Batsch Var Research Articles

Época e ciclo de maturação de pêssegos e nectarinas no estado de São Paulo

Na Estação Experimental de Jundiaí (23°08'S), do Instituto Agronômico (IAC), controlou-se o número de dias entre a antese e a maturação dos frutos de vinte cultivates de pêssegos (Prvnus persica L. Batsch) e nectarinas (P. persica L. Batsch var. nucipersica). Com base nos resultados obtidos, elaborou-se nova tabela classificatória para ciclos de frutificação, da qual constam, respectivamente, a faixa de maturação, o número de dias entre a flora da e a colheita dos frutos e os cultivares: ultraprecoce,<74dias (Fia. 7-3); bem precoce, 75-90 dias (Flordaprince, Tropical e Maravilha); precoce, 91-120 dias (Régis-1, Jóia-1, Jóia-4, Delicioso Precoce, Centenária, Doura do-1, Aurora-1, Aurora-2, Ouromel-3 e Josefina); mediana, 121-150 dias (Canário, Cristal e Talismã); tardia, 151-180 dias (Biuti e Rei da Conserva) e bem tardia,>181 dias (Bolão).

Starch determination in horticultural plant material by an enzymic‐colorimetric procedure

AbstractThe starch content of horticultural plant material (including leaves and woody tissues such as roots, stems, twigs, trunks and bark) was determined by an enzymic procedure. A heat‐stable α‐amylase and amyloglucosidase were used to hydrolyse the starch in the finely ground plant material to glucose. The glucose produced was measured colorimetrically using a coupled glucose oxidase/peroxidase reaction. Conditions necessary for maximum glucose recovery were established. Plant material analysed included samples from macadamia (Macadamia integrifolia Maiden and Betche, trunk and bark), mango (Mangifera indica L; stems and roots), lychee (Litchi chinensis Sonn; leaves, stems, twigs and roots), pineapple (Ananas comosus (L) Merrill; leaves, stems and roots) and nectarine (Prunus persica (L) Batsch var nucipersica (Suckow) C K Schneid; twigs, shoots, branches, limbs, roots and trunk). Starch values ranged from less than 14% to greater than 30%. The method allows assessment of variations in the starch content of perennial plants and may be used in crop management.

Decay Control and Quality Maintenance after Moist Air Heat Treatment of Individually Plastic-wrapped Nectarines

Abstract Moist air heat treatment at 52C for 15 min prevented decay in individually plastic-wrapped or naked nectarine [Prunus persica (L.) Batsch var. nectarina (Ait.) Maxim.] fruit puncture-inoculated with Monilinia fructicola (Wint.) Honey. Heat treatment for 5 or 10 min slowed decay development, but did not prevent it. In treatments where decay occurred, the wrap increased decay. Heat treatment tests at 52C for 15, 30, 45 min slowed softening and ethylene production of fruit. Wrapping alone reduced ethylene production 75% and respiration 12%, but did not significantly influence softening. The wrap reduced or eliminated undesirable skin browning associated with heat treatments.

Rearing, Large-Scale Tests, and Egg Response to Confirm Efficacy of a Methyl Bromide Quarantine Treatment for Codling Moth (Lepidoptera: Tortricidae) on Exported Nectarines

Methods to rear codling moth (CM), Cydia pomonella (L.), adults to produce mass numbers of eggs to coincide with the seasonal maturation of nectarines, Prunus persica (L.) Batsch var. nucipersica Schneid., are described. Large-scale confirmatory tests of a methyl bromide (MB) quarantine treatment of 48 g/m3 MB for 2 h at 21°C developed to control CM on exported nectarines were done in four tests on 1-d-old eggs on ‘May Grand‘ and ‘Firebrite’ nectarines. No eggs (n = 93,744) survived the MB fumigation, and percentage hatch in the untreated controls (n = 7,180) was 78.2 ± 8.7 (x ±SEM). Security of the quarantine treatment calculated as the true survival proportion was ≤S32per million at the 95% confidence level. The concentration times time (CT) products equaled 66.4 ± 1.1 g h/m3. The embryo and yolk of eggs treated with MB showed abnormal development and evidence of severe damage within 24 h after exposure. Approximately 18.8-41.4% of treated CM eggs on nectarines held at 23°C developed yellow or yellow-orange pigmentation 9-16 d after fumigation. Approximately 1.35 ± 3.6% of the embryos continued development 15-16 dafter MB fumigation and showed head capsule sclerotization, but embryogenesis was incomplete.

