Light studies in a spacing trial with apple on a dwarfing and a semi-dwarfing rootstock

Light interception by the orchard canopies in a spacing trial with Golden Delicious and Jonathan on M IX and on M II was measured in 1968, 1969 and 1970. In 1969 and 1970 light distribution over the Golden Delicious hedges in the high-density plots was also measured and related to fruit and foliage distribution and to fruit quality. Simultaneously, integrated light readings at 100–200 locations were taken over 24-hour periods, using a photochemical method.Although all plots attained their ceiling yield level in 1967, the 6th year after planting, light interception continued to increase from 1968 to 1970. In the low-density plots — 1100 trees per ha on M IX and 660 trees per ha on M II — the canopies intercepted roughly half of the incident light and yields levelled off at 40 tons per ha. The high-density M IX plot (3300 trees per ha) intercepted two-thirds, the high-density M II plot (2260 trees per ha) more than three-quarters of incident light. Both plots yielded more than 70 tons per ha in 1967 and 1968, but thereafter the yield level dropped, especially for trees on M II, presumably because of mounting inter-tree competition for light.Light levels in the hedges in the high-density plots at equal distances from the hedge perimeter were very much the same for both varieties, for both rootstocks and in the two years. Light levels fell sharply towards the interior and bottom parts of the hedges. The main advantage of the M IX hedge was its smaller cross section, leaving little room for a poorly illuminated centre. At lower light levels weight per fruit and especially fruit colour declined, but the relation between light level and fruit quality was not consistent for both rootstocks and in both years. These inconsistencies could be explained on the basis of differences in pruning system, affecting the type of wood on which the fruit is borne.Fruit was concentrated in the interior part of the hedges, so that a high proportion of the crop suffered from the poor light conditions in this part. Fruit distribution was generally correlated with foliage distribution. In the M IX hedge by far the highest leaf density was found in the centre of the hedge. This is an advantage in comparison with the large leaf area — relatively unproductive and casting much shade — in the top of the M II hedge. Light measurements before and after fruit removal suggested that the shade cast by the fruit is negligible as compared to shading by the foliage.It is concluded that canopy architecture in the high-density M IX plot, with a leaf area index of 2.15, is close to the optimum for single row planting systems in Northwest Europe. Gains in percentage light interception, as in the high-density M II plot, are associated with a greatly inferior light distribution over the canopy, leading to lower yields per unit growth and deterioration of fruit quality. In addition to light, pruning strongly influences fruit quality.     

Mikroklima-, Farb- und Geschmacksverbesserung durch Licht reflektierende Folie zu verschiedenen Auslegeterminen bei ��Elstar��- und ��Jonagold�� ?pfeln unter schwarzem und wei?em Hagelnetz

