MINERAL ELEMENTS CONCENTRATION IN HEALTHY AND INFECTED DATE BUNCH FADING DISORDER

Date bunch fading is a new disorder that caused heavy damage to the Iran’s date palm plantations in recent years. It was first reported from Kahnodge area in Kerman province on the ‘Mozafati’ cultivar in 1989 and gradually distributed to the other main date producing provinces such as Hormozgan, Bushehr, Sistan and Baluchestan, Fars and Khuzestan. This disorder is often observed on soft and mid-ripening cultivars such as ‘Mozafati’, ‘Kabkab’, ‘Mordaseng’, ‘Kalotae’, ‘Sayer’, ‘Barhee’, ‘Khasee’, etc. Unfortunately most of these cultivars are trading and prevailing cultivars of Iran. Due to the high economic importance of this disorder many projects have been carried out in different fields in order to determine the causal agent. One of these projects was determination of nutrient elements in leaf and fruit of healthy and infected date palm to date bunch fading. In this study two orchards were selected and twenty 15-years-old trees of date palm (‘Khasee’) were used from each orchard. Fruit samples were collected at 6 stages, each stage consisting of 25-30 fruits at random basis from each date palm from 20th June to 15th Aug. Leaf samples were collected at 4 stages, each stage consisting of 25-30 leaflets consisting of sampling the middle pair of leaflets from the second row leaves on the mid position of rachis at random basis from each date palm from 30th March to 15th Aug. Then they were transported from the orchard to the laboratory. Healthy and disordered date palms were distinguished in the orchard after incidence of disorder. Due to the number of samples and different infection on each palm (the infection percent was 0 to 100) samples in a relation of 6 completely infected and 6 completely healthy date palms were analyzed for the concentration of nutrients such as N, P, K, Ca, Mg, Fe, Cu, Zn and Mn. The concentration of mineral elements in healthy and infected date palms were compared with the T-test with MSTATC and the fluctuation of mineral nutrient concentration was graphed. The results showed that:

• From the observed concentrations it showed that healthy date palms had a significantly higher concentration of P, K and Zn of fruit and P of leaf than the infected date palms.
• Although there were no significant differences in N, Fe, Cu and Mn of fruit and N, K, Fe, Zn, Cu and Mn of leaf in healthy and infected date palms, the graphs showed that healthy date palm had higher N, Fe, ZN and Cu of fruit, Cu of leaf and lower Mn concentration of leaf and fruit than infected date palms.