Performance of direct-seeded basmati rice in loamy sand in semi-arid sub-tropical India

One of the resource conservation technologies for rice (Oryza sativa) is direct seeding technique, which may be more water efficient and labour cost-effective apart from being conducive for mechanization. The crop establishment during the initial stages may depend upon the method of direct seeding, cultivar and seed rate. A study was carried out during 2004–2005 to evaluate the effect of different seeding techniques, cultivars and seed rates on the performance of direct-seeded basmati rice in loamy sand (coarse loamy, calcareous, mixed hyperthermic, Typic Ustipsamments) at Punjab Agricultural University, Ludhiana, India. The treatments in main plots included four seeding techniques (broadcast in puddled plots, direct drilling in puddled plots, direct drilling in compacted plots and direct drilling under unpuddled and uncompacted conditions). The subplots treatments comprised of two cultivars (Pusa Basmati-1 and Basmati-386) and three seed rates (at 30, 40 and 50 kg ha⁻¹).

The moisture retention and bulk density at harvest were sufficiently lower in uncompacted/unpuddled plots than compacted or puddled plots more so in 0–30 cm soil layer. The crop stand establishment was higher in direct-drilled compacted plots with 50 kg seed ha⁻¹. It was higher in Pusa Basmati-1 than Basmati-386. The direct drilling after compaction produced 28% higher biomass than uncompacted/unpuddled plots. Similar trend was observed in leaf area index and effective tillers. Effective tillers were significantly higher with 30 kg seed ha⁻¹and were higher in Pusa Basmati-1 than Basmati-386. The root mass density of basmati rice in 0–15 cm soil layer at 45 days after sowing was 1549 g m⁻³ in compacted soils, 1258 g m⁻³ in broadcasting in puddled soil and 994 g m⁻³ with direct drilling in puddled soil. The grain yield of basmati rice was 44% and 30% higher in direct-drilled compacted and puddled plots, respectively, than uncompacted/unpuddled plots.     

Monitoring the temporal changes in herbicide-resistant Amaranthus tuberculatus: a landscape-scale probability-based estimation in Iowa

Background

A landscape-scale probability-based sampling of Iowa soybean [Glycine max (L.) Merr.] fields was conducted in 2013 and 2019; Amaranthus tuberculatus [Moq.] J.D. Sauer seed was collected from 97 random geospatial selected fields. The objectives were to evaluate the prevalence and distribution of herbicide-resistant A. tuberculatus (waterhemp) in soybean fields and evaluate temporal changes over 6 years. Amaranthus tuberculatus seedlings were evaluated for resistance to imazethapyr, atrazine, glyphosate, lactofen and mesotrione at 1× and 4× label rates.

Results

Resistance to imazethapyr, glyphosate, lactofen and mesotrione at the 1× rate increased significantly from 2013 to 2019 and was found in 99%, 97%, 16% and 15% of Iowa A. tuberculatus populations in 2019, respectively. Resistance to atrazine at the 4× rate increased over time; atrazine resistance was found in 68% of populations in 2019. Three-way multiple herbicide-resistant A. tuberculatus was the most frequent and increased significantly to 4× rates from 16% in 2013 to 43% of populations in 2019. All A. tuberculatus populations resistant to HPPD-inhibitor herbicides also were resistant to atrazine.

Conclusion

To the best of our knowledge, this is the first probability-based study that presented evolution of A. tuberculatus herbicide resistance over time. The results demonstrated that imazethapyr, atrazine and glyphosate resistance in Iowa A. tuberculatus populations was frequent whereas resistance to lactofen and mesotrione was less frequent. Most Iowa A. tuberculatus populations evolved resistance to multiple sites of action over time. The results of our study are widely applicable given the similarities in weed management practices throughout the Midwest United States. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Primary experimental infection of riverine buffaloes with Fasciola gigantica.

