Field studies were conducted during four consecutive tomato (Lycopersicon esculentum) -cucumber (Cucumis sativus) rotations to examine the longterm residual effects of tomato methyl bromide (MBr) alternatives on soilborne pests in double-cropped cucumber. Four treatments were established in tomato fields: a) nontreated control; b) MBr + chloropicrin (Pic) (67:33 by weight) at a rate of 350 lb/acre; c) tank-mixed pebulate + napropamide at 4 and 2 lb/acre, respectively, followed by 1,3-dichloropropene (1,3-D) + Pic (83:17 by volume) at 40 gal/acre; and d) napropamide at 2 lb/acre followed by soil solarization for 7 to 8 weeks. Each of the following seasons, cucumber was planted in the same tomato plots without removing mulch films. For nutsedge [purple nutsedge (Cyperus rotundus) and yellow nutsedge (C. esculentus)] densities, napropamide followed by solarization plots had equal control (≤15 plants/m2) as MBr + Pic during all four cropping seasons. However, nematode control with solarization was inconsistent. Marketable yield data proved that fumigation in tomato fields with either MBr + Pic or pebulate + napropamide followed by 1,3-D + Pic had a long-term effect on double-cropped cucumber.
James P. Gilreath, Timothy N. Motis, Bielinski M. Santos, Joseph W. Noling, Salvadore J. Locascio, and Daniel O. Chellemi
Douglas V. Shaw and Kirk D. Larson
Yield for annual California strawberry (Fragaria ×ananassa Duch.) production systems in soils treated with combinations of methyl bromide–chloropicrin (MB:CP) were compared with four alternative soil treatment systems using meta-analysis. Studies represent 11 production seasons, and were conducted at three distinct locations in California. Fumigation with mixtures of methyl bromide (MB) and chloropicrin (CP) increased yield significantly compared with any and all alternatives lacking MB. In a combined analysis of 45 studies, fumigation with MB:CP compounds increased yield an average of 94.4% (d+ = 2.874 ± 0.098) compared with yields for plants in nonfumigated (NF) soils. Further, the effect of MB:CP fumigation increased over the first three strawberry cultivation cycles: MB:CP–fumigated soils provided a 59.2% (d+ = 2.166 ± 0.146) yield advantage when one cycle of fumigation was omitted, a 100.2% (d+ = 3.000 ± 0.143) advantage when two cycles were omitted, and a 148.4% (d+ = 6.201 ± 0.348) yield advantage when three or more cycles of MB:CP were omitted. In a combined analysis that included 34 studies, soil fumigation with MB:CP conferred a 9.6% (d+ = 0.751 ± 0.087) yield advantage over fumigation with CP alone. Soils treated with MB:CP yielded 6.8% (d+ = 0.437 ± 0.114) more fruit than those treated with very high rates of CP (336–396 kg·ha–1), and 15.4% (d+ = 1.190 ± 0.134) more than soils treated with commercially realistic rates (168–224 kg·ha–1). Similar to the comparison using NF soils, the efficacy of very high rates of CP appeared to diminish over cycles of strawberry cultivation; MB:CP increased yield 2.2% (d+ = 0.043 ± 0.162) in the first CP production cycle, 10.6% (d+ = 0.588 ± 0.174) and 13.7% (d+ = 2.054 ± 0.401) in the following two cycles. Combinations of dichloropropene (DP) and CP were no more effective than were lower rates of CP alone, and MB:CP conferred a 14.4% (d+ = 0.962 ± 0.162) yield advantage over mixtures of DP:CP. Mixtures of MB:CP increased yield 29.8% (d+ = 3.199 ± 0.287) compared with metam sodium (MS). The standardized effect was similar when comparing MB:CP combinations with either MS or NF soils, suggesting little effect of MS on the yield response. Chemical names used: trichloronitromethane (chloropicrin); 1,3-dichloropropene (dichloropropene); sodium N-methyldithiocarbamate (metam sodium).
Christopher L. Ray, Sandra B. Wilson, Kathy H. Brock, Bruce A. Fortnum, and Dennis R. Decoteau
Pest management is of primary importance to the vegetable industry in our nation. In recent years producers have undergone much scrutiny concerning their pest control strategies, which often include the use of chemical pesticides. Due to the detrimental effects of many fumigants, growers are being forced to incorporate more environmentally sound agricultural practices while still producing a healthy, marketable commodity. The effects of three different fumigants and reflective mulches on plant growth and development were studied in field-grown, staked tomatoes. Methyl bromide, Telone II, or Telone C-17 were used in fumigation of plots. The establishment of mulch color was done via applications of exterior enamel paint, white or red in color, to the surface of black polyethylene mulch. With the exception of total marketable yields, no interactions existed between mulch color and fumigant. Red mulch and Telone II treatments resulted in the highest total marketable yield. Telone II application increased early marketable yield. White mulch color increased preharvest yield and black mulch color decreased early marketable yield. Low initial populations of nematodes may be the cause for lack of response due to fumigation.
