Average Berry Weight Research Articles

An Evaluation of Fertility in Arkansas Primocane-fruiting Blackberries

Floral fertility of five primocane-fruiting (PF) blackberry (Rubus L. subgenus Rubus Watson) genotypes (‘Prime-Jim’®, APF-31, ‘Prime-Ark® 45’, APF-59, and APF-77) and three floricane-fruiting (FF) genotypes (‘Navaho’, ‘Natchez’, and ‘Ouachita’) were tested under field conditions using floricane flowers with four pollination treatments: undisturbed open-pollinated, emasculated self-pollinated, emasculated and cross-pollinated with pollen from a similar fruiting type (PF × PF or FF × FF), and emasculated and cross-pollinated with pollen from a different fruiting type (PF × FF or FF × PF). During primocane flowering, three pollination treatments (undisturbed open-pollinated, emasculated selfed, and emasculated cross-pollinated) were used to further test the fertility of the five PF genotypes. Significant differences between cross-pollination treatments and self-pollination were seldom noted with more differences seen in ‘Prime-Jim’® than any other genotype. Cross-pollinating primocane flowers on ‘Prime-Jim’® resulted in significantly higher fruit set, drupelet set, and average berry weight compared with self-pollination. Fruit set among genotypes ranged from 68.5 to 96.7%, and drupelet set rating ranged from 4.3 to 6.9 for floricane flowers. For open-pollinated primocane flowers, fruit set ranged from 63.9 to 92.1%, and drupelet set rating ranged from 4.3 to 7.2. The genotypes APF-31, APF-59, and APF-77 showed a marked improvement over ‘Prime-Jim’® in both percent fruit set and drupelet set of floricane and primocane flowers. The results indicated that fertility appears to be sufficient in all the genotypes evaluated and that the later-generation PF genotypes show improvement in fertility over ‘Prime-Jim’®. Pollen viability (using both chemical viability testing and in vitro germination testing), stigma receptivity, and pollen tube growth (using florescence) were evaluated in a controlled environment to determine if any improvements could be noticed when comparing a selection of later-generation PF genotypes (APF-31,' Prime-Ark® 45', APF-59, and APF-77) with ‘Prime-Jim’® and ‘Prime-Jan’®. Genotypes APF-31, APF-59, and APF-77 had significantly more viable pollen and pollen germination than ‘Prime-Jan’®. Stigma receptivity was observed in all genotypes. Pollen tube growth did not appear to be inhibited after self-pollination in any genotype studied, although significantly greater florescence resulting from pollen tube growth was seen after cross-pollination compared with self-pollination for APF-59. There were no significant differences in pollen tube growth between cross- and self-pollination for any other genotype.

Produtos alternativos na proteção da videira contra o míldio

O objetivo deste trabalho foi avaliar a eficiência de produtos alternativos na proteção da videira (Vitis vinifera) contra o míldio (Plasmopara viticola), bem como determinar a influência desses produtos na qualidade dos frutos da cultivar Merlot. Para o controle da doença, foram utilizados produtos à base de extratos vegetais, manano-oligossacarídeos fosforilados, fosfitos e acibenzolar-S-metil, além de fungicidas tradicionais. A intensidade do míldio em folhas e cachos, a produtividade, o número total de cachos por parcela, o peso médio do cacho e baga e as características analíticas do mosto foram avaliados nas safras de 2007/2008 e 2008/2009. Os fosfitos proporcionaram proteção contra o míldio da videira, com produtividade semelhante à do tratamento com fungicidas tradicionais. Os tratamentos baseados em manano-oligossacarídeos fosforilados, acibenzolar-S-metil e extratos vegetais não apresentaram controle eficiente do míldio. Os produtos alternativos testados não influenciam a qualidade analítica dos frutos, mas proporcionam, em geral, peso médio de cachos e de bagas menor que o do tratamento com fungicidas.

