Agronomic performance of cassava genotypes from the in vitro shoot tip culture submitted to clonal cleaning / Desempenho agronômico de genótipos de mandioca provenientes do cultivo in vitro de ápices caulinares submetidos à limpeza clonal

This study aimed to evaluate the agronomic performance of cassava genotypes from the in vitro shoot tip culture to eliminate the cassava frogskin disease for several root and aerial part characteristics. Cassava plants from accessions BGM0315, BGM0464 and BGM0841 infected with cassava frogskin disease were grown in a greenhouse after clonal cleaning. Cuttings from the three accessions were subjected to tetracycline concentrations (0, 5, 10 and 15 mg L-1) for three minutes, and then maintained in an acclimatized chamber (35 ± 1 °C and 16 hour photoperiod). Shoots were disinfected for excising shoot tips (0.2 mm and 0.4 mm) and inoculated in a culture medium containing the same concentrations of tetracycline used in the cuttings. After 60 days of cultivation, the explants were transferred to medium without antibiotic, 30 days later they were acclimatized for a period of 70 days for subsequent planting in the field. Seven months after planting, agronomical evaluation was held for root and aerial part characteristics. No influence of isolated shoot tip size was noticed on agronomic characteristics, while the addition of tetracycline in the culture medium, specifically at the concentrations of 5 mg L-1 and 15 mg L-1, was favorable to the development of the root system of plants in the field. The results revealed that the agronomic performance of cassava plants derived from in vitro cultivation are higher for the production of basic propagation material for the following production cycles, as well as root production for commercial use with subsequent generation of income.

Este trabalho teve por objetivo avaliar o desempenho agronômico de genótipos de mandioca provenientes do cultivo in vitro de ápices caulinares para eliminação da doença couro de sapo (Cassava frogskin disease, CFSD), em relação a diversas características de raiz e da parte aérea. Para isso, foram utilizadas plantas de mandioca dos acessos BGM0315, BGM0464 e BGM0841 cultivadas em casa de vegetação após a limpeza clonal. Inicialmente, foram utilizadas manivas de plantas adultas infectadas com couro de sapo. Essas manivas foram submetidas a concentrações de tetraciclina (0, 5, 10 e 15 mg L-1) por 3 minutos. Posteriormente, foram mantidas em câmara climatizada (35 ± 1°C e fotoperíodo de 16 horas). Brotos foram desinfestados para excisão de ápices caulinares (0,2 mm e 0,4 mm) e inoculados em meio de cultura contendo as mesmas concentrações de tetraciclina empregadas nas manivas. Aos 60 dias de cultivo, os explantes foram transferidos para meio sem antibiótico, 30 dias após foram aclimatizadas por um período de 70 dias para posterior plantio em campo. Aos sete meses após o plantio realizou-se a avaliação agronômica para características de raiz e parte aérea. Não houve influência do tamanho do ápice caulinar isoladamente nas características agronômicas avaliadas, enquanto que a adição de tetraciclina no meio de cultura, especificamente nas concentrações de 5 e 15 mg L-1, foi favorável ao desenvolvimento do sistema radicular das plantas no campo. Os resultados evidenciaram que o desempenho agronômico de plantas de mandioca provenientes do cultivo in vitro são elevados para produção de material propagativo básico para os ciclos seguintes de produção, bem como para produção de raízes para uso comercial com consequente geração de renda.

Nitrogênio no crescimento da planta e na qualidade de raízes da mandioquinha-salsa / Nitrogen on plant growth and storage root quality of Arracacha

RESUMO: O nitrogênio (N) é o segundo nutriente mais absorvido pela mandioquinha-salsa. No entanto, ainda existem dúvidas sobre a influência que esse nutriente pode exercer sobre o crescimento da planta e a qualidade das raízes de reserva. Assim, objetivou-se com este trabalho avaliar a influência da adubação nitrogenada no crescimento da planta e na qualidade físico-química e nutricional das raízes de mandioquinha-salsa. O experimento foi conduzido em um Latossolo Vermelho distrófico de textura arenosa, no delineamento experimental de blocos ao acaso, com quatro repetições. Os tratamentos foram constituídos pelas doses de 0, 50, 100 e 200kg ha-1 de N. O crescimento das partes vegetativas da planta de mandioquinha-salsa aumentou linearmente com a adubação nitrogenada, mas a massa média e a produtividade das raízes de reserva aumentaram até as doses estimadas de 121 e 148kg ha-1 de N, respectivamente. A adubação nitrogenada aumentou os teores de amido e de proteína das raízes e diminuiu os teores de açúcares totais, porém, sem influenciar a qualidade nutricional delas.

ABSTRACT: Nitrogen (N) is the second most absorbed nutrient by Arracacha. However, there are still doubts about the influence that this nutrient can have on plant growth and the quality of the storage roots. Thus, the aim of this research was to evaluate the influence of nitrogen fertilization on plant growth and physical-chemical and nutritional quality of storage roots of Arracacha. The experiment was conducted on an Oxisol of sandy texture, in a randomized complete block design, with four replications. The treatments consisted of rates of 0, 50, 100, and 200kg ha-1 N. Growth of vegetative parts of Arracacha increased linearly with nitrogen fertilization, but the storage root mean weight and the yield of storage roots increased up to estimated rates of 121 and 148kg ha-1 N, respectively. Nitrogen fertilization increased the starch and protein content of the storage roots and reduced the content of total sugar, but without affecting the nutritional quality of the same.

