Young guava plants were grown in a nutrient solution in the presence of 0, 5, 10, 15, 20 and 25 mg L-1 aluminum, with pH being kept at 4.0. After 110 days, the plants were harvested and their content of macronutrients, Cu, Fe, Mn, Zn and Al were determined. Visual toxicity symptoms, developed under 20 and 25 mg L-1 aluminum, were as follows: reduction in height, absence of branching, decrease in diameter of stem dark roots and smaller leaves presenting […]

A soil sampler was designed and constructed to extract and evaluate undisturbed 75 mm diameter core samples at a depth of up to 0.60 m. Soil sample quality was evaluated and compared using traditional methods. The sampler consisted of a removable polyvinyl chloride (PVC) standard sewage pipe to receive the soil, an aluminium encasing sleeve and a steel conic cutting, surrounded by an auger with three cutting chisels. The soil sampler was adapted to a specially-designed off-road vehicle (VAS). The […]

Root growth impairment has sometimes been attributed to zinc deficiency. A greenhouse experiment was conducted in Botucatu, SP, Brazil, in 1997/98, using 2.5 L pots. Zinc redistribution within the plant and the effect of zinc deficiency on root growth were studied in corn (Zea mays) plants grown in nutrient solution containing from 0.0 to 2.0 µmol L-1 of Zn. Half of the pots also received foliar application of Zn. The experiment was terminated 40 days after plant emergence. Dry matter […]

The effects of different weed control methods in coffee (Coffea arabica L.) on some soil physical quality indicators were studied. The essay was installed in 1977 at the EPAMIG Experimental station in São Sebastião do Paraíso (MG), Brazil, in a coffee plantation on a Dusky Red Latosol. Coffee cultivar ‘Catuaí Vermelho’ LCH 2077-2-5-99 was planted at 4x1m spacing. Mower (RÇ), coffee tandem disk harrow (GR), rotary tiller (RT), post (HC) and pre-emergency herbicides (HR) and hand hoe (CM), were used […]

Imazaquin herbicide is an organic molecule presenting ionizable functional groups, with its sorption depending on soil pH and electrical charges. In this research, sorption of imazaquin was evaluated on an Anionic Acrudox at different soil depths and pH values. Radiolabelled (14C) molecules were employed to study imazaquin sorption, which was estimated by the difference between applied concentration and that remaining in solution. The sorption data were fitted to Freundlich equation to determine the sorption coefficient values (Kf), which were, overall, […]

The aim of this work was to evaluate the influence of seed pelleting with lime and with ‘Magnesian Thermophosphate’ on ionic absorption of three sorghum genotypes (Sorghum bicolor (L.) Moench), cv BRS 701, BRS 304 e BRS 601. Pelletized and non-pelletized seeds were germinated during eight days at room temperature. After this period, eight plants with uniform root and shoot development, from each treatment, were transferred to a Hoagland solution. Phosphorus and potassium absorption parameters were determined after 20 days. […]

Root system growth of the common bean, variety IAC-Carioca, under center pivot irrigation in rotation with fallow; corn; black oat; sunn hemp (Crotalaria juncea L.); pigeon pea [Cajanus cajan (L.) Millsp.] and velvet bean (Mucuna aterrima) was evaluated during a non-conventional (Autumn – Winter) cultivation period, from 1993 to 1995, on a typic Haplorthox soil, at an experimental area of the Instituto Agronômico, in Ribeirão Preto, São Paulo, Brazil. The crop sequences of common bean with corn and green manure […]

Soybean [Glycine max (L.) Merrill] plants establish a symbiosis with bacteria belonging to the genus Bradyrhizobium, realizing the biological N2 fixation process. The inoculation with selected rhizobial strains guarantees the maximization of the biological process. In Brazil, almost 13 million doses of inoculants, mainly peat based, are commercialized annually. However, the peat adhesion to the soybean seeds is low, requiring the use of adhesives. The current recommendation is the use of a water sugar cane solution at 25%, but this […]

In order to be used in a program of inoculation, efficient arbuscular mycorrhizal fungi (AMF) must be able to cope with the indigeneous fungal population. An experiment was conducted under greenhouse conditions at the Embrapa Cassava and Fruit Crops in Cruz das Almas (BA), Brazil, with the objective to evaluate the competitive capability of selected fungi, using natural soil with Tainung no. 1 variety. A Yellow Oxisol with 3 mg dm-3 of available P was used. Three exotic and three […]

Soybean [Glycine max (L.) Merrill] inoculation and reinoculation are essential to guarantee the maximization of the biological N2 fixation process. Most inoculants commercialized for soybean in Brazil are peat-based, but there are doubts about the dose of peat inoculant which should be recommended, specially under stressing conditions or in areas previously inoculated. Therefore, for the central region of Brazil, the recommendation is 1.000 g of inoculant/50 kg of seeds, with a sugar cane solution as adhesive. However, in this study […]