scholarly journals Brown Bead of Broccoli. I. Response of the Physiological Disorder to Management Practices

HortScience ◽  
2001 ◽  
Vol 36 (7) ◽  
pp. 1224-1227
Author(s):  
Sylvie Jenni ◽  
Pierre Dutilleul ◽  
Stephen Yamasaki ◽  
Nicolas Tremblay

To investigate whether brown bead can be reduced by various cultural practices, a 3-year field study was conducted on a 600-acre broccoli (Brassica oleracea L., Italica group) farm in southwestern Quebec. Factors studied included N fertilization, soil series, previous crop, season of bed forming, or planting method. Four N treatments were randomly applied to two blocks in 41 fields of `Everest' broccoli: 85-0-0, 85-54-0, 85-54-54, and 85-54-108; the first number indicating N (kg·ha-1) applied before planting; the second, N applied 5 weeks after planting; and the last, N applied 7 weeks after planting. Over the 3-year study, brown bead affected 11% of the broccoli heads and accounted for one-third of the rejects. Brown bead severity on individual heads was described on a 0-8 scale. Plots with greater N applications (i.e., 85-54-54, 85-54-108) had significantly (P < 0.001) lower proportions of plants with brown bead compared with plots with lower N applications. Brown bead incidence reacted similarly from year to year to N fertilization and soil type. However, fertilization interacted with soil type. The less N was applied, the more soil effect was important. Soil effect was maximum at a low N level (85-0-0) with 2.5 times more plants showing brown bead in the Saint Blaise series than in the Sainte Rosalie series. Bed type, previous crop, or planting type did not affect the incidence of brown bead.

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Gosaye Eshetu ◽  
Yekedem Bimrew ◽  
Hassen Shifa

Field survey was conducted in south eastern Ethiopia to determine the disease intensity of chocolate spot and rust and to investigate the association of disease intensity (incidence and severity) with environmental factors and crop cultural practices. A total of 280 faba bean fields were surveyed in eight districts, and type of cropping system, weed management practices, crop growth stage, previous crop in the field, and sowing date were recorded. The associations of disease intensity with independent variables were evaluated using logistic regression model. Mean disease incidence of chocolate spot varied from 70.9 to 93.2% in most fields while percentage severity index (PSI) ranged from 10.5 to 47.1%. In a reduced multiple variable model, chocolate PSI ≤ 30% showed high probability of association with mixed cropping system, good weed management practices, late planting, and when faba bean was rotated with vegetables and cereals. The mean disease incidence of faba bean rust was varied from 23.6 to 78.2%, while the mean PSI of rust was varied from 4.8 to 37.9%. In Gasera, Dinsho, and Agarfa districts, poor weed management practices, fields planted in the month of July, and when previous crop was legume had a high probability of association to (>20) rust PSI in a multiple variable reduced model. In contrast, soil types, fertilizer applied, and fungicides sprayed were not associated with disease intensity. The present study has identified cropping system, planting date, previous crop, district, and weed management practices as important variables that influence faba bean chocolate spot and rust epidemics in diversified fields. Therefore, proper weeding management practices, late planting, crop rotation habit, and other related farm practices should be carried out to reduce chocolate spot and rust impact until resistant faba bean genotypes are developed and distributed to the area.


HortScience ◽  
2001 ◽  
Vol 36 (7) ◽  
pp. 1228-1234 ◽  
Author(s):  
Sylvie Jenni ◽  
Pierre Dutilleul ◽  
Stephen Yamasaki ◽  
Nicolas Tremblay

