Showing papers in "Journal of Horticultural Science in 1977"
TL;DR: Methods are described for propagating M.26 apple rootstocks in vitro which make possible the production of more than 60 000 shoots from a single shoot tip in eight months, which can be readily rooted and grown-on in pots.
Abstract: SummaryMethods are described for propagating M.26 apple rootstocks in vitro which make possible the production of more than 60 000 shoots from a single shoot tip in eight months. These can be readily rooted and grown-on in pots. There was no indication that culture in vitro produced mutations or abnormalities in the plants.
96 citations
TL;DR: There was a marked interaction between shading and crop load in their influence on flower bud formation, fruit set and fruit size, which suggests that the effect of shading for one year may partially pre-adapt the tree for such conditions in the following year.
Abstract: SummaryCox’s Orange Pippin apple trees on M.26 rootstock were shaded so as to receive 37, 25 or 11 % of full daylight during the post-blossom growing season in either or both 1970 and 1971 and their flowering and fruit development and yield were compared with those on control trees. Shading reduced fruitlet retention and fruit size and percentage dry matter in the year of shading. It also reduced flower bud formation and had a residual adverse influence on the percentage of flowers which set fruit in the following year. As a consequence of these latter effects, that of shade on yield in the year following shading was at least as great as its effect in the year of shading. There was a marked interaction between shading and crop load in their influence on flower bud formation, fruit set and fruit size, which suggests that the effect of shading for one year may partially pre-adapt the tree for such conditions in the following year. The possible roles of substrate competition and hormonal influences are discu...
78 citations
TL;DR: In this paper, the effects of irrigation on fruit set and fruit development were discussed, and it was found that irrigation applied only during the period of fruit development had a favorable influence on yield as well as on the efficiency of water utilization.
Abstract: SummaryIn drip irrigation experiments where water was applied daily it was found that low water tensions could be maintained in the soil to a range of 10 to 20 centibars and that these conditions had a considerable influence on yield and quality of processing tomatoes, Lycopersicon esculentum cv VF 317. The response of the plant in different growth stages to low soil water tensions was studied. Irrigation during the period of fruit set and fruit development was found to increase yield levels by 53 t ha-1 compared with non-irrigated plants. Irrigation applied only during the period of fruit development had a favourable influence on yield as well as on the efficiency of water utilization. However, irrigation at this stage had an unfavourable influence on fruit quality characteristics, namely, total soluble solids, acidity, viscosity and vitamin C. The effects of irrigation on fruit set and fruit development are discussed.
75 citations
TL;DR: Fruits grown under shade had less dry matter and starch per unit fresh weight and lower rates of ethylene and CO2 production per unit weight at harvest, but samples harvested at different dates showed no evidence of any marked shift in the onset of the respiration climacteric.
Abstract: SummaryCox’s Orange Pippin apple trees on M.26 rootstock were shaded so as to receive 37, 25 or 11% of full daylight during the post-blossom growing season in either or both of 1970 and 1971, and the growth, composition and quality of their fruits at harvest and after storage compared with those from control trees. In 1972 a separate experiment using Cox on M.9 involved shading to 34 or 13% of full daylight. Shading reduced fruit size, through reductions of cell size and the number of cells per fruit, fruit colour and the degree of skin cracking and russeting. Fruits grown under shade had less dry matter and starch per unit fresh weight and lower rates of ethylene and CO2 production per unit weight at harvest, but samples harvested at different dates showed no evidence of any marked shift in the onset of the respiration climacteric. The incidence of core flush and shrivelling in storage was increased by shading during the growing season. There was no evidence that the concentrations of N, P, K, Ca or Mg d...
71 citations
TL;DR: The rate of pollen tube growth increased with a rise in temperature, but abnormal growth was frequently observed at 33/28 and tubes failed to reach the ovary at 17/12, and endosperm and embryo development was observed to occur at 25/20 but not at33/28 or 17/ 12 although a positive effect of...
