**7.2. Biological control**

of *Fol* from different locations at Minia, Assuit and New Valley governorates, which were

124 Fusarium - Plant Diseases, Pathogen Diversity, Genetic Diversity, Resistance and Molecular Markers

Altaf et al. (2014) have characterized 15 *Fol* isolates (Fol-1 to Fol-15) collected from nine district of Pakistan on the basis of their pathogenicity and morphology [68]. Recently, Pouralibaba et al. (2016, 2017) have identify seven pathotypes (1–7) of *Fol* on the basis of their different pattern of virulence on lentil genotypes. Fifty-two *Fol* isolates originated from Iran, Syria and Algeria were used in the study. The results suggest that the pathogen 7 was virulent on all the accessions under study and there was no correlation found between the pathotype and the geographical origin of the isolates. The study was further confirmed by analyzing histopathology pattern of infection on resistant/susceptible varieties by pathotypes 1 and 7, which suggests that lower disease index was measured with plants inoculated with pathotypes 1 but not with pathotype 2 [69, 70]. Further studies are required to identify region specific pathogenic races using differen-

tial lines for conferring resistance against them in the respective agro-climatic regions.

Due to the presence of high mutations and variations among the pathogen populations limit the effectiveness of natural resistance in the host plants against the pathogens [71]. Therefore, it is important to access the variability among the pathogen and regarding its host resistance for a successful breeding program. It is also important to replace the low yielding genotypes and disease susceptible varieties with those of high yielding and disease resistance ones.

The forma specialis of lentil has a very limited host range and can induce disease of lentil only under natural conditions. Khare (1980) and Taheri et al. (2010) studied the host range of *Fol* by inoculating it on plants such as cowpea, french bean, bengal gram, lathyrus, mungbean, urdbean, pea, soybean, tomato and eggplant (Solanaceae), melon (Cucurbitaceae) or red gram which results in no infection [53, 72]. Recent host range studies on soybean, chickpea and

Different Fusarium wilt management are used by lentil growers in different countries. These include cultural, biological, chemical, host plant resistance and an integration of two or more

Several fungicides have been tested against the *Fol* in different parts of the world. The study reveals that the systemic fungicides found to be superior to non-systemic fungicides in inhibiting the fungal mycelial growth in plates as well as in pot seed treatment. Benomyl (76.6%) showed the most positive results against the pathogen followed by thiophanate methyl (73.0%) whereas non-systemic fungicides viz. captan (67.8%) and dithane M-45 (62.3%) were the least efficient in reducing the fungal growth compared to the systemic fungicides [74]. On the other hand, Kasyap et al. (2008) has found much reduced fungal growth with captan (88.3%) [75].

varied in their virulence [67].

**6. Host ranges**

control options.

**7.1. Chemical control**

tomato did not result to infection [73].

**7. Fusarium wilt management options**

Biological control is known to be the best and effective method, against soil-borne pathogens. This method has many advantages such as environment friendly, cost effective and extended plant protection. Many fungal and bacterial species like *Pseudomonas*, *Trichoderma* and *Streptomyces* have antagonistic effect on Fusarium wilt of lentil. Among them *Trichoderma* species are been extensively used as bio-control agent against soil and seed-borne diseases [74]. A study revealed that the seed treatment with *Gliocladium virens* + *P. fluorescens* + carboxin and *Bacillus subtilis* + carboxin + *T. harzianum*/*T. viride*/*G. virens* have been found more effective in controlling Fusarium wilt incidence in lentil [79, 80]. In the recent study, two species of *Trichoderma* were employed against highly virulent isolate of *Fusarium* responsible for lentil wilt. The results revealed that *T. harzianum* was highly effective in controlling wilt disease in comparison to other isolate, when applied as a soil drench [74].

In an experiment conducted by Garkoti et al. (2013) observed significant reduction in disease incidence and maximum grain yield in field trials using 'Pant L-639' a popular cultivar against lentil wilt with *T. harzianum* + *Pseudomonas fluorescence* [81]. Similarly, in another report the result suggest that the disease severity was reduced with increased plant height with the combination of *T. harzianum* + *S. vermifera* [82]. Likewise, El-Hassan and Gowen (2006) has evaluated the formulation and delivery of the bacterial antagonist *Bacillus subtilis* against Fusarium wilt of lentil. The result reveal that the seed treatments with formulations of *B. subtilis* on glucose, talc and peat significantly enhanced its biocontrol activity against *Fusarium* compared with a treatment in which spores were applied directly to seed [83]. Additionally, several studies have also proved the importance of the organic material in reducing the disease incidence caused by plant pathogen like bacteria [84], fungi [85] and nematode [86] species.
