Explore the vast range of titles available.

The experiment was conducted in a private orchard in the Altun Kopri sub-district of Dibs district, Kirkuk Governorate, for the growing season (2024) to study the effect of fruit thinning and spraying with salicylic acid, nano calcium, and boron on the quantitative characteristics of grape fruits of the Zaytouni variety. The factorial experiment was conducted using a split-split plot system according to the R.C.B.D design of randomized complete blocks. This study included three factors: thinning at three levels: A1 (without thinning), A2 (total thinning), and A3 (partial thinning). The second factor was spraying with salicylic acid at three levels: B1 (control) (without spraying), B2 (75 mg L−1), and B3 (150 mg L−1). The third factor included spraying with nano calcium and boron as follows: C1 (control) (spraying with water only), C2 (spraying with 45 mg L−1 of boron), and C3 (spraying with 150 mg L−1 of nano calcium). The results showed that treatment A3 significantly excelled in the following traits: vine leaf area, number of clusters, and 100-berry weight, while A2 had a significant effect on leaf total chlorophyll content and cluster weight. While treatment A1 was significantly associated with cluster weight and total vine yield, the results showed that treatment B3 led to a significant increase in leaf area, number of clusters, 100-berry weight and total plant yield. Treatment C3 had a significant effect on total plant yield. The interaction treatment A3B3 significantly effected vine leaf area, number of clusters, and 100-berry weight, whereas the interaction treatment A2B3 significantly affected leaf total chlorophyll content and cluster weight. The interaction treatment A2B2 had a significant effect on total chlorophyll, and treatment A1B3 significantly affected total plant yield. While A3C1, A3C2, and A3C3 significantly excelled in the traits of vine leaf area and 100-berry weight, the Bi-interaction between A3C2 and A3C3 excelled in the trait of cluster number, while the cross between A2C3 excelled in the trait of total leaf chlorophyll content. Bi-interactions (A1C1, A1C2, and A1C3) and crosses (A2C1, A2C2, and A2C3) excelled in the trait of cluster weight. While A1C2 and A1C3 excelled in the trait of total plant yield, the Bi- interaction between B1C3, B2C1, and B3C3 excelled in the trait of total leaf chlorophyll content. The cross between B3C3 significantly excelled in terms of the cluster number and total vine yield. For the triple crosses, A3B3C3 was significantly enhanced in most traits.

Apple ( Borkh.) is the most important fruit in the EU. The total yield is more than 11 million tons.year , 15% of which is that of the early apple varieties. Several papers have already been published on the efficacy of crown and fruit thinning in the 20th century. Nowadays, hybrid varieties and intensive crown types are used in modernized systems. Our research was carried out in a Hungarian orchard during two cultivation periods. We studied two early apple varieties (Idaho, Gala Must) to determine how fruit thinning affected the quantity and quality of fruits. We found that the effectiveness of non-thinned technology is similar or slightly better compared to fruit thinning, after the second harvest. The average yield of Idaho apples per tree per harvest was 35.9 vs. 24.8 kg, while that of Gala Must was 50.8 vs. 59.2 kg (with thinning vs. without thinning). To assess quality, we measured water-soluble sugars, NO , NO and vitamin C content. Immediately, after the harvest, a surprisingly high vitamin C content was found in the fruits (4.4 mg.100 g on average), which, however, decomposed after 3 months of storage. We also determined the pathway of the decomposition of vitamin C.