The clinical course of the primary experimental Fasciola gigantica infection was investigated in riverine buffalo calves of the Murrah breed. Nine male calves aged 12-15 months were randomly assigned to two groups of five (Group I) and four (Group II) animals. Each animal in Group I, was orally infected with 1000 metacercariae (mc) of F. gigantica, whereas Group II animals did not receive any infection dose and served as uninfected controls. No clinical signs of fasciolosis were observed until the sixth week post-infection (PI). Group I animals, however, developed recognised symptoms of acute fasciolosis, comprising apyrexic inappetance, anemia, poor weight gain, diarrhoea and sub-mandibular and facial oedema, respectively, from 5, 6, 8, 16 and 17 weeks PI. The signs were intermittent in nature and of variable duration. The prepatent period was of 92-97 days (mean 95.2 +/- 3.1). One of the five infected animals died on Day 147 PI. At necropsy, 36.8 +/- 11.0% of the infection dose was recovered as adult fluke population. The gross lesions were primarily biliary in nature. Group II, the uninfected controls, throughout the study period of 165 days PI, did not show any symptom and were negative for F. gigantica. The study demonstrated that the onset of adverse effects of F. gigantica on the growth and health of the infected host was mainly noted during late prepatency much before coprological prediction and diagnosis. The significance of preventive therapy against fasciolosis during prepatency has been stressed in endemic areas.     

Effect of domestic processing on total and extractable calcium and zinc content of Bathua ( Chenopodium album) and Fenugreek (Trigonella foenum graecum) leaves

Bathua (Chenopodium album) and fenugreek (Trigonella foenum graecum) stored in polyethylene bags and without packaging for 24 or 48 hours in a refrigerator at 5 or 30 ^°C in polyethylene bags. The fresh leaves were also dried (oven and sun); blanched (5, 10 or 15 min) and cooked in an open pan and a pressure cooker. The processed leaves were analyzed for total and extractable calcium and zinc content. The Ca and Zn content of these leaves varied from 970 to 2230 and 10.50 to 12.30 mg/100 g DM and the percentage HCl-extractability was 80.34 to 83.04 and 82.43 to 83.90, respectively. Non significant effects of drying and storage were observed on total Ca and Zn content and HCl-extractability while blanching and cooking resulted in significant improvement of HCl-extractability of these two minerals. Thus, cooking and blanching are good ways to improve the HCl-extractability of Ca and Zn.     

Effects of Weed Removal in Clusterbean (Cyamopsis tetragonoloba) under Different Rainfall Situations in an Arid Region

In dry land agriculture, intensity and type of weed pressure depend upon the rainfall pattern during the crop season. A two year field study was conducted to determine the effect of time of weed removal in clusterbean ( Cyamopsis tetragonoloba (L.) Taub.). Treatments consisting of weed removal at 10, 20, 30,40 and 50 days after sowing were compared with clean weeded and unweeded controls. The xerophytic weeds Gisekia pharnacioides (L.) M., Mollugo cerviana (L.) Ser. and Tribulus terrestris L. dominated in the low and erratic 1993 rainfall season while grassy weeds such as Eragrostis pilosa (Beauv) were predominant in the 1994 season with well-distributed rainfall. The number of weeds was maximum at 30 days after sowing (DAS) in 1993 and at 40 DAS in 1994. The dry weight of weeds increased up to 50 DAS in 1993 and up to harvest in 1994. Removing weeds at 20 or 30 DAS increased the number of pods per plant, water use efficiency and seed yield of clusterbean. Water consumption was higher in unweeded plots. Water use efficiency decreased with the increase in time of weed removal beyond 20 days after crop sowing.     

Isolation of A/Equi-2 virus during 1987 equine influenza epidemic in India

Processing of nasal materials from clinical cases during the 1987 influenza epidemic in Northern and Central India resulted in the isolation of two haemagglutinating agents; one each from donkeys and horses at Bhiwani in Haryana State and Ludhiana in Punjab State, respectively. These were typed as Influenza A/Equi-2 viruses by haemagglutination inhibition test. The two isolates were designated as A/Equi-2/Bhiwani/1/87 and A/Equi-2/Ludhiana/1/87. The Bhiwani/87 isolate was confirmed to have H3N8 antigenic structure and was indistinguishable from the Miami/63 strain of A/Equi-2 virus. However, the A/Equi-2 Ludhiana/87 isolate was closely related to the Fontainebleau/79 strain of A/equi-2 virus.     

