ISHS Acta Horticulturae 726: IV International Symposium on Pistachios and Almonds
EFFECT OF PREHARVEST SPRAYING OF PISTACHIO TREES WITH SODIUM DIACETATE AS MOLD INHIBITOR |
| Authors: | M.H. Fooladi, A.G. Tafti |
| Keywords: | aflatoxin, early split nuts, tattered nuts. |
| Abstract:
The purpose of this study was to determine the efficacy of sodium diacetate as mold inhibitor to prevent aflatoxin contamination of early split and tattered pistachio nuts in orchard. The experiment was carried out in a well-managed orchard located at Rafsanjan. The experimental design was split plot with completely randomized block design, with three replicates. The whole plot consisted of time of spraying (45 days and 20 days prior to harvest) and sub-plots consisted of the dosage of mold inhibitor, 1-control (without any spray) 2- spraying with pure water 3- spraying with 0.4% ( w/v) sodium diacetate solution in water. At harvest time from each experimental unit the total number of nuts, unsplit, blank, natural nuts (with intact hull), early split, tattered with smooth hull, tattered with dry and shriveled hull nuts were counted and recorded as percentage. Early split, normal split nuts and tattered nuts were collected for aflatoxin analysis. Aflatoxin analyses were done by TLC Scanner. The results indicated that 45 days prior to harvest spraying pistachio trees with 0.4% sodium diacetate solution significantly (p<5%) reduced early split and tattering of nuts. The same results were obtained with spraying with water; water spray was much more effective even than sodium diacetate solution. Spraying the trees with water 20 days before harvest significantly reduced tattered nuts with smooth hulls. The time of spray did not have significant effect on the variables measured except spraying 45 days before harvest that increased split nuts significantly. Aflatoxin analyses of samples revealed that, in both water and sodium diacetate treated samples, spraying caused to increase aflatoxin contamination compaired to control group. Spraying with sodium diacetate was more effective in increasing aflatoxin formation in early split nuts than water spray. Spraying 45 days before harvest increased aflatoxin content of early split nuts which occur earlier in season, whereas, spraying 20 days prior to harvest increased aflatoxins of tattered nuts with smooth hulls that occur near the harvesting period. At this time, our results do not support recommending that growers change cultural practices, such as use of sodium diacetate or type of irrigation prior to harvest. | |
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