نشریه علوم و فناوری پسته
پیاپی 13 (پاییز و زمستان 1401)

Gummosis (Phytophthora Crown and Root Rot) is one of the Most Important Diseases of Pistachio Trees. In Order to Evaluate the Relative Resistance of 29 Rootstocks of Pistacia to this Disease, a Factorial Experiment was Conducted with Two Factors Rootstocks Type and Disease Stress, Based on Completely Randomized Design with Three Replications. Two-Month-old Pistachio Seedlings were Artificially Inoculated with Phytophthora Drechsleri and After Six Months, Evaluation Was Done. The Resistance of Rootstocks was Evaluated by Determining the Percent of Crown Rot Girdling, Disease Severity and Mortality Indices and Measuring the Stem Length, Stem and Root Dry Weight Traits in Control and Stress levels. The Results Showed that There was a Significant Difference Between the Studied Rootstocks in Terms of Resistance to Disease. The Disease Stress Caused a Decrease in Stem Length, Stem and Root Dry Weight of Seedlings. The Atlantica Had the lowest Amount of Crown Girdling (20%) and Disease Severity (17%) and in Terms of Disease Severity, it Showed a Significant Difference with other Rootstocks. The Sarakhs Rootstock Had also the Highest Amount of Crown Girdling (95%), Disease Severity (90%) and Mortality (55.55%) and in Terms of These Indices, it was Significantly Different from other Rootstocks. Therefore, Atlantica was the most Resistant and Sarakhs the most Susceptible Pistacia Rootstocks Against Gummosis Disease. The Cluster Analysis Divided the Rootstocks into Four Groups: Resistant (Atlantica, Integerrima and UCB1), Moderately Resistant (Mutika, Benebaghi, Kalleghouchi, Ghazvini, Gholamrezaei, Italiaei, Ahmad Aghaei, M5 and BK1), and Moderately Susceptible and Susceptible .

This research was carried out in order to identify healthy pistachio plant from stressed varieties by using Sentinel 2A satellite image of MSI sensor and Landsat 8 sensor of OLI satellite in Varamin city. Satellite images help to identify a healthy plant by using the reflection of electromagnetic waves in the apparent structure of the plant. The amount of this reflection varies depending on the leaf surface, type of disease, vegetation density, distribution and vegetative state of the plant during a year. In the current research, NDVI, NDRE, NDMI, and SAVI indices were used in the two months of May and August during the years 2015-2016 as a factor in describing the vegetation status. In the first stage, the images related to the study area were prepared and the desired layers were placed on top of each other in the GIS environment. In the next step, using the artificial neural network algorithm, the studied area was classified into three parts: pistachio, non-pistachio and soil, and continued research on the pistachio area. Then the correlation of NDVI with other three indices was calculated in four specified times. The results showed that in May, there was a correlation of 0.9819 between SAVI soil index and NDVI freshness index compared to August, and this value was higher than the other two indices in both years. Considering that an increase in the SAVI index indicates a decrease in the freshness of vegetation, this index can be used to evaluate the health of pistachio orchards.

To study the effect of arbuscular mycorrhizal fungus on salt resistance of UCB1 pistachio rootstock, a greenhouse experiment was achieved as factorial based on a completely randomized design with two factors of arbuscular mycorrhiza at two levels (with and without mycorrhiza) and water salinity at four levels (EC0.5 as control, EC5, EC10 and EC15 dS.m-1) with five repetitions. 18-month-old UCB1 plants propagated by tissue culture were obtained from Touba company in Kerman and inoculated with Funneliformis mosseae. Plants were grown for 70 days in greenhouse conditions (30±3 ºC and 32% of average relative humidity) and after ensuring of root colonization, they were subjected to salt stress for two months. The results showed that salinity caused a decrease in dry weight, stem height, number and surface of leaves, relative water content of leaves and phosphorus, potassium and magnesium uptake, while the amount of proline and total soluble sugars, sodium and chloride in leaves and roots were increased compared to control. Root symbiosis of UCB1 seedlings with arbuscular mycorrhizal fungus significantly mitigate the adverse effects of salinity stress compared to non-mycorrhizal seedlings. Root colonization of UCB1 pistachio seedlings was decreased under salinity stress. Based on the results, the inoculation of UCB1 plants with the above arbuscular mycorrhiza led to increase in salt stress resistance.

