**Author details**

*3.3.3. "Pesta" granules*

74 Biological Approaches for Controlling Weeds

not viable in the final product [49, 57, 143–145].

(12%) for more than 2 years [145].

*3.3.4. Stabilize granules*

The production of Pesta granules is based on the technology of pasta production. Inoculum suspension (52 mL), wheat semolina flour (80 g) and kaolin (20 g) are mixed to produce dough. The dough is passed through a pasta maker after that it is dried, crashed and sieved. The technique was tried for encapsulation of conidia of potential mycoherbicides (*Alternaria cassiae*, *A. crassa*, *Colletotrichum truncatum* and *Fusarium lateritium*) as well for stabilization of entomopathogenic nematodes [142, 143]. Melanized fungal structures as pigmented conidia, chlamydospores, microsclerotia and sclerotia granules are generally compatible to Pesta process while non-pigmented conidia of *F. oxysporum*, *C. truncatum*, *Trematophoma lignicola* were

Microslecrotia of *C. truncatum* survived in Pesta granules and remained to produce virulent conidia (for biocontrol of weed *Sesbania exaltata*) for 52 weeks at 25°С low water activity (aw 0.18–0.29), and for 10 years at 4°С [57, 146] while the fungal conidia can be stored no more than 32 weeks [147]. Interestingly, that during the process of encapsulation of *Alternaria alternata* conidia with Pesta process, the number of colony forming units increased due to destroying their aggregations. The virulence of the fungus was stable at a low relative air humidity

The composition of Pesta granules can be easily modified. Shabana et al. [148] evaluated various compositions for *Fusarium oxysporum* f. sp. *orthoceras* using 3% (w/w) sucrose, corn flour, glycerol, starch WaterLock B209, cellulose and yeast extract. The last component improved viability of chlamydospores as well as of microconidia in the granules. However, the prepared samples showed appropriate viability (60–80% for 12 months) under 25°C and relative humidity 11–12%; under higher temperature (25°C) and humidity (51–53%) viability of the fungus dramatically decreased by the 4–8th month of storage [148]. The biocontrol efficacy of *Aspergillus alliaceus* against parasitic weeds (*Orobanche* spp.) incorporated in Pesta granules

For encapsulation of conidia of potential mycopesticides (*C. truncatum*, *Alternaria* sp., *Paecilomyces fumoroseus*, *Aspergillius flavus*, *A. parasiticus*) produced by solid and liquid state fermentation the twin-screw extrusion was successfully tested. Ingredients were mixed in the mixer of an extruder and resulted Pesta granules were dried by fluid bed drying at 50°С. The inoculum produced by solid-state fermentation was shown to be less sensitive to whole the stabilization

The main components of these granules are a membrane stabilizer (for instance, sucrose at the concentration 10–65% from granules weight), a water absorbance agent (starch), a filler (diathomaceous earth, silica Hi-Sil® at the concentration 5–20%). Additionally, the granules can include vegetable oil (ca. 20%), UV-protectant, preservatives and other inert fillers [151]. For example, sucrose (4 parts), starch (1 part), unrefined vegetable oil (1 part), silica gel (1.5 parts) and biological suspension (4 parts) are mixed and extruded; the resulted pasta is conventionally dried and

was improved by addition of potato broth or sorghum meal [149].

process than the biomaterial from the liquid culture [150].

Alexander Berestetskiy\* and Sofia Sokornova \*Address all correspondence to: aberestetskiy@vizr.spb.ru All-Russian Institute of Plant Protection, Saint-Petersburg, Russia
