scholarly journals Mustard Cover Crops for Control Soilborne Disease and Weeds, and Nitrogen Cycling in Cool Season Vegetable Production in the Salinas Valley

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 832C-832
Author(s):  
Richard Smith* ◽  
Krishna Subbarao ◽  
Steve Koike ◽  
Steve Fennimore ◽  
Adelia Barber

Growers in the Salinas Valley are not able to rotate away from lettuce to other crops such as broccoli, as often as would be desirable due to economic pressures such as high land rents and lower economic returns for rotational crops. This aggravates problems with key soilborne diseases such as Sclerotinia minor, Lettuce Drop. Mustard cover crops (Brassica juncea and Sinapis alba) are short-season alternative rotational crops that are being examined in the Salinas Valley for the potential that they have to reduce soilborne disease and weeds. Mustard cover crops have been have been shown to suppress various soilborne diseases and there are also indications that they can provide limited control of some weed species. However, no studies have shown the impact of mustard cover crops under field conditions on S. minor. In 2003 we conducted preliminary studies on the incidence of S. minor and weeds following mustard cover crops in comparison with a bare control or an area cover cropped to Merced Rye (Secale cereale). There was a slight, but significant reduction of S. minor infection in one of three trials following mustard cover crops. Mustard cover crops also reduced emergence of Shepherd's Purse (Capsella bursa-pastoris) and Common Purslane (Portulaca oleracea) these studies. Mustard cover crops have distinct nitrogen cycling characteristics. They were shown to reach a peak of release of nitrogen in 30 to 50 days following incorporation into the soil. The levels of nitrogen that are released by mustard cover crops were substantial and could be useful in nitrogen fertilizer programs for subsequent vegetable crops.

2018 ◽  
Vol 19 (4) ◽  
pp. 332-337 ◽  
Author(s):  
Fulya Baysal-Gurel ◽  
Prabha Liyanapathiranage ◽  
Jill Mullican

Soilborne diseases reduce crop performance, increase costs to the nursery producers, and can cause potential ecological damage to the natural environment. In particular, soilborne diseases caused by Phytophthora nicotianae and Rhizoctonia solani are the most economically important problems of southeastern U.S. nursery producers. Methyl bromide was widely used as a standard treatment in many parts of the world until the implementation of the Montreal Protocol. Since then, many chemical and nonchemical soilborne disease management methods have been tested but are not yet providing effective and consistent results like methyl bromide. Cover crops that belong to the Brassicaceae family can be incorporated into the soil to control soilborne diseases, and this process is widely known as biofumigation. Glucosinolates that are available inside Brassicaceae plant cells can be hydrolyzed into isothiocyanates, and these compounds are proven to be highly biocidal to many microorganisms (including fungi, oomycetes, nematodes, and bacteria), insects, and germinating weed seeds. The use of biofumigant cover crops is a newer area of research in woody ornamental nursery production that has been previously explored most extensively in row crop, vegetable, fruit, and flower production. This review article compiles previous research observations in biofumigation while emphasizing the potential of biofumigation to control diseases in nursery production caused by soilborne pathogens.


1999 ◽  
Vol 9 (3) ◽  
pp. 373-379 ◽  
Author(s):  
Ronald D. Morse

Advantages of no-till (NT) production systems are acknowledged throughout the world. During the 1990s, production of NT vegetable crops has increased for both direct seeded and transplanted crops. Increased interest in reduced-tillage systems among research workers and vegetable growers is attributed to: 1) development and commercialization of NT transplanters and seeders, 2) advancements in the technology and practice of producing and managing high-residue cover crop mulches, and 3) improvements and acceptance of integrated weed management techniques. Results from research experiments and grower's fields over the years has shown that success with NT transplanted crops is highly dependent on achieving key production objectives, including: 1) production of dense, uniformly distributed cover crops; 2) skillful management of cover crops before transplanting, leaving a heavy, uniformly distributed killed mulch cover over the soil surface; 3) establishment of transplants into cover crops with minimum disturbance of surface residues and surface soil; and 4) adoption of year-round weed control strategies.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 806C-806
Author(s):  
Kathryn E. Brunson ◽  
Sharad C. Phatak ◽  
J. Danny Gay ◽  
Donald R. Sumner