Abstract: SummaryAvocado plants were kept in growth cabinets at 33°C day, 28°C night (33/28); 25°C day, 20°C night (25/20); and 17°C day, 12°C night (17/12), with a 12-h photoperiod and light intensity of 26000 1x. At 33/28 and 25/20 flowers opened in the afternoon as females and again the following morning as males (type B floral cycle) with some overlap of male and female stages at 25/20. At 17/12 very few flowers had a female stage, the majority opening once only as males. The duration of the flowering period decreased with a rise in temperature as did total number of flowers opening. Reproductive growth was inhibited in favour of vegetative growth at 33/28, as exhibited by smaller floral parts and abscission of buds and flowers. The rate of pollen tube growth increased with a rise in temperature, but abnormal growth was frequently observed at 33/28 and tubes failed to reach the ovary at 17/12. Endosperm and embryo development was observed to occur at 25/20 but not at 33/28 or 17/12 although a positive effect of...
70 citations
TL;DR: Cox’s Orange Pippin apple trees on M.26 rootstock were shaded so as to receive 37, 25 or 11 % of full daylight during the post-blossom growing season in either or both 1970 and 1971 and their growth compared with that of control trees.
Abstract: SummaryCox’s Orange Pippin apple trees on M.26 rootstock were shaded so as to receive 37, 25 or 11 % of full daylight during the post-blossom growing season in either or both 1970 and 1971 and their growth compared with that of control trees. Shading had direct and also residual effects, the latter in the year following treatment. It reduced the number and weight of new shoots, the fresh weight per unit length of shoot, girth increment and leaf thickness and weight per unit area, but increased the concentrations of K and Mg in the leaves. Residual effects included a reduction in the number of shoots but increases in girth increment, in weight per unit length of shoot and in leaf dry weight per unit area and per unit fresh weight. These latter results are thought to be a consequence of reduced competition for assimilates as a result of a drastic residual effect on the number of fruits carried. In the year after shading the concentrations of N, P, Mg and Ca in the leaves were reduced and that of K increased.
41 citations
TL;DR: The interaction between vegetative canes and fruiting canes of red raspberry was examined at sites in Scotland and N. America, using a range of cultivars, which produced a biennial cropping system, in which the yield in the cropping year was considerably higher than in the conventional annual system.
Abstract: SummaryThe interaction between vegetative canes and fruiting canes of red raspberry was examined at sites in Scotland and N. America, using a range of cultivars. In the absence of vegetative canes, yields from fruiting canes were increased; and in the absence of fruiting canes, greater numbers of vegetative canes were produced. Separating the two phases in this way produced a biennial cropping system, in which the yield in the cropping year was considerably higher than in the conventional annual system. Cultivars varied both in the magnitude of their responses and in the nature of the changes in yield components influencing productivity. Among the cultivars tested the greatest response was obtained from Norfolk Giant, where cane numbers and yield per cane both contributed significantly to enhanced yield. The implications of these results for cultural methods and cultivar testing are discussed.
35 citations
TL;DR: Plantlets obtained from excised shoot tips of Solomon Islands taro cultivars remained free from detectable virus infection as judged from symptomless growth for 15 months and electron-microscopic examination of sap.
Abstract: SummaryExcised shoot tips from apical or axillary buds of Solomon Islands (SI) taro cultivars formed plantlets when cultured in vitro on agar or in liquid. Proliferation of shoots or extensive callus formation did not occur. Similar results were obtained with cultivars from Hawaii. Expiants from a California cultivar on Linsmaier- Skoog (LS) medium supplemented with 15 ppm IAA or 2 ppm 2, 4, 5-T formed callus. When subcultured onto LS containing adenine, N-benzyl-9-(tetrahydro-2H-pyran-2-yl) the callus formed plantlets and undifferentiated tissue. Expiants from SI and Hawaiian cultivars did not form callus. Plantlets obtained from excised shoot tips remained free from detectable virus infection as judged from symptomless growth for 15 months and electron-microscopic examination of sap.
