Fruit Dry Matter Accumulation Research Articles

Fruit Crop Species with Agrivoltaic Systems: A Critical Review

As the world seeks alternatives to fossil fuels, agrivoltaics offer a promising solution by integrating solar panels with farming practices. This review examines three key agrivoltaic setups—static tilted, full-sun tracking, and agronomic tracking—dissecting their engineering features’ roles in optimizing both the electricity yield and the fruit productivity of some fruit crops. We emphasize the microclimatic modifications induced by agrivoltaic systems, mainly encompassing changes in solar radiation, air temperature, humidity, and wind. The data collected in this survey reveal a strong spatial heterogeneity distribution over different locations and a significant influence on fruit crops’ growth, yield, and quality, with variations among species. Such findings on the overall performance recommend a 30% shading threshold to prevent substantial declines in fruit characteristics, i.e., fruit yield and quality. Shading conditions over this threshold influence the leaf morphophysiological characteristics, impacting the photosynthesis capacity and fruit dry matter accumulation. This emphasizes the importance of further investigation into spectral radiation quality and carbon assimilation kinetics as daily responses for different fruit species to be cultivated in such new environments. Starting from this point, this review underscores the need to extend studies on various fruit crops, particularly those cultivated in semi-arid horticultural regions (i.e., for saving water), and suggests the use of comprehensive and standardized indicators for comparability across studies. Finally, the authors conclude that engineering improvements, along with new research programs on agrivoltaic systems, could lead to agricultural, environmental, and economic sustainability, as well as their practical implementation and attractiveness to farmers in the coming years.

Effect of organic and synthetic mulches on some morpho-physiological and yield parameters of ‘Zard’ olive cultivar subjected to three irrigation levels in field conditions

Olive is one of the most important crops in arid and semi-arid areas. Prolonged water stress in these regions may adversely affect olive plant quality and productivity of fruits. To address the mitigation of unfavorable consequences of drought stress, the use of water-retaining mulches can be a beneficial solution. To achieve this purpose, the responses of olive cultivar ‘Zard’ as affected by mulch amendment [olive pomace, animal manure, nylon film, superabsorbent and control (without mulch)] and irrigation level (100 %ET as a normal condition and both 75 %ET and 50 %ET to simulate moderate and severe drought stress, respectively) were assayed. As a result, drought stress significantly retarded growth parameters, but fruit dry matter accumulation indicated the opposite behavior. Chlorophyll a + b, calcium, potassium, relative water content, and fruit yield also represented a declining tendency in severity-dependent behavior and conversely, sodium, antioxidant enzyme activity (catalase and peroxidase), oxidative markers, pulp/pit ratio, osmolytes (proline and total carbohydrates), and phenolic content increased in olive trees exposed to drought stress. Animal manure and especially olive pomace as organic mulches notably exhibited pragmatic influences on morpho-physiological as well as yield traits and improved pomological characteristics, regardless of tree water status. It was concluded that mulches used as water retaining agents, especially olive pomace and animal manure, can be effectively used to promote drought tolerance, growth and yield of olive trees growing in water deficit conditions. In general, using natural mulches is a good way to overcome drought stress.

Field Investigation into Tree Fates from Recent Apple Tree Decline: Abrupt Hydraulic Failure Versus Gradual Hydraulic Loss

In the last decade, a sporadic tree health syndrome affecting high-density apple plantings in North America has become known as Rapid Apple Decline (RAD) or Sudden Apple Decline (SAD). The affected apple trees were typically grafted on small dwarfing rootstocks, often displayed necrosis at the graft union, and suffered from sudden mortality that occurred over 2–3 weeks amid the growing season or a gradual decline. In 2019 and 2020, we conducted a multi-site investigation in the south Okanagan, British Columbia, Canada, to assess the stem hydraulic characteristics, stomatal conductance, leaf δ13C‰, and fruit dry matter accumulation of the declining trees during disease progression. In trees that died, mortality appeared to be associated with severe disruption in xylem water transport at the damaged graft union, followed by abrupt hydraulic failure. In contrast, symptomatic trees that did not die exhibited the moderately declined plant water relations and a reduction in fruit dry matter accumulation followed by either further deterioration or eventual recovery. This pattern indicates the risk of carbohydrate depletion over gradual hydraulic decline and the importance of timely horticultural remedies. In the present study, we discuss potential horticultural practices to mitigate hydraulic dysfunctions and enhance crop tolerance.

