<p>Chick pea is a leading pulse crop of India, grown in an area of 6.31 million ha with annual production of 5.08 million tones contributing 29% of area and 38.05% of pulse production. <italic>S. rolfsii</italic> causing collar rot is an important soil borne disease. Hence, The present investigation aimed to see the effect of different media, temperatures and pH on the growth of <italic>S. rolfsii</italic>.</p><p>Six media <italic>viz.</italic>, Richard's kerr's, dextrose nitrate agar, rice meal, chick pea meal and PDA were evaluated to find out the best medium for the growth and sclerotial formation of <italic>S. rolfsii</italic>. Twenty ml of medium was poured in each Petri plates. Five mm discs were cut with the help of sterilized cork borer from the margin of a 4 days old pure culture grown on PDA. One disc of the culture was placed in inverted position in the centre of each Petri plates. Observation for mean radial growth were recorded at 4 and 7 days after inoculation at 27±2°C in BOD incubator.</p><p>The study was conducted to find out the most suitable temperature for mycelial growth. The Petri plates poured with PD medium were inoculated with 5 mm disc of the pathogen of a 4 days old culture, incubated at 15, 20, 25, 30 and 35°C. Observation for mean radial growth were recorded at 4 and 8 days after inoculation. The effect of different pH ranging from 4, 5, 6, 7, 8 and 9 on the growth of the pathogen was evaluated on PDA. The pH of the medium was adjusted before autoclaving with the help of digital pH meter, by addition of 0.1 N HCl or 0.1 N NaOH. Twenty ml of medium was poured in each Petri plates. The Petri plates were inoculated with 4 days old pure culture of <italic>S. rolfsii</italic> and Petri plates were incubated in BOD incubator at 27±2°C. Three replications were maintained for each treatment and observations for radial growth after 3, 5 and 7 days interval were recorded.</p><p>The maximum radial growth of <italic>S. rolfsii</italic> was measured on P.D.A. (82.2 & 90.0 mm) at 4 and 7 days after inoculation, followed by chick pea meal agar. rice meal agar and Richards agar media (<xref ref-type="table" rid="tab001a">Table 1a</xref>). Tripathi (<xref ref-type="bibr" rid="bib004">2006</xref>) reported that maltose supported best growth of fungus. The mycelial growth of <italic>S. rolfsii</italic> was significantly higher at 30°C followed by 35°C in 4 and 8 days after inoculation (<xref ref-type="table" rid="tab001b">Table 1b</xref>). Maheshwari <italic>et al.</italic>, (<xref ref-type="bibr" rid="bib002">2000</xref>) reported similar findings on temperature and pH. The mycelial growth of <italic>S. rolfsii</italic> differed significantly at varying pH (<xref ref-type="table" rid="tab001c">Table 1c</xref>). Significantly maximum mycelial growth at 5 and 7 days after inoculation followed by pH 6 and pH 7. Ahamad <italic>et al.</italic> (2000); Sharma <italic>et al.</italic> (<xref ref-type="bibr" rid="bib003">2005</xref>) observed same trends in fungal growth. <table-wrap id="tab001a"><label>Table 1a</label><caption><p>Effect of different media temperature and pH on radial growth of <italic>Sclerotium rolfii</italic></p></caption><table><thead><tr><th rowspan="3">Media</th><th colspan="2" align="center">Radial growth* (mm) after</th></tr><tr><th colspan="2"><hr /></th></tr><tr><th align="center">4 days</th><th align="center">7 days</th></tr></thead><tbody><tr><td colspan="3"><hr /></td></tr><tr><td valign="top">Kerr's Agar</td><td align="center" valign="top">2.4</td><td align="center" valign="top">26.8</td></tr><tr><td valign="top">Dextrose Nitrate Agar</td><td align="center" valign="top">22.3</td><td align="center" valign="top">36.5</td></tr><tr><td valign="top">Richards</td><td align="center" valign="top">60.2</td><td align="center" valign="top">75.9</td></tr><tr><td valign="top">Rice Meal Agar</td><td align="center" valign="top">71.2</td><td align="center" valign="top">80.5</td></tr><tr><td valign="top">Chickpea Meal Agar</td><td align="center" valign="top">79.5</td><td align="center" valign="top">84.3</td></tr><tr><td valign="top">P.D.A.