33 citations
TL;DR: Neither the propagation treatment nor the use of an antitranspirant coating effectively altered the leaf conductance of unrooted cuttings, so that cutting turgor must be determined mainly by the vapour pressure gradient between leaf and air.
Abstract: SummaryLeaf conductance was measured on Cornus and Rhododendron cuttings subjected to various rooting treatments, then transferred to a controlled environment cabinet for the duration of the measurements. The treatments which produced fastest rooting and higher leaf conductances were (i) mist plus muslin cover and (ii) a polyethylene wrap. On freshly prepared cuttings leaf conductance fell quickly, then increased as rooting progressed. The observed leaf conductance was linearly related to the length of the longest root present, but the initial stages of root formation could be seen before leaf conductance increased. Neither the propagation treatment nor the use of an antitranspirant coating effectively altered the leaf conductance of unrooted cuttings, so that cutting turgor must be determined mainly by the vapour pressure gradient between leaf and air.
33 citations
TL;DR: The leaves, most of which persisted for two years or more, showed the highest potential for carbohydrate production and storage and appeared to function both in translocation and storage.
Abstract: SummarySeasonal samples of leaves, stems and roots were collected from cv Ascolano olive trees in their third year of growth from cuttings and analysed for changes in dry weight, component 80% methanol-soluble carbohydrates and polysaccharide resources extracted after hydrolysis with 5% trichloroacetic acid. The main components of 80% methanol extracts were sucrose, glucose, fructose and mannitol. There were times during the winter when fructose could not be detected but it was present in a moderate amount during the summer growing season. Mannitol was always the major component and appeared to function both in translocation and storage. Seasonal fluctuations in relative carbohydrate contents occurred throughout but with least amplitude in the roots. The leaves, most of which persisted for two years or more, showed the highest potential for carbohydrate production and storage.
32 citations
TL;DR: Experiments with flowers of Cox’s Orange Pippin apples have shown that semi- compatible pollen tubes produced by self-pollination may effect fertilization and therefore fruit set.
Abstract: SummaryExperiments with flowers of Cox’s Orange Pippin apples have shown that semi- compatible pollen tubes produced by self-pollination may effect fertilization and therefore fruit set. Pseudocompatibility was maximized by pollinating old flowers with large quantities of pollen, and maintaining a temperature of about 20°C during the period of pollen tube growth. The evidence suggests that, with some or all of the above conditions, fertile flowers are able to set fruit with self-pollination.
TL;DR: The possibility of cultivating three species of Labiatae in Israel was investigated and the reaction to nitrogen fertilizer and other cultivation factors considered and satisfactory yields were obtained.
Abstract: SummaryThe possibility of cultivating three species of Labiatae in Israel was investigated and the reaction to nitrogen fertilizer and other cultivation factors considered. Satisfactory yields were obtained. Cultivation of oregano in order to obtain its volatile oil also appears feasible.
TL;DR: In this article, the effect of removing individual trusses from glasshouse-grown tomatoes was investigated and the results were discussed in terms of carbohydrate source/sink relationships, which indicated that most of the translocated material received by a truss is derived from the leaves in its immediate vicinity.
Abstract: SummaryThe effect of removing individual trusses from glasshouse-grown tomatoes was investigated and the results are discussed in terms of carbohydrate source/sink relationships. Removing a truss resulted in yield increases on some of the remaining trusses both above and below the one removed, the largest increases occurring on the trusses adjacent to the removed truss with smaller increases on the more distant ones. This general pattern of yield increases occurred whichever of the first nine trusses was removed. The total yield from plants reduced to nine trusses varied from 91% to 99% of the yield from the control plants with ten trusses, depending on the position of the truss removed. The results suggest that most of the translocated material receive by a truss is derived from the leaves in its immediate vicinity. Also that the removal of a truss sink results in apical and basal movement of the available assimilate to the remaining trusses, perhaps via the internal and external phloem.
TL;DR: The evidence suggests that flower initiation cannot begin while an axillary bud is subject to apical dominance, and that after its removal another factor results in the production of shoots with a relatively constant number of leaves.
