HETEROSIS STUDIES FOR YIELD AND YIELD CONTRIBUTING TRAITS OF UPLAND COTTON IN LINE X TESTER DESIGN

A Line x Tester analysis was conducted in upland cotton with 56 hybrids along with their parents to estimate the magnitude of heterosis for yield and yield contributing characters. The analysis revealed presence of considerable variation among all the parents and hybrids. Seed cotton yield recorded highest average heterosis (12.62 %) followed by number of bolls per plant (10.61 %) and number of sympodia per plant (2.23 %). Highest heterotic effect for seed cotton yield was observed in cross Galama x IC 356932 for both relative heterosis (113.14 %) and heterobeltiosis (94.23 %) followed by BC 68-2 x HAG 1055 (91.00 % and 85.86% respectively) which also exhibited highest heterosis over mid parent (86.95 %) and better parent (82.48 %) for number of bolls per plant, an important yield contributing character. The hybrid NA 1325 x L 604 recorded highest per se performance for yield (218.5 g) was found to exhibit highest heterosis (56.12 %) over commercial check. Therefore, from the present study, it is clear that, the hybrids Galama x IC 356932, BC 68-2 x HAG 1055 and NA 1325 x L 604 could be used in future breeding programme for obtaining good transgressive segregants for important yield contributing traits and commercial exploitation of heterosis

Evaluation of phenology-based insecticide strategies for fall armyworm (Spodoptera frugiperda) management in maize in India

The invasive fall armyworm (Spodoptera frugiperda J.E. Smith) poses a significant threat to maize productivity in India, yet optimal insecticide application strategies aligned with crop phenology remain underexplored. A comprehensive field investigation was undertaken at the Maize Research Centre, Rajendranagar, Hyderabad, across three consecutive Kharif seasons (2020-2022) to assess the performance of chlorantraniliprole 18.5 % SC (soluble concentrate) (applied at 0.4 ml/L) in controlling the invasive pest Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae), commonly known as the fall armyworm (FAW), in maize. The experimental layout followed a randomized block design, incorporating multiple insecticide application timings based on crop phenology (7, 10, 14 and 20 days after germination) and pest incidence thresholds (5 % and 10 %), in addition to an untreated control for comparison.Among the evaluated strategies, the sequential application of chlorantraniliprole at the V2 (7 DAG) and V4 (14 DAG) vegetative stages proved to be the most effective. This treatment significantly minimized FAW infestation, registering a mean infestation of only 12.33 %, along with the lowest leaf injury rating (1.98) on the modified Davis scale and the highest recorded grain yield (81.30 q/ha). A closely comparable result was achieved with applications at the V3 (10 DAG) and V5 (20 DAG) stages, which showed a slightly higher mean infestation (13.71 %) but identical leaf injury scores (1.98) and a near-equivalent grain yield (81.11 q/ha). The findings underscore the importance of timely insecticide applications during the early vegetative stages, particularly V2 and V4, to suppress FAW populationseffectively and optimize maize productivity. This research highlights the critical role of growth stage-based pest management in enhancing crop health and yield outcomes under FAW pressure

Greener Journal of Agricultural Sciences The Effect of Environment on Combining Ability and Heterosis in Hybrid Rice

Study was undertaken to estimate the combining ability and heterosis for yield and yield contributing characters over environments. Environment, Crosses, GCA and SCA, and their various interactions with environment were significant suggesting that the hybrids did not have the same relative performances among environments. An evaluation of combining ability across the environment indicated that both general and specific combining ability effects are important but predominance of non-additive genetic variance indicated the presence of heterozygosity in the population. As such this type of genetic variance is non-fixable hence; heterosis breeding is effective for crop improvement. Line IR-79156A, IR-68897 and tester R-51 during both the seasons and testers R-47, R-48, R-49, R-52, IR-64 and IR-10198 during kharif and line R-42, IR-66, R-43, R-46, R-56 and IR-13419 during rabi were the promising general combiners for grain yield per plant and other traits. These parents used as testers and lines in the cross combinations would be able to realize good hybrids. Considering high physical grain quality parameters as well as per se performance, sca effects (High x high or high x low gca effects of each cross) and standard heterosis, hybrids viz., IR-80555A x R-51 and IR-79156A x R-44 during kharif and IR-79156A x R-43, IR-68897A x R-51 and IR-68897A x R-52 during rabi have been identified as promising rice hybrids

Effect of Gibberellic Acid (GA3) on the Yield Attributing Traits during a Cold Period in Rice

