scholarly journals 248 Influence of Early Rowcover Removal and Supported Rowcovers on Yield, Earliness, and Fruit Size of Strawberries Grown under Plasticulture

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 433F-434
Author(s):  
Peter Nitzsche ◽  
Joseph Fiola

Growers in Northern New Jersey are slowly adopting strawberry plasticulture as an improved production system. One advantage of the system is early fruit production. Early fruit usually brings high prices in the marketplace. With early production, however, there is an increased risk of a late frost damaging flowers and fruit. Removing floating rowcover winter protection earlier than flowering may cause strawberries to bloom later, reducing the risk of frost damage. Supporting the rowcovers above the crop with wire hoops may also provide better winter protection and improve fruit production. In 2 years of field trials, removing floating rowcovers 2 weeks before anticipated bloom reduced early yield and delayed the first harvest by 2 to 3 days. Total marketable yield and average fruit weight were not significantly influenced by early removal. Plants with rowcovers supported with wire hoops did not produce significantly greater total yields or average fruit weights than plants protected by unsupported rowcovers. The wire hoops caused damage to the rowcovers, which may make their use in commercial production impractical.

Horticulturae ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 34
Author(s):  
Christopher Menzel

Five strawberry (Fragaria × ananassa Duch.) cultivars were grown in Queensland, Australia to determine whether higher temperatures affect production. Transplants were planted on 29 April and data collected on growth, marketable yield, fruit weight and the incidence of small fruit less than 12 g until 28 October. Additional data were collected on fruit soluble solids content (SSC) and titratable acidity (TA) from 16 September to 28 October. Minimum temperatures were 2 °C to 4 °C higher than the long-term averages from 1965 to 1990. Changes in marketable yield followed a dose-logistic pattern (p < 0.001, R2s = 0.99). There was a strong negative relationship between fruit weight (marketable) and the average daily mean temperature in the four or seven weeks before harvest from 29 July to 28 October (p < 0.001, R2s = 0.90). There were no significant relationships between SSC and TA, and temperatures in the eight days before harvest from 16 September to 28 October (p > 0.05). The plants continued to produce a marketable crop towards the end of the season, but the fruit were small and more expensive to harvest. Higher temperatures in the future are likely to affect the economics of strawberry production in subtropical locations.


2018 ◽  
Vol 10 (1) ◽  
pp. 358-362
Author(s):  
D. P. Sharma ◽  
Niranjan Singh

Pruning of fruit trees is an important aspect for the improvement of fruit quality and to minimize the pests and disease attack. Pruning was performed in the month of December in seven year old unpruned trees of Punica granatum cv. Knadhdri Kabuli having many interfering branching and a heavy infestation of bacterial blight orchard. The pruning treatments viz., T1: Retention of 15cm fruiting shoot length, T2: Retention of 30cm fruiting shoot length, T3: Retention of 45cm fruiting shoot length, T4: Retention of 60cm fruiting shoot length and T5: control (No heading back and no thinning) plant. The results of the present investigation revealed that among different pruning treatment, the best results in terms of shoot extension (56.34 cm), fruit size (Diameter 9.66 cm and Length 9.65 cm, fruit weight (278.50 g), marketable yield (10.25 kg) and fruit qualities were in fruits from T1 and T2 where retention of 15cm fruiting shoot length respectively and retention of 30cm fruiting shoot length were maintained. However, maximum fruit set (54.73%) was recorded in control, and it decreased with increasing pruning intensity. The pruning treatments also proved beneficial in controlling bacterial blight on fruit (12.86%) and leaf surface (26.60%) to some extent.


1969 ◽  
Vol 73 (2) ◽  
pp. 141-148
Author(s):  
Juan G. Cruz-Castillo ◽  
Arturo Cedeño-Maldonado

Interest in commercial production of soursop has increased recently in several countries of Tropical America. The work presented here deals with some aspects of the practice of defoliation and its relation to flowering and fruit production of soursop. Treatments used to evaluate defoliation were 1) control; 2) defoliation by hand; 3) potassium iodide at 1.5%; 4) Ethrel at 1500 mg/1; and 5) Ethrel at 2,000 mg/1. The sum of the growth of new lateral branches was significantly superior in all treatments compared to that of the control, with approximately 100 cm of new growth 9 months after treatment. Defoliation by hand and with Ethrel at 1500 and 200 mg/1 shifted formation of new flowers toward the region near the apex of branches. Total flower number 9 months after treatment was statistically superior in the treatments of defoliation by hand and by 1,500 mg/1 Ethrel, with 362 and 370 flowers, respectively. Total fruit production per year was significantly greater in the 1.5% potassium iodide treatment with 21 fruits/trees and a fruit weight at 15.27 kg.


