Evaluation of Some Imported Pecan Varieties Under Giza Governorate Environmental Conditions

Abstract

This evaluation included morphological, flowering, yield and fruit quality, physical characteristics as well as kernel oil fatty acids composition and the ability to vegetative propagation by grafting. The Effect of environmental conditions on dichogamy phenomenon was also studied. It can be clearly noticed that, there is a positive relation between shoot length & diameter, av. No. of leaves per shoot and internodes length, where Burkett variety was the superior in this concern, while, Pawnee variety exceeded the others in twig length and No. of shoots/twig. Desirable var. recorded the highest No. / of leaflets/leave and leaflet area. Western Schley had smaller tree size. There was an obvious varietals difference in pecan bud developmental stages (dormant, vegetative and starting buds for staminate or pistillate inflorescences). The highest No. of the abovementioned buds as well as total No. of such buds and No. of fruits/shoot was observed in Western Schley variety except for No. of vegetative buds. Fruit set (%) averaged between 66.04 & 66.04 in Wichita to reach 85.60 & 82.57 in Desirable. Number of days in which pollen shed coincides with stigma receptivity varied between the studied varieties, where there was more consistent period of overlap in Pawnee, Success & Western Schley varieties. The previously mentioned varieties can be classified as protandrous (type, 1), whereas, Burkett, Desirable & Wichita varieties as protogynous ( 2). Moreover, Wichita can be considered a good pollinator for most other studied varieties. Pollen shedding period in Wichita extended with the increase of relative humidity and lower temperature. Burkett followed by Success varieties started and ended to crack shuck and harvesting earlier than other varieties. Western Schley, Desirable & Burkett varieties had an excellent kernel ercentage, respectively, whereas, Pawnee variety was the poorest. Varieties with high nut weight had lower No. of nuts /kg. Desirable followed by Burkett produced the highest yield, while, Success was the lowest. In regard to kernel oil content (%), Desirable followed by Western Schley kernels were the richest. The main compositional characteristic of pecan kernel was the high concentration of oleic acid and very low content of Linolinec acid. It is also interesting to note that, successful grafts (%) varied between varieties from 33.33 % in Western Schley to reach 93.33 & 91.66 % in Desirable & Success, respectively. As a conclusion under the same conditions of the present study Burkett & Success may be recommended as early cropping varieties; Wichita as a good pollinator; Western Schley as a small size tree which can be helpful in increasing number of trees / Fed. which in turn increases yield/Fed. as well as may facilitate the trees cultural practices. The primary pecan varieties Desirable & Burkett performed superior to other varieties in terms of yield; Western Schley and Desirable as varieties that have higher percentages of kernel and oil content and Desirable & Success are characterized by their easy...

Evaluation of Some Pecan Varieties Growing under Drip Irrigation System at El-Behera Governorate, Egypt Environmental Condition

“…The opposite was observed in Desirable during the 1 st season (122.0 nuts/ kg) and Grazona in the 2 nd one (139.70 nuts/ kg) that means they had the smallest nuts. These results were confirmed by Awad, (2002) and the former studies where Abou-Taleb et al, (2010) recorded the highest number of nuts/kg for Burkett and Wichita cvs. While Desirable cv.…”

“…while, Grazona and Desirable have the highest percentage of shell in the 1 st season (41.99 & 42.11). Exactly the contrary was found by , Awad, (2002) and Abou-Taleb et al (2010), Desirable nuts were the longest and superior in shape index while, Burkett nuts recorded the lowest shape index but it has the highest nut weight. Also, Burkett and Wichita cvs.…”

“…Generally, Herrera (2005), Abou-Taleb et al (2010) and Gowda (2011) stated that, linoleic acid is responsible for oxidation and rancidity in pecan kernel. Linoleic acid varies widely in different varieties and from year to year.…”

“…The flowering system must be understand for choosing appropriate cultivars in the design of productive orchards and plant type 1 with type 2 for maximum pollination and subsequent productivity (Abou-Taleb et al, 2004 andSudheer et al, 2005). While, Grauke and Thompson (1996) and Abou-Taleb et al (2010) showed that, the degree of dichogomy depends on the environment which influence in cultivars with different degrees of overlapping.…”