Abstract Objectives This study investigated the effects of different thinning treatments on yield, fruit quality, and leaf photosynthesis of ‘Xiahui 5’ peach (Prunus persica (L.) Batsch). Materials and Methods The suitable thinning period and loading capacity of ‘Xiahui 5’ peach were explored in production and a theoretical basis for efficient and high-yield cultivation of ‘Xiahui 5’ peach was provided, including blossom-thinning+fruit-thinning at 20 d after full bloom (DAFB)+fruit thinning at 40 DAFB, blossom-thinning+fruit-thinning at 40 DAFB, fruit-thinning at 20 DAFB+fruit-thinning at 40 DAFB, and fruit-thinning at 40 DAFB, with neither blossom-thinning nor fruit-thinning as control. The yield, fruit quality, and leaf photosynthesis were detected. The thinning treatments were carried out between April and May 2012 in Nanjing City, Jiangsu Province, China. The intensity of thinning with spacing was approximately 20 cm between fruits. Results Thinning fruit twice (20 DAFB+40 DAFB) saved labour (260.4 h/ha) and improved the weight (186.45 g) of individual fruit, the yield (980.55 kg/ha), and the internal and external fruit quality (red saturation, the ratio between red and yellow saturation), as well as enhancing the water-use efficiency (8.19 mmol/mol) and apparent CO2-use efficiency (140.58 mmol/mol) values of leaves. The effect of thinning fruit twice was better than blossom thinning+fruit thinning, or fruit thinning only once. Conclusions Collectively, thinning blossoms and fruit is a blossom- and fruit-management method suitable for peach production areas in the middle and lower reaches of the Yangtze River in China. In addition, thinning fruit twice (20 DAFB+40 DAFB) during the young fruit period and before entering the core-hardening period is suitable for achieving a reasonable load of ‘Xiahui 5’ peach. Flower thinning was not the recommended strategy for ‘Xiahui 5’ peach in terms of a reasonable load.

Cultivation practices such as fruit thinning and soil management with ground covers are commonly applied in Citrus orchards, yet their physiological impact on young trees remains poorly documented. This study evaluated the effects of manual fruit thinning and weed-control mesh on vegetative growth, fruit development, and leaf mineral composition of Citrus sinensis L. Osbeck cv. ‘Navelina’ grafted on Citrus macrophylla. A six-month field experiment was conducted in southeastern Spain under semi-arid Mediterranean conditions using six treatments that combined different soil coverage and subsurface drainage systems. After physiological fruit drop, trees were standardized to ten fruits per plant. Vegetative parameters (canopy and trunk dimensions), fruit growth (size, juice content), and foliar nutrient concentrations were monitored. Trees with ground cover showed significantly greater canopy expansion and juice yield compared to uncovered controls. A negative correlation between fruit number and canopy-to-fruit volume ratio highlighted the trade-off between vegetative vigor and fruit load. Foliar analysis revealed lower micronutrient concentrations (Fe, Mn, B, Zn) in uncovered trees, suggesting reduced nutritional status. These findings demonstrate that combining early thinning with weed-control mesh promotes vegetative vigor, improves juice yield, and enhances nutrient uptake, providing practical insights for optimizing orchard establishment and early Citrus productivity in water-limited environments.

In many fruit trees, the thinning of buds, flowers, or fruits is used to increase the leaf area-to-fruit ratio (LA:F) and reduce competition for carbohydrates. Meanwhile, calcium (Ca) sprays during fruit development are also used to increase fruit quality and postharvest storage. Such practices have been recommended to increase fruit firmness and reduce fruit cracking in sweet cherries. To understand the effects of foliar Ca sprays and crop load reductions in the combination ‘Lapins’/‘Colt’, trained as the Kym Green Bush, a factorial experiment to determine the interactions between both managements was established in the Central Valley of Chile during the 2018/2019 growing season. Two levels of crop load (CL) were established—thinned (50% crop load) and unthinned (100% crop load) during Stage I of fruit development (31 days after full bloom, DAFB). Three timings of foliar applications of CaCl2 (TFA; 0.8%) were evaluated: early 26 DAFB, later 39 DAFB, or late 62 DAFB. Natural fruit contents and concentrations of Ca were determined on unsprayed control trees. Fruit from the thinned trees were significantly larger and heavier and had a higher titratable acidity than unthinned trees did. Significant interactions between TFA and CL were observed for SSC, without a clear trend. Thinned trees were less affected by pedicel detachment, browning, and fruit decay after 45 d of storage (0 °C). In unthinned trees, a foliar CaCl2 spray at Stage I allowed a higher fruit firmness than CaCl2 sprays at Stage II and III of fruit development. The CaCl2 applications at 39 or 62 DAFB reduced the incidence of cracking in thinned trees. Natural Ca concentrations decreased during fruit development, indicating a cessation of Ca import and a dilution by subsequent growth. Our results suggest that the early reduction of crop load has positive effects on fruit quality and condition during storage, and early Ca sprays (Stage I) improve fruit textural properties, even under high crop loads.

