Evaluation of chemical alternatives to methyl bromide in tomato crops in China

Crop Protection 67 (2015) 223e227

Contents lists available at ScienceDirect

Crop Protection journal homepage: www.elsevier.com/locate/cropro

Evaluation of chemical alternatives to methyl bromide in tomato crops in China Kang Qiao a, *, Zhongtang Wang b, d, Min Wei b, **, Hongyan Wang c, Yang Wang a, Kaiyun Wang a a

College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, People's Republic of China College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, People's Republic of China Cotton Research Center, Shandong Academy of Agricultural Sciences, Jinan, Shandong 250100, People's Republic of China d Shandong Institute of Pomology, Tai'an Shandong 271000, People's Republic of China b c

a r t i c l e i n f o

a b s t r a c t

Article history: Received 17 June 2014 Received in revised form 18 October 2014 Accepted 20 October 2014 Available online

Tomato is a high-value cash crop in China that requires vigorous transplants free of pathogens. However, local tomato growers commonly face heavy root-knot nematode and weed infestations, especially while phasing out methyl bromide (MB). The soil fumigants chloropicrin (CP), 1,3-dichloropropene (1,3-D) and dazomet (DZ) were evaluated at several rates alone and in combination as alternatives to MB soil fumigation in tomato production. Field trials revealed that used alone, CP, 1,3-D and DZ were not comparable to MB in the reduction of Meloidogyne incognita, weeds or increase of tomato marketable yield. Only the combination of reduced rates of 1,3-D and CP which had excellent nematicide efficacy and good to moderate weed control, matched the efficacy of MB. The present data indicate that the combination of 1,3-D plus CP is an efficient MB alternative for managing nematodes and weeds in tomato crops and can be used in integrated pest management programs. To get a better weeds control efficacy, it is recommended to add herbicides to the two fumigants combination. © 2014 Elsevier Ltd. All rights reserved.

Keywords: Soil fumigation Methyl bromide alternatives Nematode Weed control Tomato

1. Introduction Tomato (Solanum lycopersicum L.) is a major vegetable crop worldwide. In China, area under tomato production was more than 1,500,000 ha in 2009 and the production reached 34,000,000 t, placing China as the world's leader both in cultivated area and production (Gao et al., 2011). In recent years, tomato yield losses have been strongly associated with soil exhaustion, weeds and, especially, root nematodes which are a consequence of monoculture (Collange et al., 2011). At present, the standard soil pests management practice in tomato crop production systems is pre-plant soil fumigation with methyl bromide (MB). MB has been used in China for over 20 years and is effective in controlling fungi, bacteria, soil-borne viruses, insects, mites, nematodes and rodents (MBTOC, 2002). MB has provided a reliable return on investment for soil pest control;

* Corresponding author. College of Plant Protection, Shandong Agricultural University, 61 Daizong Street, Tai'an, Shandong 271018, People's Republic of China. Tel.: þ86 0538 8248596. ** Corresponding author. E-mail address: [email protected] (K. Qiao). http://dx.doi.org/10.1016/j.cropro.2014.10.017 0261-2194/© 2014 Elsevier Ltd. All rights reserved.

growers thus have obtained good profits when using it and have therefore become dependent on it. Although MB is one of the most useful chemicals for pest management, the 1992 Montreal Protocol, included MB on the list of ozone-depleting substances (UNEP, 2000). The withdrawal of MB from use as an agricultural fumigant has raised concerns the agricultural production will be negatively impacted if effective and economical alternatives are not identified. Many chemical alternatives and their combinations have been suggested as MB replacements and have been tested in field experiments to evaluate their efficacies in controlling various soil pests (Devkota et al., 2013; Cao et al., 2014; Mao et al., 2014a). Among substitutive chemicals, currently registered alternatives to MB are chloropicrin (CP); 1,3-dichloropropene (1,3-D); methyl isothiocyanate (MITC) generators such as Metam sodium (MNa) and Dazomet (DZ), abamectin (AB) and their combinations (Qiao et al., 2012; Mao et al., 2012; Yan et al., 2012). Other alternatives to MB fumigation may be the use of non-chemical methods, such as soil solarization, organic amendments and biocontrol agents (Klein et al., 2011; Caboni et al., 2013; Hu et al., 2013). However, nonchemical control methods alone are often unsuitable because they do not provide the broad-spectrum activity or the degree of consistency achieved with MB fumigation (Chellemi, 2002).

