The use of heat to control the rotting of Cox's Orange Pippin apples by Gloeosporium spp

Dipping in warm water successfully reduced the incidence of infection of Cox's Orange Pippin apples by Gloeosporium spp. Treatment of fruit loaded after harvest with spores of G. perennans was most successful if carried out 3–9 days after inoculation; later treatment was less effective. Infection taking place late in the growing season was relatively more susceptible to treatment than infections established on less mature fruit. Steam/air mixtures provided a successful, alternative source of heat; accelerated cooling after treatment with such mixtures did not reduce their effect. Browning of the skin and increased incidence of rotting by Penicillium spp. may follow heat treatment. With liquid cultures heat has a greater effect on germinated than on ungerminated spores and over the range of temperatures used for treating apples results in delayed fungal development rather than eradication.     

The potential of a sucrose ester coating material for improving the storage and shelf-life qualities of Cox's Orange Pippin apples

A sucrose-ester coating material was tested for its potential as a storage technique and as an extender of the shelf life of apple (cv. Cox's Orange Pippin). Apples treated with 1·25% sucrose ester formulation were stored in air at 3·5°C for up to 5 months. Sucrose ester treatment did not reduce detrimental changes in terms of fruit firmness, yellowing and weight loss but did increase core flush incidence. When applied after storage, the sucrose ester reduced yellowing and loss of firmness and markedly increased internal carbon dioxide levels during a 21 day simulated marketing period. Effects were enhanced with increasing sucrose ester concentrations between 1% and 4%. Sucrose ester did not markedly reduce weight loss in the fruit, did not cause accumulation of alcohol or induce any internal physiological disorders during the simulated marketing period. Treatment of fruit with an external atmosphere containing 8% carbon dioxide, a level similar to that found in fruit treated with 3% sucrose ester, did not have the same effects as 3% sucrose ester on firmness or ground colour changes, suggesting that the effects of the sucrose ester are not solely the result of the raised carbon dioxide level.     

The effect of a post-harvest heat-treatment on the storage behaviour of Cox's Orange Pippin apple fruits

Samples from a wide range of commercially grown Cox's Orange Pippin apple fruits were immersed in water at 45° C. for 10 min. to control rotting due to Gloeosporium spp. In two seasons the incidence of rotting following storage for 19 weeks at 3·3° C. (38° F.) was reduced to about 40% of the level in the untreated samples. However, there was a marked increase in the incidence of breakdown and core flush in the treated fruit, particularly when stored in a controlled atmosphere of 5% CO₂, 3 % O₂. A similar but less severe increase in the incidence of breakdown was also recorded in the second season in treated fruit stored in 2% O₂ (with continuous removal of CO₂). The treated fruit tended to develop a more yellow ground colour and softened more rapidly during storage in 5% CO₂, 3% O₂. It is concluded that the treatment advances fruit senescence and that the increased incidence of physiological disorders is likely to limit the use of this method for the control of Gloeosporium rotting in English-grown Cox apples.     

The Photosynthetic Activity of Cox's Orange Pippin Apple Flowers in Relation to Fruit Setting

The ability of green parts of Cox's apple flowers (sepals, receptacleand pedicel) to photosynthesise was demonstrated using ¹⁴CO,feed experiments and an infra-red gas analysis (IRGA) system.The sepals had the greatest ability, comparable with that ofleaves, followed by the receptacle. Sepals and leaves fixedthe same amount of CO₂ in the dark. Photosynthesis and respirationrates in orchard flowers were measured in comparison to thoseof leaves. Flower gross photosynthesis (GP) was about a thirdof that of leaves at the balloon stage and 15 d after full bloomin 1987, but this ratio was much less at full bloom (FB) inthe same year. GP in flowers decreased rapidly with fruitletenlargement. It was estimated that flower photosynthesis significantly contributedto their carbohydrate balance (15-33%) during the floweringand fruit setting periods. The highest contributions were made at the green cluster stage(33%) and between 6 and 11 d after FB (27%), the period whenthe fruit set had been initiated. Removal of sepals, the mainphotosynthetic parts of the flower, at the pink bud stage decreasedinitial set. The results suggest that flower photosynthesismight play an important role in flower growth and fruit setting.Copyright1994, 1999 Academic Press Apple, photosynthesis, respiration, fruit setting, flower photosynthesis, sepal removal     

Stomatal and Chlorophyll Distribution of Cox's Orange Pippin Apple Flowers Relative to Other Cluster Parts

Surface area, chlorophyll concentration and stomatal size anddensity were measured for all green components of floral clusterson Cox's Orange Pippin apple trees to assess their relativepotential for photosynthesis. Before flower opening, sepalsand receptacles had chlorophyll concentrations similar to thosefound in the laminae of rosette leaves. But, whereas the concentrationin rosette leaves continued to increased until fruit set, thosein the sepals and receptacles decreased. Sepals had a greater mature stomatal density than leaf laminaeshortly after bud burst; although both densities increased,that on the laminae later exceeded that on sepals. Flowers contributed significantly to the green surface are (40%),chlorophyll content (30%) and mature stomatal number (25%) offloral clusters at the green cluster stage, but these contributionsthen decreased. Cox apple flowers appear to have the potentialfor contributing significantly to their carbohydrate requirementat a time when the rosette leaves are not thought to be exportersof photosynthate.Copyright 1993, 1999 Academic Press Malus pumila, apples flowers, chlorophyll, stomata, surface area, flower photosynthesis     

Xylem Development in the Gynoecium of the Apple (Malus pumila L.) Cv, Cox's Orange Pippin

