The effect of cultivar, chitosan and storage period on qualitative charactetristics of date palm fruits (phoenix dactylifera l.) And their infection with the saw-toothed grain beetle

Abstract

A storage experiment was carried out to study the the role of chitosan in controlling the infection of three date palm cultivars (Phoenix dactylifera L.) which were Bream, Khalas and Habssi with saw-toothed grain beetle (Oryzaephilus surinamensis L.). As samples were prepared from dates infected with the beetle from one of the dates stores in the province of Basrah and were identified in the department of plant protection at the faculty of Agriculture University of Basra. Beetles were bred under the laboratory conditions. Three cultuvars of dates (Bream, Khalas and Habssi )were prepared and dipped in three concentrations of chitosan (0%, 1%, 2%) then put in cork packages. Fruits were polluted by the beetle from the colony which was prepared beforehand and then stored at room temperature starting from 5/1/2017 for four months. A factorial experiment was designed from three factors: cultivars, chitosan treatments and storage periods using Complete Randomized Design( CRD) with three replicates. The most important results showed the superiority of Habbsi in the controlling of the beetle, the loss of weight of fruits and the high content of the fruits of the total soluble solids. The highest percentage of weight loss was in the fruits of the Bream cultivar. The results indicated that the treatment with 2% chitosan was the best in reducing the percentage of beetle infection and the percentage of weight loss of fruits. The results showed that the loss of weight and total soluble solids increased with the increment of storage periods. The results of the statistical analysis indicate that the highest percentage of total soluble solids was recorded in the non-chitosan treated fruits of Habbsi date palm cultivar after four months of storage.