Velvetbean (Mucuna deeringiana L.) has been used as part of the crop rotation in low-input vegetable production in southern Georgia to help suppress populations of root-knot nematode (Meloidogyne incognita) for the past 2 years. Over-wintering cover crops of crimson and subterranean clovers were used the low-input plots and rye was the plow-down cover crop in the conventional plots. Tomatoes, peppers, and eggplant were the vegetable crops grown in these production systems. Following the final harvest in 1992, use of nematicides in the low-input plots was discontinued and velvetbean was then planted into the low-input plots and disked in after 90 days. Results from the 1993–94 soil samples taken before and after velvetbean showed a continuing trend of reduced nematode numbers where velvetbean had been, while most conventional plots that had nematicides applied resulted in increases in nematode populations.


Author(s):  
Navjot Singh Brar ◽  
Tarun Kumar ◽  
Prashant Kaushik

Climate variation and change are an unavoidable phenomenon faced by the natural habitat of this planet. For getting potential yield from vegetable crops under the changing climate conditions, the practical strategies at field level can serve as a guideline for the farmers. Moreover, there are several strategies available for mitigating the harmful effects of climate change. In this manuscript, efforts have been made for reviewing the mitigating strategies against the impact of climate change in vegetable crops via conventional approaches. Considering the situation, the information reviewed revealed that significant result of conventional approaches with climate-smart adoptions strategies has a direct bearing on vegetable production for the increasing population in frenziedly changing climate scenario.


2021 ◽  
Author(s):  
Dushyant D. Champaneri ◽  
Naren K. Patel

Photo selective shade net is a product made of plastic fibers connected together with each other, forming a regular porous structure and allowing gases, liquid and light to pass through. It has a capacity to selectively filter the intercepted solar radiation, in addition to their protective function. Vegetables are considered as protective food which are highly perishable in nature. High temperature due to global warming, climate change and excessive use of chemicals are some of the burning issues of vegetable production. Photo selective shade net can be a partial solution for these problems. Vegetable crops grown under different photo selective shade net shows productive responses thus by application of various Photo selective shade nets we can improve the quality as well as production of vegetable crops.


HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 600-603 ◽  
Author(s):  
Nancy G. Creamer ◽  
Keith R. Baldwin

Summer cover crops can produce biomass, contribute nitrogen to cropping systems, increase soil organic matter, and suppress weeds. Through fixation of atmospheric N2 and uptake of soil residual N, they also contribute to the N requirement of subsequent vegetable crops. Six legumes {cowpea (Vigna unguiculata L.), sesbania (Sesbania exaltata L.), soybean (Glycine max L.), hairy indigo (Indigofera hirsutum L.), velvetbean [Mucuna deeringiana (Bort.) Merr.], and lablab (Lablab purpureus L.)}; two nonlegume broadleaved species [buckwheat (Fagopyrum esculentum Moench) and sesame (Sesamum indicum L.)]; and five grasses {sorghum-sudangrass [Sorghum bicolor (L) Moench × S. sudanense (P) Stapf.], sudangrass [S. sudanense (P) Stapf.], Japanese millet [Echinochloa frumentacea (Roxb.) Link], pearl millet [Pennisetum glaucum (L). R. Br.], and German foxtail millet [Setaria italica (L.) Beauv.)]}, were planted in raised beds alone or in mixtures in 1995 at Plymouth, and in 1996 at Goldsboro, N.C. Biomass production for the legumes ranged from 1420 (velvetbean) to 4807 kg·ha-1 (sesbania). Low velvetbean biomass was attributed to poor germination in this study. Nitrogen in the aboveground biomass for the legumes ranged from 32 (velvetbean) to 97 kg·ha-1 (sesbania). All of the legumes except velvetbean were competitive with weeds. Lablab did not suppress weeds as well as did cover crops producing higher biomass. Aboveground biomass for grasses varied from 3918 (Japanese millet) to 8792 kg·ha-1 (sorghum-sudangrass). While N for the grasses ranged from 39 (Japanese millet) to 88 kg·ha-1 (sorghum-sudangrass), the C: N ratios were very high. Additional N would be needed for fall-planted vegetable crops to overcome immobilization of N. All of the grass cover crops reduced weeds as relative to the weedy control plot. Species that performed well together as a mixture at both sites included Japanese millet/soybean and sorghum-sudangrass/cowpea.


