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The present investigation was carried out at two summer seasons of 2011 and 2012 at two different locations. Sids Research Station in Upper Egypt and Sakha Research Station in North Delta of the Agricultural Research Center, Egypt. Each experiment was designed as a randomized complete block design with three replications. The objective of this investigation is aimed to study the behavior of genetic interspecific of maize-teosinte crosses under two locations. Twenty one crosses were made among three teosinte (Euchlaena maxicana) as male tester parents and seven genotypes (Zea mays) as female maize parents in 2011 season in 2012 summer season. The 21 F1 and their ten parents were planted in two experiments in the two locations (Sakha and Sids stations). Main finding could be summarized as follows: 1-Genotypes appeared to be varied from location to another with respect to their means for most of the studied characters. 2-The parent Maize SC10 had highest and desirable means for all the studied characters and tester Sakha (teosinte) produced highest means for all studied traits. 3-The crosses (SC168 x inbred lines) (SC125 x Sakha) and (inbred line 7 x inbred line 3) were the best for all the studied traits. 4-The best desirable GCA effects in maize fresh yield in kg/plant, stem diameter and dry matter % were found in the single cross 168. The favorable fresh yield in kg/plant was inbred line 34 for number of leaves/plant were inbred line 7 and the two parent inbred line 7 and SC124 for number of leaves/plant. 5-The results indicated that the desirable general combining ability effects teosinte for dry mater % and dry yield/plant in Damietta parent and the desirable for number of leaves/plant for parent line 3 and Sakha. 6-The results revealed that the best desirable estimates of SCA for fresh yield in kg/plant, number of stems/plant, dry matter and number of leaves/plant were the cross (L2 x T1) . In general, the best desirable for most of the studied characters were parents SC168 and inbred line 3 for breeding programs

Two experiments were carried out at Sakha Agriculture Research Station, Cotton Research Institute, Agriculture Research Center, Egypt. The aim of this investigation was to study heterosis and combining ability for the most important traits of cotton (boll weight, seed cotton yield, lint yield, lint percentage, number of bolls per plant and seed index). Eight cotton genotypes 10229 x G.86, G.45, Pima S1, Suven, TNB, CB.58, G. 70 and G. 93 were crossed in half diallel mating design in 2011 season to obtain 28 single crosses. These parents and their respective 28 F1 crosses were evaluated in two planting dates (April and May) in a randomized complete blocks design in 2012 season. The results obtained could be summarized as follows:- 1- Highly significant mean square values were obtained for genotypes, genotypes x dates, parents x dates, crosses x dates for all the studied traits. 2- The best general combiner for most of studied traits was parent (10229 x G. 86). Also the best general combiners for most of studied traits were crosses (10229 x G. 86) x Pima S1, G.45 x G.70, CB.58 x G.70 and CB.58 x G.93 3- The parent (10229 x G. 86) had the best general combining ability for boll weight, seed cotton yield, lint yield and lint percentage under two sowing dates and their combined. 4- The crosses CB.58 x G.93 and G.45 x G.70 showed highly significant desirable specific combining ability for boll weight, seed cotton yield, lint yield and number of bolls per plant at two sowing dates and their combined. 5- Positive heterotic effects relative to the mid-parent were found for most of the traits in the crosses (10229 x G.86) x G.45, G.45 x Suven, G.45 x G.70, TNB x G.70 and C.B 58 x G.93. Also positive heterotic effects relative to the better parent were found for most of the traits in the crosses (10229 x G.86) x TNB, G.45 x Suven and G.45 x G.70 over two planting dates and their combined. 6- Dominance effects were important in the inheritance of boll weight, seed cotton yield and number of bolls per plant traits. The additive gene effects contribute the major portion of gene pool for lint yield, lint percentage and seed index traits. 7- Heritability estimates in narrow sense were low to high for all the studied traits, ranged from 32.17% for seed cotton yield to 91% for boll weight for the combined data. 8- From these results it could be concluded that the crosses CB.58 x G.93 and G.45 x G.70 appeared to be promising for late-planted tolerance therefore could be exploited in breeding program aiming to improve late-planting tolerance.