Influence of pinnae position, leaf age and some fungicides on the development of graphiola leaf spot on date palm

الملخص EN

Fifteen date palm (Phoenix dactylifera L.) cultivars were evaluated against leaf spot or false smut caused by Graphiola phoenicis (Mung.) Poit.

The % infection and number of sori caused by Graphiola were compared in relation to leaf age and pinnae position on leaves.

Most of the cultivars did not express disease symptoms on their one year old leaves.

However, significant correlations between % infection and number of sori for second and third year old leaves were established.

Correlation studies and ‘t’ test revealed that recording disease severity on middle and basal position of pinnae and second year old leaves represent a better indicator for evaluation of cultivars against Graphiola leaf spot.

Thus, cultivar ‘Abdul Rehman’ and ‘Muskat no.

2’ were found to be the most tolerant while ‘Bint Ashia’ and ‘Pakistan’were categorised as highly susceptible to Graphiola infection.

On the basis of minimum apparent infection rate (r), four sprays of carbendazim + mancozeb (0.1+0.3%) or copper oxychloride (0.2%) at an interval of 30 days starting from November were found significantly superior in controlling Graphiola leaf spot on a susceptible cultivar ‘ Halaway’