224

K. Qiao et al. / Crop Protection 67 (2015) 223e227

The present work was initiated to evaluate the most widely used logical alternatives for substituting MB under typical greenhouse conditions in north China. The experimental activities were carried out in tomato greenhouses which were infested with root-knot nematodes and weeds.

2. Materials and methods Field trials were established in August 2011, in two commercial farms near Beiteng country, Tai'an city, Shandong province, China. Both farms were in conventional crop production for more than 10 years before the start of the experiments. The selected experimental sites had a history of heavy natural Meloidogyne incognita (Kofoid & White) Chitwood (southern root-knot nematode) and weed infestations. The soils at the experimental sites were sieved through a 2-mm mesh, and then mixed together, respectively. Particle size analyses were performed using the pipette method (Schinner et al., 1995). Total organic matter was determined by dry heating at 550  C for 8 h and calculating the weight loss following the heating process. The pH was measured in a 1:2.5 soil to H2O extract. Soil moisture content was determined by heating soil in a drying oven at 105 ± 5  C for 8 h until mass constancy was achieved, then subtracting dry weight from fresh weight (Margesin and Schinner, 2005). Soil characteristics of trials I and II are provided in Table 1. The following products were used in the study: (a) MB as a reference treatment (98% gas, ai, Lianyungang Dead Sea Bromine Compounds Co., Ltd., Jiangsu, China); (b) CP (99.5% liquid, ai, Dalian Dyestuffs & Chemicals Co., China); (c) 1,3-D (92% emulsifiable concentrate, ai, Shengpeng Bio-Tech Co., Ltd., China); (d) DZ (98% microgranule, ai, Nantong Shizhuang Chemical Co., Ltd., China); (e) abamectin as a routine treatment (0.5% granule, ai, Jinan Shibang Chemical Co., Ltd., China). The soil mulches were 0.06 mm low density polyethylene film (LDPE) (Baoding Baoshuo Plastic Co., Ltd., Hebei province, China). Treatments were arranged in a randomized complete block design with five replications. Plot size was 40 m2, and there were about 120 tomato plants per plot. The tested treatments were MB, CP, 1,3-D, 1,3-D plus CP, DZ, AB, and untreated control. Application rates of fumigants were based on previous studies and label application directions. Chemical formulations and application rates are provided in Table 2. Prior to treatment establishment, the plots were disked twice before planting beds were made. Each plot was irrigated with 1.3 cm of water the day before fumigation to allow for better bedding. On the day of fumigation (August 1, 2011), MB, CP, 1,3-D, 1,3-D plus CP, and DZ were chisel injected into soil 0.25 m deep and 0.50 m apart just on the planting rows and then the planting rows were bedded and pressed 0.80 m wide at the base, 0.70 m wide at the top, 0.20 m high, and spaced 0.70 m apart on center. Abamectin was applied to the soil by pouring and immediately incorporated to 0.20 m depth through disking and then bedded as described above. Immediately after application of fumigants, beds were pressed and covered with LDPE mulch film. Plastic films were removed from the site 10 days after application. Then six-week-old tomato seedlings were transplanted into the top of the beds 3 weeks after treatment (WAT). Raised beds were 1.5 m apart and each contained 20 tomato plants spaced

Table 2 Experimental program for Trial I & II. Chemicals and formulationa

Rate (kg ha1)

Application method

Abbreviation

MB (98% gas) CP (99.5% liquid) 1,3-D (92% emulsifiable concentrate) 1,3-D plus CP DZ (98% microgranule) AB (0.5% granule) Untreated control

400 500 300

Chisel injection Chisel injection Chisel injection

MB 400 CP 500 1,3-D 300

150 plus 250 300 50 e

Chisel injection Chisel injection Root pouring e

1,3-D þ CP DZ 300 AB 50 e

a Abbreviations: MB ¼ methyl bromide; CP ¼ chloropicrin; 1,3-D ¼ 1,3dichloropropene; DZ ¼ Dazomet; AB ¼ abamectin.