Fruit colouration of the bi-coloured apple cvs ??Elstar Elshof?? and ??Jonagold Wilmuta?? on M9 under hailnet is often hampered due to light deprivation in the autumn, caused by shorter photoperiod, declining solar angle and decreasing light intensity. Therefore, reflective ground cover (Extenday^®) was spread early (beginning of July) or late (beginning of August) either side of the tree rows under white (88?C92% light transmission) or black (80?C84% light transmission) hailnet at the University of Bonn, Campus Klein-Altendorf (50.4°N), Germany, to improve fruit quality, particularly fruit colouration and taste, particularly sugar content. The five-year-old apple trees on M9 rootstock, spaced at 3.5 m?×?1 m, were planted in N-S orientation to optimise light utilisation; adjacent uncovered trees without reflective ground cover without hailnet served as control. The ground covers improved light reflection perpendicular from the ground in the middle of the alleyways by 14% at 90° angle, but by 5-fold at a 45° angle into the periphery of the tree canopy, both measured 1 m above ground. The diurnal course of light reflection 1 m from the ground differed distinctly from that of incident radiation: The latter depended on the East or West side of the tree row. By contrast, light reflection values depended solely on the use of reflective ground cover irrespective of hailnet and row orientation. Relative humidity and air temperature appeared unaffected by the use of reflective mulch; sunburn did not appear in any of the treatments. 1,200 colour measurements showed that the reflective ground covers improved red colouration of the downward-facing, lower and tree-facing, inner side of apple fruit of both varieties from 91?C99°hue colour angle (green) in the uncovered control to 51?C59°hue (red) irrespective of the date of spreading the mulch i.e. early or late. By contrast, no differences were observed in the sun-exposed, outer side of the fruit. The lowest fruit firmness and lowest sugar content were observed in apple fruit under the black hail-net. The firmest fruit with the largest sugar concentration (as a measure of taste) were observed in all trials with reflective mulch, particularly in the lower third of the tree canopy, starting from the uncovered control, the white hailnet to the black hailnet; sugar concentration improved with the time of mulching. Overall, the shorter time of mulching of 4 versus 8 weeks prior to anticipated harvest from the beginning of July (for cv. ??Elstar??) and mid-August (for cv. ??Jonagold??) proved sufficient for improving fruit quality, colouration and taste under both white and black hailnet at 50°N. Based on an expected 10-year lifespan with reduced UV-exposure under hailnet in North-western Europe, this currently most expensive reflective ground cover increased gross returns by 560?C840 ?/ha/year due to more well-coloured class 1 apples and a smaller percentage of poorly coloured apples (?<?25% blush) compared with the material cost of 700 or 350 ?/ha/year, if used once or twice a year, but without any labour cost involved. Financial returns varied between 210 and 490 ?/ha/year, based on double use per season of the light reflecting material, whereas single use only reached the break-even point. Hailnets are expected to increase due to climate change associated with better light conditions for reflection in the autumn and taller tree training leading to more shade in the lower tree canopy; new alternative reflective, low cost ground covers may then contribute to better utilisation of light otherwise lost in the alleyways and better economy for use in a fruit orchard.     

Improvement of quality and storability of apple cv. Aroma by adjustment of some pre-harvest conditions

To improve the quality of the important Swedish apple cultivar Aroma and increase its resistance to bruising and storage decay, three studies were conducted at Kivik research station during the period 1998–2003. The effects of tree age, pruning time and nitrogen fertilization were investigated. Fruits from young trees (younger than 6 years) had a lower resistance to bruising and Pezicula malicorticis decay, while fruits from trees older than 20 years seemed to show a quality and storability decline. Choosing a suitable summer pruning time was an effective factor for fruit storage potential. Thinning cut during August (5–6 weeks before harvesting) improved fruit colour and decreased decay without negatively influencing tree yield. Applying fertigation according to fruit development phase and soil nitrogen content had a very important influence on fruit quality and storability. Appropriate nutrition supply produced more deeply coloured fruit that maintained their quality after storage for 4 months. The bruising sensitivity of cv. Aroma apples was correlated with their N and K/Ca content. More coloured fruits showed less sensitivity to bruising.     

Performance of ‘Discovery’ apple on M.9, M.26 and MM.106 rootstocks at two densities

Summary

The apple rootstocks M.9, M.26, and MM.106 were evaluated for their efficiency in bringing ‘Discovery’ apple trees into production. The experiment, carried out over a ten- year period compared two planting densities at 1666 and 3333 trees per ha. Tree vigour differences between rootstocks were measured in term of trunk growth, tree volume, weight of branches pruned off and final weight of the above-ground parts of the trees. Fruit production is presented both as total yield and as the weight of first class fruit. Fruit colour development is also shown. Cropping efficiency is calculated and presented in relation to the different vigour measurements. The results confirm that ‘Discovery’ is slow to come into production. M.9 was the most productive rootstock, but due to vigour differences MM.106 gave the same yields per tree, although the latter had the lower yield efficiency. M.26 performed poorly; its vigour was similar to M.9 but it produced the lowest yields.     