Dynamics of growth and nitrogen accumulation and utilization of young apple trees.

Taking 6-year-old Yanfu3/SH6/Malus hupehensis Rehd. as the test material, the dynamics of plant growth and nitrogen (N) accumulation under seven periods from germination stage to fruit maturity stage were examined by destructive analysis. The absorption, utilization, and distribution of fertilizer N were studied by 15N isotope tracer technique to clarify the N accumulation dynamics of apple trees and the maximum efficiency period of fertilizer N, and to provide theoretical basis for scientific application of N fertilizer. The results showed that the net accumulation of dry matter was 4.51 kg in germination stage (March 25) to fruit maturity stage (210 d after budbreak), with fruit accounting for 66.5%, the leaves and new shoots accounting for 20.2%, and the perennial organs accounting for 13.3%. The dry matter accumulation in 30-60 d after budbreak was the fastest, accounting for 42.9% of the whole treatment period. The fruit dry matter accumulation in 120-180 d after budbreak was the fastest, which accounted for 70% of the whole treatment period. The total N accumulation of the plant was 29.1 g, which increased rapidly in the 30-60 d and 120-180 d after budbreak by 7.2 g and 12.8 g, respectively accounting for 24.7% and 44% of the whole treatment period. The N accumulation of leaves and new shoots was the fastest in 0-60 d after budbreak, which accounted for 69.1% of the whole period. The N accumulation of fruit was the fastest in 120-180 d after budbreak, accounting for 60.8% of the whole period. The N accumulation of the perennial organ decreased first and then increased, and reached the lowest level at 60 d after budbreak. The 15N utilization rate of plant differed significantly in different periods which was at a high level in 30-60 d,120-150 d and 150-180 d after budbreak with 2.3%, 4.1% and 4.0% respectively. The 15N distribution rate in perennial organs in each period showed a high level, that of the new born organ increased first and then decreased which reached the highest level of 38.4% in 30-60 d after budbreak. The fruit reached the highest in 120-150 d and 150-180 d after budbreak by 15.0% and 16.6% respectively. Therefore, the key period of N accumulation in leaves and shoots was 30-60 d after budbreak, and that in fruit was 120-180 d after budbreak. The period with maximum efficiency for fertilizer N was at 30-60 d and 120-180 d after budbreak.

Partição de assimilados e biometria de duas cultivares de pimenta em ambiente protegido

The study aimed to comparatively evaluate the partition of assimilates between biometrics and two cultivars of pepper over the crop cycle. Plants were collected from the fourteenth day after transplanting (DAT) at regular intervals of fourteen days after the transplant by the end of the crop cycle. Evaluations were made of dry leaves (Wf), stem (WC), root (WR), fruit (WFR) and the rate of dry matter production of leaves (Cf), stem (CC), root (Cr), fruit (CFR), number of leaves and plant height. The cultivar Vulcao presented a higher allocation of dry matter in leaf, stem and root, but the Doce gave a higher dry matter accumulation in fruit which is the part of commercial interest.

Manipulation of fruit dry matter accumulation and fruit size in ‘Scifresh’ apple through alteration of the carbon supply, and its relationship with apoplastic sugar composition