Fontes de cálcio aplicadas no solo e sua relação com a qualidade da uva 'Vênus'

O objetivo deste trabalho foi avaliar o efeito da aplicação de diferentes fontes de Ca2+ no solo sobre o teor deste nutriente no solo, nas folhas e nos frutos, e sobre atributos físico-químicos e conservação pós-colheita da uva 'Vênus' (Vitis labrusca x V. vinifera). O delineamento foi em blocos ao acaso, com quatro repetições. Utilizaram-se os seguintes tratamentos: T1 - testemunha (sem aplicação de Ca2+ no solo); T2 - cloreto de cálcio; T3 - gesso agrícola; T4 - Nitrabor®; T5 - cal hidratada, e T6 - borra de celulose. Para todas as fontes, aplicou-se o equivalente a 80 kg de Ca2+ ha-1, parcelados em três aplicações, a cada 21 dias, a partir do início da brotação da videira. Avaliou-se o teor de macronutrientes no solo, nas folhas e frutos. Na maturação, foram coletados quatro cachos por parcela, sendo dois cachos avaliados por ocasião da colheita e dois cachos mantidos sob temperatura ambiente e atmosfera modificada, sendo avaliados após cinco dias. Em geral, as fontes de Ca2+ proporcionaram maior teor de Ca2+ no solo, nas folhas e nos frutos. O Nitrabor® e o gesso agrícola aumentaram o peso médio de bagas. As fontes de Ca2+ reduziram a perda de peso, o degrane e a incidência de podridões dos frutos em pós-colheita.

FOLIAR APPLICATION OF CALCIUM AND BORON INFLUENCES PHYSIOLOGICAL DISORDERS, FRUIT YIELD AND QUALITY OF STRAWBERRY (F. × ANANASSA DUCH.)

Studies were conducted to determine the influence of pre-harvest foliar application of Ca, B and their combination on physiological disorders, fruit yield and quality of strawberry. The treatments consisted of (i) five sprays of calcium as CaCl 2 (first spray was performed at the petal fall stage and later at 7 days interval), (ii) three sprays of boron as boric acid (first spray at the beginning of flowering and later at 15 day interval), (iii) combination of (i) and (ii), and (iv) plants sprayed with water served as the control. Results indicated that fruit harvested from plants, which were sprayed either with Ca or Ca+B had lesser incidence of albinism and grey mould significantly than those harvested from plants sprayed either B alone or not treated. Although, B alone could not influence the incidence of albinism and grey mould, it reduced fruit malformation significantly. Further, pre-harvest application either of Ca or B or Ca+B could not influence the average berry weight and total fruit yield but marketable fruit yield differed significantly among the treatments. The lowest marketable fruit yield was recorded in plants under control, and the highest in plants sprayed with Ca+B (20% higher compared to control). Similarly, fruit receiving Ca or Ca+B were firmer had lower TSS, higher acidity and ascorbic acid content at the time of harvest and storage for 5 days (10°C and 90% RH) than those harvested from plants under control. Our studies clearly indicated that sequential foliar application of Ca+B can be recommended for reducing the incidence of albinism, malformation and grey mould in strawberry, and to get higher marketable yield.

Effects of Plant Growth Regulator on Endogenous Hormone Levels during the Period of the Red Globe Growth

Objective. The present study was aimed to elucidate the dynamic changes of endogenous hormone levels during the fruit growth and the changing regulation of endogenous hormone levels between normal and abnormal fruits. Methods. After using exogenous GA3 and GA3+6-BA, endogenous hormone levels such as indoleacetic acid(IAA), cytokinin(ZR), abscisic acid(ABA) and gibberellin(GA3) in normal fruits and rigid abnormal ones were determined by enzyme-linked immunosorbent assays(ELISA), respectively. Results. The results indicated that the treatments of 20mg/kg GA3 and the combination of 20mg/kg GA3+10 mg/kg 6-BA had no remarkable effects on increasing average weight of berries where the vertical diameter of grape fruits was longer than the transverse diameter. Exogenous hormone GA3 and GA3+6-BA mixture also affected the endogenous hormone levels. The content of IAA, ABA and ZR was lower in the rigid abnormal fruits than that in the normal ones, respectively, and those levels during the rapid growth period were nearly in accordance with those during the slow growth period. Conclusion. The fruit growth was closely related to the endogenous hormone levels.

EVALUATION OF SOME GRAPE VARIETIES IN THE ARID IRRIGATED REGION OF NORTHWEST INDIA

EVALUATION OF SOME GRAPE VARIETIES IN THE ARID IRRIGATED REGION OF NORTHWEST INDIA

Impact of main productivity components on formation of Strawberry yield (Fragaria ananassa Duch.)