Abstract: SummaryThe initiation of leaves and flowers by selected axillary buds of the glasshouse rose cultivar Sonia (syn. Sweet Promise) has been studied both while their extension growth was inhibited by apical dominance and after the inhibition had been removed at one of two times (“early” or “late”). Leaf initiation occurred during growth inhibition so that leaf primordia accumulated in the axillary buds. Flower initiation began, with both treatment times, only after removing apical dominance. Although the total number of leaf primordia formed before the flower was greater in plants of the “late” treatment, the axillary shoots produced in both treatments had similar numbers of leaves with expanded leaflets. Thus many leaf primordia of the “late” treatment plants became scales. The evidence suggests that flower initiation cannot begin while an axillary bud is subject to apical dominance, and that after its removal another factor results in the production of shoots with a relatively constant number of leaves wit...
TL;DR: During the winter months the rate of leaf initiation appeared to be decreased to a lesser extent than the growth in dry weight, which itself was decreased less than growth in leaf area.
Abstract: SummaryThe growth of a number of onion cultivars sown on different dates during late summer in several years was assessed by regular sampling. The growth during the winter of five different winter-hardy cultivars was very similar, whereas that of Rijnsburger Bola, a cultivar normally sown in spring, was clearly slower. Sowing date was shown to affect final yield through its effect on overwintering size, which in turn influenced bulb size at harvest, the proportion of plants which bolted and the extent of winter losses. During the winter months the rate of leaf initiation appeared to be decreased to a lesser extent than the growth in dry weight, which itself was decreased less than growth in leaf area. The growth of the winter-hardy cultivars from all sowing dates and seasons was well summarized by a single linear relationship between the logarithm of plant dry weight and the accumulated day-degrees between 6° and 20°C from the day of seedling emergence. Using this relationship together with temperature re...
TL;DR: Leaf analysis showed that total Ca in leaves does not indicate the functional Ca status of plants or necessarily reflect the Ca supply to the fruit, andCalcium thresholds derived according to “Boundary Line” concepts are proposed for predicting the incidence of bitter pit in apples.
Abstract: SummaryCalcium stress to the roots, especially during the early stages of apple fruit development, induced bitter pit in the fruits; the pit appeared deep in the fruit cortex of cv Egremont Russet, unlike the sub-cuticular layer pit induced in other apple culti vars. Marginal leaf scorch symptoms in the old leaves were induced by Ca deficiency: the symptoms became acute when combined with Mg deficiency (induced by Ca deficiency and extra K). The development of fine roots and root hairs was also adversely affected by Ca deficiency. Leaf analysis showed that total Ca in leaves does not indicate the functional Ca status of plants or necessarily reflect the Ca supply to the fruit. Extra K decreased leaf Ca and Mg and increased leaf K concentrations. Bitter pit was positively related to fruit size and to K in apple peel, and was negatively related to Mg and Ca in peel and to Ca++ in the juice. Calcium thresholds derived according to “Boundary Line” concepts are proposed for predicting the incidence of bitter p...
TL;DR: Although ethephon concentration and bag type affected ripening, their effects were relatively small; endogenous factors controlling ripening were more important.
Abstract: SummaryFruits of the Shahani date cultivar (Phoenix dactylifera L.) were harvested at intervals of two weeks from 12 July to 20 September 1975 from a commercial orchard in Jahrom, Iran. At each harvest fruits were treated with 0, 125, 250, 500, 1 000 or 2 000 ppm ethephon and stored in sealed bags or bags with 10 holes. The percentage dry weights of pulp and seed, titratable acidity, soluble solids and respiration rates increased, whereas pH, firmness and astringency decreased with greater maturity. The application of ethephon increased respiration and titratable acidity significantly. Although ethephon concentration and bag type affected ripening, their effects were relatively small; endogenous factors controlling ripening were more important.
TL;DR: Application of PBA to flower buds at an early stage of development increased both the diameter and the fresh weight of carnation flowers or chrysanthemum inflorescences when fully open and decreased with age of the bud at the time of treatment.