0.50 m apart in the row. Plants were staked and tied as needed during the season. Ordinary flood irrigation was provided according to the water requirements of the tomatoes. Insecticides and fungicides were applied weekly beginning 3 WAT following current recommended practices. No herbicides were applied in order to evaluate the effect of these treatments in controlling weeds. During the tomato growing season, plant heights were measured on 10 plants per plot at 7 and 10 WAT. Plant vigor was evaluated at 8 WAT and visually assessed using a percentage scale where 100% represented optimum plant vigor and 0% indicated plant death. Nematode populations were determined at 6, 9, and 12 WAT by extracting soil samples with a soil probe (2.5 cm wide and 20 cm deep) from the rhizosphere of 10 plants per plot, then nematodes were counted from 100 cm3 of soil using a standard sieving and centrifugation procedure (Jenkins, 1964). The classification of this isolate was performed by perineal configuration, esterase electrophoretic pattern, and host range analyses. Root galling index was determined at 14 WAT by digging the roots of six plants per plot and evaluating root damage using a 0e10 scale where 0 ¼ no galls and 10 ¼ 100% of roots galled (Barker et al., 1986). Emerged weeds were identified and counted in one or two subsamples in each main plot unit at 6 WAT and standardized to a 1 m2 area. Shortly after the weed counts were completed, plots were handweeded, and total handweeding time for each main plot was recorded (Hanson et al., 2010). In all the trials, the marketable tomato fruits were harvested twice (12 and 14 WAT), which was a typical practice in north China greenhouse and graded according to current market standards into the large, medium and small categories. Trial dates for treatment, planting, and evaluation are provided in Table 3. Prior to analysis, data expressed as percentages were arcsine transformed to homogenize variances. Sources of variation were treatments and blocks. The effects of different fumigation treatments were examined using analysis of variance (ANOVA) and when the F-test was significant at P < 0.05, treatment means were compared using the StudenteNewmaneKeuls test at P ¼ 0.05 (SPSS, version 15.0 for Windows). 3. Results Chemical treatments significantly affected plant height and vigor at 7, 10, 8 WAT, respectively (Table 4). Just as expected, the untreated controls in trial I and trial II had the lowest plant height (66 and 69 cm, 7 WAT; 114 and 105 cm, 10 WAT). The highest plant heights were both obtained in plots treated with 400 kg ha1 of MB

Table 1 Soil characteristics in the experimental sites. Sites

pH (1:2.5)

Organic matter (g kg1)

Soil density (g cm3)

Available P (mg kg1)

Available K (mg kg1)

Silt (%)

Clay (%)

Sand (%)

Soil moisture (%)