</td><td align="center" valign="top">82.2</td><td align="center" valign="top">90.0</td></tr><tr><td valign="top">SEm±</td><td align="center" valign="top">0.6</td><td align="center" valign="top">0.6</td></tr><tr><td valign="top">CD (P=0.05)</td><td align="center" valign="top">1.8</td><td align="center" valign="top">1.9</td></tr></tbody></table></table-wrap><table-wrap id="tab001b"><label>Table 1b</label><caption><p>On temperatures</p></caption><table><thead><tr><th rowspan="3">Temperature (°C)</th><th colspan="2" align="center">Radial growth* (mm) after</th></tr><tr><th colspan="2"><hr /></th></tr><tr><th align="center">4 days</th><th align="center">8 days</th></tr></thead><tbody><tr><td colspan="3"><hr /></td></tr><tr><td valign="top">15</td><td align="center" valign="top">6.5</td><td align="center" valign="top">8.1</td></tr><tr><td valign="top">20</td><td align="center" valign="top">19.0</td><td align="center" valign="top">42.9</td></tr><tr><td valign="top">25</td><td align="center" valign="top">30.4</td><td align="center" valign="top">75.3</td></tr><tr><td valign="top">30</td><td align="center" valign="top">49.2</td><td align="center" valign="top">88.9</td></tr><tr><td valign="top">35</td><td align="center" valign="top">43.9</td><td align="center" valign="top">83.4</td></tr><tr><td valign="top">SEm±</td><td align="center" valign="top">1.5</td><td align="center" valign="top">2.5</td></tr><tr><td valign="top">CD (P=0.05)</td><td align="center" valign="top">4.7</td><td align="center" valign="top">8.0</td></tr></tbody></table></table-wrap><table-wrap id="tab001c"><label>Table 1c</label><caption><p>On pH</p></caption><table><thead><tr><th rowspan="3">PH</th><th colspan="3" align="center">Radial growth<xref ref-type="table-fn" rid="tab001c-fn001">*</xref> (mm) after</th></tr><tr><th colspan="3"><hr /></th></tr><tr><th align="center">4 days</th><th align="center">5 days</th><th align="center">7 days</th></tr></thead><tbody><tr><td colspan="4"><hr /></td></tr><tr><td valign="top">4</td><td align="center" valign="top">27.3</td><td align="center" valign="top">48.2</td><td align="center" valign="top">58.0</td></tr><tr><td valign="top">5</td><td align="center" valign="top">50.1</td><td align="center" valign="top">77.6</td><td align="center" valign="top">84.8</td></tr><tr><td valign="top">6</td><td align="center" valign="top">47.8</td><td align="center" valign="top">59.4</td><td align="center" valign="top">77.0</td></tr><tr><td valign="top">7</td><td align="center" valign="top">38.7</td><td align="center" valign="top">52.0</td><td align="center" valign="top">64.5</td></tr><tr><td valign="top">8</td><td align="center" valign="top">31.0</td><td align="center" valign="top">44.5</td><td align="center" valign="top">59.3</td></tr><tr><td valign="top">9</td><td align="center" valign="top">21.0</td><td align="center" valign="top">39.8</td><td align="center" valign="top">48.5</td></tr><tr><td valign="top">SEm±</td><td align="center" valign="top">2.0</td><td align="center" valign="top">1.5</td><td align="center" valign="top">2.1</td></tr><tr><td valign="top">CD (P=0.05)</td><td align="center" valign="top">6.2</td><td align="center" valign="top">4.7</td><td align="center" valign="top">6.4</td></tr></tbody><tfoot><tr><td colspan="4"><hr /></td></tr><tr><td colspan="4"><fn id="tab001c-fn001"><p>* Average of three replications</p></fn></td></tr></tfoot></table></table-wrap></p></sec></body><back><ref-list><title>References