Effect of Panchakavya on Soil Enzyme Activity in Ashwagandha.

The study was carried out to investigate the effect of panchakavya made from cow (PK-C) and buffalo (PK-B) products on urease and dehydrogenase activity and root yield of Ashwagandha and it revealed that soil application of PK-C @ 15% recorded the highest urease activity at both the stages of crop (85.24, 44.56 at flowering and harvest during rabi 2007-08 and 81.07, 35.50 μg of NH4 + released g-1 soil h-1 at flowering and harvest in kharif 2008). The highest dehydrogenase activity also noticed in the same treatment (91.05, 49.05 μg of TPF g-1 soil day-1 at flowering, harvest during rabi 2007-08 and 81.00,, 39.64 μg of TPF g-1 soil day-1 at flowering, harvest in kharif 2008) during both the years. The highest dry root yield was recorded with PK - C @ 5% - 4 sprays (290 and 280 kg ha-1 during both the years, respectively).

Effect of Autotoxicity and Soil Microbes in Continuous Cropping Soil on Angelica sinensis Seedling Growth and Rhizosphere Soil Microbial Population / 中草药·英文版

Objective: To study the effect of autotoxicity and the co-effect of autotoxicity and soil microbes from continuous cropping soil on Angelica sinensis growth, root yield and content of essential oils, and soil microbal population. Methods: The pot experiments were conducted upon A. sinensis seedlings in continuous cropping soil. At the different growth stages, we determined the seedlings in growth parameters, root yield, content of essential oils, ethanol extract, and cultivable microbial populations in rhizosphere soil. Results: A. sinensis seedlings were significantly inhibited in growth, root yield and quality. Compared with the control, the composition and structure of soil microbes were changed and the diversity indexes of bacteria functional groups were reduced in rhizosphere soil of A. sinensis. A. sinensis cropping problems were more seriously after the treatment with combination of autotoxicity and soil microbes than with autotoxicity alone. Conclusions: The autotoxicity and soil microbes from continuous cropping soil of A. sinensis could cause the continuous cropping obstacle together.

Prácticas agrícolas para el cultivo de Xanthium strumarium L (guizazo de caballo) con fines terapéuticos / Agricultural practices for the culture of Xanthium strumanium L (guizazo de caballo) with therapeutic aims

Xanthium strumarium (guizazo de caballo) se encuentra entre las plantas con antividad antimitótica. OBJETIVOS: determinar en esta especie los aspectos agrícolas que garanticen el adecuado material vegetal. MÉTODOS: se realizaron estudios durante 2007-2009, donde se evaluaron dos fechas de siembra: junio y julio; dos distancias de siembra 90 x 30 cm y 90 x 50 cm y dos momentos de cosecha: 3 meses de edad (parte aérea y raíces) en plantas que presentaban estado de floración-fructificación y 4 meses de edad (solo raíces) en plantas en fructificación. Las semillas, obtenidas de areales silvestres, se sembraron en parcelas, 3 repeticiones en cada caso. Se evaluó la altura de las plantas en el momento de la cosecha, se seleccionaron 10 plantas/parcelas y se cosecharon 39 plantas/parcelas en la distancia de 90 x 30 cm y 24 plantas en la distancia de 90 x 50 cm, en el caso del follaje se evaluaron los rendimientos de 10 plantas/parcelas en cada caso. RESULTADOS: se observó que bajo cultivo la altura de las plantas fueron mayores en las que se sembraron en junio, con distancia de 90 x 30 cm, en tanto que en las de julio se comportaron de forma similar, independientemente a las distancias de siembra empleadas y en correspondencia con ello los rendimientos resultaron iguales; sin embargo, cuando se quieren cosechar también las raíces, es preferible hacer la cosecha a los 3 meses de edad y, en este caso, los mayores valores se presentaron en las siembras de julio, con distancia de 90 x 30 cm. CONCLUSIÓN: para el aprovechamiento de la planta con doble propósito: parte aérea y raíces, pues en ambas se ha encontrado la actividad antimitótica, la siembra se debe realizar entre junio y julio a la distancia de 90 x 30 cm y recolectarse el material a la edad de 3 meses

Xanthium strumarium (guizazo de caballo) is among the plants with antimitotic activity. OBJECTIVES: to determine in this species the agricultural features to guarantee the appropriate plant material. METHODS: during 2007-2009 studies were conducted to assess to sow dates: June and July; two sow distances 90 x 30 cm and 90 x 50 cm at two sow periods: three months of age (aerial parts and roots) in plants with a flowering-fructification states and four months of age (only roots) in plants in fructification process. Seeds obtained from wild aerial plants were sowed in plots, three repetitions in each case. The plants height was assessed at the harvest moment, choosing 10 plants/lots and 39 plants/lots were growed at a 90 x 30 cm distance and 24 plants at the 90 x 50 cm distance, in the case of foliage the yields of 10 plants/lots were assessed in each case. RESULTS: there was that at culture the plants heights were higher in those sowed in June at a 90 x 30 cm distance while those sowed in July behaved in a similar way independently of the sow distances used and in correspondence with it, the yields were similar; however, when we desire to grow also the roots, it is preferable to grow at three months of age, and in this case, the higher values were in sows of July at a 90 x 30 cm distance. CONCLUSION: for the plant exploitation with a double aim: aerial parts and roots, since in both there is antimitotic activity, sow must to be performed between June and July at a 90 x 30 cm distance and to harvest the material at three months age