Pest Management Of Apple Farmers

In Morocco, apple orchards cover a surface area of about 48,671ha. In 2016, apple production was approximately 686, 964 metric tons with an average yield of 20t/ha (Anonymous, 2017 as cited in Khoudane, 2018). This sector generates 3 million working days, and about 10 billion dirhams of annual turnover for the country (Alami, 2017). The main production areas are located in the mountainous regions of the Middle and High Atlas.

Nearly 50% of the area is concentrated in the region of Meknes-Tafilalet. There are about 39,000 apple farmers nationwide and 79% of them have very small orchards (less than 1ha) (MADRPM, 2014). Apples are subject to more than 70 plant diseases, of which the vast majority is caused by pathogenic fungi. The most common diseases are apple scab (Venturia inaequalis), powdery mildew (Podosphaera leucotricha), tree root rot diseases (Phytophthora spp. ) and fire blight (Erwinia amylovora). In apple-producing regions, disease control is a major annual expense for farmers. Several diseases such as apple scab caused by V. inaequalis have been extensively studied worldwide (Ferree and Warrington, 2003). The insect pest damage caused to apple trees in Morocco is mainly due to codling moth Cydia pomonella L. (Lepidoptera, Tortricidae); aphids, especially Aphis pomi de Geer (Homoptera: Aphididae); spider mites represented by Panonychus ulmi Koch (Acari: Tetranychidae) and Tetranychus urticae Koch (Acari: Tetranychidae); and San Jose scale, Quadraspidiotus perniciosus Comstock (Hemiptera: Diaspididae) (Vicente et al, 2003). Weeds and other flora compete with apple trees for nutrients and water, especially in newly established orchards (Walsh et al, 1996). Meteorological conditions are important environmental factors affecting apple quality. Adverse weather conditions cause water shortage, low chilling requirements, hailstorms and frosts. As a result, fruit quality is compromised by physical injury and reduced leaf area. In addition, the risk of pathogen penetration via injury is greater.

Alternating periods of high and low temperatures in winter disrupt bud dormancy and the process of flower differentiation (Maazouz, 2016). Moreover, extreme climate events such as freeze injury during the blooming period as well as high temperature and heat during the swelling period can directly affect apple quality (Qu and Zhou, 2016). Insufficient chilling greatly influences flower initiation and fruit coloration along with deterioration in fruit texture and taste. Further, lack of proper chilling is also posing serious problems like scab disease, premature leaf fall and infestation of red spider mite in apple (Rai et al. , 2015). With regard to pest control, it is difficult to establish a calendar-based treatment for all situations (Oukabli, 2004).