APPS

Annals of Plant Protection Sciences

0971-3573

Society of Plant Protection Sciences

apps-14-2-057

SHORT COMMUNICATION

Physiological studies on Sclerotium rolfsii causing collar rot of chick pea

Tripathi

B.P.

Khare

Department of Plant Pathology, Indira Gandhi Agricultural University, Raipur 492 006, India.

92006

142476477

<p>Chick pea is a leading pulse crop of India, grown in an area of 6.31 million ha with annual production of 5.08 million tones contributing 29% of area and 38.05% of pulse production. <italic>S. rolfsii</italic> causing collar rot is an important soil borne disease. Hence, The present investigation aimed to see the effect of different media, temperatures and pH on the growth of <italic>S. rolfsii</italic>.</p><p>Six media <italic>viz.</italic>, Richard's kerr's, dextrose nitrate agar, rice meal, chick pea meal and PDA were evaluated to find out the best medium for the growth and sclerotial formation of <italic>S. rolfsii</italic>. Twenty ml of medium was poured in each Petri plates. Five mm discs were cut with the help of sterilized cork borer from the margin of a 4 days old pure culture grown on PDA. One disc of the culture was placed in inverted position in the centre of each Petri plates. Observation for mean radial growth were recorded at 4 and 7 days after inoculation at 27±2°C in BOD incubator.</p><p>The study was conducted to find out the most suitable temperature for mycelial growth. The Petri plates poured with PD medium were inoculated with 5 mm disc of the pathogen of a 4 days old culture, incubated at 15, 20, 25, 30 and 35°C. Observation for mean radial growth were recorded at 4 and 8 days after inoculation. The effect of different pH ranging from 4, 5, 6, 7, 8 and 9 on the growth of the pathogen was evaluated on PDA. The pH of the medium was adjusted before autoclaving with the help of digital pH meter, by addition of 0.1 N HCl or 0.1 N NaOH. Twenty ml of medium was poured in each Petri plates. The Petri plates were inoculated with 4 days old pure culture of <italic>S. rolfsii</italic> and Petri plates were incubated in BOD incubator at 27±2°C. Three replications were maintained for each treatment and observations for radial growth after 3, 5 and 7 days interval were recorded.</p><p>The maximum radial growth of <italic>S. rolfsii</italic> was measured on P.D.A. (82.2 & 90.0 mm) at 4 and 7 days after inoculation, followed by chick pea meal agar. rice meal agar and Richards agar media (<xref ref-type="table" rid="tab001a">Table 1a</xref>). Tripathi (<xref ref-type="bibr" rid="bib004">2006</xref>) reported that maltose supported best growth of fungus. The mycelial growth of <italic>S. rolfsii</italic> was significantly higher at 30°C followed by 35°C in 4 and 8 days after inoculation (<xref ref-type="table" rid="tab001b">Table 1b</xref>). Maheshwari <italic>et al.</italic>, (<xref ref-type="bibr" rid="bib002">2000</xref>) reported similar findings on temperature and pH. The mycelial growth of <italic>S. rolfsii</italic> differed significantly at varying pH (<xref ref-type="table" rid="tab001c">Table 1c</xref>). Significantly maximum mycelial growth at 5 and 7 days after inoculation followed by pH 6 and pH 7. Ahamad <italic>et al.</italic> (2000); Sharma <italic>et al.</italic> (<xref ref-type="bibr" rid="bib003">2005</xref>) observed same trends in fungal growth. <table-wrap id="tab001a"><label>Table 1a</label><caption><p>Effect of different media temperature and pH on radial growth of <italic>Sclerotium rolfii</italic></p></caption><table><thead><tr><th rowspan="3">Media</th><th colspan="2" align="center">Radial growth* (mm) after</th></tr><tr><th colspan="2"><hr /></th></tr><tr><th align="center">4 days</th><th align="center">7 days</th></tr></thead><tbody><tr><td colspan="3"><hr /></td></tr><tr><td valign="top">Kerr's Agar</td><td align="center" valign="top">2.4</td><td align="center" valign="top">26.8</td></tr><tr><td valign="top">Dextrose Nitrate Agar</td><td align="center" valign="top">22.3</td><td align="center" valign="top">36.5</td></tr><tr><td valign="top">Richards</td><td align="center" valign="top">60.2</td><td align="center" valign="top">75.9</td></tr><tr><td valign="top">Rice Meal Agar</td><td align="center" valign="top">71.2</td><td align="center" valign="top">80.5</td></tr><tr><td valign="top">Chickpea Meal Agar</td><td align="center" valign="top">79.5</td><td align="center" valign="top">84.3</td></tr><tr><td valign="top">P.D.A.