scholarly journals Pre-plant Dipping of Strawberry Transplants for Control of Colletotrichum acutatum

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1012A-1012
Author(s):  
Oleg Daugovish ◽  
Doug Gubler

Strawberry anthracnose caused by Colletotrichum acutatum may kill strawberry plants or reduce plant vigor and marketable yield, resulting in multimillion dollar losses to strawberry industry. The fungus is often carried with transplants from nurseries to production fields undetected. The studies in one summer and two winter seasons near Oxnard, Calif., evaluated 30-second pre-plant dipping in ten fungicide solutions or water washing of transplants inoculated with C. acutatum as a means of reducing infection and improving fruit yield. In summer-planted `Baeza,' the pathogen caused severe die-back and reduced marketable fruit yield 89% in inoculated, untreated controls compared to non-inoculated plants while plants dipped in Switch (cyprodynil + fludioxynil) at 0.38 g/L had 33% yield reduction. Other fungicides provided even less protection, resulting in 53% to 89% yield losses. During cooler winter seasons the pathogen remained latent and lesions appeared on `Camarosa' when the day-night air temperatures reached 16 °C or more, 7–14 days after rain. None of the treatments reduced fruit lesion development, however, among plants dipped in strobilurin fungicides only 3% had C. acutatum symptoms (including early die-back) as opposed to 26% in inoculated, untreated controls. Plants dipped in Switch, Quadris (azoxystrobin), or Pristine (pyraclostrobin + boscalid) yielded similar to non-inoculated, untreated controls in 2003 and 10% to 12% more in 2005. These studies showed that strobilurin fungicides did not prevent fruit infection (indicating need for foliar in-season control) but improved marketable yield compared to the inoculated, untreated plants. Temperatures over 16 °C and precipitation may significantly increase disease development.

Author(s):  
Jaspa Samwel ◽  
Theodosy Msogoya ◽  
Abdul Kudra ◽  
Hosea Dunstan Mtui ◽  
Anna Baltazari ◽  
...  

Abstract Background Orange (Citrus sinensis L.) production in Tanzania is constrained by several pre-harvest factors that include pests. Hexanal, sprayed as Enhanced Freshness Formulation (EFF) is a relatively new technology that has been reported to reduce pre-harvest loss in fruits. However, the effects of hexanal on pre-harvest yield loss of orange are not known. We studied the effects of hexanal as EFF on yield losses of three sweet orange cultivars namely, Early Valencia, Jaffa, and Late Valencia. Factorial experiments tested the effects of EFF concentration, variety, and time of EFF application on number of dropped fruit, percentage of non-marketable fruit and incidence of pest damage. Results Results showed significant negative correlation (p < 0.001) between EFF and the percentage of dropped fruit, non-marketable yield, and incidence of pest damage. An increase in hexanal concentration by 1%, is expected to reduce number of dropped fruit by 50, percentage of non-marketable by 35.6, and incidences of pest damage by 36.5% keeping other factors constant. Results also show significant association (p < 0.001) between time of hexanal application and non-marketable yield. Percentage of dropped fruit is expected to increase by 1 for each day away from harvest, keeping other factors constant. Conclusion Pre-harvest application of hexanal as EFF can significantly reduce number of dropped fruits, percentage of non-marketable fruit and incidence of pest damage.


HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 438a-438
Author(s):  
Yaying Wu ◽  
Brian A. Kahn ◽  
John B. Solie

We are developing a mechanical harvest system for okra [Abelmoschus esculentus (L.) Moench]. Our objective was to identify a high-density (HD) plant arrangement and a harvest timing that would maximize marketable fruit yield per hectare with a destructive harvest. We compared destructively harvested plants grown at spacings of (in cm) 15 × 15, 23 × 23, and 30 × 30 with hand-harvested plants grown at 90 × 23 cm. Within HD treatments, marketable fruit weight increased inconsistently as plant density increased. The 30 × 30-cm spacing was not dense enough. Branching decreased and the position of the first marketable fruit attachment moved up as plant density increased. Delaying destructive harvest until many over-mature fruit were present often did not increase marketable fruit yield and always reduced the proportion of total harvested fruit weight due to marketable fruit. Overall, percentages of marketable yield obtained by destructive harvests of HD plants were low compared to the cumulative marketable yield from control plants. However, the labor-saving potential was high. A prototype machine for harvest of HD okra has been developed, and further testing is planned.