There has been studied impact of main productivity components (number of spurs, peduncles, flowers, ovaries and average berry weight) on formation of Strawberry yield of introduced varieties and varieties and hybrid forms of national breeding. It is established that high Strawberry yield in the crop of first fruit-bearing year is caused by not less than 9 spurs, 14 peduncles, 153 flowers, 115 ovaries per linier meter and average berry weight over 18 g.

ENVIRONMENTAL EFFECT ON ANTIOXIDANT CONTENT OF TEN RASPBERRY CULTIVARS

ENVIRONMENTAL EFFECT ON ANTIOXIDANT CONTENT OF TEN RASPBERRY CULTIVARS

Delayed winter spur-pruning in New Zealand can alter yield components of Merlot grapevines

The effects of delayed winter spur-pruning on yield, yield components and fruit composition of Merlot vines was evaluated within a commercial vineyard in Marlborough, New Zealand. Vines were spur-pruned, trained using vertical shoot positioning, trickle irrigated and grafted to Kober 5BB rootstock. Delaying pruning from July (usual winter pruning time in New Zealand) until up to October (when apical shoots on canes were 5 cm long) resulted in yield increases of up to 93%, 63%, and 82% over the three seasons of experimentation. These yield increases reflected higher average berry weight and in turn bunch weights. The increase in average berry weight was associated with a change in the relative abundance of different berry types. Later pruning increased the proportion of large seeded berries while the proportion of smaller seedless berries and live green ovaries (shot berries) decreased. The delayed pruning may have enhanced fertilisation of flowers and development of seeds by postponing flowering to a time when climatic conditions are more favourable; measurements of shoot lengths support this proposal. By delaying winter pruning until after budburst the development of basal nodes was inhibited, so that budburst on the resulting spurs was also delayed.

Influence of Vine Vigor on Grape (Vitis viniferaL. Cv. Pinot Noir) Anthocyanins. 1. Anthocyanin Concentration and Composition in Fruit

The relationships between grapevine (Vitis vinifera) vigor variation and resulting fruit anthocyanin accumulation and composition were investigated. The study was conducted in a commercial vineyard consisting of the same clone, rootstock, age, and vineyard management practices. The experimental design involved assigning vigor zones in two vineyard sites based upon differences in vine growth. Fruits and wines were analyzed by HPLC from designated vigor zones in 2003 and 2004. Average berry weight (grams), average dry skin weight (milligrams), degrees Brix, and pH were higher and titratable acidity (grams per liter) was lower in 2003 compared to 2004. In 2003, only the highest and lowest vigor zones had differences in berry weight, whereas there were no differences in 2004. In both years, high vigor zones had lower degrees Brix and higher titratable acidity (milligrams per liter). Accumulation of anthocyanins (milligrams per berry) was greater in 2003 compared to 2004. There was a trend for lower anthocyanin concentration (milligrams per berry) in high vigor zones in both years. In 2004 compared to 2003, there was a higher proportion of malvidin-3-O-glucoside and lower proportions of the other four anthocyanins (delphinidin-, cyanidin-, petunidin-, and peonidin-3-O-glucosides) found in Pinot Noir. In both years, site A had proportionally higher peonidin-3-O-glucoside and lower malvidin-3-O-glucoside than site B. Some of these differences may be related to the higher exposure and temperatures found in site B compared to site A and also in the low vigor zones.

(114) Performance of Cranberry Varieties on an Upland Site in Michigan

Twenty cranberry (Vaccinium macrocarpon) genotypes were evaluated for five seasons in an experimental upland planting in southwest Michigan. Beds were constructed on a silty clay loam soil by excavating to grade, and filled with 30 to 45 cm of sand. Four 2 × 2-m plots of each genotype were planted in 1996. Fruit were harvested with hand scoops from 2000 to 2005. Yield per plot, average berry weight, and percent berries exhibiting decay were determined. Sound fruit were also stored at 2 °C for 4 to 8 weeks and sorted to determine the percentage of fruit developing decay in storage. Fungi were isolated and identified by morphological characteristics. Genotypes producing the highest average yields were `Stevens', `Ben Lear', #35, `LeMunyon', and `Franklin'. Varieties with the highest average berry weight were `Pilgrim', `Stevens', `Baines', `Beckwith', `Searles', and #35. Genotypes with lower rot incidence at harvest were #35, `Early Black', and `Foxboro Howes', whereas `Howes' and #35 developed the least rot during storage. Fungi commonly isolated from decaying fruit were Colletotrichum sp., Coleophoma empetri, Phomopsis vaccinii, Phyllosticta vaccinii, Fusicoccum putrefaciens, Botrytis cinerea, Pestalotia sp., and Allantophomopsis sp. Prevalence of specific fungi differed among cranberry genotypes.

