to estimate the Damage and economical evaluation o various control technique o ZeuzerapyrinaL in walnut trees

Zeuzera pyrina L. is one o the most important borer pests in our country. Pest damage started expanding rom the second decade o the seventies due to the occurrence o successive droughts. This pest has signiicant hosts among the ruit trees. Pome trees like apple, pears and quince are the most important hosts. The other host tree is walnut. The scope o the damage is currently higher in eastern and central province in the country. Pest damage starts with dryness at the tip o the branches, and then reduction in the yield and inally complete dry up o the host tree. Thereore, the damage caused, taking into account the cost o re-cultivation and the time required or economically proitable ruit production would be very high. Thus reduction o the damage and spread o this pest in the country is very important. One o the most important aspects o the pest management is determination o the economical injury level and presentation o optimum management strategies to reduce it. The present study was undertaken in two parts to gain access to this important issue and to select the most eicient, eective and economical strategy. During the on arm survey, ater choosing the pioneer armers, inormation was collected by two staged cluster sampling method using questionnaires and technical investigations in two stages during the cultivation year. The quantity o damage and economical evaluation o various control measures by partial budgeting was perormed using the method o estimation o unctions and statistical analysis. The beneit and cost ratio showed that all the treatments under investigation are economically justiied. The least o them that is the integrated use o chemical compounds and recision was 1.53. The most eicient treatment in controlling the damage was the integrated use o sex pheromone and chemical control which was about 69% in Kerman Province and the least was o recision o the twigs in south Khorasan province. Priority investment analysis showed that the method o integrated use o sex pheromone and chemical control, chemical control, integrated use o chemical control and recision o twigs and eventually the method o recision o twigs were ranked rom 1 to 4 in the two provinces under investigation