In order to investigate their relationships with brown bead, a data set composed of 48 variables characterizing the developmental rate, climate, and nutrients in the soil and in the tissues of heads of broccoli (Brassica oleracea L., Italica group) was collected from 328 plots (41 experimental fields over 3 year× 4 N fertilization level× 2 blocks). The four N treatments were 85-0-0, 85-54-0, 85-54-54, and 85-54-108, the first number indicating the N level (kg·ha-1) applied before planting; the second, N level applied 5 weeks after planting; and the last, N level applied 7 weeks after planting. Broccoli plants were either direct-seeded (26 experimental fields) or transplanted (15 experimental fields). Whether direct-seeded or transplanted, fast-developing broccoli plants showed a lower incidence of brown bead. More particularly, heads of transplanted broccoli plants experiencing warmer temperatures had a lower brown bead incidence and severity. A regular supply of water decreased the incidence and severity of the physiological disorder in both direct-seeded and transplanted broccoli plants. Low levels of Ca and high levels of Mg and K in mature broccoli head tissues were associated with a higher incidence of brown bead. Multiple-regression models were developed to predict the percentage of broccoli heads with brown bead for direct-seeded plants (R2 = 0.76; n = 104), and for transplanted plants (R2 = 0.69; n = 44). For direct-seeded broccoli, solar radiation between the button stage (head diameter of 2.5 cm) and maturity (head diameter of 10 cm), as well as soil and tissue Mg content, were among the first variables to enter the regression models. In general, more solar radiation and less precipitation translated into more heads showing brown bead symptoms. For transplanted broccoli plants, the minimum temperature from the button stage to maturity was a key variable in the prediction of the percentage of heads with brown bead and the corresponding index of severity.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 495d-495
Author(s):  
J. Farias-Larios ◽  
A. Michel-Rosales

In Western Mexico, melon production depends on high-input systems to maximize yield and product quality. Tillage, plasticulture, fumigation with methyl bromide, and fertigation, are the principal management practices in these systems. However, at present several problems has been found: pests as sweetpotato whitefly (Bemisia tabaci Gennadius), aphids (Myzus and Aphis), leafminer (Liryomiza sativae); diseases as Fusarium, Verticilium, and Pseudoperenospora, and weeds demand high pesticide utilization and labor. There is a growing demand for alternative cultural practices, with an emphasis on reducing off-farm input labor and chemicals. Our research is based on use of organic mulches, such as: rice straw, mature maize leaves, banana leaves, sugarcane bagasse, coconut leaves, and living mulches with annual legume cover crop in melons with crop rotation, such as: Canavalia, Stilozobium, Crotalaria, and Clitoria species. Also, inoculations with mycorrhizal arbuscular fungi for honeydew and cantaloupe melon seedlings production are been assayed in greenhouse conditions for a transplant system. The use of life barriers with sorghum, marigold, and other aromatic native plants in conjunction with a colored yellow systems traps for monitoring pests is being studied as well. While that the pest control is based in commercial formulations of Beauveria bassiana for biological control. The first results of this research show that the Glomus intraradices, G. fasciculatum, G. etunicatum, and G. mosseae reached 38.5%, 33.5%, 27.0%, and 31.0% of root infection levels, respectively. Honeydew melons production with rice and corn straw mulches shows an beneficial effect with 113.30 and 111.20 kg/plot of 10 m2 compared with bare soil with 100.20 kg. The proposed system likely also lowers production cost and is applicable to small- and large-scale melon production.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 501e-502
Author(s):  
Cody J. White ◽  
Michael A. Schnelle ◽  
Gerrit W. Cuperus

A survey was designed to assess high-risk areas with respect to environmental contamination, specifically how it relates to water quality. Oklahoma growers of all economic levels, retail and/or wholesale, were queried at their place of business for their current state of implementing best management practices (BMPs) and other strategic actions that could potentially affect current and future water quality standards. Specific areas such as the physical environment of the nursery, primary pesticides and fertilizers used, Integrated Pest Management (IPM) practices, and employee safety training were covered as well as other aspects germane to preserving and protecting current water quality and related environmental issues. More than 75 nurseries were surveyed and given the opportunity to participate in future training at Oklahoma State Univ. Results indicated that nurseries have not fully implemented many BMPs, but have adopted fundamental IPM approaches. The stage is set for the implementation of the next phase of expansion and refinement into ecologically based programs such as propagation and sale of low pesticide input plant materials, improved cultural practices, and the integration of environmentally sound management approaches. As an example, many growers are in the process of phasing out calendar-based pesticide application programs in favor of aesthetic and/or economic threshold-driven pesticide spray programs.


2006 ◽  
Vol 16 (3) ◽  
pp. 408-412 ◽  
Author(s):  
Nicolas Tremblay ◽  
Carl Bélec

Weather is the primary driver of both plant growth and soil conditions. As a consequence of unpredictable weather effects on crop requirements, more inputs are being applied as an insurance policy. Best management practices (BMPs) are therefore about using minimal input for maximal return in a context of unpredictable weather events. This paper proposes a set of complementary actions and tools as BMP for nitrogen (N) fertilization of vegetable crops: 1) planning from an N budget, 2) reference plot establishment, and 3) crop sensing prior to in-season N application based on a saturation index related to N requirement.