SummaryThe supply of carbon to fruit on whole apple trees of ‘Scifresh’ grafted onto M.9 rootstock was altered by adjustment of the crop load [43% removal at 60 d or 90 d after full bloom (DAFB)], by three periods of 75% shading (from 60 – 90, 90 – 120, or 60 – 120 DAFB), or by a combined treatment of fruit removal at 60 DAFB and shading from 60 – 120 DAFB. Altering the timing and duration of shading, and crop load adjustment, resulted in changes in fruit dry matter concentration (DMC), with a range at harvest from 14.0 – 17.5%. Thinning to reduce the crop load enhanced fruit DMC, with greater effects on both fruit DMC and mean fruit fresh weight the earlier it was done. Shading reduced fruit DMC, with greater reductions the longer the shade was left over the trees. All treatments had greater effects on fruit DMC and fruit quality (flesh firmness and soluble solids concentration) at harvest than on mean fruit fresh weight. This trial also provided fruit samples for measurements of both the carbohydrate content and apoplastic composition of cortical tissues. Starch contents and total apoplastic sugar concentrations were increased by reductions in crop load and were decreased by shading, with starch content being the most responsive. Apoplastic sugar concentrations increased during fruit development. The relative order of abundance of sugars in the apoplast and in the symplast plus vacuole was similar, although differences in the ratios of sugars were evident, with sorbitol accounting for ≤ 10% of the total sugar content in the apoplast and ≤ 3% in the symplast plus vacuole. This work has revealed the possibility of using apoplastic sugar concentration as an indicator of the carbohydrate supply to apple fruit.

OPTIMISING KIWIFRUIT VINE PERFORMANCE FOR HIGH PRODUCTIVITY AND SUPERIOR FRUIT TASTE

Kiwifruit production systems in New Zealand are driven by the need to achieve both high productivity (yield of Class 1 fruit per canopy hectare) and superior fruit taste for consumers. Fruit dry matter content at harvest (DMC) is used as a proxy for potential taste of ripe fruit, and growers receive incentives to produce high DMC fruit. High DMC fruit would be considered c. 17% for 'Hayward' and c. 18.5% for 'Hort16A', with starch accounting for most of the DMC at commercial harvest. Vine management systems need to optimise both fruit number and fruit size per unit area of canopy as well as maximising the partitioning of carbohydrate to the fruit, to achieve this high starch content. In New Zealand, a number of plant management techniques have been introduced to manage fresh and dry matter accumulation in fruit over the last 10 years. This has occurred by an active process of intensive research, development and technology transfer extension. Techniques successfully introduced include girdling, management of fruit biostimulants, gel pruning, cane stringing and thinning. By integrating these techniques with existing orchard management procedures and ongoing fine tuning of on-orchard systems, top performing growers can consistently deliver both high productivity and high taste potential. In this paper, we outline several of these management techniques.

Potassium Uptake and Partitioning Relative to Dry Matter Accumulation in Cotton Cultivars Differing in Maturity

Dry matter may accumulate faster in fruit of earlier maturing cotton (Gossypium hirsutum L.) cultivars than in later cultivars, requiring more rapid K uptake and/or partitioning to developing bolls. Faster K uptake may require higher K fertility. We examined K uptake and partitioning relative to dry matter accumulation during boll filling of two cultivars contrasting in maturity, under two K fertility regimes at Jackson, TN. Plots fertilized with 56 kg K ha−1 yr−1 received the recommended rate of K, while plots receiving 112 kg K ha−1 yr−1 were overfertilized with K. ‘PM 1218 BG/RR’ (PVP 200000213) matured earlier than ‘DP 555 BG/RR’ (PVP 200200047) in 2005, and ‘FM 960BR’ PVP 200400224 matured earlier than DP 555 BG/RR in 2006, but not 2007. Higher K fertility did not increase lint yields, but it delayed maturity in two of 3 yr. During boll filling, the earlier cultivar accumulated more dry matter and K in fruit than the later cultivar, and accumulated them faster in 2 of 3 yr. Higher K fertility shifted the partitioning of dry matter and K to vegetative organs relative to fruit. The proportion of plant K in fruit exceeded the proportion of dry matter in fruit, and the difference increased during boll filling. Evidently, K translocation to fruit exceeded dry matter accumulation in fruit, indicating that boll filling was not limited by K. Neither the K‐uptake ratio (total aboveground K relative to residual soil K plus fertilizer K) nor the K‐utilization ratio (lint produced per unit plant K) differed between cultivars with sufficient K fertility.

A comparison of the combined effect of water stress and crop load on fruit growth during different phenological stages in young peach trees.