Field Evaluation of Strawberry Genotypes for Tolerance to Black Root Rot on Fumigated and Nonfumigated Soil

Black root rot (BRR) is a widespread disease of strawberry (Fragari×ananassa Duchnesne) that causes the death of feeder roots and the degradation of structural roots. The major causal organisms of BRR include Rhizoctonia fragariae Husain and W.E. McKeen, Pythium Pringsh., and Pratylenchus penetrans (Cobb) Filipjev and Schuurmans Stekhoven. The current method of control for black root rot is methyl-bromide fumigation; however, methyl bromide is scheduled to be phased out in 2005, and its effects are short-lived in matted-row systems. The objectives of the study were to measure levels of tolerance to BRR in 20 strawberry genotypes and to determine which pathogens were present in the soil. The genotypes were planted in four blocks each of methyl-bromide fumigated and nonfumigated soil, and were evaluated for crown number, number of flowers per crown, yield, and average berry weight over 2 years. The results showed that all three pathogens were present in the field, and that there was a significant genotype × fumigation interaction for yield and crown number in both years. The cultivars Bounty, Cabot, and Cavendish, all released from the breeding program in Nova Scotia, displayed tolerance to the pathogens that cause BRR.

PHYSIOLOGICAL, GROWTH, YIELD AND QUALITY RESPONSES OF ´SHIRAZ´ BERRIES MANIPULATED USING PRD AND DRIP IRRIGATION

A study was conducted to investigate the effect of partial rootzone drying (PRD) in comparison to drip irrigation with two different water levels (0.45 and 0.9 ETc) on the physiological, growth, yield and quality responses of nine-year old 'Shiraz' grapevines in north-eastern Victoria, Australia. The amount of water rather than the application of PRD had a more significant effect on vine response. Average berry weight was unaffected but yield and berry number was reduced through influences that arose the previous season as well as the current season. There was some evidence that the application of PRD resulted in the maintenance of leaf function as measured by photosynthesis, transpiration and stomatal conductance pre- and post-veraison, however, this difference was not reflected in yield or growth parameters. As indicated by high pH and low acid levels the relatively high evaporative demand and small rooting volume of the vines at this site resulted in the vines experiencing repeated periods of stress between irrigations. The contrasting results of different PRD studies, including this trial, clearly indicate that the response of vines to PRD treatments is not easily defined and that vine management, soil types, irrigation amount and climate play a critical role in a grapevine's response to PRD. At this high stress site vines irrigated near or below potential crop evapotranspiration (Et-c) did not respond to PRD.

(369) Field and Greenhouse Evaluation of Strawberry Genotypes for Tolerance to Black Root Rot Pathogens

Black root rot is a widespread disease of strawberry (Fragaria×ananassa Duchnesne) that causes the death of feeder roots and the degradation of structural roots. The major causal organisms of black root rot include Rhizoctonia fragariae Husain and W.E. McKeen, Pythiumspp. and Pratylenchuspenetrans(Cobb) Filipjev and Schuurmans Stekhoven. The current method of control for black root rot is methyl-bromide fumigation; however, methyl bromide is scheduled to be phased out in 2005, and its effects are short-lived in matted-row systems. The objectives of the study were to measure levels of tolerance to black root rot in 20 strawberry genotypes and to determine which pathogens were present in the soil. The genotypes were planted in four blocks each of methyl-bromide fumigated and nonfumigated soil, and were evaluated for crown number, number of flowers per crown, yield, and average berry weight over two years. The results showed that all three pathogens were present in the field, and that there was a significant genotype × fumigation interaction for yield and crown number in both years. The cultivars Bounty, Cabot, and Cavendish, all released from the breeding program in Nova Scotia, displayed tolerance to the pathogens that cause BRR. Greenhouse studies were conducted using a subset of the genotypes to determine if any one pathogen causes more damage than others, and to determine if susceptibility to a particular pathogen varies between genotypes.