1992 ◽  
Vol 2 (1) ◽  
pp. 121-125 ◽  
Author(s):  
George J. Hochmuth

Efficient N management practices usually involve many potential strategies, but always involve choosing the correct amount of N and the coupling of N management to efficient water management. Nitrogen management strategies are integral parts of improved production practices recommended by land-grant universities such as the Institute of Food and Agricultural Sciences, Univ. of Florida. This paper, which draws heavily on research and experience in Florida, outlines the concepts and technologies for managing vegetable N fertilization to minimize negative impacts on the environment.


Soil Horizons ◽  
1992 ◽  
Vol 33 (4) ◽  
pp. 75 ◽  
Author(s):  
Roy W. Simonson
Keyword(s):  

2012 ◽  
Vol 9 (1) ◽  
pp. 57-70 ◽  
Author(s):  
L. Lassaletta ◽  
E. Romero ◽  
G. Billen ◽  
J. Garnier ◽  
H. García-Gómez ◽  
...  

Abstract. Despite the particular management practices and climate characteristics of the Mediterranean regions, the literature dealing with N budgets in large catchments subjected to Mediterranean conditions is scarce. The present study aims to deepen our knowledge on the N cycle within the Ebro River Basin (NE Spain) by means of two different approaches: (1) calculating a global N budget in the Ebro River Basin and (2) calculating a series of detailed regional budgets at higher geographical resolution. N inputs and outputs were spatialized by creating a map based on the most detailed information available. Fluvial and atmospheric N export was estimated together with N retention. The Ebro River Basin annually receives a relatively high amount of new N (5118 kg N km−2 yr−1), mostly in the form of synthetic fertilizers (50%). Although it is a highly productive catchment, the net N input as food and feed import is also high (33%). Only 8% of this N is finally exported to the delta zone. Several territorial units characterized by different predominant uses (rainfed agriculture, irrigated agriculture and pastures) have differentiated N dynamics. However, due to the high density of irrigation channels and reservoirs that characterize Mediterranean catchments, N retention is very high in all of them (median value, 91%). These results indicate that problems of eutrophication due to N delivery in the coastal area may not be too severe but that high N retention values may instead lead to problems within the catchment, such as pollution of aquifers and rivers, as well as high atmospheric emissions. The most promising management measures are those devoted to reducing agricultural surpluses through a better balanced N fertilization.


Author(s):  
C. Naidin

In this paper, we analyze the influence of N and P fertilization on wheat yields, taking into account the previous crop and the level of rainfall accumulated until the end of the growth stages in plant development. In the wheat crops developed on the reddish-brown low luvi soil found at ARDS Simnic, the N fertilization has favorable effects in moderate doses (60 - 100 kg N/ha after corn and 60 - 90 kg N/ha after peas), while in higher doses (120 - 160 kg N/ha) fertilization determines a fall in production, both in the case of rainfall deficit and excess. The P has favorable effects on wheat crops, especially when the previous crop is peas. The rainfall quantity, as well as its repartition along the vegetation period, influences the wheat crop, causing great variations from year to year. The obtained data shows that rainfall deficit as well as rainfall excess determines a drop in wheat production; relatively high and stable average productions can be obtained in the case of rainfall levels close to the multi annual averages in different plant development stages.


Author(s):  
Shilpa . ◽  
Priyanka Bijalwan ◽  
Y.R. Shukla

Background: Yield of summer tomato do not always reach the full production potential. Improved management such as, training and pruning could improve the yield and fruit quality of tomatoes. The production of the healthy and improved quality tomato crop depends on various cultural practices like training systems as it prevents overcrowding for sunlight thus improves air circulation under humid and moist conditions where tomato plants are more prone to fungal diseases, avoids poor fruit set and assimilates competition. Methods: The study was carried out during kharif seasons of 2017 and 2018 with Solan Lalima variety, in the Research Farm of Dr. YSP UHF Nauni, Solan, HP to find out the response of plants to management practices on yield, quality and cost of production. The experiment consisting of two planting methods, three mulching treatments, two level of training system, laid out in randomized complete block design with three repetitions. Result: Plants trained to two stem gave the maximum fruit TSS (4.75 oB), ascorbic acid content (30.79 mg/100 g), lycopene content (5.84 mg/100 g) and shelf life (11.35 days). From the economics, it was apparent that tomato produced by the two stem training system exhibited better performance in terms of benefit cost ratio.


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