Pistachio Yield Research Articles

Soil and Groundwater Relationships with Pistachio Yield in the Rafsanjan Area, Iran

This study was conducted to examine the spatial variability of groundwater quality factors and to determine soil physicochemical properties in order to distinguish their relationships with pistachio yield in the Rafsanjan area, Iran. One hundred fifty-seven water samples from the wells of the studied area were evaluated for electrical conductivity (EC), sodium (Na+), calcium (Ca2+), magnesium (Mg2+), sulfate (SO4 2–), bicarbonate (HCO3 –), chloride (Cl–), total hardness, and sodium adsorption ratio (SAR). Groundwater levels of the wells were also recorded. The EC and SAR values of groundwater for some of the wells separately compared with pistachio yield in the orchards irrigated with these wells. Six pistachio gardens with the same management but in different parts were selected, and each garden was divided in two (desired and undesired) parts. In each part of these orchards, soil samples were randomly taken in three replicates from depths of 0–40 and 40–80 cm to determine soil properties. One soil profile was also excavated for soil classification in each part of these gardens. Groundwater in most of the area had EC > 8 dS m–1 and SAR ≥ 13 (meq L–1)0.5. The lowest qualities of groundwater were found in the eastern, southern, and the northern parts of the area, where water's negative effects on pistachio yield have been reported. Statistical results for selected gardens showed that pistachio yield was affected considerably by salinity and clay content of the soils. Modern irrigation techniques and mixing high-quality water with poor-quality water in the area is necessary to prevent the reduction of the water table in the area. Preparing continuous soil salinity and texture maps are recommended for proper pistachio management in the area.

THE EFFECTS OF VARIOUS FOLIAR FERTILIZERS ON THE TREE DEVELOPMENT, YIELD AND NUT QUALITY IN PISTACHIO

The objective of the study was to determine the effects of different foliar fertilizers on tree development, fruit yield and quality in pistachio cv. Siirt. The experiment was conducted at the Nut Research and Application Center (SEKAMER) of Kahramanmaras Sutcu Imam University-Turkey. In the experiment Flora-x, G-Leonardit, G-Helke, G-Potajell and urea were sprayed on pistachio trees. The foliar fertilizer treatments did not significantly affect the average length and diameter of pistacho shoots. Number of fruit buds in the following year were improved by the fertilizer treatments (except urea). Wider canopies were also obtained by some of the fertilizer treatments. Flora-x and G-Leonardite apperared to be the most effective treatments in improving the weights of fresh nuts with hull. Foliar fertilizers also affected the width, length and height of fresh nuts. All foliar fertilizers improved the splitting percentages of the pistachio cultivar. Also, foliar fertilizers increased the weight of 100 nuts with shell. Flora-x and G-Leonardite consistently increased the width, length and height of nuts compared to other fertilizers or control treatment. The last two foliar fertilizers also positively affected the kernel weight of nuts. As in other fruit species, foliar fertilizer application is needed for increasing the pistachio yield and nut quality.

Spatial Variability of Groundwater Quality and its Relationship with Pistachio Yield in Anar Region, Iran

Spatial Variability of Groundwater Quality and its Relationship with Pistachio Yield in Anar Region, Iran

Shoot Preformation and Neoformation in Pistachio: Influences on Bearing Habit and Yield Components

Rootstock significantly alters the pattern of shoot growth of pistachio (Pistacia vera) cv. Kerman. Trees grown on P. atlantica typically produce a single flush of spring growth, whereas trees on P. integerrima selection PGI and P. atlantica × P. integerrima selection UCB-1 can produce multiple flushes during the season. We have shown that the spring flush is entirely preformed in the dormant bud for all three rootstocks, but later flushes are neoformed, that is, nodes are initiated and extended during the same season. Shoots producing both preformed and neoformed growth have lower yield efficiency than those producing only preformed growth. Additionally, yield components of the crop from shoots with both preformed and neoformed growth was different than for shoots producing only preformed growth. However, these differences do not appear to be significant at the whole tree level. These data suggest that neoformed growth can both compete with fruit growth for available resources (lower yield efficiency) and act as an additional source (altered yield components), depending on the factor being measured. Controlling neoformed growth may potentially increase pistachio yield through a shift to the more efficient preformed shoots while at the same time lowering orchard maintenance costs by reducing required pruning. We have data to indicate that regulated deficit irrigation and new pruning techniques may be viable methods for controlling neoformed growth in pistachio without affecting yield.