بررسی تأثیر تغذیه در کاهش بیماری آنتراکنوز درختان گردو

The interaction between plants and pathogens can be influenced by multiple factors such as nutrients. Nitrogen (N) is an essential macronutrient for plant normal growth, development and resistance to abiotic and biotic stresses. For evaluation the effect of nutrition on severity of walnut anthracnose, an experiment was conducted based on a randomized completely design with 3 replications under controlled environmental conditions. Walnut seedlings were sprayed monthly with 100 ml of nutritional solutions (nitrogen, nitrogen + phosphorus, nitrogen + potassium, nitrogen + phosphorus + potassium) from April through December 2022. Leaf samples for chemical analysis were obtained prior to inoculation. Then seedlings were inoculated with spore suspension 2 × 105 spores ml−1 and maintained in controlled environmental conditions (temperature 20-22 ° C, humidity > 75% and followed by 12h photoperiod). Traits such as number of infected leaves, number of infected spots, percentage of infected leaf area, presence or absence of acervulus and its number, diameter of diseased spots and disease index were used as criteria to evaluate the severity of walnut anthracnose. Analysis of variance showed significant difference between of treatments in all of the studied traits (P<0.001). Use of nutrition compared to lack of nutrition, reduced the severity of anthracnose. The number of anthracnose lesions, percentage of infected leaf area and disease index decreased as the nitrogen content of black walnut leaves increased. The results of this research can be used as a basis for further research and selection of suitable nutritional regime for walnut trees to increase the quantitative and qualitative yield and reduction severity of walnut anthracnose.