Abdul M. Lodhi

FIRST REPORT OF PANAMA WILT DISEASE OF BANANA CAUSED BY FUSARIUM OXYSPORUM f. sp. CUBENSE IN PAKISTAN

In Pakistan, Dwarf Cavendish bananas are grown on 30.000 ha with an annual production of 141.200 tons. In 2012-13, bananas grown in the district of Thatta (Sindh province) came down with an unknown disease, which was also observed in the Hyderabad region. Severely affected plants showed a conspicuous yellowing, followed by their death. Cross-sectioned pseudostems disclosed the presence of reddish-brown to dark-brown discolouration of vascular tissues and rhizome. Fruits had a reduced size. Isolations carried out on PDA from pseudostem, rhizome and roots yielded the consistent recovery of Fusarium oxysporum f. sp. cubense, the agent of Panama disease, which was identified based on morphology of: (i) macroconidia, sickle-shaped mostly 3 septate (occasionally 5 septate), pointed at both ends, 30-60x3-5 μm in size, borne on single phialides; (ii) microconidia, kidney shaped, without septation, produced on false heads, 5-12x3-5 μm in size. The optimum temperature for colony growth and sporulation was 25°C and 30°C, respectively. For pathogenicity tests, 12-week-old banana plantlets of cv. Basri were inoculated with 30 ml of a conidial suspension (106 conida/ml). Wilt symptoms developed after 45 days on the inoculated plants from which the same fungus used for inoculation was recovered. Thus, Pakistani banana plantations are affected by Panama wilt, a devastating disease that has damaged thousands of hectares of banana plantations in different parts of the world (Ploetz, 2000). The cultivation of banana in Pakistan is at high risk, as Panama wilt has the potential to cause losses similar to those induced by the epidemic of banana bunchy top disease, which virtually eradicated banana cultivation from the Sindh in 1980s (Khalid et al., 1993).

In vitro evaluation of various fungicides against Fusarium solani isolated from Dalbergia sissoo dieback

1 Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China. 2 Department of Plant Pathology, Sindh Agriculture University, Tandojam, Pakistan. 3 Department of Plant Pathology, Lasbela University of Agriculture, Water and Marine Sciences, Uthal, Pakistan. 4 Dates value Addition Project, Khairpur Mirs, Pakistan Agricultural Research Council, Islamabad, Pakistan.

Effect of neem (Azadirachta indica) products on seedling growth of shisham dieback

In present study, the efficacy of different neem (Azadirachta indica A. Juss) products namely neem oil, neem seed decoction, neem seed without coat, neem seed coat and neem leaf extract were tested for in vitro growth of shisham seedlings inoculated with Fusarium solani isolated from shisham dieback. Two concentrations (5 and 15%) of each neem product were used in the study. Three different methods were employed for neem products application that is, spray, direct mixing in soil and injected at root zone of shisham seedlings. Neem products used as spray increase the growth of inoculated shisham seedlings as compared to injected at root zone or mixed with soil. Neem oil (15%) used as spray increased root and shoot length and weight of inoculated shisham seedling (28.667 and 34.000 cm) (2.300 and 2.966 g) followed by neem seed decoction (25.000 and 29.667 cm) (1.967 and 2.566 g), neem seed without coat (22.667 and 28.333 cm) (1.867 and 1.900 g) and neem leaf extract (19.000 and 27.667 cm) (1.600 and 1.800 g) as compared to untreated and inoculated shisham plants (0.332 and 0.766 g), respectively. All the neem products showed significant reduction in the growth of shisham seedlings. Neem oil, neem seed decoction, neem seed without coat and neem leaf extract also decreased percent disease intensity as compared to untreated control. The results showed that neem products have potential for the management of shisham dieback.