No description available.

Septoria leaf spot was detected in the United States for the first time in 1964 within an experimental pistachio planting at Brownwood, Texas. The first observation of the same disease in Arizona pistachio trees did not occur until 1986. In 1988, a survey of the 2,000 acres of pistachio orchards in southeastern Arizona revealed a widespread incidence of the disease. Since the initial discovery of the disease, Septoria leaf spot has appeared annually in some of the Arizona pistachio acreage. The onset and severity of the disease is influenced by summer rainfall that occurs in this region. Disease management trials conducted since 1992 have shown that as few as two applications of chlorothalonil in July and August can virtually prevent disease development. Applications of copper hydroxide or benomyl alone or in combination also effectively arrest disease development. Leaves around nut clusters on infected trees not receiving fungicide treatments were usually senescent at crop maturity, whereas leaves on treated trees showed no sign of senescence. Pistachio trees infected with Septoria leaf spot and not treated with an effective fungicide can defoliate in the autumn up to 2 months prematurely.

The fungicide, benomyl (Benlate) was foliar applied by a commercial air blast sprayer at the rate of 1.0 lb. a.i. per acre in early to late August. Treatments varied with a number of applications i.e. one or two and were compared to an untreated control. Benomyl significantly reduced leaf necrosis surrounding nut clusters and the number of leaf spot lesions when compared to control. One or two applications were equally effective in controlling Septoria leaf spot.

Septoria leaf spot was detected in the United States for the first time in 1964 within an experimental pistachio planting at Brownwood, Texas. The first observation of the same disease in Arizona pistachio trees did not occur until 1986. In 1988, a survey of the 2,000 acres of pistachio orchards in southeastern Arizona revealed a widespread incidence of the disease. Since the initial discovery of the disease, Septoria leaf spot has appeared annually in some Arizona pistachio orchards. The onset and severity of the disease is influenced by summer rainfall that occurs in this region. Pistachio trees infected with Septoria leaf spot and not treated with an effective fungicide can defoliate in the autumn up to 2 months prematurely. The objective of this field study was to evaluate the efficacy of several different fungicides against this disease. All fungicides were applied to tree foliage on June 26 and July 31, 2001. Disease severity was lowest on trees treated with Flint (trifloxystrobin) and Abound (azoxystrobin). Other materials that significantly reduced the final level of disease compared to nontreated trees included Break (propiconazole), Procop R (copper hydroxide) and Elite (tebuconazole).

Septoria leaf spot was detected in the United States for the first time in 1964 within an experimental pistachio planting at Brownwood, Texas. The first observation of the same disease in Arizona pistachio trees did not occur until 1986. In 1988, a survey of the 2,000 acres of pistachio orchards in southeastern Arizona revealed a widespread incidence of the disease. Since the initial discovery of the disease, Septoria leaf spot has appeared annually in some Arizona pistachio acreage. The onset and severity of the disease is influenced by summer rainfall that occurs in this region. Pistachio trees infected with Septoria leaf spot and not treated with an effective fungicide can defoliate in the autumn up to 2 months prematurely. The objective of this field study was to evaluate the efficacy of several different fungicides against this disease. All fungicides were applied to tree foliage on July 13 and August 10, 1999. Disease severity was lowest on trees treated with Flint (trifloxystrobin). Other materials that significantly reduced the final level of disease compared to nontreated trees included Abound (azoxystrobin), Break (propiconazole), and Procop R (copper hydroxide).

Thesis (Ph. D.)--University of Adelaide, Dept. of Horticulture, viticulture and ocnology, 1996. / Copy of author's previously published article inserted. Includes bibliographical references (leaves 127-154).

