Built in refuge for the management of Pink Bollworm, Pectinophora gossypiella Saunders (Gelichidae: Lepidoptera) in Bt cotton

Field experiment was conducted at the Main Agricultural Research Station, University of Agricultural Sciences, Raichur during 2012-13 to identify and evaluate the suitable refuge strategy systems for pink bollworm resistance management in Bt cotton (Gossypium hirsutum L.) cultivation. The experiment was laid out in randomized complete block design with nine refuge systems : 0 % N-Bt (BIR), 5 % N-Bt (BIR), 10 % N-Bt (BIR), 15 % N-Bt (BIR), 20% N-Bt perimeter refuge, 100% Non Bt, 50% Non Bt, 10% structured refuge and 20% structured refuge as treatments with three replications in replacement series. Significantly lowest incidence (3.55 larvae/plant) and number of bolls with exit holes (11.22) due to pink bollworm was recorded in 0% BIR (41.25 q/ha) followed by 5 % N-Bt (BIR) with yield of 38.74 q/ha and this was on par with 10 % N-Bt (BIR) with yield of 37.79 is next best refuge systems with Bt cotton for higher production and greater economic benefits

Efficacy of Fungicides and Commercially Available Organic Products against Blight of Cotton Caused by Alternaria macrospora

An attempt was made to test available formulation of fungicides and commercially available organic products for their efficacy under laboratory condition, an experiment was carried out at Department of Plant pathology, Raichur, Karnataka, India by using poison food technique. Among the commercially available organic products tested, fatty alcohol and diluents has recorded significantly higher mycelial inhibition of 100 per cent at the concentration of 5 and 10 per cent. In case of contact fungicides propineb 70% WP, metiram 70% WP and mancozeb 75 % WP recorded 100 per cent mycelial inhibition, with respect to systemic fungicides hexaconazole 5% EC, propiconazole 25% EC and difenoconazole 25% WP and among the combi fungicides azoxystrobin 8.3% + mancozeb 66.7% WG were most effective in 100 per cent inhibition of mycelial growth of Alternaria macrospora over the control. The commercially available organic product fatty alcohol and diluents, propineb 70% WP, hexaconazole 5% EC, propiconazole 25% EC and azoxystrobin 8.3% + mancozeb 66.7 % WG were found to be effective against inhibition of mycelial growth of Alternaria macrospora

Studies on the response of normal and irradiated pink bollworm males towards pheromone source

Sterile Insect Technique (SIT) is the right eco-friendly method to overcome the pink bollworm Pectinophora gossypiella (Saunder) menace. In SIT attractiveness of released moths to their natural counterpart is most important as such this ability was examined in our study. For this, newly emerged five virgin female gamma irradiated with 0–250 Gy were used. These females were placed inside small plastic vial provided with aeration and suspended inside the delta traps by providing 10% honey solution. Traps were placed in the field during evening. Moth catches in each trap were counted and removed daily and these observations continued up to 5 days. In a same manner irradiated males were released separately inside the field cage to know its attractiveness to virgin female. The results indicated that attraction of male moths to irradiated virgin females decreased significantly with increasing doses of radiation i.e., at 200 and 250 Gy. The number of males captured per female was greatest on day 2nd due to its peak sexual activity, i.e., 25.60, 23.05, 19.45, 14, 9.4 and 5.9 moths at 0, 50, 100, 150, 150, 200, and 250 Gy, respectively. Gamma radiation also affected the irradiated males to find their natural mates at a higher dose; however, the maximum number of 5.30, 5.95 and 5.10 irradiated male moths were attracted to the natural pheromone secreted by female moths at 50, 100 and 150 Gy respectively, compared to the 6.80 moths at 0 Gy. The results on attractiveness of irradiated male moths towards virgin female-baited traps were considered a good measure of male competitiveness

Studies on Reproductive Biology of Yellow Stem Borer, Scirpophaga incertulas Walker (Lepidoptera: Pyralidae) in the Changing Climate Scenario