SummaryThe combined effect of fruit load and water stress on fruit water content and dry-matter accumulation was analysed for three phenological stages of fruit growth. Irrigation treatments were no irrigation during Stage I (NI-SI), Stage II (NI-SII), or Stage III (NI-SIII) compared with a fully irrigated control. Three thinning treatments were imposed within each irrigation treatment resulting in fruit loads ranging from low to high. Fruit harvests at the end of Stage I, II and III were used to determine total tree fruit fresh and dry matter after each stage of fruit development. Fruit water accumulation was highly sensitive to the effect of water stress at high fruit loads in all fruit developmental phases, but reductions in fruit water content were more apparent during Stages II and III than during Stage I. On the other hand, fruit dry-matter accumulation was relatively insensitive to water stress at any fruit load level and developmental stage. However, reductions in dry-matter accumulation were obtained during Stage III from those trees that were not irrigated during Stage I (NISI). Since these reductions occurred only for mid-to-high fruit load conditions, the decreases in fruit growth during Stage III appeared to be related to a carbon source limitation. The possible reasons for this source limitation are discussed.

Individual and combined effects of shading and thinning chemicals on abscission and dry-matter accumulation of ‘Royal Gala’ apple fruit

SummaryShade and chemical thinning treatments were applied to mature ‘Royal Gala’/M.26 apple trees either alone or in combination to study their effects on the pattern of abscission and growth of spur fruit. Natural fruit drop occurred in two distinct waves in both years; the first wave peaked 20 d after bloom (DAB) at a weekly abscission rate of c 15% in both years. The second wave of fruit drop in 2001 occurred earlier and was more intense than in the previous season. Application of NAA as a bloom thinner increased the maximum weekly abscission rate during the first wave of fruit drop in both years. Chemical fruit thinning treatments (Carbaryl in 2000, BA or delayed lime sulphur in 2001) had no effect on abscission or growth of spur fruit. Covering trees with 80% shade cloth for 3 d (2000) or 5 d (2001) stimulated a wave of fruit abscission that peaked c 10–15 d after removal of the cloth. Shade during the period from 20–25 DAB stimulated more fruit drop than earlier shade treatments, resulting in weekly abscission rates as high as 70%.There were no additive effects of combining thinning chemicals and shade treatments on abscission of fruit from spurs. However, additive effects of shade and thinning treatments were observed when measured as whole-tree crop density values, indicating that abscission of fruit from one-year wood was stimulated when low light conditions preceded application of (fruit) thinning chemicals. Shading trees from 34–39 DAB in 2000 resulted in a transient reduction and subsequent increase in the rate of dry-matter accumulation in fruit that were retained. Considerable challenges lie ahead in developing models of fruit growth that can account for the inter-dependent effects of light and crop load on fruit abscission and development that exist within an orchard environment.

Growth and physiological responses of cotton (Gossypium hirsutum L.) to elevated carbon dioxide and ultraviolet‐B radiation under controlled environmental conditions

ABSTRACTBetter understanding of crop responses to projected changes in climate is an important requirement. An experiment was conducted in sunlit, controlled environment chambers known as soil–plant–atmosphere–research units to determine the interactive effects of atmospheric carbon dioxide concentration [CO2] and ultraviolet‐B (UV‐B) radiation on cotton (Gossypium hirsutum L.) growth, development and leaf photosynthetic characteristics. Six treatments were used, comprising two levels of [CO2] (360 and 720 µmol mol−1) and three levels of 0 (control), 7.7 and 15.1 kJ m−2 d−1 biologically effective UV‐B radiations within each CO2 level. Treatments were imposed for 66 d from emergence until 3 weeks after the first flower stage. Plants grown in elevated [CO2] had greater leaf area and higher leaf photosynthesis, non‐structural carbohydrates, and total biomass than plants in ambient [CO2]. Neither dry matter partitioning among plant organs nor pigment concentrations was affected by elevated [CO2]. On the other hand, high UV‐B (15.1 kJ m−2 d−1) radiation treatment altered growth resulting in shorter stem and branch lengths and smaller leaf area. Shorter plants at high UV‐B radiation were related to internode lengths rather than the number of mainstem nodes. Fruit dry matter accumulation was most sensitive to UV‐B radiation due to fruit abscission. Even under 7.7 kJ m−2 d−1 of UV‐B radiation, fruit dry weight was significantly lower than the control although total biomass and leaf photosynthesis did not differ from the control. The UV‐B radiation of 15.1 kJ m−2 d−1 reduced both total (43%) and fruit (88%) dry weights due to smaller leaf area and lower leaf net photosynthesis. Elevated [CO2] did not ameliorate the adverse effects of UV‐B radiation on cotton growth and physiology, particularly the boll retention under UV‐B stress.