Relationships between canopy size,light interception and productivity in conventional avocado planting systems

Avocado (Persea americana Mill.) is a relatively under-developed tree crop, grown commercially in climates ranging from tropical to temperate. Orchard productivity across a broad range of tree crops has been demonstrated to be related to total light interception. However, little information is currently available for avocado. Here we document the relationships between canopy volume per hectare, total orchard light interception and yield per ha for avocados of cultivar ‘Hass’ grown in low density planting systems. Total orchard light interception increased with canopy volume, with increases in light interception per unit canopy volume becoming smaller at the higher levels of canopy volume/ha. Yield/ha increased with light interception and canopy volume up to approximately 80–84% total light interception and 30,000–35,000 m³ canopy volume/ha. It is unclear whether the trend in yield/ ha at the very highest measured levels of orchard light interception and canopy volume should be described as plateauing or declining. Mean fruit weight decreased as light interception increased, although the relationship varied between seasons. For these conventional planting systems there is no yield benefit from increasing canopy light interception above 80–84%, and there may be yield decline at higher levels of orchard light interception.     

Two new planting systems for early ripening peaches (Prunus persica L. Batsch): Yield and fruit quality in four low-chill cultivars

Summary

Trees of peach cvs Flordastar, Flordaprince, Flordacrest and Maravilha, low in chill requirement (Flordaprince 150; Flordacrest 350 C.U.), with a short fruit development period (Flordaprince 90; Flordacrest 110 d) and a very early ripening time (Flordastar mid May; Flordacrest first week of June), were planted in Sicily (37° 30′ Lat. N) both in a medium (667 trees per ha) and a high density (2000 trees per ha) plantation system. In the medium density planting system, the trees were trained to a Fusetto, and in the high density to a Y-shape. Both in the Fusetto and Y, the size of the trees was controlled by severe pruning soon after harvest, consisting in the shortening of most of the one year old wood. From mid June to October, the trees of all four cultivars were able to recover a “fruiting canopy”; flower bud density, flower fertility, fruit set, fruit quality and crop efficiency were not affected by the severe summer pruning. Due to the planting density and the pruning, the tree growth was restricted: no platforms or ladders were required to perform the cultivation techniques at the top of the Fusetto nor was the wire-trellis necessary to sustain the Y-shaped trees. To distinguish these training systems from the original ones, Fusetto and Tatura trellis, we called them “dwarfed Fusetto” (dF) and “free standing Tatura” (fsT), respectively. Although production per tree was higher in the dF, due to planting density fsT yielded more per hectare.     

Fruit thinning in ‘Conference’ pear grown under deficit irrigation: Implications for fruit quality at harvest and after cold storage

Fruit thinning in pear is feasible for mitigation of water stress effects. However, it is not well known how fruit quality at harvest and after cold storage is affected by pre-harvest water stress. Even less is known about the effects of fruit thinning on quality under these circumstances. To elucidate these, we applied deficit irrigation (DI) and fruit thinning treatments to ‘Conference’ pear over the growing seasons of 2008 and 2009. At the onset of Stage II (80 and 67 days before harvest in 2008 and 2009, respectively), two irrigation treatments were applied: full irrigation (FI) and DI. FI trees received 100% of crop evapotranspiration (ETc). DI trees received no irrigation during the first three weeks of Stage II to induce water stress, but then received 20% of ETc to ensure tree survival. From bud-break until the onset of Stage II and during post-harvest, FI and DI trees received 100% of ETc. Each irrigation treatment received two thinning levels: no thinning leaving commercial crop load (∼180 fruits tree⁻¹), and hand-thinning at the onset of Stage II leaving a light crop load (∼85 fruits tree⁻¹). Under commercial crop loads, DI trees were moderately water-stressed and this had some positive effects on fruit quality. DI increased fruit firmness (FF), soluble solids concentrations (SSC) and acidity at harvest while no changes were observed in fruit maturity (based on ethylene production). Differences in FF and acidity at harvest between FI and DI fruit were maintained during cold storage. DI also reduced fruit weight loss during storage. But fruit size was reduced under DI. Fruit thinning under DI resulted in better fruit composition with no detrimental effect on fresh-market yield compared to un-thinned fruit. Fruit size at harvest and SSC values after five months of cold storage were higher in fruit from thinned trees than fruit from un-thinned trees. Fruit thinning increased fruit ethylene production, indicating advanced maturity. This may lead to earlier harvest which is desirable in years with impending drought. Fruit thinning is therefore a useful technique to enhance pear marketability under water shortage.     