Abstract: SummaryFoliar sprays of the synthetic cytokin, 6-benzylamino-9-(tetrahydropyran-2-yl)-9H-purine (PBA), increased branching in carnation, chrysanthemum, poinsettia, petunia and fuchsia, which showed varying levels of tolerance. In no instance did PBA reduce plant height. Applications of PBA to carnation and chrysanthemum stimulated branching in both intact and pinched plants. Treatment a few days prior to pinching produced more uniform development of new laterals. Response to the compound was most favourable under optimum growing conditions. Under relatively poor light intensity the laterals exhibited a reluctance for continued elongation and showed marked chlorosis. Application of PBA to flower buds at an early stage of development increased both the diameter and the fresh weight of carnation flowers or chrysanthemum inflorescences when fully open. Response to the compound decreased with age of the bud at the time of treatment. In carnation the effects on size were accompanied by an increase in petal area...
TL;DR: A technique was developed for producing established apple trees on their own roots derived from adventitious shoots regenerating from scion cultivar root cuttings, although the final establishment rate was somewhat lower.
Abstract: SummaryA technique was developed for producing established apple trees on their own roots. They were derived from adventitious shoots regenerating from scion cultivar root cuttings. Provided they were excavated in late autumn, root cuttings of such cvs as Lord Lambourne and Lord Derby (15 cm long and 1.5 cm diam.) could produce up to ten shoots each and survive for up to nine months. Regeneration vigour could be increased with cold storage, and treatment of cuttings with cytokinin. When young shoots (3–6 cm long) were detached and treated with 50 mg 1-1 IBA, approximately 90 % rooting was achieved under mist, although the final establishment rate was somewhat lower. Anatomically, adventitious buds arose spontaneously and at random in the cortex parenchyma and only later became continuous with the vascular cambium. For commercial use the practical and economic aspects of this technique require further investigation.
TL;DR: A practical way of preventing thermodormancy is to soak lettuce seeds for 15 min in a 70–100 mg 1-1 solution of kinetin in dichloromethane, which does not wet the seeds, yet permits sufficient Kinetin to be taken up to enable them, even when sown more than a year later, to germinate in complete darkness at considerab...
Abstract: SummaryImbibed lettuce seeds become thermodormant even at moderately high temperatures (above 27°C), and this tendency is intensified by the absence of light. Moreover, such seeds can then no longer germinate at certain lower temperatures which would have permitted the germination of non-dormant seeds, and either light or an appreciably lower temperature is required to break this induced dormancy. The timing and the duration of the high temperature period are critical. A long enough cool period preceding a warm one during imbibition will prevent thermodormancy ; and a temperature that could induce thermodormancy, given for a short period early during imbibition, may even accelerate germination.A practical way of preventing thermodormancy is to soak lettuce seeds for 15 min in a 70–100 mg 1-1 solution of kinetin in dichloromethane. This does not wet the seeds, yet permits sufficient kinetin to be taken up to enable them, even when sown more than a year later, to germinate in complete darkness at considerab...
TL;DR: Sowing parsnip seeds ‘primed’ in salts or polyethylene glycol solutions gave, on average, 1.8 days earlier seedling emergence than from untreated seeds.
Abstract: SummarySowing parsnip seeds ‘primed’ in salts (KNO3+K3PO4Hc2O) or polyethylene glycol solutions gave, on average, 1.8 days earlier seedling emergence than from untreated seeds. Sowing seeds subjected to different numbers and lengths of cycles of wetting and drying (‘hardening’) advanced seedling emergence by a similar amount. However, the earlier emergence from these seed treatments was small compared with that obtained by fluid-sowing pre-germinated seeds which advanced emergence by c. 4-0 days. Sowing pre-germinated seeds also increased the final percentage emergence by c. 60% compared with untreated, hardened and primed seeds, and at an early sowing reduced the spread of emergence.
TL;DR: Fruit growth rate was measured for different ratios of fruit number and leaf area on twin-top trees, where the two parts consisted of either Golden Delicious or of Graasten, or of one of each cultivar.
