Allelopathy and allelochemical quantitative analysis in Pinto peanut (Arachis pintoi)

Pinto peanut (Arachis pintoi) considered as a perennial legume animal fed plant with good soil fertility improvement was uesed for its allelopathy that had been reported on the germination of Ageratum conyzoides L, Comnyza canadensis L. Cronq., Bidens pilosa L., Solanum lycopersicum and Capsicum annum. through the solutions extracted from different parts of pinto peanut on mustard greens (Brassica juncea), barnyardgrass (Echinochloa crus-galli) and junglerice (Echinochloa colonum). Consideration of the growth of hypocotyls and rootlets at 48 hours after incubation with pinto peanut extracts, results showed that 1.0 g/ml of the methanolic pinto peanut stem extract greatly inhibited 100% mustard greens growth, 77.7% and 93.5% the hypocotyls and rootlets growth of barnyardgrass, 57.2% and 92.7% the hypocotyls and rootlets growth of junglerice, respectively. The allelopathic activity after liquid-liquid extraction of the ethyl acetate phase greater than the aqueous phase. Allelopathic extract loading from C18 chromatographic column was purified by HPLC to obtain 6 phenolic compounds with the contents in 1 g fresh pinto peanut weight were 0.214 μg (cinamic acid), 0.8344 μg (caffeic acid), 7.7676 μg (coumaric acid), 2.2354 μg (ferullic acid), 0.045 μg (2-4 dimehydroxy benzoic) and 32.1162 μg (salicylic acid). These results should be accordingly considered in the production of biological herbicides.

Nódulos presentes en leguminosas asociadas a pasturas de Brachiaria sp en la Amazonia Colombiana

Se estudiaron 23 pasturas de Brachiaria sp dedicadas a la producción bovina doble propósito, para identificar especies de leguminosas presentes y obtener muestras de raíces para extracción y recuento de nódulos. Toda el área correspondió a un total de 149,14 ha, donde solo 84,26 ha contaban con la presencia de leguminosas Desmodium sp, Pueraria phaseoloides, Galactia striata, Arachis pintoi, Stylosanthes sp, Mimosa púdica y Centrosema sp, cuya cobertura fue del 2,89% de dicha área. La especie con mayor porcentaje de cobertura promedio fue A.pintoi con 5,36% seguida de Stylosanthes sp con 5%, G.striata con 3,89% y P.phaseoloides con 2,62%. Las restantes se encontraron en un rango inferior a 2% del área de pastura. Se halló en el estudio un mínimo de 7 nódulos en raíces de Centrosema sp y G.striata, así como un número máximo de 194 nódulos en Desmodium sp. Las cantidades superiores a 100 nódulos por planta solo correspondieron a Desmodium sp, el cual reveló una inoculación satisfactoria que se asoció con su potencial de fijación de nitrógeno mediada por simbiosis. La especie con menor número de nódulos fue M. púdica, hallada en el 4,3% de las pasturas evaluadas, siendo la única de las leguminosas muestreadas que no es consumida directamente por los bovinos y se desarrolla como especie no deseada, indicadora de estados de degradación de pasturas.

Risk Reduction and Productivity Increase Through Integrating Arachis pintoi in Cattle Production Systems in the Colombian Orinoquía

In many parts of the foothills of the Orinoquía region of Colombia, cattle production takes place on poorly drained soils. The region is dominated by extensive grazing systems of Brachiaira humidicola cv. Humidicola, a grass with high adaptation potential under temporal waterlogging conditions. Inadequate management practices and low soil fertility result in degradation, however, with important negative effects on pasture productivity and the quality and provision of (soil) ecosystem services–a situation that is likely to worsen in the near future due to climate change. Against this background, AGROSAVIA (Corporación Colombiana de Investigación Agropecuaria) selected Arachis pintoi CIAT 22160 cv. Centauro (Centauro) as a promising alternative for the sustainable intensification of livestock production and rehabilitation of degraded areas. This study assesses dual-purpose milk production in the foothills of the Colombian Orinoquía from an economic perspective. We compare two production systems: the Centauro–Brachiaira humidicola cv. Humidicola association (new system) and Brachiaira humidicola cv. Humidicola as a monoculture (traditional system). We used cashflow and risk assessment models to estimate economic indicators. The projections for economic returns consider changes in forage characteristics under regional climate change scenarios RCP (2.6, 8.5). The LIFE-SIM model was used to simulate dairy production. Results show that the inclusion of Centauro has the potential to increase animal productivity and profitability under different market scenarios. The impact of climatic variables on forage production is considerable in both climate change scenarios. Both total area and potential distribution of Centauro could change, and biomass production could decline. Brachiaira humidicola cv. Humidicola showed better persistence due to higher nitrogen levels in soil when grown in association with Centauro. The legume also provides a number of ecosystem services, such as improving soil structure and composition, and also contributes to reducing greenhouse gas emissions. This helps to improve the adaptation and mitigation capacity of the system.