Sandra L. Barbour, Kathy H. Brock, B.A. Fortnum, and Dennis R. Decoreau
Pest control-related problems jeopardize the advancement of our nation's vegetable industry. Because of the adverse effects of many fumigants. the grower is increasingly pressured to utilize sustainable. environmentally sound agricultural practices yet still maintain a marketable, blemish-free product.
The effects of wavelength selective mulches and three different fumigants on overall plant development and nematode control were studied in field grown, staked tomatoes. Plots were fumigated with methyl bromide. Telone II, or Telone C17. Within rows, mulch color was established by application of either white or red exterior enamel paint to the black plastic surface of polyethylene mulch. Reflective light from each mulch color was measured using a LiCor 1800 Spectroradiometer. Temperature below the mulch surface was monitored with a datalogger.
Prior to the first marketable harvest, plants grown on white mulch produced greater fruit weight and total dry weight than plants grown on black or red mulch. Total marketable yields, however. were not significantly different between the three mulches. Early and marketable yields from fumigated plots did not differ from control treatments. The lack of response due to fumigation may have been due to low initial nematode populations in the field.
Doug Sanders, Luz M. Reyes, David Monks, Frank Louws, and James Driver
We evaluated the influence of three compost sources and compost amended with T382 with fumigant Telone C-35 and various combinations of compost and Telone C-35 on the yield and pest management of cucumber, pepper, tomato, collard, southern pea, and summer squash in a multicrop rotational system. In the first year, there were few differences between the compost treatments and Telone C-35, but all treatments resulted in more yield than the control. In the second year, all compost treatments and/or Telone C-35 improved total and marketable yield of cucumber, pepper, tomato, southern pea, and summer squash. Furthermore, in the second year, Telone C-35 treat-ments produced more yield than some of the compost treatments in tomatoes. Combining Telone C-35 with compost did not differ from either treatment alone. Nematode and disease assessments were not consistent and will be discussed in further detail.
Gladis M. Zinati, Herbert H. Bryan, Waldemar Klassen, and Aref A. Abdul-Baki
In the quest to produce tomatoes without using methyl bromide, cover crops including sunnhemp, cowpea, hairy vetch, and sorghum sudan were planted on calcareous gravelly soils of southern Florida in Oct. 1998. These crops, singly or in mix, were grown on raised beds for 3 months before they were mowed down with no tillage. Sorghum sudan was plowed down and covered with plastic mulch, a conventional farming practice. In addition, uncropped plots fertilized with 6 N–2.6P–10K at 0 or 1124 kg·ha–1 were either treated with or without methyl bromide-chloropicrin and plowed down. `Sanibel' tomatoes (Lycopersicon esculentum Mill) were transplanted in two plant densities (one row vs. two rows on a bed) immediately after mowing. Tomatoes were fertigated with 112 N and 186 K kg·ha–1 during the growing season. Sunnhemp biomass alone or in mix with cowpea was higher than any other treatment. Biomass of sorghum sudan and hairy vetch were lowest. Canopy coverage, nutrient content of cover crops, and their effects on tomato growth, nutrient content, and yield will be discussed.
Inga A. Zasada, Clyde L. Elmore, Lani E. Yakabe, and James D. MacDonald
efficacious alternative, cut flower and bulb producers face potentially serious production limitations. It is extremely important that alternatives be developed to manage the pests formerly managed by methyl bromide. However, because of the diversity of the
Sanjeev K. Bangarwa, Jason K. Norsworthy, Edward E. Gbur, and John D. Mattice
challenging in polyethylene-mulched vegetables in the absence of methyl bromide, especially for purple nutsedge, which can easily penetrate polyethylene mulch ( Patterson, 1998 ). Thus, there is an urgent need to develop an effective alternative to methyl
Judy A. Thies, Don W. Dickson, and Richard L. Fery
chamber tests in which expression of the N gene was compromised. Root-knot nematode-resistant bell peppers should provide economical and environmentally compatible alternatives to methyl bromide and other nematicides for managing M. incognita in sub
Robert E. Uhlig, George Bird, Robert J. Richardson, and Bernard H. Zandstra
bromide Natl. Ctr. for Food and Agr. Policy Washington, D.C Csinos, A.S. Johnson, W.C. Johnson, A.W. Sumner, D.R. McPherson, R.M. Gitaitis, R.D. 1997 Alternative fumigants for methyl bromide in tobacco and pepper transplant production Crop Prot. 16 585 594