This study was conducted with the aim of investigating the role of ventilation in reducing the spoilage of fresh pistachios during transportation from orchard to the terminal. Pistachio prepared from Ahmad Aghaei variety (10 kg) were stored in two different conditions with a plastic mesh basket (with ventilation) and a non-mesh plastic basket (without ventilation). The changes in temperature, humidity, weight loss, the amount of mold and fungus were investigated during 4 days of storage of pistachio samples. Also, the sensory evaluation of the samples (in terms of color, appearance, taste and flavor) was done by the evaluators using QDA* method. The results of this research showed that all the selected parameters of the two treatments during 4 days (including temperature, humidity and weight loss, the amount of mold and fungus), have a significant difference (p ≤ 0.05). highest temperature during 4 days related to the non-mesh basket was 21°C on the fourth day and the lowest temperature was 16.9°C in the mesh basket on the second day. The highest weight loss was observed in the mesh basket on the fourth day of storage. on the fourth day of storage, the number of fungi and mold was 326.5 and 320 in the mesh basket and 650 and 675.5 in the non-mesh basket, respectively. The score of sensory features of the mesh basket in terms of appearance (8), taste (10.9), color (11.7), texture (9.9) and smell (10.6), was significantly better than non-mesh basket (respectively 6.4, 8.7, 8.9, 8.3 and 9.1) (p≤0.05).

Pistachio are one of the strategic and important horticultural products. In order to increase the quantitative and qualitative characteristics of pistachio trees, foliar spraying with vitamins is done in order to remove the limitations during the growth stages. The present study was conducted as a factorial experiment based on a randomized complete block design with 5 treatments and 4 replications. The treatments included vitamin thiamine with concentrations of 200 and 400 µ/l and niacin of 250 and 500 µ/l, and trees that were not given any of the above treatments were considered as controls. Foliar spraying was done in two stages (the first stage, 30 days after flowering and the second stage, 45 days after flowering). Characteristics such as leaf area, chlorophyll index, percentage of indehiscent, percentage of deformed fruits, fruit weight, number of fruits per cluster, cluster weight and yield were studied. The results showed that as a result of using thiamine 400 µ/l and niacin 500 µ/l, leaf surface, chlorophyll index, smile, fruit weight, number of fruits per cluster, cluster weight and yield at the stage of 45 days after full flower increased. Also, the percentage indehiscent, the percentage of blankness, and the percentage of deformed fruits have decreased as a result of the use of treatments.

Common pistachio psylla is one of the first-rate pests of pistachios and one of the native pests in pistachio farms in Iran and neighboring countries. The spread and outbreak of this pest requires a review of chemical control to reduce the consumption of pesticides, as well as the identification and use of environmentally friendly non-chemical methods. In this research, the effect of the natural biochar on activating the defense responses of pistachio trees and the feasibility of inducing resistance to control pistachio psylla was investigated by comparing the changes in the density of eggs and nymphs in different leaf levels during two generations. Changes in activity of catalase and peroxidase and non-enzymatic plant defense were investigated. The density of eggs and nymphs affected by the application of biochar decreased significantly from the seventh day onwards compared to the control and reached its lowest level on the twenty-eighth day. In connection with the change in the density of the nymphs, the eta value in the Wilks' Lambda test for the interaction effect of time and treatment was determined as 0.129. The amount of silicon accumulated in the leaves affected by biochar foliar application as an effective physical defense increased by 1.1 times after 48 hours and subsequently by 1.4 times after 14 days compared to the control treatment. Based on the obtained results, the use of biochar can create direct defense and induce resistance of pistachio trees to pistachio psylla by increasing the level of factors inhibiting nutrition and spawning.