Author(s):  
Gisley Karoline Emerick Bitancourt Alves ◽  
Antônio Carlos Simões ◽  
Regina Lúcia Félix Ferreira ◽  
Sebastião Elviro Araújo Neto

A importância alimentar do tomate orgânico aliado a sua baixa produção na Amazônia e a necessidade de baixo uso de insumos para seu cultivo ecológico o objetivo deste trabalho foi avaliar a produtividade de cultivares de tomate orgânico cultivado em campo e ambiente protegido com alto e baixo nível de insumos. Os experimentos foram conduzidos em ambiente protegido e campo, ambos no delineamento em blocos casualizados completos, em esquema de parcelas subdivididas 2 x 3, sendo a parcela principal composta por dois níveis de insumos e a subparcela pelas cultivares copa (Santa Kruz Kada, IPA 6 e Santa Clara), com cinco repetições de cinco plantas cada. As variáveis avaliadas foram: massa média de frutos total e comercial (g fruto-1), número de frutos total e comercial por planta, produtividade total e comercial de frutos (kg ha-1). A cultivar IPA 6 em cultivo protegido exigiu maior uso de insumos para aumentar a massa média de fruto total e comercial, produtividade total e comercial, em campo pode se utilizar baixo nível de insumo. O alto uso de insumos é necessário para aumentar a produtividade total e comercial para a cv. Santa Clara em cultivo à campo, ambiente que também necessita de alto uso de insumos para aumentar a massa média de fruto total e comercial a produtividade comercial da cultivar Santa Kruz. Productivity of organic tomato grown in different environments and levels of inputsAbstract: The importance of organic tomato feed associated with their low production in the Amazon and the need for low input to its ecological farming the objective of this study was to evaluate the productivity of organic tomato cultivars grown in field and greenhouse with high and low level inputs. The experiments were conducted under greenhouse and field conditions, both in randomized complete block design comprising plots subdivided into subplots. The plots encompassed of two levels of inputs, while the subplots contained the (Santa Kruz Kada, 6 and IPA Santa Clara), with five replicates of five plants each. The variables evaluated were: total fruit mass and marketable fruit mass (g fruit-1), number of total and marketable fruit per plant, total and marketable fruit yield (kg ha-1). The cultivar IPA 6 in greenhouse demanded greater use of inputs to increase the total and marketable fruit mass, total and marketable yield in field can be used for low level input. The high use of inputs is necessary to increase the total and marketable yield for cv. Santa Clara in the growing field, environment which also requires high use of inputs to increase the total and marketable fruit mass, marketable fruit yield of cultivar Santa Kruz.


HortScience ◽  
1996 ◽  
Vol 31 (6) ◽  
pp. 914B-914
Author(s):  
M.P.N. Gent ◽  
Y.Z. Ma

What is the effect of constant compared to intermittent heating of the shoot and root on growth, nutrient status, and yield of greenhouse tomato (Lycopersicon esculentum Mill)? Seedlings were transplanted early, on 4 Mar. 1994 and 1 Mar. 1995, or late, on 25 Mar. 1994 and 31 Mar. 1995, into troughs of peat-lite mix. The troughs were heated to 21C by buried tubing, either constantly, or for 12 h during the day or the night, or they were not heated. The greenhouses had either 14/14C or 22/6C day/night minimum air temperatures. After 2 weeks, early transplants had the greatest leaf weight with constant root heat and least with no heat. Root weight was greater for 14/14C than 22/6C air heat. With 14/14C air heat, only the no-root heat reduced leaf weight, whereas with 22/6C air heat, root heat ranking was constant > day > night ≈no heat. With late transplants, only the no heat reduced leaf weight. Most nutrient concentrations were less in late than in early transplants. Number of fruit, and number and weight of marketable fruit produced by 1 July from early transplants was affected by root heat; the ranking was constant heat > day > night > no heat. The 22/6C air heat increased marketable yield because of fewer small, irregular and blossom end rot fruit. Root heat had no effect on yield of late transplants.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1583
Author(s):  
Ibrahim Musa ◽  
Mohd Y. Rafii ◽  
Khairulmazmi Ahmad ◽  
Shairul Izan Ramlee ◽  
Muhammad Asyraf Md Hatta ◽  
...  