Posição dos frutos e seu efeito na repartição da matéria seca da planta do tomateiro

Plantas de tomateiro foram cultivadas no interior de estufas de polietileno no decorrer da primavera e do outono com o objetivo de determinar o efeito da posição dos frutos sobre a distribuição da matéria seca entre as partes vegetativas e os frutos. Os tratamentos foram constituídos por plantas conduzidas com uma haste (controle) ou duas hastes por planta, com frutos localizados somente sobre a haste principal ou distribuídos sobre as duas hastes. Em cada época, o número de inflorescências por planta foi mantido idêntico em todos os tratamentos, igual a oito na primavera e dez no outono, enquanto o número de folhas por planta foi, respectivamente, 27 e 37 nas plantas-controle e 52 e 65, em média, nas plantas com duas hastes. Na primavera, as plantas com duas hastes acumularam uma média de 155g de matéria seca de frutos, e aquelas com uma haste apenas 95g. No outono, esse parâmetro não mostrou diferença significativa entre os tratamentos: valores de 99g nas plantas com uma haste e uma média de 78 g naquelas com duas hastes. Nos dois experimentos, não foram observadas diferenças significativas entre os tratamentos com duas hastes por planta, independentemente da posição dos frutos sobre a planta. No outono, a fração da matéria seca total alocada para os frutos foi de 0,40 nas plantas com uma haste e em média de 0,24 nas plantas com duas hastes, indicando uma possível redução na força de dreno dos frutos. Concluiu-se que a posição dos frutos não modificou a distribuição da matéria seca da planta e que os resultados suportaram a hipótese de um "pool" único de assimilados circulando livremente no interior da planta do tomateiro.

The contribution of fruit photosynthesis to the carbon requirement of cucumber fruits as affected by irradiance, temperature and ontogeny

The photosynthetic contribution of a fruit to its carbon requirement throughout ontogeny and under different growing conditions was quantified in cucumber (Cucumis sativus L. cv. Corona). In addition, the effects of shading on fruit dry matter accumulation and the diurnal course of the elongation rate were studied. Fruit darkening had no photomorphogenic effect on fruit growth, while the cumulative photosynthetic contribution of a fruit to its own carbon requirement ranged from 1 to 5%. During the day there was always a net CO2 efflux. The photosynthetic rate per fruit, calculated as the difference between rates of CO2 exchange in light and dark, increased during fruit ontogeny, while the photosynthetic rate per unit fruit surface area declined. The latter was not dependent on fruit size. The photosynthetic activity per unit surface area of fruits was estimated to be about 20–30% as efficient as that of leaves. The rate of calculated photosynthesis was reduced by 60–65% when the photosynthetically active radiation incident on the fruit decreased from 200 to 50 μmol m−2 s−1. Temperature (20–30°C) had no pronounced effect on the rate of calculated fruit photosynthesis when fruits of the same developmental stage (temperature sum) were compared. However, the relative photosynthetic contribution of a fruit to its carbon requirement increased when temperature decreased. Moreover, this contribution increased when irradiance increased or fruit growth was reduced by competing fruits. During fruit ontogeny the daily photosynthetic contribution was highest (up to 15%) in young and old fruits, with a small growth rate.

Growth, sucrose synthase, and invertase activities of developing Phaseolus vulgaris L. fruits