QUALITY EVALUATION OF RED AND WHITE CURRANT CULTIVARS

The objective of this study was to determine the quality of red and white currant cultivars and the changes in quality after storage. Quality of 7 red currant, 'Fertodi Korai', 'Red Dutch', 'Rachnovskaya', 'Heinemann's Rote Spatlese', 'Rovada', 'Varshevicha', and 'Viksnes Sarkanas', and 4 white currant, 'Cirvja Piets', 'White Dutch', 'Viksnes Baltas', and 'Werdavia', cultivars was determined. Ascorbic acid, total anthocyanins, and soluble solids contents of fresh and frozen berries were measured. Average berry weight and the number of flowers per raceme were evaluated. 'White Dutch' and Latvian 'Cirvja Piets' have the highest ascorbic acid content, Latvian 'Viksnes Sarkanas' and 'Varshevicha' have high anthocyanin content, and 'Werdavia', 'Heinemann's Rote Spatlese', and 'Red Duch' recorded the highest soluble solids content. 'Heinemann's Rote Spatlese' and 'Rovada' gave the largest number of flowers per raceme. Frozen storage did not influence anthocyanin and soluble solids content, but significantly reduced ascorbic acid content for both red and white currant cultivars by 18.2% and 19.0% respectively in 2002 and 2003. The least ascorbic acid loss was in red currant 'Viksnes Sarkanas' (4.15%). The best white currant cultivars for fresh market following integrated analysis were 'White Dutch', 'Cirvja Piets', and 'Werdavia'. The best red currant cultivars were 'Heinemann's Rote Spatlese', 'Fertodi Korai' and 'Viksnes Sarkanas'.

Effect of Rachis Position on Size and Maturity of Cabernet Sauvignon Berries

As part of a crop forecasting study, the variability in grape berry maturity and weight within individual clusters of Cabernet Sauvignon were determined. Each cluster was weighed as a whole and the number of berries within the cluster was counted. The difference between bottom berry weight and average berry weight was found to be statistically significant. Four berries were chosen systematically from the four sides of each cluster’s top, middle, and bottom region, yielding measurements of four variates: (1) top berry Brix, (2) middle berry Brix, (3) bottom berry Brix, and (4) Brix determined by mixing the juice extracted from all of each cluster’s remaining berries. Each of the replicates of variate (4) values were then subtracted from the corresponding measurements of variates (1), (2), and (3). The mean of the bottom berries’ difference in Brix from the entire cluster’s Brix was found to differ from zero significantly. This suggests that the Brix of a cluster may be represented poorly by berries near the bottom of the cluster.

Off-season Strawberry Production under High Tunnel Compared to Open Field in Kansas

High tunnel strawberry (Fragaria × ananassa) production experiment was conducted in south central Kansas, which consisted of two cultivars and four tunnels. The same experimental design was conducted under field conditions. The objectives of this study were to compare strawberry production and quality under high tunnels to those grown in the field and to assess the potential for high tunnels for early-season strawberry production. Plug plants of `Sweet Charlie' and `Chandler' were planted October 18. Plants were spaced at 12” × 12 “in double rows on raised beds covered with black plastic mulch. Protected plants under high tunnels had 100% winter survival rate compared to 60% of the field plants. Yield and berry quality of the high tunnel plants were by far better than those of field grown plants. Plant growth under high tunnels was about three to four fold higher than the unprotected field plants. `Sweet Charlie' flowered in early February and produced berries one week earlier than `Chandler'. Both cultivars were harvest from early April through late May at weekly interval. `Sweet Charlie' in early April produced an average berry weight of 14 g, soluble solids of 8 °Brix, and the largest average berry weight was 15 g. `Chandler' harvested late April produced larger berries than `Sweet Charlie' with the largest average berry weight of 35 g compared to 31 g for `Sweet Charlie'. In mid May, `Chandler' produced 72% higher yield than `Sweet Charlie'. High tunnel not only produced higher yield and better quality berries than field strawberries but it has a potential to produce early crop and extend the season production of strawberry in Kansas.

