Thesis (Ph.D.) - Cairo University - Faculty of Agriculture - Department of Vegetable

This study was carried out during the period from 2013 to 2015 at the Agricultural Experiment Station of the Faculty of Agriculture, University of Cairo, Giza, Egypt. The first experiment aimed at evaluating 23 genotypes of summer squash (Cucurbita pepo), viz., PEP 11 (P₁), PEP 17 (P₂), PEP 238 (P₃), PEP 263 (P₄), PEP 281 (P₅), PEP 286 (P₆), PEP 317 (P₇), PEP 529 (P₈), PEP 530 (P₉), PEP 610 (P₁₀), PEP 1635 (P₁₁), PEP 1636 (P₁₂), PEP 1641 (P₁₃), PEP 1642 (P₁₄), PEP 1651 (P₁₅), PEP 1661 (P₁₆), PEP 1672 (P₁₇), PEP 1684 (P₁₈), PEP 1687 (P₁₉), PEP 1688 (P₂₀), PEP 1692 (P₂₁), PEP 1763 (P₂₂) and cv. Eskandarani (P₂₃) and 21 of their hybrids for some vegetative, flowering and yield characters during the 2014 and 2015 summer seasons under open field conditions. The highest significant values for plant length and number of branches / plant were in P₁₇; for sex ratio was in P₁, P₂ and P₂₁; for fruit length was in P₇; for fruit diameter, flesh thickness and flesh thickness / fruit diameter was in P₂₁; for average fruit weight was in P₁₂; for yield was in P₇, P₁₁, P₁₄, P₁₆ and P₂₃; while the least significant number of nodes to the first female flower was in P₁ and P₂. The highest significant values for plant length were in the hybrids P₁₂ {u00D7} P₃, P₂ {u00D7} P₁₂, P₅ {u00D7} P₆, P₅ {u00D7} P₁₃, P₉ {u00D7} P₁₁ and P₁₆ {u00D7} P₂; for number of branches / plant was in hybrid P₁₂ {u00D7} P₃; for sex ratio was in hybrids P₂₃ {u00D7} P₁₃ and P₇ {u00D7} P₂₃; for fruit length was in hybrid P₁₄ {u00D7} P₂; for fruit diameter was in the check hybrid Sama; for fruit weight was in hybrid Sama, P₂ {u00D7} P₁₁, P₂{u₀₀D₇} P₁₂ and P₁₆ {u00D7} P₁₁; for yield was in hybrid Sama, P₂ {u00D7} P₁₂, P₅ {u00D7} P₂, P₁₃ {u00D7} P₂ and P₂₃ {u00D7} P₁₃; for flesh thickness was in hybrid P₂ {u00D7} P₁₂, P₂ {u00D7} P₁₁, P₁₁ {u00D7} P₅ and P₁₄ {u00D7} P₂ ; for flesh thickness / fruit diameter was in the hybrid P₁₁ {u00D7} P₅; while the lowest significant number of nodes to the first female flower was in hybrids P₂₃ {u00D7} P₁₃, P₇ {u00D7} P₂₃, P₁₃ {u00D7} P₄ and P₁₅{u₀₀D₇} P₂₃. Significant heterobeltiosis and standard heterosis were found in some hybrids for all studied traits, except fruit diameter, fruit weight and yield for standard heterosis and, except flesh thickness / fruit diameter for heterobeltiosis.

Issued also as CD