2019 ◽  
Vol 37 (4) ◽  
pp. 445-450
Author(s):  
Jadir B Pinheiro ◽  
Giovani Olegario da Silva ◽  
Danielle Biscaia ◽  
Amanda G Macedo ◽  
Núbia Maria Correia

ABSTRACT Root-knot nematodes cause great damage to vegetable crops in Brazil, besides having a large range of host plants, such as weeds. Weeds can maintain the inoculums or even favor the multiplication of these nematodes. In this study we evaluated the reaction of selected weed species, present in a vegetable production area, to root-knot nematodes Meloidogyne incognita and M. enterolobii. The trials were conducted in a greenhouse at Embrapa Hortaliças, Brasília-DF, in a completely randomized design with six replicates. Fifteen weed species were evaluated for M. incognita race 1, and 16 weed species were evaluated for M. enterolobii. Two tomato cultivars were evaluated as resistance and susceptibility standards. Gall index (IG), egg mass index (IMO), number of eggs per gram of roots (eggs/g roots) and reproduction factor (FR) were evaluated. M. enterolobii survives and multiplies more easily in weeds collected in vegetable production areas than M. incognita race 1 and, the great majority of weed species evaluated in this study are hosts of both nematode species. Only the species Urena lobata, Sonchus oleraceus, Euphorbia heterophylla, Melampodium perfoliatum and Tagetes sp. were immune to M. incognita race 1. All evaluated species are either hosts or favor the multiplication of M. enterolobii. The species which are the most susceptible to M. incognita race 1, and therefore require greater control of crops infected by this nematode are Ipomoea nil, I. triloba and Eleusine indica, and for M. enterolobii are I. nil, Solanum americanum, Hyptis suaveolens, Portulaca oleracea, I. triloba and Euphorbia heterophylla.


Plant Disease ◽  
2004 ◽  
Vol 88 (2) ◽  
pp. 221-221 ◽  
Author(s):  
S. T. Koike ◽  
R. F. Smith ◽  
P. W. Crous ◽  
J. Z. Groenewald