HortScience ◽  
1992 ◽  
Vol 27 (7) ◽  
pp. 787-789 ◽  
Author(s):  
Aref Abdul-Baki ◽  
C. Spence ◽  
R. Hoover

Field experiments were conducted to a) maximize total yield of fresh-market field tomato (Lycopersicon esculentum Mill.) cultivars using black polyethylene mulch (BPM), and b) increase fruit size and yield during the last 5 weeks of the production period by reducing the number of synthate sinks per plant through eliminating all flowers that appeared during this period. Unmulched treatments under trickle irrigation and multiple applications of soluble fertilizer yielded an average of 43 t·ha-1 for `Sunny' and `Pik-Rite' over the two planting dates. With BPM, total yield increased by 95% to 84 t·ha-1. Although total yield increases due to BPM over the control were highly significant in both cultivars and over the two planting dates, yield increases were higher for the early than for the optimum planting date. BPM also significantly increased early production of `Pik-Rite' but not `Sunny', and the increase in early production was more pronounced for the optimum than the early planting date. Sink reduction during the last 5 weeks of the growing season had no effect on yield or fruit weight during that period.


HortScience ◽  
2000 ◽  
Vol 35 (7) ◽  
pp. 1263-1264 ◽  
Author(s):  
E.W. Stover ◽  
P.J. Stoffella ◽  
S.A. Garrison ◽  
D.I. Leskovar ◽  
D.C. Sanders ◽  
...  

A commercial mixture of 1-naphthaleneacetamide and 1-naphthaleneacetic acid (Amcotone) was applied to tomato (Lycopersicon esculentum Mill.) and pepper (Capsicum annuum L.) at various timings from early bloom through early fruit development to evaluate effects on fruit size and both early and total marketable yield. Amcotone was applied at rates from 10 to 40 mg·L-1, at three sites for each of the species studied. Measured yield response variables in tomato did not differ between the control and Amcotone treatments, regardless of location. Amcotone treatments did not affect yields or fruit size for pepper at the New Jersey or Texas sites. However, at Ft. Pierce, Fla., early marketable yield of pepper was increased in plots receiving three Amcotone applications at 10 mg·L-1, but total marketable yield was significantly reduced in all plots receiving more than two Amcotone sprays, and mean fruit weight was reduced by all Amcotone treatments. Early and total marketable yield of pepper at Ft. Pierce were markedly reduced in plots receiving four applications of 40 mg·L-1, which was a high rate used to assess potential phytotoxicity. While minimal benefit from auxin application was observed in this study, earlier studies suggest that these results may have been influenced by favorable environmental conditions for fruit development or negative effects on unopened flowers during all Amcotone spray applications.


HortScience ◽  
2008 ◽  
Vol 43 (5) ◽  
pp. 1492-1494 ◽  
Author(s):  
Darren E. Robinson ◽  
Kristen McNaughton ◽  
Nader Soltani

Pepper growers currently have limited access to many effective broadleaf herbicides. Field trials were conducted over a 3-year period in Ontario to study the effect of tank mixtures of sulfentrazone (100 or 200 g·ha−1 a.i.) with either s-metolachlor (1200 or 2400 g·ha−1 a.i.) or dimethenamid-p (750 or 1500 g·ha−1 a.i.) on transplanted bell pepper. Under weed-free conditions, there was no visual injury or reduction in plant height, fruit number, fruit size, or marketable yield of transplanted pepper with pretransplant applications of sulfentrazone applied in tank mixtures with s-metolachlor or dimethenamid-p. The tank mixture of sulfentrazone + s-metolachlor gave greater than 85% control of redroot pigweed (Amaranthus retroflexus) and eastern black nightshade (Solanum ptycanthum), but only 70% to 76% control of velvetleaf (Abutilon theophrasti), common ragweed (Ambrosia artemisiifolia), and common lambsquarters (Chenopodium album). The combination of sulfentrazone + dimethenamid-p provided good to excellent control of all weed species except velvetleaf. Based on this study, sulfentrazone and dimethenamid-p have potential for minor use registration in pepper.


HortScience ◽  
2008 ◽  
Vol 43 (6) ◽  
pp. 1852-1856 ◽  
Author(s):  
Eleni Tsantili ◽  
Miltiadis V. Christopoulos ◽  
Constantinos A. Pontikis ◽  
Pantousis Kaltsikes ◽  
Chariklia Kallianou ◽  
...  