Trial I Trial II

7.2 6.7

16.8 21.3

1.2 1.3

248.5 363.2

653.9 542.8

67.3 78.2

8.3 6.7

24.4 15.1

14.2 16.1

K. Qiao et al. / Crop Protection 67 (2015) 223e227

225

Table 3 Relevant trial dates and other details. Sites

Fumigant application

Tarp removal

Tomato transplant

Nematode populations investigation

Root galling index determination

Plant growth evaluation

Weed populations evaluation

End of the trial

Tomato cultivar

Last crop

Trial I

01/08/11

11/08/11

20/08/11

06/11/11

19/09/11 09/10/11

11/09/11

08/02/12

Chaoqun Fenguan F1

Tomato

Trial II

01/08/11

12/08/11

21/08/11

09/09/11 29/09/11 19/10/11 10/09/11 30/09/11 20/10/11

07/11/11

20/09/11 21/10/11

12/09/11

11/02/12

Holland No.8

Tomato

(MB 400). However, there was no statistical difference between treatment with MB and the combination of 1,3-D and CP (1,3D þ CP). Other treatments resulted in a plant height intermediate between that obtained from the MB treatments and the untreated control. It was observed that effects of these treatments on plant vigor followed a similar trend to the plant height. The highest plant vigor was obtained in plots treated with MB (92% and 94%), while the lowest was found in the untreated control (78% and 75%). Treatments of CP 500, 1,3-D 300, DZ 300 and AB 50 had intermediate plant vigor (Table 4). Chemical treatments significantly affected nematode population and root galling index (Table 4). M. incognita was isolated but the counts of other kinds of nematodes were at low levels. M. incognita levels were significantly higher in the untreated control compared with all other treatments. In both trials, treatments involving MB and 1,3-D were effective in lowering population levels of root-knot nematodes. Tomatoes grown in the untreated plots had the greatest number of nematodes and the highest root galling index in both trials (7.5 and 7.0) (Table 2). It was found that MB 400 was the most effective treatment for reducing galling from rootknot nematodes (3.2 and 2.5). However, there was no statistical difference between treatment with MB 400, 1,3-D 300 and 1,3Table 4 Effect of chemical programs on nematodes, plant height and vigor in two field trials in Shandong province, China. Chemicals

Trial I MB 400 CP 500 1,3-D 300 1,3-D þ CP DZ 300 AB 50 Control Trial II MB 400 CP 500 1,3-D 300 1,3-D þ CP DZ 300 AB 50 Control

Nematodes in 100 cm3 soila

Root Plant heightc (cm) galling 7 WAT 10 WAT indexb

Plant vigord

6 WAT

9 WAT

12 WAT

18.5de 48.5bc 16.3c 19.3d 61.3b 38.0c 72.7a

25.7d 61.0b 26.3cd 24.3d 64.0b 48.0c 79.3a

4.9c 45.0a 8.0b 5.0c 25.3b 25.0b 42.7a

3.2d 6.3b 3.5d 3.9cd 5.2bc 4.8c 7.5a

92a 72c 79b 92a 74bc 82b 66d

136a 124b 125b 135a 125b 120c 114d

92a 82b 84b 89ab 82b 83b 78c

21.6d 51.1b 29.5cd 18.7d 41.3c 48.5bc 68.3a

31.3c 58.3b 34.5c 26.8d 34.8c 58.4b 75.4a

12.7cd 35.8b 16.2c 10.1d 15.8d 35.1b 52.7a

2.5d 5.2b 3.7c 2.4d 3.0cd 5.1b 7.0a

92a 72cd 83b 89ab 82b 79c 69d

131a 120c 123b 130a 125b 115cd 105d

94a 85b 85b 92a 83b 80bc 75c

a Nematodes (Meloidogyne incognita (Kofoid & White) Chitwood) in 100 cm3 soil were counted at 6, 9 and 12 WAT using a standard sieving and centrifugation procedure in both growing seasons. b Nematode root galling index determined at 14 WAT obtained using a 0e10 scale where 0 ¼ no galls and 10 ¼ 100% of roots galled. c Plant height was determined at 7 and 10 WAT in the two field trials. d Plant vigor was determined at 8 WAT, using a 0e100% scale where 0% ¼ plant death and 100% ¼ optimum growth. e Data are arithmetic means of five replications and means separated with StudenteNewmaneKeuls test (P ¼ 0.05). Numbers in the same column followed by the same letter are not significantly different according to StudenteNewmaneKeuls test (P ¼ 0.05).

