Plant height.

Plant height of the centrol tiller was noted in centimeters from the base upto the earhead excluding awns.

Number of tillers per plant.

The number of fertile tillers borne by the plant were counted a few days before harvesting.

Spike length.

Spike length of three randomly taken spikes was measured in centimeters from the base to the tip excluding awns and then averaged.

Number of kernels per spike.

The total number of kernels were manually counted of three randomly taken spikes per plant and then averaged.

100 Kernels weight.

One hundred kernels from the produce of the individual plant was randomly taken and their weight in grams was recorded.

Grain yield per plant.

Yield of grains per plant was recorded in grams with torsion balance.

The entire data was processed according to Fisher's method for analysis of variance on average values.

Results and Discussion

Recently many plant breeders have suggested that heterosis does occur in bread wheat and if proper combination of parents is ascertained, it can be used commercially in hybrid wheat breeding programmes.

As it is seen from Table 1 and 2, mean squares for parents and for crosses were highly significant for all the characters including grain yield.

Plant height.

Nearly all the hybrids showed positive heterosis, except one hybrid to better perental value. As regards the mean performance, the hybrids were 15.68 percent taller than the better parent. Cross LU 75 x Mexipak 65, showed highest increase of 22.91 percent and 30.32 percent to better and mid parental value respectively.

The results obtained are in confirmation with those of HRASKA (1975), who reported 10 percent increase over mid parent.

Number of tillers per plant.

This is an important component of yield in wheat. As it is clear from table 3, all the hybrids expressed heterosis for this character except one hybrid of cross Pak-70 x Torim, which showed a negative heterosis of 22.4 and -17.16 percent as compared with their respective superior and mid parents. On the basis of over all mean performance, the hybrids bore 37.68 percent and 35.81 percent more tillers than the mid and superior parents respectively.

The results are in agreement with those obtained by CHOUDHRY et al. (1974), who reported significant heterosis to this character.