The effect of three preharvest sprays with water or 58.5 mm calcium chloride (CaCl2) on texture and other quality attributes was investigated in ‘Konservolia’ olives harvested at the black-ripe stage and measured after 1 and 15 days of storage in air at 10 °C with 85% relative humidity. Effects on fruit calcium (Ca) and magnesium (Mg) concentrations during the period of spray applications were also studied. Concentrations of Ca, Mg, and chlorophyll and photosynthesis rate in leaves were measured on the day of final fruit harvest. No foliar or fruit toxicity was observed. In leaves, Ca sprays increased Mg but did not affect Ca and chlorophyll concentration and photosynthesis rate. In fruits, Ca sprays prevented the gradual decrease in Ca concentration that occurred in untreated fruits and maintained Mg at constant levels during ripening on the tree but did not affect fruit size and oil content as measured 1 day after storage. Ca-treated fruits were firmer with lower soluble pectin (SP) concentration and higher calcium pectate (CaP) than controls in both storage days, whereas the protopectin levels were similar in all fruits. Results showed positive linear correlation between Ca concentration and either firmness or CaP, whereas that between Ca and SP was negative as found in fruits stored for 1 day. Fruit production rates of carbon dioxide and ethylene, L* and chroma (C*) of peel, and hue angle (h°) of flesh were unaffected either by Ca treatment or storage time. Ca treatment did not affect fruit weight loss, the decreases in peel h° and flesh L*, but increased flesh C* during storage. The results indicate positive effects of preharvest calcium sprays on olive firmness without any negative effect on fruits or leaves.


2019 ◽  
Vol 10 (5) ◽  
pp. 69-81
Author(s):  
Rosemiro Dos Santos Galate ◽  
Jessivaldo Rodrigues Galvão ◽  
Tiago Kesajiro Moraes Yakuwa ◽  
Deivison Rodrigues da Silva ◽  
Merilene Do Socorro Silva Costa ◽  
...  

Açaí palm (Euterpe oleracea Mart.) is a native palm tree from the Eastern Amazon, Brazil. It is considered an economically viable source of anthocyanins for the dye and medicine industries. This study aimed to estimate the phenotypic variability and to select genotypes for genetic improvement. Descriptive statistics were used to estimate phenotypic variability. Truncated selection was performed for fruit production per bunch. The collected samples presented the highest fruit yield per cluster of all studied region. Number of fruits per cluster and stem circumference are possibly controlled by few genes. longitudinal fruit diameter may have recessive genes that are decreasing fruit size. Fruit weight, seed weight, pulp weight, number of stem per plant, total cluster length, fruit weight per cluster and pulp yield per fruit presented frequency distribution in favor of heterozygotes. There some characteristics controlled by few genes, with evidence of selection and spontaneous domestication of the matrices.


2008 ◽  
Vol 18 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Ramón A. Arancibia ◽  
Carl E. Motsenbocker

Plasticulture has been successfully used to enhance growth and yield of horticultural crops, and also for season extension in cooler climates. The effect of three plastic mulches (silver on black, photoselective thermal green, and black) in combination with spunbonded polyester rowcover (0.9 oz/yard2) on spring-planted watermelon (Citrullus lanatus) production was investigated. Two red-fleshed cultivars [Sangria (seeded) and Crimson Jewel (triploid)] were used. Plastic mulches increased early and total marketable yield in comparison with bare ground for both cultivars, but net benefit increased in ‘Crimson Jewel’ only. In contrast, yield and net benefit were the same among plastic mulches. Rowcover increased soil and air temperature, with the effect being greatest at lower ambient temperatures. During a near-freeze event, air temperature under the rowcover was about 7.2 °F higher than without a rowcover. Rowcover increased early and total marketable yield, but fruit weight decreased in both cultivars. Yield distribution into three fruit size categories was inconsistent between the cultivars. In ‘Sangria’, the large fruit category had the highest yield proportion for all treatments. In contrast, the highest yield proportion of ‘Crimson Jewel’, with exception of mulch without rowcover, corresponded to small fruit. Rowcover increased gross income at wholesale prices, but net benefit was not different from without rowcover. Protection of high-value plants, such as triploid watermelon, against light freezes, however, may still justify the use of rowcover in early plantings.


2013 ◽  
Vol 138 (3) ◽  
pp. 159-166 ◽  
Author(s):  
Hazel Y. Wetzstein ◽  
Weiguang Yi ◽  
Justin A. Porter ◽  
Nadav Ravid

Pomegranate trees (Punica granatum) produce large numbers of both hermaphroditic (bisexual) flowers that produce fruit and functionally male flowers that characteristically abort. Excessive production of male flowers can result in decreased yields resulting from their inability to set fruit. Within hermaphroditic flowers, sex expression appears to follow a spectrum ranging from those exhibiting strong to weak pistil development. Unknown is the scope that flower quality plays in influencing fruit production. A description of floral characteristics and how they vary with flowers of different sizes and positions is lacking in pomegranate and was the focus of this study. Furthermore, the effects of flower size and position on fruit set and fruit size were evaluated. This study documents that flower size characteristics and ovule development can be quite variable and are related to flower type and position. Single and terminal flowers within a cluster were larger than lateral flowers. In addition, lateral flowers exhibited a high frequency of flowers with poor ovule development sufficient to negatively impact fruiting in that flower type. Ovule numbers per flower were significantly influenced by flower size with more ovules in larger flowers. Pollination studies verified significantly higher fruit set and fruit weight, and larger commercial size distributions were obtained with larger vs. smaller flowers. Thus, flower quality is an important issue in pomegranate. Cultural and environmental factors that influence flower size and vigor may have a direct consequence on fruit production and yield.


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