MANAGEMENT OF ROOT KNOT NEMATODES AND FUSARIUM WILT OF TOMATO BY PRE-TREATMENT OF SEEDLINGS WITH BIOLOGICAL AND CHEMICAL AGENTS

Transcription

1 MANAGEMENT OF ROOT KNOT NEMATODES AND FUSARIUM WILT OF TOMATO BY PRE-TREATMENT OF SEEDLINGS WITH BIOLOGICAL AND CHEMICAL AGENTS Authors Wanja Njoroge, Dr. Muthomi and Prof.Kimenju Department of Plant Science and Crop Protection Faculty of Agriculture University of Nairobi

2 Introduction Tomato (Lycopersicon esculentum L.) is an annual sub-tropical fruit used as a vegetable source of vitamin A and C and Potassium (Anita et.al.2009). Excellent source of lycopene, linked to the prevention of types of cancer, heart disease and premature aging. Constrains; pest and diseases

3 . OBJECTIVES Determine effect of biological and chemical pretreatment of tomato seedlings in management of root knot nematodes. Determine effect of biological and chemical pretreatment of tomato seedlings in management of Fusarium wilt. Determination of the Synergistic effect of botanical and biological agents in management of root knot nematodes and Fusarium wilt of tomato.

4 MATERIALS AND METHODS Raising of money maker tomato seedlings Sterilization of growing media Potting of growing media Extraction and preparation of root knot nematode inoculums Isolation and culture of Fusarium wilt pathogen inoculum Inoculation of soil with root knot nematodes

5 RESULTS AND DISCUSSIONS

6 Effect of chemical and biological pretreatment of tomato seedlings on root knot nematode infestation Innoculation of soil with root knot nematodes Transplanting of seedlings treatments consisted of sterilized growth media composed of soil and sand at a ratio of 2:1 with (i) Marshal 250 ec as a chemical agent (ii) Neemraj which is derived from neem kernel whose active ingredient is Azadiractin 0.30% ec, a botanical agent (iii) PL Plus a biological agent which contains spores of the fungi, Paecilomyces lilacinus (iv) water alone (v) Root knot nematode inoculum.

7 Effect on the number of root galls and nematode population Significant reduction in the number of root galls, galling index and the population of Juveniles in the soil (Fig 1). Chemical agent Marshal 250ec was the most effective in reducing both the number of galls and juvenile population Biological formulation, PL plus was the least effective. Very high levels of nematode population were extracted in soils where no treatment was applied.

8 Figure 1: Percentage reduction in the number of galls, gall index, and Juveniles population

9 Objective 2: Effect of biological and chemical pretreatment on Fusarium wilt Treatments (i) Root guard which contains Trichorderma, Bacillus, Aspergillus, Chatomium, Escherichia, Azotobacter spp as biological control agent (ii) Neemraj which is derived from neem kernel whose active ingredient is Azadiractin 0.3% EC, a botanical agent (iii) Phosphite a fungicide whose active ingredient is potassium phosphate 53%. (iv) Controls growth media inoculated with Fusarium and un inoculated growth media

10 Effect on Fusarium wilt symptoms and stem infection increased the shoot dry weight and plant height in comparision to the inoculated control. reduced the number of yellow leaves, dead leaves, stem discoloration and the Fusarium re isolated. All the formulations were effective in reduction of stem discolouration, Root guard was most effective in supression of Fusarium wilt ( figure 2) Root guard and neemraj are effective biological formulations for the control of fusarium wilt and can be used for pre treatment of seedlings.

11 Figure 2: Percentage reduction in stem discolouration and Fusarium re- isolated

12 Objective 3: Effect of combining biological formulations on root knot nematode and Fusarium wilt infection Treatment i. Root guard which contains Trichorderma, Bacillus, Aspergillus, Chatomium, Escherichia, Azotobacter spp as biological control agent ii. (ii) Neemraj which is derived from neem kernel whose active ingredient is Azadiractin 0.30% EC, a botanical agent iii. (iii) PL Plus a biological agent which contains spores of the fungi, Paecilomyces lilacinus iv. (iv) Pl plus and root guard v. (v) Pl plus and Neemraj vi. (vi) Root guard and Neemraj vii. controls consisting of un inoculated media and media inoculated with both nematode and Fusarium inoculums.

13 Objective 3: Effect of combining chemical and biological formulations on root knot nematode and Fusarium wilt infection The individual and combined treatments were very effective in reducing the number of galls, galling index and juveniles in the soil. All the treatments were very effective in reducing the number of juveniles in the soil (90%) except for root guard which reduced the number of juveniles in the soil by about 60%. Individual and combined biological formulations can be used to control root knot nematodes in a fusarium and root knot nematode interraction

14 Figure 3: Percent reduction in number of galls, galling Index and juvenile population

15 Effect on Fusarium wilt symptoms and stem infection Root guard was the most effective individual treatment reducing stem discolouration by 100% and thefusarium reisolated by 80%. All the combined treatments; Pl plus and Neemraj, Root guard and neemraj and Pl plus and Root guard were very effective in reducing the stem discoloration (100%) and the amount of Fusarium re isolated (80% ) Combination of biological formulations are more effective in suppresion of Fusarium wilt

16 Figure 4: Percent reduction in stem discoloration and Fusarium re isolation

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