Studies on reproductive biology of yellow stem borer, Scirpophaga incertulas walker in the changing climate scenario conducted at Agriculture Research Station, Gangavathi during 2020-22.Results on post eclosion behavior of yellow stem borer revealed that the maximum female moths emerged between 18:00 and 21:00 hrs from among the emerged moth the female calling was observed between 23:00 and 02:00 hrs. The time of mating commenced after the calling period and was observed between 23:00 and 03:00 hrs. The average pre-oviposition period, oviposition period and post-oviposition period were completed in 1.09 ± 0.09, 1.28 ± 0.17 and 0.85 ± 0.25 days, respectively. The longevity of adult females and males was about 3.23 ± 0.29 and 2.66 ± 0.33 days, respectively. The total number of eggs laid varied from 68 to 221 in number with an average of 146.95 ± 43.98 per female. The Operational and intrinsic sex ratio of YSB were observed to be female-biased with 1:1.35 and 1:1.44 of male to female moths, respectively

Avaliação de germoplasma de camomila e densidade de semeadura na produção e composição do óleo essencial Evaluation of germplasm and seeding rate over the production and composition of chamomile essential oil

O cultivo de camomila na região Sul do Brasil tem sido realizado utilizando-se como material genético a cultivar Mandirituba. Apesar da produção de capítulos florais e teor de óleos essenciais apresentado por esta cultivar ser considerado satisfatório, tem sido observada nas regiões produtoras a ocorrência de problemas fitossanitários que resultam em perdas significativas da produção. Este trabalho teve como objetivos comparar materiais genéticos de camomila provenientes da Holanda, Dinamarca e Mandirituba, e avaliar o efeito de diferentes densidades de semeadura no desenvolvimento das plantas, produção de capítulos, rendimento e qualidade do óleo essencial da cultivar Mandirituba, atualmente cultivada na região. Os experimentos foram conduzidos no município de Piraquara (PR). A extração do óleo essencial foi realizada por hidrodestilação em aparelho tipo Clevenger e a determinação da composição do óleo foi feita por cromatografia em fase gasosa acoplada ao espectrômetro de massa (GC/MS). Os materiais genéticos provenientes da Holanda e de Mandirituba apresentaram maior produção de biomassa seca de capítulos, em relação ao material genético da Dinamarca. A cultivar Mandirituba apresentou o maior rendimento de óleo essencial (4,71 mL g-1 ms), sendo também superior em relação à produtividade de óleo essencial (2,40 L ha-1). Os materiais procedentes da Dinamarca e de Mandirituba apresentaram composição do óleo essencial semelhantes. A densidade de plantio de 1,0 kg ha-1 da cultivar Mandirituba resultou em melhor desenvolvimento das plantas e maior produção de óleo essencial. Quantidades superiores a 3,0 kg ha-1 de sementes não resultaram em maior densidade de plantas tendo em vista a alta competição e percentual de plântulas mortas.<br>The cultivar Mandirituba is the only genetic material for chamomile cultivation in southern Brazil. Besides the limitations regarding floral buds and the yield of essential oil presented by this cultivar, phytosanitary problems have also been observed. The objectives of this work were to compare the genetic materials from the Netherlands, Denmark and Mandirituba and to evaluate the effect of seeding rate on floral heads development and essential oil production, yield and quality. The experiments were carried out at field conditions in Piraquara, Paraná state, Brazil. The essential oil extraction was obtained by hydrodistillation using a Clevenger apparatus and the oil composition was analyzed by gas chromatography coupled to mass spectrometry (GC/MS). The genetic materials from the Netherlands and Mandirituba presented statistically higher dry mass accumulation than the ones from Denmark. However the material from Mandirituba showed a great essential oil yield (4.7 mL g-1 ms) and productivity (2.40 L ha-1). The genetic material from Denmark and Mandirituba showed similar essential oil composition. The density of 1.0 kg ha-1 for cultivar Mandirituba resulted on great plant development and essential oil production. The use of 3.0 kg ha-1 of seeds did not increase plant density due to the high plant competition