Laboratory Evaluations of Oriental Fruit Moth (Lepidoptera: Tortricidae) Oviposition and Larval Survival on Five Species of Stone Fruits

Oriental fruit moth (OFM), Crapholita molesta (Busck), oviposition on fruit and first-instar survival on vegetative shoots were studied in laboratory tests with nectarine, Prunus persica (L.) Batsch var nucipetsica; peach, P. persica (L.); plum, P. saliciana Lind.; apricot, P. atmeniaca L.; and cherry, P. avium L., cultivars. OFM oviposition on fruit at four different maturity stages was significantly lower on mature, packed nectarines and significantly higher on mature, packed peaches. Significantly more eggs were laid on the stem end of nectarine, peach, and plum fruits than other fruit parts. In tests among earlythrough late-season cultivars within each stone fruit species, oviposition was significantly higher on ‘Red Diamond’ nectarines, ‘Redtop’ peaches, and ’Laroda’ plums, and significantly lower on ‘Fantasia’ nectarines and ‘Roysum’ plums. In tests with mixed stone fruit species, significantly fewer eggs were laid on ‘Elberta,’ ‘Elegant Lady,’ and ‘O’Henry’ peaches, and significantly more eggs were laid on ‘Laroda’ plums. Low oviposition on peaches may be related to pubescence. Vegetative shoots injured by larval feeding generally produced gum, but uninjured shoots and shoots that supported first instars to later larval or pupal stages rarely produced gum. Larvae successfully completed normal development to adults on larval diet combined with aqueous extracts of peach tree gum. Stone fruit gum appears to be an induced host response which creates a mechanical barrier to larval attack.

Laboratory Evaluations of Codling Moth (Lepidoptera: Tortricidae) Oviposition on Three Species of Stone Fruit Grown in California

Codling moth (CM), Cydia pomonella (L.), ovipositional behavior in laboratory tests was studied on nectarines, Prunus persica (L.) Batsch var. nucipersica , peaches, P. persica (L.) Batsch, and plums, P. salicina Lindl., maturing at different times of the growing season. Neither stage of fruit maturity nor skin color of nectarines influenced CM oviposition. CM oviposited more eggs on mature, packed peaches than on firm, immature green peaches and oviposited more eggs on firm, immature green plums than on more mature plums. The calyx and stem ends of nectarines, peaches, and plums were the most acceptable ovipositional sites on each fruit. Low numbers of CM eggs were removed from ovipositional sites when nectarines were passed through a packinghouse washer. No significant differences were found in CM oviposition among cultivars within each stone fruit species, except that a significantly higher number of CM eggs were oviposited on plums of the ‘Queen Ann’ cultivar. CM oviposition on seasonal cultivars was compared in tests among mixed stone fruit species.

Methyl Bromide Fumigation to Control the Oriental Fruit Moth (Lepidoptera: Tortricidae) in Nectarines

Responses of 24-h-old eggs and first through fifth in stars of the oriental fruit moth (OFM), Grapholita molesta (Busck), in artificially infested nectarines, Prunus persica (L.) Batsch var. nucipersica Schneid, to methyl bromide (MB) fumigation for 2 h at 21°C is reported. Eggs were least susceptible and first in stars were most susceptible when LC50’s and concentrations to cause 100% mortality were compared. A MB dose of 30 g/m3 resulted in 100% egg mortality. A currently used MB quarantine fumigation schedule of 32 g/m3 for 2 h at 16–26°C was determined to be efficacious against OFM in nectarines for export to British Columbia.

Methyl Bromide Fumigation for Quarantine Control of Codling Moth (Lepidoptera: Tortricidae) on Nectarines

A methyl bromide (MB) fumigation of 48 g/m3 for 2 h at 21°C or above was developed for control of codling moth (CM), Cydia pomonella (L.), on six early to midseason nectarine, Prunus persica (L.) Batsch var. nucipersica Schneid, cultivars, including ‘May Grand’, ‘Firebrite’, ‘Red Diamond’, ‘Spring Red’, ‘Summer Grand’, and ‘Fantasia’. The fumigation treatment was based on mortality data from 24-h-old eggs, the CM life stage least susceptible to MB that may infest early to midseason fresh, packed nectarines. No differences in egg susceptibility to MB were found among five infested nectarine cultivars. MB was more toxic to CM eggs on ‘Summer Grand’. Doses (30.0–40.0 g/m3) and concentration times time (CT) products required to cause 100% CM egg mortality were determined. Large-scale tests of the proposed MB fumigation quarantine treatment caused 100% mortality of 6,187 CM eggs.

Phytotoxic Responses of Cherries, Nectarines, Peaches, Pears, and Plums Fumigated with Methyl Bromide for Control of Mediterranean Fruit Fly1

Abstract Cultivars of sweet cherry (Prunus avium L.), nectarine [P. persica (L.) Batsch var. nectarina (Ait.) Maxim.] peach [P. persica (L.) Batsch], pear (Pyrus communis L.) and plum (Prunus salicina Lindl.) differed in their phytotoxic responses to methyl bromide (MB) fumigation treatments designed to control the Mediterranean fruit fly (Ceratitis capitata Wied.) without use of a subsequent cold treatment. Phytotoxic responses were relatively mild or negligible in most cultivars fumigated at 21°C with 48 g MB/m3 for 2 hours, 48 g/m3 for 3 hours, or 32 g/m3 for 4 hours. A few of the cultivars tested were very susceptible to MB injury. In some cultivars, both the control and fumigated lots exhibited symptoms of injury that apparently were not related to the fumigations but were caused by packinghouse handling or orchard practices. The fumigations slowed the ripening of cherries and plums. Decay of nectarines was slightly greater in fumigated than in control lots of fruit.