Efficacy of Selected Plant Extracts against <i>Pyricularia grisea</i>, Causal Agent of Rice Blast Disease

Abstract

Rice blast disease, caused by a seed-borne fungus Pyricularia grisea, is an important and serious disease of rice (Oryza sativa L.) worldwide. The disease has been reported to cause yield losses of up to 40% in Tanzania. Studies were conducted to determine the effect of aqueous extracts of Aloe vera, Allium sativum, Annona muricata, Azadirachta indica, Bidens pilosa, Camellia sinensis, Chrysanthemum coccineum, processed Coffee arabica, Datura stramonium, Nicotiana tabacum and Zingiber officinalis for control of rice blast disease (Pyricularia grisea) in-vitro and in-vivo. The results indicate that processed C. arabica at 10% and 25% (v/v) had the highest (81.12%) and (89.40%) inhibitory effect, respectively, against P. grisea. Aqueous extract from N. tabacum at 10% concentration ranked third (80.35%) in inhibiting P. grisea. These were followed by extracts from 25% A. vera (79.45%) and 25% C. coccineum flower (78.83%). The results also indicate that, extracts from A. indica, A. vera, A. sativum, C. arabica, D. stramonium, C. sinensis, Z. officinalis and N. tabacum did not have any phytotoxic effect on seed germination, shoot height, root length, dry weight, seedling growth and seedling vigour index. These plant extracts can thus be used for rice seed treatment to manage rice blast disease.

Inhibitory Effects of Bamboo Leaf on the Growth of Pyricularia grisea Fungus

“…The use of plant extracts to control the infestation of fungi on rice was potent and environmentally friendly compared with synthetic fungicides [21]. In a previous work, Hubert et al [8] reported that aqueous extracts of Coffee arabica at 10% and 25% (v/v) exhibited 81.12 and 89.40% inhibition on P. grisea, respectively. Suriani et al [22] documented that the crude extract of Piper canium inhibited mycelial growth of P. grisea.…”

“…In addition, extracts from E. aromatica, P. guineense, and G. kola could serve as bio-fungicides against the growth of P. grisea [7]. Several other plants have been tested and showed significant results against P. grisea [7][8][9]. However, the application of plant extracts in agricultural practice is labor-intensive and costly.…”

Efficacy of Aqueous Leaf Extract of Medicinal Plants against Blast and Brown Spot Disease of Rice

“…Gohel and Chauhan (2015) reported that Neem leaf extract were found effective but comparably less significant than standard fungicides and bio-agent in minimizing leaf blast intensity in rice. Hubert et al, (2015) observed that extracts from C.arabica, N. tabacum, A. vera, A. indica, were found significant to manage rice blast disease in-vitro and in-vivo.…”

Susceptibility of Selected Multi-Drug Resistant Clinical Isolates to Different Leaf Extracts of Senna alata

“…The solvents utilized for the extraction are ethanol (100%), methanol (100%) and hot water. A slightly modified method of Hubert et al (2015) was adopted for the extraction processes. Precisely, one hundred grams (100 g) of the fine powered leaf was weighed using a weighing balance (A&D, UK); this weighed sample was immersed in 200 ml of each of the above mentioned solvents contained in three different carefully labeled conical flasks, to obtain three different extracts, which were accompanied by vigorous shaking for five (5) minutes and thereafter allowed to remain on the rotating shaker for 24 hours.…”