Screening insectary refugia plants that increase the performance of Diadegma semiclausum Hellen (Hymenoptera: Ichneumonidae) against diamondback moth larvae

Asmoro PP, Dadang, Pudjianto, Winasa IW. 2021. Screening insectary refugia plants that increase the performance of Diadegma semiclausum Hellen (Hymenoptera: Ichneumonidae) against diamondback moth larvae. Biodiversitas 22: 4254-4260. Habitat manipulation through the planting of insectary refugia plants is one way of controlling pests. These refugia plants serve as the source of nutrients that improve the fitness of parasitoid against insect pests. In the cabbage agroecosystem, the presence of refugia plants is expected to benefit the parasitoid D. semiclausum. This study aimed to select insectary refugia plants beneficial for the D. semiclausum in term of attracting and increasing their longevity, and parasitization ability against P. xylostella larvae. Ten species of refugia plants were used in this study, i.e., Ageratum conyzoides, Galinsoga parviflora, Sphagneticola trilobata, Synedrella nodiflora, Portulaca oleracea, Rorippa indica, Brassica rapa, Apium graveolens, Ocimum basilicum, and Arachis pintoi. The methods used in this study included testing the response of the imago olfactory to refugia plants and its effect on the longevity and parasitization level. The results showed that of the ten species of investigated, R. indica and A. graveolens were the most attractive for the presence of parasitoids. The two refugia plants could also increase the longevity and parasitization rate compared to the water treatment. R. indica and A. graveolens are recommended as refuge plants in the cabbage agroecosystems to control P. xylostella.

CUTTING ABILITY AND GROWTH OF THREE COVER CROPS [ ARACHIS PINTOI (L.) KRAPOV & W.C. GREG. ARACHIS REPENS (L.) HANDRO DESMODIUMADSCENDENS (SW.) DC.] IN NURSERY

In the search for alternative practices to the excessive use of herbicides for control of weediness, strategies based on the domestication and multiplication of cover crops are more and more explored. The propagation by cuttingof these plants have been the subject of numerous studies because of unavailability andcost-prohibitive of their seeds. The aim of this study was to compare the growthandcuttingabilityofA. repens, A. pintoï and D.adscendens. These cover plants were propagated by cutting in coir and put on raised bamboo clays with shade, in greenhouse. For each specie, parameters of vegetative recovery and growth were assessed. The results reported that recovery abilities were most important toA. pintoï (89.35%) and A. repens (86.39%). However, plant growth was better for D. adscendens, with a vigour index more than double with that ofboth theother species. The results obtained show that these three cover crop species are relatively easy to propagate by cutting in nursery.D. adscendens and A. repens are potentially usable in large scaleas cover cropstocontrol weeds in agricultural parcels.

Pengaruh Aplikasi Insektisida dan Teknik Pengendalian Gulma Terhadap Kelimpahan Populasi dan Intensitas Serangan Hama Utama pada Tanaman Lada (Piper nigrum L.)