Effect of part-tree flower thinning on fruiting,vegetative growth and leaf photosynthesis in ‘Cox’s Orange Pippin’ apple

Flower clusters were removed at full bloom from ten year old ‘Cox’s Orange Pippin’ trees on M.9 rootstocks, over the whole tree, on alternate branches or on whole sides. Mean fruit weight per tree at harvest was linearly dependent on leaf area per fruit and on light interception per fruit, both relationships accounting for over 90% of the variance. These relationships did not differ between treatments, implying either a mobile pool of carbohydrate or photosynthetic adjustment within the tree to crop load. Measurements of leaf photosynthesis in July and September showed no statistically significant differences in photosynthetic rate of spur or extension shoot leaves on bearing or non-bearing branches. Although the treatments caused no overall effects on shoot growth or leaf area per tree, sides of trees without fruit had greater leaf area and shoot growth than did sides bearing fruit. Fruit mineral composition and percentage dry weight were not affected by treatment except where the treatments significantly altered fruit size. In the following spring, although the treatments did not affect the total number of flower buds produced, branches that were deflowered in the previous spring carried significantly more flower buds than did branches which had cropped.     

Pruning Trials With Worcester Pearmain Apple

Three pruning treatments were compared on Worcester Pearmain on M.IV rootstock, viz.: open-centre tree, established-spur pruned; delayed open-centre tree, established-spur pruned; regulated pruned tree. In the fifteenth year secondary treatments were begun, the trees being pruned either annually or in alternate years, with and without fruit thinning by hand. The trees were grubbed after 21 years and scion weights were obtained.

There were no important differences in growth and cropping between open-centre and delayed open-centre trees. Regulated trees had an 11% smaller area of branch spread than established-spur pruned trees at 21 years. At 15 years there was no significant difference between treatments in total weight of prunings, but three times as much old wood as new had been removed from regulated trees compared with two and a half times as much new wood as old from established-spur pruned trees. During a 6-year period, the same weight of wood was removed from alternate-year pruned trees as from those pruned annually.

During the first 10 years regulated trees yielded twice as much fruit as did established-spur pruned ones, and 49% more during the second 10-year period. In many years, in the absence of fruit thinning, regulated trees bore smaller fruits than did established-spur pruned trees. Regulated trees had more red colour on the fruits than established-spur pruned trees, and alternate-year pruning, whether regulated or established-spur, gave more red colour on the fruits than did annual pruning, especially in seasons following no pruning. Alternate-year pruning had no harmful effect upon fruit size. Fruit thinning had no important effect upon red colour but it increased the percentage crop weight in the larger size grades, especially on established-spur pruned trees. The regulated method is well suited to the growth habit of Worcester provided that the fruit is thinned by hand or chemical spray in years of heavy setting.

The relative ratios between total crop : scion weight and crop 15–21 years : scion weight, were similar; scion weights were twice as heavy as weights of prunings.     

Factors Affecting the Storage Behaviour of Papaya Fruit

Fruits of the papaya cultivar Solo 63/2 were damaged when stored at or below 45 °F (7 °C). Wrapping the fruit in polyethylene bags reduced weight loss during storage but increased the development of saprophytic fungi. Perforated polyethylene bags similarly reduced weight loss but did not increase fungal development.

Careful harvesting significantly reduced fungal infection, thus giving the fruits better flavour and longer storage life. The optimum stage of maturity for satisfactory storage and subsequent ripening was when the yellow colour was just beginning to develop in the funicles. Fruits from hermaphrodite trees were superior in flavour to those from female trees but behaved similarly during storage.     

