Use of morphological differences, between true hybrids and off types in grow out test (GOT) for genetic purity analysis, are not always apparent and cannot be recognised easily. Further, morphological traits are costly, tedious to score and environment sensitive. Alternatively, it is suggested that recent breakthrough in molecular markers can be employed in genetic purity analysis. The genetic purity of three cotton hybrids (TCHB 4510, TCHB 2310 and TCHB 213) that are widely cultivated in Tamil Nadu, India were assessed by GOT and molecular markers. A total of 400 individuals from each one of the three hybrids were raised in the field and morphological traits were recorded. Results of this GOT have shown that TCHB 2310 had lowest genetic purity (62.5%) followed by TCHB 4510 (78.2%) and TCHB 213 (95.2%). Simple sequence repeats (SSR) marker analysis of parents that were involved in the production of all the three hybrids have shown that 45 out of 150 SSRs were polymorphic among the parents. From this set of polymorphic SSRs, BNL686, BNL1679, BNL3971, BNL3955, CIR407 and CIR413 were selected to test the genetic purity of hybrid seeds since they have produced clear, scorable and unambiguous polymorphic bands among the parents. All the three hybrids were clearly distinguished from their selfed females and off types using these six SSRs. Hence, it is proposed that these SSR markers can be used in efficient analysis of hybrid seed purity since this technique is simple to use, more accurate and not affected by environment when compared with GOT.

The dawdling development in genetic improvement of cotton with conventional breeding program is chiefly due to lack of complete knowledge on and precise manipulation of fiber productivity and quality. Naturally available cotton continues to be a resource for the upcoming breeding program, and contemporary technologies to exploit the available natural variation are outlined in this paper for further improvement of fiber. Particularly emphasis is given to application, obstacles, and perspectives of marker-assisted breeding since it appears to be more promising in manipulating novel genes that are available in the cotton germplasm. Deployment of system quantitative genetics in marker-assisted breeding program would be essential to realize its role in cotton. At the same time, role of genetic engineering and in vitro mutagenesis cannot be ruled out in genetic improvement of cotton.

Aim: Genetically complementary parents and amount of heritability of economic traits determines the successful development of breeding population, hybrids and varieties. The studies on heterosis and combining ability are useful in formulating effective breeding strategies and selection of suitable parents for crosses in breeding program. Study Design: During the study period24 F1hybrids and their 10 parents were evaluated along with commercial check (‘Shakthi’) in a randomized block design (RBD) with three replication. Place and Duration of the Study: The present study was conducted at Adhiparasakthi Agricultural College farm, Kalavai, Vellore district of Tamil Nadu state during summer 2014. Methodology: The experimental material consist of 24 F1 hybrids developed from six lines (EC755648, EC755653, EC 755654, IC52303, IC755652 IC111515 ) and three tester (Arakka Anamika, Parbhani, Pusa Sawani VRO 22 ). These were evaluated along with commercial check (‘Shakthi’) in a randomized block design with three replication. The observation were recorded for 14 yield and yield contributing characters. Results: The results inferred that the predominance of non-additive gene action was observed for all the traits. Among the parents, the overall study of gca effects suggested that parent EC 755648 and Parbhanikranti were significant general combiner for yield, these can be used to improve hybrids with desirable traits in future. Significant positive SCA effects were found for all the studied traits. Conclusion: Among the hybrids, EC755653 x ArakkaAnamikaand IC111515 x ParbhaniKrantishowed desirable standard heterosis percentage over the check Shakthi along with good sca effects and per se performance for yield and other important yield contributing traits, thus it can be effectively be exploited in hybrid breeding programme.

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A field experiment was conducted during Kharif, 2018 to evaluate the efficacy of different insecticides against blister beetle, Mylabris pustulata (Thunberg) in pigeon pea. Among the seven treatments tested, Flubendiamide 480SC @ 30 g a.i ha -1 was found to be effective and recorded 2.67 and 3.56 numbers plant -1 , respectively at 3 and 7 DAT after first spray followed by the treatment Indoxacarb 15.8 SC @ 73 g a.i ha -1 which recorded 2.78 and 3.56 numbers plant -1 . The third treatment proved to be effective was Deltamethrin 2.8 EC @ 12.5 g a.i ha -1 with the population of 3.22 and 3.78 numbers plant -1 . The similar trend of efficacy was noticed even after the second spray also. The order of efficacy of treatments in the population reduction of blister beetles was Flubendiamide 480 SC @ 30 g a.i ha -1 > indoxacarb 15.8 SC @ 73 g a.i ha -1 > Deltamethrin 2.8 EC @ 12.5 g a.i ha -1 > Cypermethrin 25 EC @ 25 g a.i ha -1 > Lambda cyhalothrin 5 EC @25 g a.i ha -1 > NSKE 5%. As that of results on the efficacy of insecticides, the reduction per cent in the blister beetle population also follows the similar trend of different treatments tested. This effectiveness also reflected in the highest grain yield of 1140.20 kg ha -1 in Flubendiamide 480 SC @ 30 g a.i ha -1 with a yield increase of 36.47 % over untreated check. This was followed by indoxacarb 15.8 SC @ 73 g a.i ha -1 (1102.3 kg ha -1 ) > Deltamethrin 2.8 EC @ 12.5 g a.i ha -1 (1072.0 kg ha -1 ) > Cypermethrin 25 EC@ 25 g a.i ha -1 (996.4 kg ha -1 ) > Lambda cyhalothrin 5 EC @ 25 g a.i ha -1 (991.7 kg ha -1 ) > NSKE 5% (951.70 kg ha -1 ) .