Gibberellic acid is an essential growth promoter that aids in the systematic plant growth. Studies on the impact of GA3 during cold period discovered a positive effect on the growth of rice plants. The current study evaluated the impact of various concentrations of GA3 on the yielding attributes of rice during cold stress in the rice varities, JGL 18047, BPT 5204, and RNR 15048. All the quantitative traits showed significant variation among the genotypes and treatments. Gibberellins applied at low concentrations during seedling stage (1, 2 or 3 gm/200 m2 of nursery area) revealed higher quantitative trait values compared to higher concnetartions (5 and 10  gm). Among all the three varities, RNR 15048 was found to be the best variety than the others in terms of yielding triats. Therefore, GA3 applied at a concentration of 1gm, 2gm or 3gm promotes the rice plant growth during cold periods and results in higher yield. Among these, 2 gm of GA3 for 200 m2 of nurcessary area was found to be the best in aiding the crop growth during cold phase

Effect of Gibberellic Acid (GA3) on the Yield Attributing Traits during a Cold Period in Rice

Gibberellic acid is an essential growth promoter that aids in the systematic plant growth. Studies on the impact of GA3 during cold period discovered a positive effect on the growth of rice plants. The current study evaluated the impact of various concentrations of GA3 on the yielding attributes of rice during cold stress in the rice varities, JGL 1804, BPT 5204, and RNR 15048. All the quantitative traits showed significant variation among the genotypes and treatments. Gibberellins applied at low concentrations during seedling stage (1, 2 or 3 gm/200 m2 of nursery area) revealed higher quantitative trait values compared to higher concnetartions (5 and 10  gm). Among all the three varities, RNR 15048 was found to be the best variety than the others in terms of yielding triats. Therefore, GA3 applied at a concentration of 1gm, 2gm or 3gm promotes the rice plant growth during cold periods and results in higher yield. Among these, 2 gm of GA3 for 200 m2 of nurcessary area was found to be the best in aiding the crop growth during cold phase.</jats:p

Studies on Cultural, Morphological and Pathogenic Variability among the Isolates of F. verticillioides Associated with Maize Stalk Rot in Telangana State, India

Maize (Zea mays L.) is one of the important cereal crops of the world and world’s third most leading cereal crop, after wheat and rice. Maize is affected by various biotic and abiotic stresses. Among the biotic stresses, fusarium wilt of maize caused by Fusarium verticillioides is most serious disease of maize. Tweleve isolates of F. vericillioides were studied for its cultural, morphological and pathogenic variability. Microconidia were hyaline, oval to club shaped with a flattened base and measured 5.12-7.11 μm X 2.04-3.18 μm (L×W). Macroconidia were sickle shaped with 3-5 septa and measured 20.01-31.12 μm X 2.01-3.21 μm (L×W). The radial mycelial growth of test isolates ranged from 4.32 mm to 8.65 mm at 10 days after inoculationon on PDA medium. However, maximum mycelial growth was recorded by the isolate F-ISO-5 in all the three mediums and mean maximum growth of isolates were observed in CMA. The fungal colony of Fusarium isolates on PDA were initially white, floccose which turned&nbsp; purple to dark brown after 7 days of incubation at 28 ± 2ºC. Cultures developed pigmentation like pink, light purple, dark violet which varied with age. All the tested isolates were pathogenic on tested maize cultivar (kaveri- 50). However, the disease severity was varied among the isolates. Fusarium isolates F-ISO-7 was highly virulent which caused severe disease upon inoculation with disease score of 8.0 on 1-9 scale followed by&nbsp; F-ISO-1, F-ISO-3, F-ISO-4, F-ISO-5, F-ISO-6 and F-ISO-8

Isolation and In vitro Studies of Native Isolates of Bacillus subtilison Maize Stalk Rot Incited by Fusarium verticillioides

Fusarium wilt of maize is a widely distributed and the most destructive disease caused by Fusarium verticillioides. The main objective of this experiment is to identify the effective Bacillus isolates against Fusarium verticillioides under in vitro condition. A total of 10 Bacillus spp. isolates were isolated from rhizhosphere region of maize plants in different locations of Telangana state and tested for antagonistic activity at department of plant pathology, Maize Research Centre, Agricultural Research Institute, Rajendranagar. All the isolates of Bacillus spp. were used for determining theirbio efficacy against Fusarium verticillioides. All the isolates not shown similar bio efficacy and differerd in their antagonistic activity against F. verticillioides mycelial growth. Among them the isolates B-ISO-3 and B-ISO-2 were found to record significantly higher percent reduction of mycelial growth 63.3 and 62.8 % respectively, followed by B-ISO-9 which recorded 61.3%t reduction of mycelial growth over control. The lowest percent reduction of mycelial growth was recorded with the isolate B-IS0-8 (34.2 %) over control