摘要:

Tip breakdown is a serious postharvest disorder of asparagus(Asparagus offtcinalis)which can result in severe wastage and quality loss. We report significant variation amongst plants in their susceptibility to this disorder. This variation may be genetic in origin, but the results presented are equivocal on this. Plants with low levels of tip breakdown had higher levels of soluble carbohydrate in spear tips than plants susceptible to the disorder. Protein levels and postharvest accumulation of ammonia were not significantly different in plants with low levels of tip breakdown compared to plants with high levels. The possibilities for selecting resistant plants are discussed.

ISSN:0114-0671    

DOI:10.1080/01140671.1994.9513809

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Quality parameters were measured in two seasons for seeds produced from early (sown November, harvested January) and late (sown December, harvested February) crops of garden pea(Pisum sativumL.) ‘Pania’. Harvest was by hand at 15% seed moisture content (SMC). Time of sowing had no effect on the germination of the seeds produced, but did affect seed vigour as both conductivity and hollow heart were greater in seeds from the November sown crop, and as a consequence, expected field emergence (EFE) was significantly lower. At a 40% SMC harvest in the second year of study, germination and conductivity did not differ between the two sowing dates and so the EFE also did not differ significantly. However as harvest was delayed until 25 and 15% SMC, there was a higher hollow heart incidence and higher conductivity in seeds from the early crop compared with the late crop. Seeds from the November sowing encountered greater climatic extremes (temperature, rainfall, and relative humidity) during their maturation in January than seeds from the December sowing which matured in February. Although the data are only from one cultivar at one site over two seasons, the results suggest that pea seed vigour and hence potential field and storage performance could be improved by sowing to avoid detrimental climate effects during seed development and ripening.

ISSN:0114-0671    

DOI:10.1080/01140671.1994.9513810

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Changes in flesh firmness of kiwifruit(Actinidia deliciosa)in response to fruit temperature were characterised for fruit removed from storage at 0°C at a range of levels of firmness generated by the normal softening associated with fruit ripening. Firmness was less after 24 h equilibration to 20°C (f2) than when measured immediately after removal from coolstorage(f1). Fruit regained firmness upon recooling to 0°C (f3) which, as a proportion of], occurred to greater extent in soft fruit than firmer fruit which were in the rapid phase of fruit softening. Thus, the firmness temperature coefficient(kft, %/°C, a measure of the percentage change in firmness caused by a given temperature change) of kiwifruit was itself shown to be a function of flesh firmness. It is suggested this resulted from contributions from two processes: a direct, reversible, physical effect that was a linear function of temperature; and in the phase of rapid fruit softening, an irreversible, physiological loss of firmness associated with stimulated fruit ripening at elevated temperature. Fitted functions relatingkfTto f1and f2were used to develop expressions which permit approximate calculation off2givenf1and vice versa. These expressions could be used to link more effectively research data obtained at 20°C with commercial assessments of fruit firmness made on fruit at 0°C e.g., by correcting estimates of time required for fruit to soften to commercially important firmness thresholds.

ISSN:0114-0671    

DOI:10.1080/01140671.1994.9513811

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The root systems of willow‐tree shelter root systems and adjacent kiwifruit root systems, and measurements of gravimetric soil water content, were mapped in three orchards on deep Te Puke soils, in the North Island of New Zealand. Fruit yields were also obtained from the first (5–6 m from the shelter) and middle (4th or 5th row, 19–24 m from the shelter) rows of the sampled blocks. The three orchards were aged between 11 and 14 years, and each used a different shelter root‐pruning method, i.e., (1) regular annual root pruning where shelter roots were cut on both sides of trees every spring with a 0.8 m deep slit c. 2.5 m from the shelter; (2) occasional root pruning where shelter roots had been cut once 2 years before the experiment; and (3) no root pruning. Root‐length density data were obtained from cores sampled randomly in the 5–6 m headland region between the shelter row and the first row of kiwifruit vines to 2 m depth, and from the first two rows of kiwifruit (up to 10.2 m from the shelter) to 1 m depth. More dead roots were found in the two root‐pruned treatments between the pruning slits and the first row of kiwifruit (P<0.02). However, root pruning had no significant effect on live willow roots in the adjacent two rows of kiwifruit(P <0.05). Mean live willow root‐length densities over all orchards in the 0–1 m layer were: 0.06 104m/m3between the shelter and the 1 st row of kiwifruit; and 0.04 104m/m3between the 1st and 2nd rows. Cumulative distributions of ranked data were used to compare treatments. Root pruning treatments had no significant effects on soil water contents(P <0.05), but soil water contents were significantly lower within 5 m from the shelter(P <0.001) compared to more than 5 m distant. The data indicate that shelter roots quickly grow under root‐pruning slits and subsequent pruning is probably ineffective for decreasing water competition in deep soils. Fruit yields and average fruit weights did not differ between root pruning treatments, but the c. 50% lower yields in the kiwifruit row adjacent to the shelter were in agreement with other results which showed that shading from cloth substantially reduced fruit yields.

ISSN:0114-0671    

DOI:10.1080/01140671.1994.9513812

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:0114-0671    

DOI:10.1080/01140671.1994.9513813

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor