pistachio

Guidelines for California Pistachio Growers

2009 Edition

California Pistachio Research Board

ABSTRACT: Different methods have been applied to recycle pistachio’s green hulls, the most important of which are siloing and drying pistachio hulls (using industrial dryers). In both methods, hulls should lose their initial moisture content, which constitutes a considerable portion of their weight. The high moisture content takes more time and energy during the drying process. The initial dewateringof hulls – pretreatment – could greatly contribute to improving the drying process.

Abstract

This report focuses on eight fruit crops (apricot, avocado, mango, fig, litchi, peach, nectarine, and pistachio) and two vegetable crops (artichoke and sweet potato). The requirements for each crop including climate, soil and water are listed in Appendix I. Some of these crops (i.e. apricot, peach, nectarine, and pistachio) require a specific chilling period to stimulate fruiting. Since different varieties have different chilling requirements, care must be taken to select the right variety for each area according to their chill hours.

In recent years, one of the most important problems of pistachio growing is increasing the salinity of soil and water which has decreased the quality and quantity of this crop. In this study, the effect of different levels of salinity on growth of pistachio rootstock cv. Badami Zarand has been evaluated. Pistachio seeds were planted in pots containing loamy sand soil and the salinity treatments were performed four weeks after germination.

Irrigation is a required management practice in pistachio nut production for higher quality and quantity. A proper irrigation management technique that maintains an optimum soil moisture and environment in the root zone increases yield of the pistachio nut tree. Since pistachio tree on the Pistacia vera rootstock does not tolerate excess water in the root zone, over-irrigation must be avoided. In the determination of water requirement of pistachio tree, pan evaporation is commonly used due to its simplicity.

ABSTRACT: Pistachio fruit components, including hulls (mesocarps and epicarps), seed coats (testas), and kernels (seeds), all contribute to variable aflatoxin content in pistachios. Fresh pistachio kernels were individually inoculated with Aspergillus flavus and incubated 7 or 10 days. Hulled, shelled kernels were either left intact or wounded prior to inoculation. Wounded kernels, with or without the seed coat, were readily colonized by A. flavus and after 10 days of incubation contained 37 times more aflatoxin than similarly treated unwounded kernels.

ABSTRACT: A survey of the fungal contamination and occurrence of aflatoxins and ochratoxin A (OTA) in 50 pistachio nut samples collected from commercial stores around Catalonia (Spain) was carried out. Aspergillus flavus was found in 30% of samples, whereas Aspergillus section Nigri, Aspergillus ochraceus, and Penicillium verrucosum were found in 40%, 2% and 26% of samples, respectively. A total of 204 fungal isolates were obtained; 70.8% of A. flavus isolates were able to produce aflatoxin B1 and B2, whereas OTA production capacity was detected in 54.4% of the A.