Grafting is regarded as an integral component of sustainable vegetable production. It is important in the management of soil-borne diseases, and reports suggest that grafting with viable rootstocks can enhance crop growth and yield. This research was conducted using splices and cleft grafting techniques to investigate graft compatibility among varieties of high yielding eggplant scion (MCV1, MCV2, CCV1, CCV2, CCV3, NCV, and TCV) grafted onto wild rootstocks (MWR, BWR, and TWR) to study their morphophysiological and yield characteristics. High yielding scions grafted onto wild relative rootstocks were compared with two controls including self-grafted and non-grafted. All the scion had a high rate of germination (≥95%) and remarkable graft success (100%) was recorded in MCV1, MCV2, and TCV using the cleft techniques. Generally, the use of rootstocks resulted in higher total and marketable fruit yield compared to the non-grafted and self-grafted scion plants, respectively. In particular, MWR and TWR rootstock conferred the highest vigour to the scion, resulting in the highest values recorded for total and marketable fruit yield, number of fruits per plant and average fruit weight. A similar result was obtained in fruit length and diameter, where long and wide fruits were observed in scions grafted onto MWR and TWR rootstocks, respectively. Grafting of high yielding eggplant scion onto resistant MWR, BWR and TWR eggplant rootstock was found to be beneficial for eggplant cultivation. The remarkable compatibility and vigour of the rootstock with scion led to the improvement in total and marketable yield of the fruits. As such, it can be concluded that the use of wild relative rootstocks of eggplant species can be a valuable method of improving eggplant production.


Author(s):  
S Gogoi ◽  
N. Mazumder ◽  
Juri Talukdar

Five hybrid brinjal varieties viz., Ketan, Vijay Kiron, Utkal Green, NV2035 Sarpan Bharata and two local cultivars viz., JC-1, Longai were evaluated at Horticultural Research Station, Kahikuchi, Guwahati as late rabi crop during 2014-16. Significant variation in plant growth parameters and fruit yield as well as on bacterial wilt incidence (Ralstonia solanacearum) were shown by all the varieties.Utkal Green recorded the highest per plant fruit yield (2.32 kg/plant) leading to the maximum total marketable yield (469.66 q/ha) and longer active fruiting duration (43.70 days).It also showed resistant reaction to bacterial wilt, recording only 12.44 per cent wilt incidence as compared to other varieties where it was in the range of 34.44 to 62.22 % at 55 days after transplanting. Although, Ketan and Vijay Kiron recorded moderately higher per plant fruit yield of 1.52 and 1.47 kg/plant,respectively but their total marketable fruit production reduced substantially due to high incidence of bacterial wilt (62.22 and 57.78%, respectively).The local cultivars, JC-1 and Longai exhibited moderately resistant reaction to bacterial wilt which registered 40.00 and 34.44 % , respectively.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 882F-882
Author(s):  
M.P.N. Gent ◽  
Y.-Z. Ma

What is the effect of constant compared to intermittent heating of the shoot and root on growth, nutrient status, and yield of greenhouse tomato (Lycopersicon esculentum Mill)? Seedlings were transplanted on 4 Mar. or 25 Mar. 1994 into troughs heated to 21C by buried tubing, either constantly, or for 12 h during the day or the night, or they were not heated. The greenhouses had either 14/14C or 22/6C day/night minimum air temperatures. After 2 weeks, the 4 Mar. transplants had the greatest leaf weight with constant root heat and least with no heat. Root weight was greater for 14/14 than 22/6 air heat. With 14/14 air heat, only the no root heat reduced leaf weight, whereas with 22/6 air heat, root heat affected leaf weight; the ranking was constant > day > night ≈ no heat. After 2 weeks, the 25 Mar. transplants had least leaf weight with no heat, and other treatments did not differ. Most nutrient concentrations were less in the 25 Mar. compared to the 4 Mar. transplants. The number of fruit, and the number and weight of marketable fruit produced by I July from 4 Mar. transplants was affected by root heat; the ranking was constant heat > day > night > no heat. The 22/6 air heat increased marketable yield, because of fewer small, irregular, and blossom end rot fruit. Root heat had no effect on yield of 25 Mar. transplants. Research supported in part by grant 93-37100-9101 from NRI Competitive grants program/USDA.