Vetches (Vicia spp.) are planted alone or in combination with other plants as cover crops in vegetable production areas of California. December 2001 through February 2003, purple (V. benghalensis) and lana woollypod (V. villosa subsp. varia) vetches in the Salinas Valley (Monterey County) developed a foliar disease. Symptoms were small (≤5 mm in diameter), circular to oblong, purple brown-to-red brown spots that were visible from the adaxial and abaxial leaf sides, and occurred lower in the plant canopy. White sporulation was visible in the spot centers. Stems were infected and had elongated, irregularly shaped, brown lesions that were <5 mm long and had white sporulation. When fungal masses or tissues from lesions were placed on acidified potato dextrose agar (LA-PDA), a fungus was consistently recovered. On LA-PDA, the isolates produced slow-growing (30 mm colony diameter in 45 days), irregularly raised, light pink and white colonies that produced dark exudates. The undersurfaces of cultures were gray black. The growth on lesions consisted of fascicles of conidiophores that were hyaline, smooth, flexuous, distinctly geniculate, and measured 20 to 120 × 2.5 to 6 µm. Conidia were hyaline, subglobose, smooth, aseptate, measured 9 to 15 × 8 to 13 µm, and formed singly. The internal transcribed spacer rDNA sequence of a representative strain (CBS 112891) was determined using standard protocols (GenBank Accession No. AY352584). A nucleotide BLAST search revealed a 94 to 97% similarity to other species of Ramularia (GenBank Accession Nos. AF222848, AF173310, AJ417496, AF362060, and AF297235). On the basis of these morphological and molecular data, the fungus was identified as Ramularia sphaeroidea Sacc. (= Ovularia sphaeroidea (Sacc.) Sacc.) (1). Pathogenicity of six isolates grown on LA-PDA was confirmed by spraying conidial suspensions (1.0 × 105 conidia per ml) onto direct-seeded, 8-week-old, potted purple and lana woollypod vetch (12 plants each). Plants were kept in a dew chamber for 48 h and maintained in a greenhouse (23 to 25°C). After 7 to 10 days, all plants developed the characteristic leaf spots and stem lesions, and R. sphaeroidea was reisolated from such symptoms. Plants treated with only water did not develop symptoms. However, because disease incidence on test plants was low, inoculum was also prepared in water amended with 1.0 ppm of Tween 20. Four pots each of purple and lana woollypod vetch were sprayed with amended or nonamended inocula, and plants were handled as described. After 10 days, plants inoculated with Tween 20 amended inoculum had significantly higher disease incidence and severity (purple = 83% of leaflets infected with a mean of 3.4 spots per leaflet; lana = 83% infected with a mean of 3.2 spots) than did plants inoculated with water-only conidial suspensions (purple = 27% and a mean of 0.4 spots; lana = 38% and a mean of 0.6 spots). Finally, two other vetches used in the Salinas Valley were inoculated with the two suspensions. After 2 weeks, common (V. sativa) and languedoc (V. sativa ‘Languedoc’) vetch showed no symptoms, and control plants of purple and lana vetch developed disease. All inoculation tests were repeated, and results were similar. To our knowledge, this is the first report of R. sphaeroidea as a pathogen of purple and lana woollypod vetches in California. Reference: (1) U. Braun. A Monograph of Cercosporella, Ramularia, and Allied Genera (Phytopathogenic Hyphomycetes) Vol. 2. IHW-Verlag, Eching, Germany, 1998.


HortScience ◽  
2019 ◽  
Vol 54 (11) ◽  
pp. 1872-1878 ◽  
Author(s):  
Manpreet Singh ◽  
Rupinder Kaur Saini ◽  
Sukhbir Singh ◽  
Sat Pal Sharma

Water shortage is one of the major challenges faced by the current agricultural systems worldwide, especially in arid and semi-arid regions. Deficit irrigation (DI), a water-saving strategy of applying less water than crop evapotranspiration (ETc) demands, has been extensively investigated in different crops, including water-intensive vegetables. The DI strategies such as regulated deficit irrigation (RDI) and partial root zone drying (PRD) generally increase water use efficiency (WUE) and have emerged as potential practices to save water for agricultural sustainability. However, in view of the sensitivity of shallow-rooted vegetable crops to water stress, DI is often associated with yield losses. A review of 134 DI reports of vegetable crops revealed significant reductions in yield under all DI levels in 52% of cases and yields statistically similar to those of full irrigation (100% ETc in most cases) under small water deficits in 44% of cases, thereby raising concerns about the sustainability of vegetable production under DI. Biochar, a carbon-rich co-product of pyrolysis of organic matter, is increasingly undergoing study as a soil amendment to mitigate drought stress and is being explored as an additional practice with DI to minimize the yield losses due to water deficits. This work reviews the effects of biochar application on growth, yield, physiology, and WUE of different vegetable crops under DI regimes to determine the potential of biochar and DI used in combination to sustain vegetable productivity in water-limited areas. Overall, the addition of biochar under DI has helped to compensate for yield losses of vegetables and further enhanced WUE. However, field studies investigating long-term soil–biochar interactions that strongly conclude the impact of biochar under moisture stress conditions are lacking.


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