D þ CP. Other treatments, CP 500, DZ 300 and AB 50 had slightly weaker effects in reducing nematode population and root galling, but better than the untreated control. Handweeding time was substantially reduced by all treatments compared with the untreated control (Table 5). The predominant grasses present were Eleusine indica (L.) Gaertn., Digitaria sanguinalis (Linn.) Scop and Arenaria serpyllifolia L. Handweeding time in both trials followed the weed count trends; all treatments resulted in 8.9e48.7% and 5.5e61.0% reduction in man-hours required for the initial weeding. Effects of chemicals programs on different weed populations exhibited a similar tendency. Weeds in plots treated with MB were greatly suppressed and had the least population. Other treatments showed some control effects; however, they did not match the efficacy of MB (Table 5). Tomato fruit weight per category and total fruit weight differed among chemical treatments as shown in Table 5. In both trials, the highest yield of large fruit was obtained in the MB treatment at the dose of 400 kg ha1 (10.2 and 11.3 t ha1), while the lowest was achieved in the untreated control (4.1 and 3.7 t ha1). Other treatments resulted in yields ranging between 6.7 and 9.5 t ha1 in trial I, whereas in trial II yields ranged between 6.3 and 10.1 t ha1. There were no significant differences among the chemicals in the large and medium fruit categories of the MB and the 1,3-D þ CP treatment. A similar trend was observed for total marketable fruit yield, where the highest yields in both trials (88.1 and 90.2 t ha1) were obtained from the MB treatment plots. In trial I, only the 1,3D þ CP treatment matched the MB treatment in total marketable yields. Other treatments (1,3-D 300, CP 500 and DZ 300) except abamectin exhibited a moderate yield increase, and there were no significant differences among these three treatments.

4. Discussion Protected vegetable is the most dynamic industry in China, playing a key role in the development of modern agriculture (Ministry of Agriculture (2010)). However, root-knot nematodes and weeds often pose substantial problems. Moreover, MB is scheduled to be withdrawn from routine use by 2015. There is an urgent need for China to find safe, effective and economically feasible MB alternatives, in order to minimize losses that may result from phasing out MB. Use of chemical alternatives for MB is an essential practice to protect many crops from nematodes and weeds (Zasada et al., 2010). However, in China, the techniques used to control soil pests need to be as simple as possible, as well as sufficiently effective and economically feasible. In China, farming still predominantly depends on manual practice. This is because many greenhouses are small and in low-lying regions, hence chemigation systems, drip irrigation and shank injection machines or large equipment cannot be used (Cao et al., 2014). This study presents the results of various MB alternatives in tomato crops in north China fields: namely, CP, 1,3-D, 1,3-D þ CP

226

K. Qiao et al. / Crop Protection 67 (2015) 223e227

Table 5 Effect of chemical programs on handweeding time, weed populations and tomato yields in two field trials in Shandong province, China. Chemicals

Trial I MB 400 CP 500 1,3-D 300 1,3-D þ CP DZ 300 AB 50 Control Trial II MB 400 CP 500 1,3-D 300 1,3-D þ CP DZ 300 AB 50 Control

Handweeding time per plot (h ha1)a

% Reduction

8.1d 12.1b 11.4c 11.6bc 12.3b 14.4a 15.8a 5.7d 6.1c 13.7ab 9.1bc 13.1b 13.8ab 14.6a

Tomato marketable yields (t ha1)