Farb- und Fruchtqualitätsverbesserung bei Äpfeln mit Monophosphat und Extenday

Monophosphates reportedly enhance red colouration of bi-coloured apple fruit by stimulating anthocyanin synthesis and, in addition with calcium or potassium, may improve fruit firmness; colour and firmness which may be restricted by the climate in Western Europe. 12-year-old cv. ‘Elstar’ apple trees at Klein-Altendorf near Bonn, Germany, were sprayed weekly with either of two monophosphates four weeks prior to harvest to improve fruit quality, i.e. colouration, sugar and firmness. White, woven reflective cloth was spread as an alternative on the grass strips between the tree rows six weeks prior to harvest for the same purpose. Untreated apple trees served as control. Neither of the three treatments affected fruit maturation, measured as Streif index. The monophosphate formulation containing calcium (Seniphos; 24% P₂O₅; 4% CaO; 2?×?10?L/ha) increased the sugar content of the cv. ‘Elstar’ apples in the outer as well as in the inner tree canopy and the reflective cloth additionally in fruit of the lower canopy close to the cloth's position on the ground. This white reflective cloth (Extenday) also affected fruit from the outer tree canopy with the largest sugar content (12.6°Brix) and firmness (7.6?kg/cm²) at harvest. The monophosphate formulation containing potassium (Rizammina 42; 8% P₂O₅, 21% K₂O; 3?×? 2.5?kg/ha) improved the category of greater 25% fruit colouration by only 3%. Both Seniphos and the reflective cloth increased this portion by 17–19%, thereby raising the portion of class-1-fruit by 8%, equivalent to additional earnings of 1,060 €/ha. The green ground colour of apples in the shaded inner canopy was retained by either monophosphate. In the well-illuminated tree periphery, however, the ground colour of fruit treated with either monophosphate was less green (more yellow-green) and the top colour was more red. The white reflective cloth induced the same positive effects on fruit colouration to a much larger extent. Both monophosphates increased fruit firmness after 4?months cold storage around 5% at a time when fruit were too soft for marketing as fresh products.     

灌溉方法与地面覆盖对柑桔果实品质、产量与冠幕光水平的影响

灌溉方法与果园地面覆盖对'Mihowase'温州蜜柑果实品质、产量、果实大小分布与冠幕光水平有一定的影响。试验在南非西开普地区连续进行了两个季节（1994／1995和1995／1996）,设微喷、滴灌及滴灌配合TyvekTM（一种白色防渗纤维纸）地面覆盖等3个处理。结果表明：处理间果实颜色、可溶性固形物含量与果汁百分率均无明显差别。然而,滴灌及滴灌结合地面覆盖处理降低果实含酸量,因而趋于提高果实固酸比。处理不显著影响果实选择性采收百分率、产量与果实大小分布。TyvekTM地面覆盖显著（P＜0．05）提高进入冠幕下部的地面反射光水平。     

Involvement of 1-methylcyclopropene in ripening of harvested mei (Prunus mume) fruit

Summary

Harvested mei (Prunus mume) fruit were stored at 20°C after exposure to 500 nl l^–1 1-methylcyclopropene (1-MCP) for 8 h. Firmness, peel colour, chlorophyll content, chlorophyllase activity, soluble solids content (SSC), titratable acidity (TA), respiration and ethylene production, and cell wall hydrolysis enzyme activities were monitored to determine the efficacy of 1-MCP treatment in delaying mei fruit ripening compared to untreated control fruit. Results showed that control ‘daqinghe’ mei fruit displayed typical climacteric patterns of respiration and ethylene production. Peak CO₂ production and ethylene production were observed after 6 d. Fruit softening was accompanied by a progressive decrease in colour parameters expressed as hue angle (h°), chlorophyll content, SSC, TA and increases in chlorophyllase, pectin methylesterase (PME) and polygalacturonase (PG) activities. 1-MCP treatment prior to the climacteric increase significantly delayed the onset of the climacteric peaks of CO₂ and ethylene production. These delays were associated with reductions in fruit softening, consistent with delaying the activities of PME and PG. Fruit treated with 1-MCP exhibited less peel colour change from green-to-yellow because of their lower levels of chlorophyllase activity and less chlorophyll breakdown. Moreover, 1-MCP treatment also significantly retarded reductions in SSC and TA compared with control fruit. The shelf-life of mei fruit ripening was increased by 4 d following 1-MCP treatment. Thus, 1-MCP treatment can markedly extend the post-harvest life of ‘daqinghe’ mei fruit.     