HortScience ◽  
2003 ◽  
Vol 38 (7) ◽  
pp. 1360-1364 ◽  
Author(s):  
Yaying Wu ◽  
Brian A. Kahn ◽  
Niels O. Maness ◽  
John B. Solie ◽  
Richard W. Whitney ◽  
...  

Okra [Abelmoschus esculentus (L.) Moench] was grown at various highly dense (HD) plant populations for destructive harvest, and compared with control plants grown at spacings of 90 × 23 cm and harvested repeatedly by hand. Our objectives were to identify a HD plant arrangement and an optimum harvest timing to maximize marketable fruit yield per hectare with a single destructive harvest, and to evaluate the potential for regrowth of cut plants followed by one or more subsequent harvests. Within HD treatments, marketable fruit weight per hectare tended to increase as the plant population density increased. Spacings of 30 × 30 cm and wider were not dense enough for the destructive harvest system due to a low marketable yield potential. Wide spacings did favor regrowth of cut plants in two experiments, but total marketable yields were still highest with the highest plant populations tested. Delaying destructive harvest until many overmature fruit were present did not consistently affect marketable fruit yield, but always decreased the proportion (by weight) of marketable fruit to total harvested fruit. Overall, percentages of marketable yield obtained by destructive harvests of plots with HD plant populations were low relative to the cumulative marketable yield from control plots. The lack of concentrated fruit set in okra remains a limiting factor for destructive harvest. However, the labor-saving potential of this system should stimulate further research.


HortScience ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 189g-190
Author(s):  
Martin P.N. Gent ◽  
Yong-Zhan Ma

What is the effect of constant compared to diurnal heating of the shoot and root on growth and yield of greenhouse tomato (Lycopersicon esculentum L.)? Seedlings were transplanted on 4 or 25 Mar. 1994 into troughs that were not heated or heated to 21C by buried tubing, either constantly or for 12 h during the day or the night. The greenhouses had either 14/14C or 26/6C day/night minimum air temperatures. After 2 weeks, leaves of the 4 Mar. transplants weighed most with constant root heat and least with no heat. Roots weighed more with 14/14C than 26/6C air heat. With 14/14C air heat, only no root heat reduced leaf weight, whereas with 26/6C air heat, leaf weight was in the order: constant > day > night - no heat. After 2 weeks, leaves of the 25 Mar. transplants weighed least with no heat, and other treatments did not differ. Root heating affected yield. By 1 July, the number of fruit and the number and weight of marketable fruit produced from 4 Mar. transplants was in the order: constant heat > day > night > no heat. The 22/6C air heat increased marketable yield because fewer fruit were small, irregular, or had blossom-end rot. Root heat had no effect on yield of 25 Mar. transplants.


2011 ◽  
Vol 23 (2) ◽  
pp. 151-156
Author(s):  
Edyta Kosterna ◽  
Anna Zaniewicz-Bajkowska ◽  
Jolanta Franczuk ◽  
Robert Rosa ◽  
Krystyna Chromińska ◽  
...  

Effect of synthetic mulches on melon (Cucumis meloL.) yieldingA field experiment was carried out in 2006-2008. The study examined the effect of soil mulching with synthetic materials (black polyethylene film, black polypropylene nonwoven 50 g m-2, and black polypropylene fabric 94 g m-2) on the fruit yield and quality of two melon cultivars (‘Seledyn’ and ‘Yupi’) grown in the field under the climatic conditions of central-eastern Poland. Specimens grown without mulching served as the control. The climatic conditions during the study years had a significant influence on the level of total, marketable and early yield of melon. The highest melon yield was obtained in 2007, which was characterised by the most favourable weather conditions for melon cultivation. The comparison of the cultivars showed that ‘Seledyn’ was better adapted to the climatic conditions of Poland. From cultivation, this cultivar achieved significantly higher early and total fruit yield compared with ‘Yupi’. ‘Seledyn’ was also characterised by a higher share of early yield of the total yield, a higher number of fruit in the early yield and a higher mean fruit weight. In turn, ‘Yupi’ produced a significantly higher share of marketable yield of the total yield and a higher number of marketable fruit.


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