was observed in either year. The increase in fruit set was not accompanied by a reduction in fruit size. The beneficial effects of foliar B application varied between years and were greater when fruit set was low. The results obtained here are in agreement with those observed in other tree species, in which foliar B applications made immediately prior to flowering or during the period of floral bud initiation significantly increased fruit set and yield. The physiological basis for this effect, however, remains unclear.

Download

Importance of Ground Vegetation in the Dispersal and Overwintering of Xylella Fastidiosa

Our goal is to determine the ability of alternate host plants, specifically "ground vegetation," ... more Our goal is to determine the ability of alternate host plants, specifically "ground vegetation," in or near almond orchards or vineyards to serve as reservoirs for Xylella fastidiosa (Xf). We surveyed ground vegetation in ALS-infected almond orchards in California's Central Valley. Plant tissue samples were collected throughout a 2 year period and processed for Xf presence using restriction enzyme digestion of RST31-RST33 polymerase chain reaction (PCR) products and bacterial culture on selective media. Overall incidence of Xf was low in the ground vegetation species, only 63 of 1369 plant samples tested positive. Of the 37 species of common ground vegetation sampled, 11 tested positive for Xf, including such common species as Sheperd's purse (Capsella bursa-pastoris), filaree (Erodium spp.), cheeseweed (Malva parvifolia), burclover (Medicago polymorpha), annual bluegrass (Poa annua) London rocket (Sisymbrium irio), chickweed (Stellaria media). There was a seasonal component to bacterial presence, with positive samples found only between November and March. Both ground vegetation and almond trees were most commonly infected with the almond strain of Xf (6 of 7 surveyed sites). ALSinfected almond samples had a Xf concentration within reported ranges, however, we were unable to accurately measure Xf titer in sampled ground vegetation for comparison.

Download