Effect of different girdling dates on tree growth,fruit characteristics and reserve accumulation in a late-maturing persimmon

Trunks of 8-year-old vigorous ‘Fuyu’ persimmon (Diospyros kaki Thunb.) were girdled to a 1 cm width on April 20 and June 10 2004. Tree growth and fruit characteristics were monitored for two years, with special emphasis on the carry-over effect in 2005. Girdling reduced trunk and shoot growth especially of April-girdled trees over two consecutive years. However, the most significant effect of girdling was in the occurrence of water sprouts: a control tree had 29.5 in 2004 and 27.3 in 2005, whereas the April-girdled trees had only 0.3 and 5.3, respectively. Girdling increased fruit set by nearly 50% and enhanced fruit colour in 2004 only. Girdling date did not significantly affect fruit size and soluble solids for two years. Fruit flesh of girdled trees in 2004, especially in the April-girdled trees, had lower N and P concentrations. The levels of starch, soluble sugars, and inorganic elements in flower-bearing distal buds measured just before new growth in 2005 were not significantly altered by the girdling in 2004.     

The relationship between yield and assimilate supply in lychee (Litchi chinensis Sonn.)

Summary

Experiments were conducted on lychee (Litchi chinensis Sonn.) in subtropical Australia (lat. 27° –29°S) to evaluate the role of assimilates on fruit retention. All the leaves of the last flush, all the leaves of the previous flush (about eight leaves per terminal shoot), or all the old leaves were removed from trees. Medium (3–5.cm diameter) or large branches (5–10.cm diameter) were girdled and defoliated after fruit set, and fruit retention compared with ungirdled and undefoliated branches. Other branches were girdled and defoliated between anthesis and fruit harvest. Finally, 20, 50 or 80% of the flowering panicles were defruited on large trees. Defoliated trees had 35 to 45% lower yields than the controls. This was despite the treatment with all the old leaves removed having a much lower leaf area index than the other defoliation treatments (1.7 vs. 2.3 and 2.8). Leaves next to the inflorescences are more important for yield than the older leaves. Fruit retention was very low on girdled branches that had been defoliated, especially when the leaves were removed in the first 20.d after anthesis. This suggests that the yields of girdled branches were determined by the availability of assimilates soon after fruit set. In contrast, the number of fruit retained on ungirdled branches was unrelated to the number of leaves, with defoliation having no effect on yield. Fruit on these branches were supported by resources from elsewhere in the tree. Thinned trees had similar yields to those of unthinned plots (65–82.kg tree^–1). Thinning apparently increased fruit retention in the remaining clusters, under a higher leaf:fruit ratio. There were large differences in the concentrations of starch in the tree, and seasonal changes, with starch declining from flowering to fruit harvest. In contrast, there were only small responses to the treatments, suggesting that the fruit were mainly dependent on current photosynthesis. Photosynthesis in the leaves behind the fruit clusters was more important than photosynthesis in the older shaded leaves.     

Annual dry-matter production by three apple cultivars at four within-row spacings in New Zealand