Abstract: SummaryFruit growth rate was measured for different ratios of fruit number and leaf area on twin-top trees, where the two parts consisted of either Golden Delicious or of Graasten, or of one of each cultivar. Leaves and fruits were removed in advance in different ways; and in one treatment leaves on one top section supplied fruits on the other top section. The growth rate for a given fruit number/leaf area ratio was higher in Graasten than in Golden Delicious fruits. No clear difference was detected between treatments where the fruits of one cultivar was supplied by leaves of its own and those where they were supplied by leaves of the opposite cultivar. Distances between leaves and fruits, up to at least one metre, did not reduce the fruit growth rate at a given fruit/leaf ratio compared to normal fruit-leaf distribution. On the other hand the dry matter percentage of the fruit decreased at the greater distances.
TL;DR: In this article, the authors used multiple regression models involving soil surface moisture content, level of compaction and watering amount to explain over 90% of the variation in seedling emergence and integral impedance.
Abstract: SummaryCalabrese seeds were sown in the field on four occasions and seeded rows were subjected to combinations of compaction and watering treatments. Plots were protected from natural rainfall. Soil crust strength (peak force needed to break through the crust) and integral impedance (work done in penetrating the soil to 15 mm depth) were obtained from penetrometer traces. For watered plots there were high negative correlations between percentage emergence and both peak force and integral impedance. There was also a high negative correlation between percentage emergence and integral impedance in non-watered plots when the penetrometer traces did not yield patterns giving distinct peak forces. No significant difference was found in the relationship of percentage emergence and integral impedance between watered and non-watered plots. Simple multiple regression models involving soil surface moisture content, level of compaction and watering amount explained over 90% of the variation in seedling emergence and ...
TL;DR: Taro seeds were germinated in vitro on several media and considerable proliferation occurred followed by the appearance of five to ten shoot tips in one cultivar in response to 15 ppm IAA.
Abstract: Taro seeds were germinated in vitro on several media. When the surfactant octadecyl-polyethoxyethanol was present at 5 mM concentration, growth was restricted and considerable proliferation occurre...
TL;DR: In this article, Merton apple trees in pot culture were supplied for four consecutive years with N, P, Ca and K at two rates, and a positive association appeared in Merton between K level and bitter pit incidence.
Abstract: SummaryMerton Worcester apple trees in pot culture were supplied for four consecutive years with N, P, Ca and K at two rates. Apples of this cultivar differed from those of cvs Cleopatra and Jonathan both in their response to nutrient supply variations and in the interrelationships among the levels of mineral elements in the fruit and bitter pit incidence at harvest. The association between fruit levels of N, P, K and Mg previously observed in the other two cultivars was absent in Merton. In two years a positive association appeared in Merton between K level and bitter pit incidence. Doubling the K supply reduced fruit Ca level and increased protein N level and bitter pit incidence. A threefold increase in the Ca supply had the opposite effect on each of these variables. Bitter pit incidence was not affected by doubling the P supply, but was increased by supplying extra N, some of which was in the form of ammonium ion. The differences found between Merton Worcester and the two cultivars studied previously...
TL;DR: In this article, the effect of the K/Ca ratio in the culture solution on the occurrence of ripening disorders in tomatoes was studied; the various solutions used were of equal osmotic pressure.
Abstract: SummaryThe effect of the K/Ca ratio in the culture solution on the occurrence of ripening disorders in tomatoes was studied; the various solutions used were of equal osmotic pressure. The symptoms observed on the fruit were yellowish stripes, running radially from calyx to apex, and yellow-green areas near the calyx; the latter probably corresponding to greenback. These disorders lessened with an increasing K/Ca ratio in the culture solution, the increase also causing the K/Ca ratio in the leaves and fruits to rise, both by a decrease in the Ca content and by an increase in the K content.As the K/Ca ratio in the solution was increased, the Mg content of the leaves at first declined, but then rose, whereas the Mg content of the fruits was increased throughout though less markedly at the higher K/Ca ratios.An increasing ratio of (K+Mg)/Ca in the leaves and fruits was also accompanied by a lower incidence of ripening disorders. It is not known whether this effect was caused by a decreased Ca content, an incr...
