Pest and disease control in almond trees

Recommendations for pest and disease control of this article are based on integrated pest management. The article includes pictures of the symptoms and signs of the main diseases described. Tables I and II include the active ingredients authorized in Spain to control the pests and diseases described. Tables III and IV include authorized insecticides against mites.
 

DISEASES

• Phomopsis canker or fruit rot (Phomopsis amygdali). Autumn infections. It attacks the end part of the shoots. Control: infected trees should be pruned the last ones and infected shoots should be burnt, protect wounds after almonds harvest. The most susceptible varieties are Alicante, Antoñeta, Constantí, Ferragnes, Francolí, Guara, Llargueta, Marcona, Ramillete, Tuono and Pauet.
• Almond red leaf blotch (Polystigma ochraceum). It can cause severe defoliations. Control: the most susceptible varieties are Guara, Tarraco, Francolí, Masbovera and Tuono. Ferragnes, Constantí, Vayro and Farraduel seem to be less attacked. Chemical control (Table I).
• Brown rot (Monilia laxa). Trees become infected at blooming if it rains and on susceptible varieties. It can affect fruits and shoots. Control: the most susceptible varieties are Marcona, Llargueta and Francolí. It is recommended to retrieve mummified fruits. Chemical control before blooming (table I).
• Xanthomonas arboricola pv. Pruni. It is a quarantine disease within the European Union so any infected tree detected must be destroyed. It is recommended to use clean plant material for new plantations.

PESTS

• Aphids: mainly the green aphid (Myzus persicae and M. varians), the mealy aphid (Hyalopterus amygdali) and the peach black aphid (Pterochloroides persicae). Control: an excess of vigour of trees should be avoided (rationalization of fertilizer applications), chemical control: to control the green aphid, trees should be sprayed at the end of blooming if aphids are present in 5% of the shoots. The mere presence of the peach black aphid is enough to spray (table II).
• The Mediterranean flathead root borer (Capnodis tenebrionis). It is common in drip-irrigated areas. It can cause severe damage in young orchards. Control: substitute hybrid rootstocks by European rootstocks, install physical barriers to prevent egg laying on the trunck, biological control with entomopathogenic fungi (Beauveria bassiana and Metarhizum anisopliae) or nematodes.
• Bark beetles mainly from the genera Xyleborus and Scolytus. They are mainly present in not taken care off plantations. Control: retrieving and burning the infected rests of the pruning.
• The lace bug Monosteira unicostata. Sucking insect which can cause tree defoliation. Adults overwinter on the trunk. Control: if it is observed in winter it can be sprayed with tau-fluvinate. After blooming, spray when <10% of the shoots are occupied. Larvae spraying must be done in spring (table II).
• Caterpillars ( Aglaope infausta and Ectomyelois ceratoniae). Control: spray with Bacillus thuringiensis, deltametrine or Lambda-cihalotrine. The control threshold is the mere presence.