Summary

Annual dry-matter production was estimated from eight year old apple trees of ‘Fuji’, ‘Braeburn’ and ‘Royal Gala’ on rootstock M.9, trained as slender spindles, in a spacing trial with trees spaced at 1.3, 1.5, 1.9 and 2.4 m within the row with tree rows 3.5 m apart. Light interception was recorded at intervals during the season. Both fresh weight yield and total dry-matter production were linear functions of light interception, with a higher slope recorded for the two late season cultivars compared with the early maturing ‘Royal Gala’. Comparison of the relationship between mid-season light interception and apple yields with published values from elsewhere, reveals that the slope of the relationship is enhanced under New Zealand conditions. The relationship suggests an upper limit of yield of 169 t ha^–1 at 90% light interception, slightly higher than the maximum yield recorded of 163 t ha^–1. Energy conversion of intercepted light over the growing season into dry-matter production was similar to that observed in the United Kingdom, suggesting that the major climatic advantage in New Zealand over the United Kingdom is the higher growing season radiation integral. Dry matter was allocated in the order fruit>woody tissue>leaves, with partitioning to the fruit of 74, 72 and 63% for ‘Braeburn’, ‘Fuji’ and ‘Royal Gala’, respectively. Under New Zealand conditions, sustainable 70% harvest index values may be achievable for mature apple trees on dwarfing rootstock with late maturing cultivars.     

Effect of hail nets on the microclimate,irrigation requirements,tree growth,and fruit yield of peach orchards in Catalonia (Spain)

Summary

Hail nets protect orchards from storm damage, but also offer potential water savings for fruit trees grown in arid areas. We investigated the effects of black nets on water use, growth, yield, and fruit quality in peach trees growing in Catalonia, Spain, over 2 years (2006 and 2007). Water savings were quantified by irrigating the netted trees to a similar midday stem water potential (Ψ_stem) as the control trees. This method was only partially successful in 2006, with the netted trees being over-watered early in the season (i.e., higher Ψ_stem than the controls), and under-watered (i.e., lower Ψ_stem than the controls) later in the season. A combination of water stress and a hail net resulted in lower yields because of a smaller fruit size. Skin colour was more enhanced in control fruit. In 2007, Ψ_stem values were similar between treatments. Any difference in tree performance was therefore due to the hail net per se. Fruit size was similar between treatments, and the lower yields of netted trees were due to decreased fruit number. There were no treatment differences in fruit skin colour or flesh firmness. Soluble solids concentrations were higher in nonnetted fruit. In both years, water savings amounted to approx. 25%, if irrigation replaced the potential evapotranspiration that was measured. Hail nets are therefore recommended for their effects on water saving in arid areas, despite lower fruit yields.     

Branch scoring encourages fruit development and climacteric in persimmon

Branch scoring of ‘Rojo Brillante’ persimmon (Diospyros kaki) increased fruit size at harvest and caused a significant shift in the distribution of fruit diameters to the larger sizes, the response magnitude depending on the date of scoring. Scoring at the 75–77 growth stage of the BBCH-scale encouraged the development of fruit which grew faster, reached commercial colour, ripening and flesh softness earlier, and therefore was harvested earlier. Although fruit weight was significantly increased by scoring, the number of fruit was not modified and there was not a significant increase in yield. Fruit from trees scored at the onset of cell enlargement stage initiate ethylene production before fruit from unscored trees. Scoring did not modify following yield.     

Influence of plant density and time of fertilizer application on growth characteristics,nutrient uptake and yield of tomato

In a factorial experiment to investigate the combined effects of plant density and time of split application of fertilizer, 4 spacings and 3 fertilizer treatments were employed. Plant populations were varied between 24,000 and 54,000 per ha. Equal amounts of NPK were applied in different split applications and at specific physiological stages.Time to 50% flowering was delayed by fertilizer application as well as by wide within-row spacing. Total leaf N and P content declined with all treatments between flowering and mature-green stage of fruits, but increased again at table-ripe stage. Leaf K content remained constant throughout the growth period.Two-split applications of NPK, one at 2 weeks after transplanting to the field and the other at fruit set, were more beneficial than either no fertilizer or 3-split applications of equal amount of fertilizer, when the third application was at mature-green stage. This was indicated by higher fruit yields with 2-split applications.Highest fruit yields were obtained when tomatoes were planted either at 30.5 cm × 91 cm single-row spacing, or at 45.5 cm × 122.0 cm, double-row spacing, both giving 36,000 plants per hectare. Fruit yields were reduced at lower and higher population densities.