ABSTRACTActivities of the sucrose‐cleaving enzymes, acid and neutral invertase and sucrose synthase, were measured in pods and seeds of developing snap bean (Phaseolus vulgaris L.) fruits, and compared with 14C‐import, elongation and dry weight accumulation. During the first 10 d post‐anthesis, pods elongated rapidly with pod dry weight increase lagging behind by several days. The temporal patterns of acid invertase activity and import coincided closely during the first part of pod development, consonant with a central role for this enzyme in converting imported sucrose during pod elongation and early dry weight accumulation. Later, sucrose synthase became the predominant enzyme of dry weight accumulation and was possibly associated with the development of phloem in pod walls. Sucrose synthase activity in seeds showed two peaks, corresponding to two phases of rapid import and dry weight accumulation; hence, sucrose synthase was associated with seed sink growth. Acid invertase activities in seeds were low and did not show a noticeable relationship with import or growth. All neutral invertase activities, during pod and seed development, were too low for it to have a dominant role in sucrose cleavage. Changes in activities of certain sucrose‐cleaving enzymes appear to be correlated with certain sink functions, including import, storage of reserves, and biosynthetic activities. The data supports the association of specific sucrose‐cleaving enzymes with the specific processes that occur in the developing pods and seeds of snap bean fruits; for example, acid invertase with pod elongation and sucrose synthase with fruit dry matter accumulation.

Effect of Temperature on the Size of Strawberry Fruit.

Strawberry, Fragaria × ananassa Duch. cv. Toyonoka, plants were grown from October onward in two glasshouses where the air temperature was controlled at either 15°or 19 °C night and day. Several days after pollination, the diameter of all the fruits in the first inflorescence (truss) was measured at approximately two-day intervals, and fully red ripe fruits were sampled. The growth of the fruits showed a double sigmoidal curve in all ranks of the inflorescence at both temperatures. The growth was faster in the higher rank fruits that developed earlier and at 19 °C than in the lower rank fruits and at 15 °C. Fresh and dry weight per fruit was larger in the higher rank fruits and at 15 °C (mean of all fruits; 0.879 g DW) than in the lower rank fruits and at 19 °C (mean of all fruits; 0.774 g DW). The total numbers of ripe fruits per inflorescence (plant) were slightly smaller at 19 °C. The values of the total fruit fresh and dry weight per inflorescence (plant) were much lower at 19 °C. The bearing fruit period from the flowering of the first flower to the ripening of the last fruit in the inflorescence was 88 days at 15 °C and 69 days at 19 °C, respectively. The daily dry weight increments of total fruit in the inflorescence (per plant) were 0.170 g at 15 °C and 0.151 g at 19 °C. It was considered that the small size of the fruits at a high temperature like 19 °C was not caused by the increase in the number of fruits. but by the low rate of dry matter accumulation in fruit.

Modeling Peach Fruit Growth and Carbohydrate Requirements: Reevaluation of the Double-sigmoid Growth Pattern

Abstract Seasonal patterns of fruit growth were measured on early and late-maturing peach (Prunus persica L. Batsch) cultivars (‘June Lady’ and ‘O’Henry’, respectively). Seasonal relative growth rates of fruit dry matter accumulation were calculated. The relationships between fruit relative growth rates and respiration were used to develop a quantitative carbon budget model of peach fruit growth and sink activity. The resulting model indicates that the double-sigmoid growth pattern of peach fruits involves only two physiologically distinct phases of sink activity instead of the three stages that are traditionally recognized. The traditional stage II of fruit growth is apparently a function of the timing of the shift between these two physiological phases of sink activity.

Functional Growth Analysis of Field Grown Strawberry

Abstract Field grown strawberry plants (Fragaria × ananassa Duch.) of an advanced breeding selection (OR-US 4681) were harvested every 3–4 days during establishment and through fruiting the next spring. Plant dry weight and leaf area increased rapidly during mid-summer, then slowed and finally ceased in October. Absolute growth rate (AGR) peaked at 1 g dry matter/day near 1 Sept., then fell to zero by early October. Over this period, there was a decrease in weekly mean temperature (37%), solar radiation (47%), and daylength (35%). Maximum values of relative growth rate (RGR) (0.044 g/g/day) and unit leaf rate (ULR) (9 g/m2/day) were determined at the start of sampling at the end of June; both rates declined steadily thereafter. The following April through June, both plant dry weight and leaf area increased exponentially, whereas RGR remained constant at 0.02 g/g/day, and ULR rose from 5.5 to 6.5 g/m2/day. The rate of dry matter accumulation in fruit was exponential, whereas it was linear in leaf lamina and stems (crowns plus petioles). A much smaller proportion of dry matter was partitioned to leaves during fruiting than during plant establishment.