Weed populations per plotc E. indicab

D. sanguinalis

A. serpyllifolia

Total

Large

Medium

Small

Total

% Increase

48.7 23.4 27.9 26.6 22.2 8.9 e

5.9d 14.1b 13.5bc 12.2c 13.2bc 18.8ab 21.3a

5.3c 12.8b 11.8b 13.3ab 16.0a 17.0a 18.5a

4.6d 16.8b 15.0c 16.5b 14.5bc 22.8a 25.8a

15.8c 43.7b 40.3b 42b 43.7b 58.6a 65.6a

10.2a 9.5ab 9.1b 9.4ab 8.7b 6.7c 4.1d

23.3a 20.1ab 19.8b 21.2ab 20.1ab 19.3b 14.7c

54.6a 47.4b 48.9b 50.6b 48.3b 38.2c 19.8d

88.1a 77b 77.8b 81.2ab 77.1b 64.2c 38.6d

128.2 99.5 101.6 110.4 99.7 66.3 e

71.0 58.2 6.2 37.7 10.3 5.5 e

0.9b 0.1c 0.3c 0.2c 1.2a 0.8ab 1.2a

3.6d 9.8c 11.2b 3.3d 11.4b 10.3bc 15.3a

5.8d 12.1c 14.2c 14.3bc 16.1b 19.2ab 23.2a

10.3d 22.0bc 25.7b 17.8c 28.7b 30.3ab 39.7a

11.3a 9.1b 9.6b 10.1ab 9.0b 6.3c 3.7d

25.1a 22.5ab 21.5b 23.2ab 22.4ab 21.1b 15.4c

53.8a 49.2b 51.9ab 51.2ab 49.3b 43.5b 21.2c

90.2a 80.8bc 83b 84.5ab 80.7bc 70.9c 40.3d

123.8 100.5 106.0 110.0 100.2 75.9

a Handweeding time per plot was determined shortly after the weed counts were completed. Data are arithmetic means of five replications and means separated with StudenteNewmaneKeuls test (P ¼ 0.05). Values followed by the same letter did not differ at the 5% significance level. b E. indica ¼ Eleusine indica (L.) Gaertn., D. sanguinalis ¼ Digitaria sanguinalis (Linn.) Scop., A. serpyllifolia ¼ Arenaria serpyllifolia L. c Weed populations were determined at 6 WAT. Data are arithmetic means of five replications and means separated with StudenteNewmaneKeuls test (P ¼ 0.05).

and DZ. All the treatments tested were effective in enhancing plant height and vigor in contrast to the traditional AB treatment and the nontreated control. The standard treatment, MB, was the top performer, with no significant differences when compared with 1,3-D þ CP. And CP, 1,3-D, DZ, used alone, were second to MB in performance. Interestingly, reduced rate of the 1,3-D plus CP treatment exhibited a better performance than the higher 1,3-D and CP doses used alone, which demonstrated the superiority of combining the two chemicals. Our study also found that application of chemical treatments resulted in reduced numbers of nematodes in soil and lower root galling indices. There are four fumigant nematicides available: MB, CP, 1,3-D and DZ. These chemicals have been used alone and in various combinations for nematode control in various crops for many years (Mao et al., 2012, 2014b). Abamectin is another product that is a routine treatment used in China (Qiao et al., 2012). Generally speaking, our results on reduction of nematode population densities and root-gall indices in this study are promising. All the fumigants tested reduced nematode population densities and root-gall indices, especially the 1,3-D þ CP treatment. On the issue of weeds, however, the results were mixed. Weed control efficacy was very good with the MB treatment, moderate with CP, 1,3-D, 1,3-D þ CP and DZ, and similar to the nontreated control for AB. Some studies found that CP, 1,3-D and DZ had certain effects on weeds (Klose et al., 2007, 2008). However, some studies revealed that 1,3-D did not control many of the troublesome weeds such as Cyperus rotundus and Cyperus esculentus (Gilreath et al., 2006). This was also the case in this study, in which CP and DZ did not control weeds as effectively as MB. Most previous studies indicated that the fumigants tested in this study could only offer moderate control of pathogens and weeds (Qiao et al., 2010). Variations in these studies may be due to the fact that the efficacy of these fumigants is dependent upon achieving an appropriate soil structure and moisture content at application followed by effective sealing of the soil surface to reduce loss of these fumigants. After all, the ultimate judgment on the success of alternatives to the MB depends on crop yield. Our results indicated that all treatments had a positive effect on tomato yield. In both trials, the highest yield was obtained in the MB treatment, while only the 1,3D þ CP treatment resulted in the same marketable yield level as MB. The result in this research with 1,3-D þ CP is in agreement with

previous studies, which proved that the combination of 1,3-D and CP would be a better alternative to MB. However, currently no single chemical or nonchemical method can exhibit the efficacy of MB (Yates et al., 2002). CP has an excellent fungicidal activity; however, it is generally less effective than MB against nematodes and weeds (Duniway, 2002). 1,3-D is known to be effective against nematodes and soilborne insects but relatively weak for the control of soilborne fungal pathogens and weeds (Flint, 2002). Dazomet is a widely used nematicide; however, its performance is inconsistent because of inadequate volatility (Martin, 2003). Based on our results, the combination of 1,3-D and CP, is recommended for use in integrated pest management and can match MB's efficacy and cost. On the other hand, to get better weed control efficacy, it is necessary to add herbicides to the two fumigants combination (Santos et al., 2006). Further evaluation of these and other pesticide combinations are needed in different areas to fully evaluate these alternatives to MB.