Unmanned aerial vehicle (UAV) liquid pollination emerges as a promising substitute for hand pollination methods. In this study, the relationship between UAV liquid pollination and fruit thinning operations was explored from the perspective of practical application. By testing droplet deposition under various flight parameters, the flight parameters for a specific pear orchard were optimized to ensure the uniform and effective distribution of the pollination solution. Results indicated that optimal droplet density (number·cm−2), area coverage (%), and deposition rate (μL·cm−2) were achieved at a flight height (FH) of 1.5 m and a flight speed (FS) of 2 m·s−1. Considering the nuanced physiological attributes of pear tree flowers during their pollination phase, the research scrutinizes the impact of application parameters such as floral stage and spraying frequency on pollination efficiency. A two-way ANOVA analysis demonstrated significant impacts of floral stage, spraying frequency, and their interaction on the fruit set rate (p < 0.01). Controlling pollination parameters can effectively regulate the fruit set rate, thereby influencing the cost and efficiency of fruit thinning. These findings contribute a theoretical framework for formulating customized pollination management strategies tailored to the specific needs of pear orchards.

Diagnostic of the nutritional status in fruit trees can be estimated using different models. However, these models usually do not fully match the character of the perennial crops and their accuracy needs to be improved. This study aimed at deepening the understanding of the aspects controlling mineral content of macro- and micronutrients and fruit quality of the apple trees with respect to the crop load and vegetative shoot growth. The focus was given on description of the nutrient content variability in time and space, its relation to important physiological events, and conditions altering their gradient in leaf and fruit. The evaluation was carried out with six years old ’Golden Delicious’ apple trees on M9, planted in an experimental orchard. Flowering rate, total yield, shoot growth intensity, mean fruit weight and quality along with mineral content of leaves, and fruit in different development stages were analysed according to intensity of natural or regulated flowering and fruit set, respectively. We found that aside of macroelements, iron, and manganese depended on the crop load. For nitrogen, phosphorus, and potassium content, their gradient increased up to 10–25% within the sufficiency range as the trees tried to maintain certain level of these nutrients in leaves and fruit simultaneously during deficit. In contrary, the higher content of Mg, Fe, and Mn related to the avoidance of deficit through up to 20–30% higher uptake in trees with higher crop load. Phosphorus, potassium, and calcium content in short fruiting shoots was more stage dependent, showing relation with the timing of cessation of particular meristematic growth activity. If no intense deficit occurred, the trees kept unrestricted initial investment of nutrients in the fruit during cell division stage whatever the crop load was. Their content at the later development stages appeared to be more dependent upon the consumption by particular sink. These findings allowed to improve the interpretation of the fruit trees nutrition status due to adaptation of the reference nutrient content in low cropping trees by a reduction of 5–10% N and P, 10–15% Ca, as well as by an increase of 15–20% K content in leaves at the stage with fruit size of 20 mm, and without change in P content at the stage of about 70% of final fruit size.

Key message The study unraveled the dynamics of mechanisms causing biennality in coffee, its consequences for competition for carbon and nitrogen and suggests means of adequately managing the problem. Imbalance in fruit load and branch growth plays a role in the occurrence of biennial bean production patterns in coffee ( Coffea arabica L.). Effects of fruit load manipulations were studied in two field experiments in the Jimma region, Ethiopia, over two consecutive years. Treatments consisted of reducing fruit loads in the pinhead stage to 25, 50, 75 % and controls keeping 100 % of the fruits per tree (treatments coded T25 through T100). Treatments were applied in the first year only. Branch growth and the formation of new leaves, drop of old leaves, light saturated rate of leaf photosynthesis ( A max ), nitrogen content of leaves on selected branches, as well yield and bean characteristics were evaluated throughout the experimental period. The study revealed that branch growth, and leaf N content per unit leaf area, N a , were inversely associated with fruit load, whereas loss of basal leaves on branches increased with fruit load and over time. A max was strongly and linearly associated with N a and declined with increase in fruit load. In the year of treatment green bean yield increased with fruit load, but in the second year the reverse was true. On aggregate over 2 years, treatment T25 and T50 out yielded treatments T75 and T100. Fruit thinning shifted the bean size distribution to larger sizes. In conclusion, fruit thinning modulated the balance between branch growth and fruit development. Thus enhanced branch growth, improved bean size and stabilized yield over years.