Growth and production of endangered Indian butter catfish,Ompok bimaculatus (Bloch) at different stocking densities in earthen ponds

Growth, survival and production of endangered Indian butter catfish (Ompok bimaculatus) fingerlings were examined at different stocking densities. The experiment was conducted for 8 months in nine earthen ponds having an area of 0.03 ha each. 30‐day‐old fingerling, stocked at 40 000 ha^?1 was designated as treatment‐1 (T1), 50 000 ha^?1 as treatment‐2 (T2) and 60 000 ha^?1 as treatment‐3 (T3). At stocking, all fingerlings were of same age group with a mean length and weight of 3.36 ± 0.08 cm and weight of 0.83 ± 0.02 g respectively. Fish in all the treatments were fed with a mixture of rice bran (50%), mustard oil cake (30%), fish meal (19%) and vitamin‐mineral premix (1%). Physicochemical parameters, plankton populations and soil parameters were at the optimum level for fish culture. Highest weight gain was observed in T1 and lowest in T3. Final length, weight and survival of fish also followed the same trend as weight gain. Highest specific growth rate was observed in T1 followed by T2 and T3. Feed conversion ratio was significantly lower in T1 followed by T2 and T3 in that order. Significantly higher amount of fish was produced in T1 than T2 and T3 respectively. Higher net benefit was obtained from T1 than from T2 and T3. Overall, the highest growth, survival and benefit of fish were obtained at a density of 40 000 fingerlings ha^?1. Hence, of the three stocking densities, 40 000 fingerlings ha^?1 appears to be the most suitable stocking density for culturing of Indian butter catfish in grow‐out system.     

Pathological studies on the southern blight of China aster (<Emphasis Type="Italic">Callistephus chinensis</Emphasis>) caused by <Emphasis Type="Italic">Sclerotium rolfsii</Emphasis>

A severe outbreak of southern blight disease of China aster was observed during the post rainy season (September–November 2015) in the Mysore and Mandya Districts of Karnataka, Southern India. The disease incidence ranged between 12 and 47%. The typical disease symptoms include water-soaked lesions on leaves, stems and on the lower stem surfaces followed by quick wilting of the whole plant with abundant production of sclerotia near the stem-soil interface. The associated fungal pathogen was isolated on potato dextrose agar (PDA) medium, on which numerous reddish-brown sclerotia were seen. A total of 26 fungal isolates were isolated and studied for the mycelial compatibility. Isolate SrCCM 1 was used for pathogenicity analysis. The results of the study showed that, there was no variation among the isolates tested. Molecular identification of the pathogen by ITS-rDNA sequences of S. rolfsii showed 100% similarity with reference sequences. Based on the cultural, morphological and molecular characteristics, the fungal pathogen was identified as Sclerotium rolfsii Sacc. (Sexual morph: Athelia rolfsii (Curzi) C.C. Tu & Kimbr). Pathogenicity tests were performed on healthy leaves, roots and stems. Typical disease symptoms on leaves, stems and roots were evident after 5, 8 and 10 days of post-inoculation. Sclerotium rolfsii is known to cause diseases in economically important crop plants. However, no reports are available on the occurrence of S. rolfsii on China aster in India.     

Bacterial populations on the phyllosphere of Mediterranean plants: influence of leaf age and leaf surface

In the present study, we estimated the size of phyllosphere bacterial populations in young and mature leaves from the same plants and also assessed the population abundance on adaxial and abaxial leaf surfaces. We examined eight perennial species naturally occurring in the same area, in Halkidiki (northern Greece). They are Arbutus unedo, Quercus coccifera, Pistacia lentiscus, and Myrtus communis (evergreen sclerophyllous species), Lavandula stoechas and Cistus incanus (drought semideciduous species), and Calamintha nepeta and Melissa officinalis (nonwoody perennial species). Young and mature leaves were examined from the four sclerophyllous evergreen species for their epiphytic bacterial colonization, and it was found that mature leaves were highly populated compared to the younger ones except in M. communis. As regards the bacterial colonization of the two leaf surfaces, no differences were found in most species except for the drought semideciduous type where the two leaf surfaces behaved differently.