Effect of organic and biological fertilizers on pomegranate trees: yield, cracking, sunburning and infestation to pomegranate fruit moth Ectomyelois ceratoniae (Lepidoptera: Pyralidae)

To investigate the effect of different fertilizers on yield and health related traits of pomegranate fruit, a field experiment was carried out during 2014 and 2015 seasons on six years old pomegranate trees cv. ‘Bajestani’ growing in sandy loam soil under drip irrigation system in Khalilabad city, Khorasan, Iran. Organic fertilizers including: cow manure (25 kg/tree), vermicompost (5 kg/tree), and granulate humic (2 kg/tree) were applied without or with biofertilizers (azetobarvar, phosphobarvar and potabarvar at 1 liter/tree) by placement method. Results showed that plants treated with combination of organic and biofertilizers had higher yield and lower fruit drop than plants treated with organic fertilizers individually. The lowest fruit cracking (7.5%, 2.25%) as well as fruit infestation with Ectomyelois ceratoniae (Zeller) (27.5%, 25.34%) were observed in the plants treated with both biofertilizers and humic in 2014 and 2015, respectively. The most infestation to E. ceratoniae was observed in control treatment (38.07%, 31.44%) in both years, respectively. Fruit sunburn was not affected by nutrition of any type in both years. Results of leaf analysis revealed that plants treated by a combination of biofertilizer and humic had higher levels of macro and micronutrients compared with untreated plants. Altogether, our results suggest that biofertilizer in combination with organic fertilizers, especially granular humic, could be used in pomegranate orchards management to improve pomegranate yield, as well as to prevent crop losses resulting from cracking, nutrient deficiency and E. ceratoniae infestation.