Acknowledgments This work was supported by the Special Fund from the Postdoctor Innovation Research Program of Shandong Province (201402018) and the National Key Technology R&D Program of China (2014BAD05B03). The authors wish to thank the chemical manufacturers for providing technical assistance for the execution of the soil fumigation treatments.

References Barker, K.R., Townshend, J.L., Bird, G.W., Thomason, I.J., Dickson, D.W., 1986. Determining nematode population responses to control agents. In: Hickey, K.D. (Ed.), Methods for Evaluating Pesticides for Control of Plant Pathogens. APS Press, St. Paul, MN, USA, pp. 283e296. Caboni, P., Saba, M., Tocco, G., Casu, L., Murgia, A., Maxia, A., MenkissogluSpiroudi, U., Ntalli, N., 2013. Nematicidal activity of mint aqueous extracts against the root-knot nematode Meloidogyne incognita. J. Agric. Food Chem. 61, 9784e9788. Cao, A., Guo, M., Yan, D., Mao, L., Wang, Q., Li, Y., Duan, X., Wang, P., 2014. Evaluation of sulfuryl fluoride as a soil fumigant in China. Pest Manag. Sci. 70, 219e227. Chellemi, D.O., 2002. Non chemical management of soilborne pests in fresh market vegetable production systems. Phytopathology 92, 1367e1372.

K. Qiao et al. / Crop Protection 67 (2015) 223e227 Collange, B., Navarrete, M., Peyre, G., Mateille, T., Tchamitchian, M., 2011. Root-knot nematode (Meloidogyne) management in vegetable crop production: the challenge of an agronomic system analysis. Crop Prot. 30, 1251e1262. Devkota, P., Norwsorthy, J.K., Rainey, R., 2013. Comparison of allyl isothiocyanate and metam sodium with methyl bromide for weed control in polyethylenemulched bell pepper. Weed Technol. 27, 468e474. Duniway, J.M., 2002. Status of chemical alternatives to methyl bromide for preplant fumigation of soil. Phytopathology 92, 1337e1343. Flint, M.L., 2002. Integrated Pest Management for Almonds, second ed. Univ. Calif. Ag. Nat. Res. Pub. 3308. 199 pp. Gao, J., Guo, G., Guo, Y., Wang, X., Zhang, Y., Du, Y., 2011. Development and reproduction of Bemisia tabaci biotype B on wild and cultivated tomato accessions. Acta Ecol. Sin. 23, 7211e7217 (in Chinese). Gilreath, J.P., Santos, B.M., Noling, J.W., Locascio, S.J., Dickson, D.W., Rosskopf, E.N., Olson, S.M., 2006. Performance of containerized and bare-root transplants with soil fumigants for Florida strawberry production. HortTechnology 16, 461e465. Hanson, B.D., Gerik, J.S., Schneider, S.M., 2010. Effects of reduced-rate methyl bromide applications under conventional and virtually impermeable plastic film in perennial crop field nurseries. Pest Manag. Sci. 66, 892e899. Hu, Y., Zhang, W., Zhang, P., Ruan, W., Zhu, X., 2013. Nematicidal activity of chaetoglobosin a produced by Chaetomium globosum NK102 against Meloidogyne incognita. J. Agric. Food Chem. 61, 41e46. Jenkins, W.R., 1964. A rapid centrifugal-flotation technique for separating nematodes from soil. Plant Dis. Report. 48, 692. Klein, E., Katan, J., Gamliel, A., 2011. Soil suppressiveness to Fusarium disease following organic amendments and solarization. Plant Dis. 95, 1116e1123. Klose, S., Ajwa, H.A., Browne, G.T., Subbarao, K.V., Martin, F.N., Fennimore, S.A., Westerdahl, B.B., 2008. Dose response of weed seeds, plant-parasitic nematodes, and pathogens to twelve rates of metam sodium in a California soil. Plant Dis. 92, 1537e1546. Klose, S., Ajwa, H.A., Fennimore, S.A., Martin, F.N., Browne, G.T., Subbarao, K.V., 2007. Dose response of weed seeds and soilborne pathogens to 1,3-D and chloropicrin. Crop Prot. 26, 535e542. Mao, L., Wang, Q., Yan, D., Ma, T., Liu, P., Shen, J., Li, Y., Ouyang, C., Guo, M., Cao, A., 2014a. Evaluation of chloropicrin as a soil fumigant against Ralstonia solanacarum in ginger (Zingiber officinale Rosc.) production in China. PLoS One 9 (3), e91767.