Lignification of the xylem within the carpellary bundles ofapple flowers spreads acropetally from a point 900–1400µm below the base of the locules. At the same time, anotherwave of lignification spreads basipetally from a point justbelow the stigma. The acropetal spread at first progresses morequickly, but at later stages the number of lignified xylem elementsjust below the stigma increases rapidly, reaching a peak justas the flower opens. This increase is very localized and thenumber declines greatly within only 25% of the stylar distancebelow the stigma. Lignification of the xylem in the bundlesserving other flower parts precedes that serving the gynoecium,and spreads basipetally from a point above the base of the locules. Malus pumila L, anatomy, apple, carpel, Cox's Orange Pippin, development, flower, gynoecium, pedicel, pistil, stigma, style, vasculature, xylem     

Ovule and Embryo Sac Development in Malus pumila L. cv. Cox's Orange Pippin, from Dormancy to Blossom

Ovule and embryo sac development in the flowers of Cox's OrangePippin apple (Malus pumila L.) were studied from dormancy topetal fall using both scanning electron and light microscopy.The relative timing was established between these developmentsand the external development of the flower bud and flower. Malus pumila L. cv. Cox's Orange Pippin, apple, Cox, SEM, ovule development, anatomy, histology     

Anthocyanin, Carotenoid, and Chlorophyll Changes in the Peel of Cox's Orange Pippin Apples during Ripening on and off the Tree

The concentrations of various peel pigments of Cox’s OrangePippin apples have been measured during ripening on the treeand during storage at 12 °C. Total chlorophyll decreased and total carotenoid increased atthe time of the respiration climacteric. These changes weremore pronounced in fruit maturing on the tree where a significantincrease of anthocyanin occurred; it did not occur in storedfruit. There was no consistent or marked difference in the ratesof destruction of chlorophylls a and b. The carotenoids found in the unripe fruit were those characteristicof photosynthetic tissue, ß-carotene, lutein, violaxanthin,and neoxanthin. These decreased to a greater or lesser extent,and at different rates, on and off the tree. Other carotenoidswhich increased greatly during ripening were identified as esters,mainly of violaxanthin. During the climacteric there is a transition from an assemblageof pigments associated with the chloroplast to that typicalof a chromoplast.     

The effect of benomyl sprays on Sclerotinia trifoliorum and yield of red clover

Benomyl sprays, applied monthly from September to January, increased the survival and dry-matter yield of red clover and decreased the numbers of apothecia of Sclerotinia trifoliorum. Two sprays increased dry-matter yield in the first harvest year, if applied between October and December, but decreased yield in the second harvest year.     

Xylem Development in the Gynoecium of the Apple (Malm pumila L.) Cv. Cox's Orange Pippin K. A. D. *J. COSTA TURA{dagger}

Lignification of the xylem within the carpellary bundles ofapple flowers spreads acropetally from a point 900–1400µm below the base of the locules. At the same time, anotherwave of lignification spreads basipetally from a point justbelow the stigma. The acropetal spread at first progresses morequickly, but at later stages the number of lignified xylem elementsjust below the stigma increases rapidly, reaching a peak justas the flower opens. This increase is very localized and thenumber declines greatly within only 25 % of the stylar distancebelow the stigma. Lignification of the xylem in the bundlesserving other flower parts precedes that serving the gynoecium,and spreads basipetally from a point above the base of the locules Malus pumila, L., anatomy, apple, carpel, Cox's Orange Pippin, development, flower, gynoecium, pedicel, pistil, stigma, style, vasculature, xylem regenreation     

Experiments with fungicide sprays in late summer and early autumn on sugar-beet root crops

Fentinhydroxide and benomyl sprayed on to sugar-beet root crops in July, August and September frequently increased yield of tops. Sugar yield was increased only if either powdery mildew or virus yellows was prevalent, when on average a single fentinhydroxide spray at 0·7 kg a.i./ha increased sugar yield by 8% and yield of tops by 13%. The mildew specific fungicide fluotrimazole also increased yield, but it could not be determined whether this was due to controlling powdery mildew or secondary parasitic fungi attacking yellows-infected plants. Repeated sprays of both fentinhydroxide and fluotrimazole, but not benomyl, appeared to be phytotoxic when applied in hot dry weather.     

Low-ethylene storage of apples cv. 'Cox's Orange Pippin': effects of 'Rapid CA' and ultra-low oxygen

Three methods of reducing ethylene accumulation in the flesh of apple fruits cv. ‘Cox's Orange Pippin’ during controlled atmosphere storage were compared with one another and with a control. They were: (a) rapid establishment of storage conditions, (b) treatment with 5% CO₂ for 15 days prior to long-term storage, and (c) lowering storage O₂ from 1.25% to 0.75%. In all cases ethylene was either allowed to accumulate or maintained below 1 μl litre^-1. When ethylene was removed from the storage atmosphere all three methods reduced internal ethylene concentrations. Although the firmness of fruits from two orchards was affected differently by ethylene removal, the effects on the retention of flesh firmness by ethylene removal and storage in 0.75% O₂ were generally additive. No adverse effects of storage in 0.75% O₂ were observed.     

Growth of helminthosporia on media containing the fungicide benomyl and the assay of benomyl using Botrytis cinerea

A bioassay using Botrytis cinerea detected 0–05 ppm benomyl in potato dextrose agar. Nine species of Cochliobolus, fourteen of Drechslera, four of Helminthosporium and five of Pyrenophora tolerated the presence of benomyl to the same extent, and grew on agar plates containing 40 ppm of the compound.     

Effect of numbers of fungicidal sprays and dates of application on control of celery leaf spot (Septoria apiicola) and on chemical residues

Experiments at two sites in each of three seasons showed that successful control of celery leaf spot depended more on the choice of fungicide than on the number of sprays and the dates of application. Organotin fungicides gave best control of celery leaf spot and with one exception residues were not detected even when the last application was given 4 weeks before harvest rather than 6 weeks.