Evaluation of Strawberry Genotypes for Tolerance to Black Root Rot

Black root rot is a serious disease of strawberry (Fragaria ×ananassa Duch.) that causes the death of feeder roots, the degradation and blackening of structural roots, and an overall decrease in plant vigor and productivity. The causal organisms of black root rot are Rhizoctonia fragariae, Pythium sp. and Pratylenchus penetrans (the root lesion nematode). Each organism alone can cause extensive damage to strawberry roots, but studies have shown that black root rot may be more severe when all organisms are present, indicating there is an interaction between the fungal organisms and the nematode. The current method of control for black root rot is methyl-bromide fumigation; however, methyl bromide is to be phased out by 2005, and it is not very effective in perennial matted-row systems. The objectives of the study are to measure levels of tolerance to black root rot in 21 strawberry genotypes. The genotypes were planted in four blocks each of methyl-bromide fumigated and non-fumigated soil, and were evaluated for crown, runner, and inflorescence number; yield; average berry weight; and root health. `Cavendish', `Kent', `Midway' and `Winona' showed the highest degree of tolerance, while `Jewel', `Mesabi', and LH50-4 (a F. virginiana genotype) were the poorest performers.

Trellising, fruit thinning and defoliation have only small effects on the performance of ‘Ruby Seedless’ grape in Morocco

SUMMARYThe effects of trellising, thinning and defoliation on growth, yield and fruit composition were investigated in grape (Vitis vinifera L., ‘Ruby Seedless’) in Morocco over two years. Vines were grown on a double tee (DT) or a triple tee (TT) using two or three cross-arms, thinned at fruit set (29 clusters) or not thinned (35 clusters), and defoliated (removal of basal leaves at veraison up to and including the leaf opposite the first retained grape cluster) or left undefoliated. The TT trellis had greater shoot growth, leaf area, and pruning weights than the DT trellis. Twenty per cent of light reached the fruiting zone in both trellis systems. In contrast, average light in this zone ranged from 52 to 969 µmol m-2; s-1 in the defoliated vines compared with 13 to 59 µmol m-2 s-1 in the undefoliated vines. Berries on defoliated vines were up to 6.K warmer than berries on the control vines. Yield per vine was not affected by any of the treatments, with an average yield of 7.53.6.1.85.kg per vine. Average berry weight was increased by 6% with either defoliation or fruit thinning. Total soluble solids were significantly (P<0.05) increased in thinned vines (17.02±0.10˚Brix) compared with unthinned vines (16.55±0.09˚Brix), whereas there was no effect of trellising and defoliation on total soluble solids. Defoliation increased fruit colour slightly in unthinned vines (absorbance values at 520.nm of 0.390 and 0.461), while thinning increased berry colour slightly in undefoliated vines (absorbance values at 520.nm of 0.390 and 0.489). Trellising, fruit thinning and defoliation have only marginal effects on the performance of grape in Morocco.

Latent Infection by Leafroll Agent GLRaV-3 Is Linked to Lower Fruit Quality in French-American Hybrid Grapevines Vidal blanc and St. Vincent

Infection of French-American hybrid grapevines by GLRaV-3 is latent, and information about the impact of the virus on the performance of these cultivars is scarce. This study compares several performance indices between Vidal blanc and St. Vincent grapevines that were naturally infected and those free of GLRaV-3. Virus infection did not affect grapevine vigor, but was linked to an approximately 5% reduction (<i>p</i> &lt; 0.001) in average berry weight in both cultivars. Titratable acidity was 5 and 9% higher (<i>p</i> &lt; 0.001) in the fruit from virus-positive St. Vincent and Vidal blanc grapevines, respectively, three to seven days prior to harvest. Also included in the study were Vidal blanc plants naturally infected by GLRaV-3 and grapevine fleck virus (GFkV). Plants with both viruses had a 7% reduction in average berry weight and titratable acidity levels were 14% higher compared to healthy plants (<i>p</i> &lt; 0.001). Graft-indexing on <i>Vitis vinifera</i> L. cv. Cabernet Franc and <i>Vitis rupestris</i> Scheele cv. St. George indicators produced typical leafroll and fleck symptoms, respectively. These results suggest that latent infections in these French-American hybrid cultivars cannot be attributed to the low virulence of the viral strains, but probably to host tolerance.