227

Mao, L.G., Wang, Q.X., Yan, D.D., Xie, H.W., Li, Y., Guo, M.X., Cao, A.C., 2012. Evaluation of the combination of 1,3-dichloropropene and dazomet as an efficient alternative to methyl bromide for cucumber production in China. Pest Manag. Sci. 68, 602e609. Mao, L., Yan, D., Wang, Q., Li, Y., Ouyang, C., Liu, P., Shen, J., Guo, M., Cao, A., 2014b. Evaluation of the combination of dimethyl disulfide and dazomet as an efficient methyl bromide alternative for cucumber production in China. J. Agric. Food Chem. http://dx.doi.org/10.1021/jf501255w. Margesin, R., Schinner, F., 2005. Manual for Soil Analysis - Monitoring and Assessing Soil Bioremediation. Springer: Verlag Berlin Heidelberg, pp. 47e49. Martin, F.N., 2003. Development of alternative strategies for management of soilborne pathogens currently controlled with methyl bromide. Annu. Rev. Phytopathol. 41, 325e350. MBTOC, 2002. Report of the Methyl Bromide Technical Options Committee, 2002 Assessment. UNEP, Nairobi, pp. 1e2. Ministry of Agriculture, 2010. China Agriculture Yearbook. China Agriculture Press, Beijing. Qiao, K., Liu, X., Wang, H.Y., Xia, X.M., Ji, X.X., Wang, K.Y., 2012. Effect of abamectin on root-knot nematodes and tomato yield. Pest Manag. Sci. 68, 853e857. Qiao, K., Wang, H.Y., Shi, X.B., Ji, X.X., Wang, K.Y., 2010. Effects of 1,3-dichloropropene on nematode, weed seed viability and soil-borne pathogen. Crop Prot. 29, 1305e1310. Santos, B.M., Gilreath, J.P., Motis, T.N., Noling, J.W., Jones, J.P., Norton, J.A., 2006. Comparing methyl bromide alternatives for soilborne disease nematode and weed management in fresh market tomato. Crop Prot. 25, 690e695. € Schinner, F., Ohlinger, R., Kandeler, E., Margesin, R., 1995. Methods in Soil Biology. Springer: Verlag Berlin Heidelberg, pp. 386e389. UNEP, 2000. Handbook for the International Treaties for the Protection of the Ozone Layer, sixth ed. Ozone Secretariat, UNEP, Nairobi, pp. 44e45. Yan, D., Wang, Q., Mao, L., Xie, H., Guo, M., Cao, A., 2012. Evaluation of chloropicrin gelatin capsule formulation as a soil fumigant for greenhouse strawberry in China. J. Agric. Food Chem. 60, 5023e5027. Yates, S.R., Gan, J., Papiernik, S.K., Dungan, R., Wang, D., 2002. Reducing fumigant emissions after soil application. Phytopathology 92, 1344e1348. Zasada, I.A., Halbrendt, J.M., Kokalis-Burelle, N., LaMondia, J., McKenry, M.V., Noling, J.W., 2010. Managing nematodes without methyl bromide. Annu. Rev. Phytopathol. 48, 311e328.