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Abstract
Fruit of ‘Valencia’ orange (Citrus sinensis Osbeck) and ‘Murcott’ tangerine (Citrus reticulata Blanco) were subjected to cold treatment at 1.1°C for 17 days as prescribed for the disinfestation of citrus of the Caribbean fruit fly (Anastrepha suspensa (Loew) in the plant protection and quarantine treatment manual. Fruit quality was evaluated during subsequent storage at 4.4°C for one week followed by 2 weeks at 21.1°. Fruit under cold treatment did not develop any physiological disorders. Fruit color and general appearance remained unaffected. Loss due to decay was 2.3% for ‘Murcott’ tangerine and 7.2% for ‘Valencia’ orange. Moisture loss for both varieties was about 5%. Fruit quality, including flavor, was found to be acceptable in ‘Murcott’ during subsequent storage. Yet the quality of ‘Valencia’ remained acceptable for one week only at 4.4°. Cartons used for packing fruit and stored at 1.1° absorbed more moisture when transferred to 21.1° than the cartons at 4.4° or 21.1° because of moisture condensation on fruit.
Flowering spurs located at interior and exterior canopy positions of `Stay-man' and `Delicious' apple (Malus domestics Borkh.) trees were girdled and/or defoliated to determine the influence on nectar production and composition. Nectar volume was less at exterior than interior canopy positions for `Delicious', but not for `Stayman'. Girdling suppressed nectar production by 92% and reduced the sugar concentration of the remaining nectar. Defoliation of nongirdled spurs had no effect on nectar sugar concentration, but defoliation of girdled spurs reduced nectar sugar concentration by 24%. Relative percentages of sucrose, glucose, and fructose, and the sucrose: hexose ratio were unaffected by any treatment. Nectar production of nongirdled spurs did not depend on the presence of spur leaves.