There is a lack of information about fertilization of pineapple grown in the State of São Paulo, Brazil. So a field experiment with pineapple 'Smooth Cayenne' was carried out to study the effects of NPK rates on yield and fruit quality. The trial was located on an Alfisol in the central part of the State of São Paulo (Agudos county). The experimental design was an incomplete NPK factorial, with 32 treatments set up in two blocks. The P was applied only at planting, at the rates of 0; 80; 160 and 320 kg/ha of P2 0(5), as superphosphate. The N and K2O rates were 0; 175; 350, and 700 kg/ha, applied as urea and potassium chloride, respectively, divided in four applications during the growth period. Response functions were adjusted to yield or to fruit characteristics in order to estimate the nutrient rates required to reach maximum values. The results showed quadratic effects of N and K on yield and a maximum of 72 t/ha of fresh fruit was attained with rates of 498 and 394 kg/ha, respectively of N and K2O. In order to reach the maximum fruit size, and to improve the percentage of first class fruit (mass greater than 2.6 kg), were necessary rates of N and K respectively 11 and 43 % higher than those for maximum yield. No effect of P rates was observed on pineapple plant growth, despite the low availability of this nutrient in the soil. The effect of N rates was negative on total soluble solids and total acidity while the opposite occurred with K, which increased also the content of vitamin C. High yield and fruit size were closely related to N and K concentrations in the leaves.

The effects of harvest maturity of mangos (Mangifera indica L.) on storage tinder various low-temperature regimes and the influence of storage on quality development during subsequent ripening at higher temperatures were investigated. The capacity for storage of mango fruit depended on harvest maturity, storage temperature, and the time of harvest within the season. Development of peel and pulp color, soluble solids concentration, pH, and softening in `Amelie', `Tommy Atkins', and `Keitt' mangos occurred progressively during storage for up to 21 days at 12C. Based on the level of ripening change that occurred during 12C storage, immature fruit showed superior storage capacity than fruit harvested at more-advanced stages of physiological maturity. On transfer to ripening temperatures (25C); however, immature fruit failed to develop full ripeness characteristics. Mature and half-mature fruit underwent limited ripening during storage at 12C, the extent of which increased with progressive harvests during the season. Ripening changes during storage for 21 days were less at 8 and 10C than at 12C. Chilling injury, as indicated by inhibition of ripening, was found at all harvest stored at 8C, and in early season harvests stored at 10C. Fruit from mid- and late-season harvests stored better at 10 than at 12C, with no apparent signs of chilling injury. Flavor of mangos ripened after low-temperature storage was less acceptable than of those ripened immediately after harvest. Suggestions are made for maximizing storage potential by controlling harvest maturity and storage temperature for progressive harvests throughout the season.

Guavas cv.`Kumagai' were packed in several plastic materials and stored at 10°C and 85±90% relative humidity (RH) for 7, 14, 21 and 28 days (3 days at 25°C). The plastic materials studied were: multilayer co-extruded polyolephine ®lm with selective permeability (PSP), low-density polyethylene ®lm (LDPE), LDPE ®lm with mineral incorporation (LDPEm) and heat-shrinkable polyolephine ®lm (SHR). Guavas not packed were taken as control samples. The physicochemical characteristics of the fruits, O 2 and CO 2 transmission rates of the packaging materials and gas composition at the package headspace were evaluated. The LDPE ®lm, 69 mm in thickness, with the lowest permeability to both O 2 and CO 2 , led to anaerobiosis and high CO 2 concentration inside the packages and promoted physiological disturbances and changes in fruit¯avour. The SHR ®lm, 15 mm in thickness, was the most permeable to CO 2 and had quite high O 2 transmission, which modi®ed the inner atmosphere of the packages slightly. The fruits packed in this ®lm showed a poorer quality than the controls, possibly due to the heat produced during the shrinking of the ®lm. The LDPEm ®lm, 24 mm in thickness, was almost as permeable to CO 2 but had reduced O 2 transmission, promoting an atmosphere of equilibrium of 3% O 2 and 4.5% CO 2 . Fruits packed in this ®lm kept their skin colour and pulp ®rmness, suitable for consumption up to 14 days. The PSP ®lm, 35 mm in thickness, had the greatest O 2 transmission but just over half of the CO 2 transmission of LDPEm, promoting an atmosphere of equilibrium of 0.5% O 2 and 4.5% CO 2 inside the packages. Fruits packed in such packages kept their physicochemical characteristics up to 21 days.