</td><td align="center" valign="top">82.2</td><td align="center" valign="top">90.0</td></tr><tr><td valign="top">SEm±</td><td align="center" valign="top">0.6</td><td align="center" valign="top">0.6</td></tr><tr><td valign="top">CD (P=0.05)</td><td align="center" valign="top">1.8</td><td align="center" valign="top">1.9</td></tr></tbody></table></table-wrap><table-wrap id="tab001b"><label>Table 1b</label><caption><p>On temperatures</p></caption><table><thead><tr><th rowspan="3">Temperature (°C)</th><th colspan="2" align="center">Radial growth* (mm) after</th></tr><tr><th colspan="2"><hr /></th></tr><tr><th align="center">4 days</th><th align="center">8 days</th></tr></thead><tbody><tr><td colspan="3"><hr /></td></tr><tr><td valign="top">15</td><td align="center" valign="top">6.5</td><td align="center" valign="top">8.1</td></tr><tr><td valign="top">20</td><td align="center" valign="top">19.0</td><td align="center" valign="top">42.9</td></tr><tr><td valign="top">25</td><td align="center" valign="top">30.4</td><td align="center" valign="top">75.3</td></tr><tr><td valign="top">30</td><td align="center" valign="top">49.2</td><td align="center" valign="top">88.9</td></tr><tr><td valign="top">35</td><td align="center" valign="top">43.9</td><td align="center" valign="top">83.4</td></tr><tr><td valign="top">SEm±</td><td align="center" valign="top">1.5</td><td align="center" valign="top">2.5</td></tr><tr><td valign="top">CD (P=0.05)</td><td align="center" valign="top">4.7</td><td align="center" valign="top">8.0</td></tr></tbody></table></table-wrap><table-wrap id="tab001c"><label>Table 1c</label><caption><p>On pH</p></caption><table><thead><tr><th rowspan="3">PH</th><th colspan="3" align="center">Radial growth<xref ref-type="table-fn" rid="tab001c-fn001">*</xref> (mm) after</th></tr><tr><th colspan="3"><hr /></th></tr><tr><th align="center">4 days</th><th align="center">5 days</th><th align="center">7 days</th></tr></thead><tbody><tr><td colspan="4"><hr /></td></tr><tr><td valign="top">4</td><td align="center" valign="top">27.3</td><td align="center" valign="top">48.2</td><td align="center" valign="top">58.0</td></tr><tr><td valign="top">5</td><td align="center" valign="top">50.1</td><td align="center" valign="top">77.6</td><td align="center" valign="top">84.8</td></tr><tr><td valign="top">6</td><td align="center" valign="top">47.8</td><td align="center" valign="top">59.4</td><td align="center" valign="top">77.0</td></tr><tr><td valign="top">7</td><td align="center" valign="top">38.7</td><td align="center" valign="top">52.0</td><td align="center" valign="top">64.5</td></tr><tr><td valign="top">8</td><td align="center" valign="top">31.0</td><td align="center" valign="top">44.5</td><td align="center" valign="top">59.3</td></tr><tr><td valign="top">9</td><td align="center" valign="top">21.0</td><td align="center" valign="top">39.8</td><td align="center" valign="top">48.5</td></tr><tr><td valign="top">SEm±</td><td align="center" valign="top">2.0</td><td align="center" valign="top">1.5</td><td align="center" valign="top">2.1</td></tr><tr><td valign="top">CD (P=0.05)</td><td align="center" valign="top">6.2</td><td align="center" valign="top">4.7</td><td align="center" valign="top">6.4</td></tr></tbody><tfoot><tr><td colspan="4"><hr /></td></tr><tr><td colspan="4"><fn id="tab001c-fn001"><p>* Average of three replications</p></fn></td></tr></tfoot></table></table-wrap></p></sec></body><back><ref-list><title>ReferencesAhamad

Agarwal

D.K.

Naram

Udit

Chauhan

S.S.

(2002). Effect of temperature, pH, light and inoculation period on growth, sporutation biomasss and gibberalic acid production. Ann. Pl. Protec. Sci.10: 343–348.Maheshwari

S.K.

Singh

D.V.

Singh

S.B.

(2000). Effect of temperatures and pH on growth and sporutation of Alternaria alternata causing Alternaria leaf spot of dolichos bean. Ann. Pl. Protec. Sci., 8: 33–35.Sharma

R.L.

Singh

B.P.

Thakur

M.P.

Thapak

S.K.

(2005). Effect of media, temperature, pH and light on the growth and speculation of Fusarium oxysporum of sp. lini.Ann. Pl. Protec. Sci., 13: 172–174.Tripathi

S.K.

(2006). Effect of media, pH, nitrogen, carbon sources and light on the growth and sporulation of Pyricularia grissea. Ann. Pl. Protec. Sci.14: 166–168.