Fruit size declines in strawberries (Fragaria × ananassa Duch.) as the season progresses in many subtropical areas, possibly due to inadequate leaf area, over-cropping, or high temperatures. An experiment was conducted to investigate the importance of these factors on fruit growth in ‘Festival’ in Queensland, Australia. Groups of plants were defoliated to remove half of the mature leaves on each plant, thinned to remove all the inflorescences on each plant, or defoliated and thinned. Control plants were left intact. Defoliation, thinning, or defoliation + thinning decreased yield (total and/or marketable) by 15% to 24% compared with the control. Defoliation, or defoliation + thinning decreased average fruit weight (total and/or marketable fruit) by 1 to 2 g compared with the control, whereas thinning had the opposite effect. The incidence of small fruit increased towards the end of the season. There were strong relationships between fruit weight and average daily mean temperature in the seven weeks before harvest (R2s greater than 0.80). Fruit weight decreased from 24 g to 8 g as the temperature increased from 16 °C to 20 °C. This response was not affected by defoliation or thinning. The strong effect of temperature on fruit size indicates a problem for production in the future in the absence of heat-tolerant cultivars.

ABSTRACT Biennial bearing is the process in fruit trees by which one year of high fruit load is followed by a very low load or no production the next year. In apple growing, this is a troublesome problem, because of the negative effect on crop yield accumulated over the years, fruit quality, and plant physiology. The objective of this study was to evaluate the biennial bearing of nine apple cultivars, grafted on two rootstocks using of the biennial bearing index (BBI). The indices were calculated for the scion cultivars Maxi-Gala, Gala Real, Royal Gala, Fuji Select, Fuji Suprema, Mishima, Daiane, and Cripps Pink based on the yields from the harvests from 2008 to 2013. The apple cultivars exhibited no significant alternate production, considering the range of variation of the index. For the M-9 rootstock, cv. Fuji Suprema showed the highest BBI. For Marubakaido/M-9, Baigent, Mishima, Fuji Select, and Maxi-Gala showed the highest indices. There was no correlation between the biennial bearing index and the stem cross section of the scion cultivars, regardless of the rootstock used. RESUMO A alternância de produção caracteriza-se por um ano de elevada carga de frutos, seguido de outro ano com produção muito baixa ou nula. Na cultura da macieira é um problema indesejável, devido ao efeito negativo sobre a produtividade acumulada ao longo dos anos, qualidade da fruta e fisiologia da planta. O objetivo do trabalho foi avaliar a alternância de produção de nove cultivares de macieira, enxertadas sobre dois porta-enxertos, por meio da aplicação do índice de alternância de produção (IAP). A partir das produtividades observadas nas safras 2008 a 2013, foram calculados os IAP para as cultivares Baigent, Maxi-Gala, Gala Real, Royal Gala, Fuji Select, Fuji Suprema, Mishima, Daiane e Cripps Pink. As cultivares de macieira não apresentaram forte alternância de produção, considerando a amplitude de variação do índice utilizado. No porta-enxerto M-9, a cultivar Fuji Suprema exibiu IAP maior que as demais cultivares. No Marubakaido/M-9, os maiores índices foram apresentados por 'Baigent', 'Mishima', 'Fuji Select' e 'Maxi-Gala'. Não houve correlação entre o índice de alternância de produção e a área transversal do caule das cultivares, independentemente do porta-enxerto utilizado.