Um experimento foi desenvolvido em Agudos (SP), num Argissolo Vermelho-Amarelo, com o objetivo de avaliar o efeito do parcelamento da adubação NPK em abacaxizeiro 'Smooth Cayenne'. Foram estudados os seguintes esquemas de fracionamento da adubação NPK: T1 (testemunha) -- N e K parcelados em quatro aplicações (60 kg ha¹ de N e de K2O em jun/95; 120, em nov/95; 250, em jan/96 e 120, em mar/96); T2 -- N e K parcelados em quatro aplicações (60 kg ha¹ de N e de K2O em jun/95; 120, em nov/95; 160, em jan/96 e 210, em mar/96); T3 -- N e K parcelados em três aplicações (90 kg ha¹ de N e de K2O em jun/95; 180, em nov/95 e 280, em jan/96); T4 -- N e K parcelados em cinco aplicações (60 kg ha¹ de N e de K2O em jun/95; 110, em nov/95; 160, em jan/96; 110, em mar/96 e 110, em maio/96); T5 -- diferiu do T1 pelo número maior de aplicações de K (cinco) e, do T4 pelo menor número de aplicações de N (quatro); nesses cinco tratamentos (T1 a T5), todo o P foi aplicado no plantio (maio/95); T6 -- N e K parcelados como no T1 e P em duas aplicações (50% no plantio e 50% em jan/96). Os frutos, colhidos 21 meses após o plantio, tiveram sua massa média e qualidade influenciadas pela forma de parcelamento da adubação com N e K; de outro modo, o fracionamento da adubação fosfatada não influenciou a produção. O parcelamento com aplicação mais tardia de N (cinco aplicações, até 12 meses após o plantio-T4) aumentou a produção, contudo, teve efeito negativo sobre o teor de sólidos solúveis dos frutos.

Mangoes (var. Tommy Atkins) were exposed to ethylene and acetylene over a range of concentrations at high humidity for 24 h at 25 "C, then ripened in air alone. Ripeness was assessed after 4 and 8 days by analysis of texture, colour development, soluble solids and acid contents.Ethylene in air at concentrations of 0.01 ml litre-] and above or acetylene at 1.0 ml litre-' were found to initiate ripening. Treatment with 0.01 ml litre-' acetylene resulted in limited softening but had no effect on the other ripening changes analysed. Individual ripening processes responded differently to treatment: texture changes were most rapidly affected, while the rate of acidity losses was often reduced in ethylene treated fruits. Acetylene-treated fruits at concentrations of 0.01 and 0.1 ml litre-' showed delayed ripening when compared to those treated with either 1-Om1 litre-' acetylene or ethylene. Increased acetylene concentrations of 2.0 ml litre-' gave a similar response to 1.0 ml litre-', although in some instances there were indications of inhibitory effects. 0 1987 Association of Applied Biologists

No abstract

Guavas cv. Kumagai fruits were packed in plastic bags and stored at 10°C and 85-90% RH during 7, 14, 21 and 28 days, followed by open exposure for 3 days at 25°C and 70-80% RH to simulate commercial handling conditions. The packaging materials used were: multilayer coextruded polyolefin film with selective permeability (PSP), low density polyethylene film (LDPE), LDPE film with mineral incorporation (LDPEm) and heat-shrinkable polyolefin film (SHR). Guavas without plastic packages were used as control samples. The concentrations of O 2 and CO 2 in the package headspace and the sensorial characteristics of the guavas (skin color, pulp texture, off-flavor and overall quality) were evaluated. The LDPE film presented the higher gas barrier and promoted the lowest O 2 level (0.1%) and the highest CO 2 concentration (19%) inside the packages. Such passive modified atmosphere induced both off-flavor and abnormal ripeness. The polyolefin heat-shrinkable film provided poor modification in the package atmosphere, so the fruits exhibited fast senescence (decay). The film incorporated with mineral provided an atmosphere of 3% O 2 and 4.5% CO 2 Downloaded from inside the packages, which kept the fruit with good sensorial characteristics for 14 days. The coextruded polyolefin film provided an atmosphere of 0.5% O 2 and 4.5% CO 2 that was sufficient to maintain the fruit with good sensorial characteristics for 28 days.

Aos meus pais José (in memoriam) e Ruth, pelos ensinamentos, amor, dedicação e, sobretudo, exemplo de vida...; À minha irmã Maria José, pelo constante apoio, incentivo e compreensão, DEDICO.