TL;DR: In this article, a growth analysis of carrots grown in water culture has shown that dry matter accumulation and growth in size are severely affected by lack of aeration of the medium, top growth being particularly affected.
Abstract: SummaryGrowth analysis of carrots grown in water culture has shown that dry matter accumulation and growth in size are severely affected by lack of aeration of the medium, top growth being particularly affected. Exposure of the top few cm of the tap root to the air ameliorates this condition to a limited extent. Although plants grown at all times without aeration appear to adapt to such conditions to some degree, a rapid change to non-aerated conditions has disastrous effects and causes severe leaf senescence. Subsequent formation of lateral roots at the upper end of the tap root may serve to increase O2 uptake by the root system. Transfer from non-aerated to fully aerated conditions provokes a rapid increase of top growth, suggesting the involvement of root-produced cytokinins. Soil compaction also has major effects on root growth and length, very loose or highly compacted conditions being detrimental to overall growth. With high compaction normally cylindrical tap roots become sharply conical.
TL;DR: The effects of endogenous carbohydrate and auxin levels on shoot regeneration from apple root cuttings were studied in relation to season and it was confirmed that auxin was directly involved in correlative inhibition of bud initiation and outgrowth.
Abstract: SummaryThe effects of endogenous carbohydrate and auxin levels on shoot regeneration from apple root cuttings were studied in relation to season. Storage polysaccharides were estimated by periodate oxidation following organic acid hydrolysis. Maximum accumulation occurred in autumn (November) coinciding with the highest regeneration potential and survival rate of cuttings. Cold storage of cuttings (5°C) increased soluble sugars and subsequently accelerated callusing and shoot production. During regeneration polysaccharides were gradually depleted, whereas soluble sugars remained constant at their initial level (1–2 g/10 g residual dry weight). Cuttings started rotting at a polysaccharide level of approximately 3 g/10 g RDW. Fluorimetrie assay of endogenous IAA confirmed that auxin was directly involved in correlative inhibition of bud initiation and outgrowth. IAA moved rapidly and acropetally within detached root cuttings causing depletion and allowing preferential bud initiation to occur at the proximal...
TL;DR: Self-compatible trees cropped earlier in the season than incompatible trees of the same progeny, and in entirely self-incompatible progenies there were no differences in cropping patterns between parents differing in S alleles.
Abstract: SummaryThe effects of self- and cross-incompatibility on yield in cocoa were studied in six Amazon X Trinitario or Amelonado progenies in two 20-year-old progeny trial areas at Tafo, Ghana. The patterns of segregation for compatibility alleles corresponded to the accepted theory of incompatibility in cocoa. Differences in yield between compatibility groups within progenies were measured by regression of yield on tree size, on a tree-by-tree basis. In progenies where half the trees were self- compatible, there were indications that the self-compatible trees were higher yielding than the incompatible trees, whereas when all the trees were self-incompatible the half with highly restricted cross compatibility were lower yielding than the half which were more freely cross-compatible. Self-compatible trees cropped earlier in the season than incompatible trees of the same progeny. In entirely self-incompatible progenies there were no differences in cropping patterns between parents differing in S alleles. There ...
TL;DR: Yields during the first six years of production were significantly higher on rough lemon and Palestine sweet lime rootstocks than on Cleopatra mandarin and Troyer citrange, but not significantly higher than on sour orange.
Abstract: SummaryCumulative yields per tree of Campbell Valencia orange during the first six years of production were significantly higher on rough lemon and Palestine sweet lime rootstocks than on Cleopatra mandarin and Troyer citrange, but not significantly higher than on sour orange. Rough lemon and Palestine sweet lime rootstocks produced significantly larger fruits than sour orange but quality was lower. Leaf analysis for eight elements showed significant differences in K, Mg and Mn but not in N, P, Cu, Fe and Zn.