Pengendalian penggerek batang lada Lophobaris piperis Marsh (Coleoptera: Curculionidae) dan penghisap buah lada Dasynus piperis China (Hemiptera: Coreidae) dapat dilakukan dengan menggunakan teknik aplikasi insektisida dan pengendalian secara kultur teknis. Penelitian ini bertujuan untuk mengetahui pengaruh teknik frekuensi aplikasi insektisida kimia dan teknik pengendalian gulma terhadap kelimpahan dan intensitas kerusakan yang diakibatkan oleh hama Lophobaris piperis Marsh and Dasynus piperis China pada tanaman lada. Penelitian dilaksanakan di kebun petani lokal dengan kriteria kebun yang dipilih berupa kombinasi antara teknik pengendalian gulma dengan metode penyiangan, herbisida dan tanaman penutup Arachis pintoi Krap. & Greg. serta frekuensi aplikasi insektisida sebanyak 2 kali dan 4 kali setahun. Hasil penelitian mendapatkan bahwa kelimpahan hama tertinggi terdapat pada kebun lada yang menerapkan teknik pengendalian gulma menggunakan penyiangan dan aplikasi herbisida yang dikombinasikan dengan aplikasi insektisida sebanyak 4 kali setahun. Intensitas kerusakan mutlak dan intensitas kerusakan relatif tertinggi ditemukan pada kebun lada dengan aplikasi insektisida sebanyak 2 kali setahun. Intensitas kerusakan cenderung menurun pada kebun lada yang menerapkan teknik pengendalian gulma menggunakan tanaman A. pintoi.

CARACTERÍSTICAS PRODUTIVAS DA PASTAGEM MISSIONEIRA-GIGANTE EM CULTIVO ESTREME E EM CONSÓRCIO COM AMENDOIM-FORRAGEIRO SOB PASTEJO

Comparou-se produção de massa seca, taxa de acúmulo de forragem, oferta de forragem e eficiência de pastejo, bem como a distribuição sazonal da produção, do cultivo estreme de Axonopus catharinensis Valls ao seu consórcio com Arachis pintoi, de setembro de 2014 a agosto de 2015 em propriedade rural de Ipumirim/SC. O delineamento experimental assumido foi o inteiramente casualizado, com 02 tratamentos: missioneira-gigante estreme (MG) e consorciada com amendoim-forrageiro (MGA), com 04 repetições (piquetes). Quando a missioneira-gigante atingia 20-25 cm de altura, ocorria a entrada das vacas em lactação para o pastejo. Os dados de pré-pastejo foram obtidos com gaiolas de exclusão e os de pós-pastejo com quadrado de madeira de 0,25 m2 lançado aleatoriamente sobre a resteva. Submeteu-se os dados à análise descritiva, testes de homogeneidade e normalidade, análise de variância e teste de comparação de médias por Tukey (p<0,05). MGA produziu 21,2 t MS ha-1 e MG 18,1 t MS ha-1. A distribuição sazonal da produção de MS foi mais equilibrada para MGA. A taxa de acúmulo de forragem, a oferta de forragem e a eficiência de pastejo foram maiores em MGA.

Phân lập và tuyển chọn một số dòng vi khuẩn từ lá thực vật có khả năng kích thích sinh trưởng cây trồng

Nghiên cứu thực hiện nhằm phân lập vi khuẩn kích thích sinh trưởng cây trồng từ lá thực vật. Môi trường nuôi cấy ammonium mineral salt (AMS) được sử dụng để phân lập vi khuẩn. Kết quả đã phân lập được 28 dòng vi khuẩn từ lá của 6 loài thực vật khác nhau gồm mồng tơi (Basella rubra L.), hoa hồng (Rosa chinensis Jacq.), chiều tím (Ruellia brittoniana), cỏ đậu (Arachis pintoi), cơm nguội (Ardisia quinquegona Blume) và bình bát dây (Coccinia grandis (L) Voigt) dựa trên hình thái và màu sắc của khuẩn lạc. Các chỉ tiêu về tỉ lệ nảy mầm, chiều dài rễ, chiều cao chồi và số rễ của hạt bắp được khảo sát để đánh giá khả năng kích thích sinh trưởng của các dòng vi khuẩn phân lập. Các dòng vi khuẩn phân lập có hình thái khuẩn lạc và tế bào rất đa dạng. Hai dòng vi khuẩn ký hiệu HH5 và MT6 làm gia tăng tỉ lệ nảy mầm và sinh trưởng của hạt bắp tốt nhất trong các dòng vi khuẩn phân lập. Bên cạnh đó, nghiên cứu còn cho thấy ở mật số 106 CFU.mL-1 cả hai dòng vi khuẩn giúp gia tăng tỉ lệ nảy mầm và sinh trưởng của cây bắp tốt hơn so với mật số 107, 108 và 109 CFU.mL-1. Kết giải mã trình tự đoạn gene 16S rRNA cho thấy hai dòng vi khuẩn HH5 và MT6 lần lượt có mối quan hệ gần...