Thesis (MScAgric)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: The climate around Prieska differs from other pistachio growing regions in the world in that it receives fewer winter chilling units, has higher maximum temperatures during winter and spring and receives summer rainfall. This possibly results in the observed delayed foliation, flower bud and inflorescence abortion, low fruit set and other flowering disorders, which lower yield potential. In order to increase yields, winter pruning, evaporative cooling and chemical rest breaking were investigated on ‘Ariyeh’, ‘Shufra’ and ‘Sirora’ pistachio trees. Tip-pruning (to remove <2.5cm) and severe heading cuts (to remove 35-45%) of one-year old wood were compared and 4% hydrogen cyanimide (Dormex®), 4% mineral oil (Budbreak®) as well as the combination (0.5% Dormex® + 4% Budbreak®) used as rest breaking agents. Bud break, reproductive bud differentiation, die-back, flower bud retention during winter and early summer as well as yield were evaluated. The results emphasised the interaction of rest breaking and pruning effects, with genetic chill requirements and environmental influences - specifically winter chill build-up. Severe pruning was detrimental to flower bud formation as well as yield. The bud break data suggests that the ability of some rest breaking chemicals to promote lateral development may be explained by their potential to impede the development of apical dominance, rather than a direct effect on the lateral buds. The inability of the chemical treatments to increase yield consistently might indicate other factors involved or that the average winter chill of Prieska is below the minimum amount necessary for adequate rest breaking effects on yield. Evaporative cooling was used to counteract potential negative effects of high maximum day temperatures during autumn and spring on flower bud retention, fruit set and yield. Cooling during autumn (May + June, Southern hemisphere), spring (August + September, Southern hemisphere) and the combination of autumn + spring were investigated during two seasons. Flower bud retention during winter and early summer, flowering patterns, as well as yield were evaluated. The significant effects obtained with evaporative cooling - specifically in autumn + spring, indicated the important role climatic conditions play during both stages of entering and exiting dormancy of pistachio trees. Although all differences are not yet clearly understood, the fact that evaporative cooling resulted in substantially higher yields in the case of ‘Ariyeh’ and ‘Shufra’ in an area with sub-optimal pre-blossom temperatures and less than 40% of the required winter chill of pistachio, emphasises its potential in horticultural management. / AFRIKAANSE OPSOMMING: Prieska se klimaat verskil van ander pistachio-produksie areas in die wêreld deurdat minder winterkoue-eenhede opgebou word, dit hoër maksimum temperature het gedurende die winter en lente en ’n somer-reënvalgebied is. Dit dra waarskynlik by tot die waargenome vertraagde bot, blomknop- en bloeiwyse abortering, lae vrugset en ander blom-afwykings. Aangesien hierdie faktore opbrengspotensiaal verlaag, is wintersnoei, verdampingsverkoeling en chemiese rusbreking ondersoek as moontlike bestuursoplossings. Tip- (om <2.5cm te verwyder) en topsnitte (om 35-45% te verwyder) van eenjarige lote is met mekaar vergelyk en 4% waterstofsianied (Dormex®), 4% minerale olie (Budbreak®) en hul kombinasie is as rusbrekers aangewend. Bot, blomknop-differensiasie, terug-sterwing, blomknopretensie gedurende winter en vroeë somer sowel as opbrengs is geëvalueer. Die resultate benadruk die onderlinge interaksie van rusbreking- en snoei-effekte met genetiese koue-behoeftes en omgewingseffekte - spesifiek die opbou van winterkoue. Topsnitte was nadelig vir blomknopvorming, sowel as opbrengs. Die bot-data doen aan die hand dat sommige chemiese rusbrekers se potensiaal om laterale breke te bevorder, verduidelik kan word deur hul vermoë om die ontwikkeling van apikale dominansie te onderdruk, eerder as ‘n direkte effek op die laterale knoppe. Die chemiese behandelings se onvermoë om opbrengs deurggaans te verbeter, mag daarop dui dat die gemiddelde winterkoue van Prieska laer is as die minimum hoeveelheid benodig alvorens chemiese rusbreker effekte op opbrengs verwag kan word. Potensiële negatiewe effekte van hoë maksimum dagtemperature gedurende die herfs en lente op blomknopretensie, vrugset en opbrengs is teengewerk deur middel van verdampingsverkoeling. Verkoeling gedurende herfs (Mei + Junie, Suidelike halfrond), lente (Augustus + September, Suidelike halfrond) en die kombinasie van herfs + lente is gedurende twee seisoene ondersoek. Blomknopretensie gedurende winter en vroeë somer, blompatrone, sowel as opbrengs is geëvalueer. Die betekenisvolle verskille verkry met verdampingsverkoeling, dui die belangrike rol aan wat klimaatstoestande gedurende beide stadiums van in-, sowel as uitgang uit dormansie speel in pistachiobome. Hoewel alle verskille nog nie verklaar kan word nie, dien die feit dat verdampingsverkoeling tot substansiële opbrengste in die geval van ‘Ariyeh’ en ‘Shufra’ kon lei in ‘n area met suboptimale voor-bot temperature en gemiddeld minder as 40% bevrediging van die kouebehoefte van pistachios, as beklemtoning van die belang daarvan as hortologiese bestuursmiddel.

No description available.

Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Kenneth Roux, Florida State University, College of Arts and Sciences, Dept. of Biological Science. Title and description from dissertation home page (viewed Jan 18,2005). Includes bibliographical references.

No description available.