Search

Copyright of Revista em Agronegócio e Meio Ambiente is the property of Revista em Agronegocio e Meio Ambiente and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Water stress can affect all aspects of plant growth and development, compromising its productive potential. The cultivation of fruit species native to the Cerrado and the study of their behavior under conditions of low water availability are necessary activities, in view of their socioeconomic and environmental potential. This study was conducted to evaluate the effect of water deficit on growth and biomass production of the cagaita tree (Eugenia dysenterica DC.), a species endemic to the Cerrado (Brazilian Savannah). The experiment was performed in a greenhouse for 120 days in a randomized block design (RBD), with a double factorial arrangement (2x5), corresponding to two cagaita mother plants and five water conditions. We evaluated the growth and leaf, stem and root functional characteristics. The most severe water deficit conditions reduced shoot growth, number of leaves, production of biomass and dry matter and increased the specific and per plant mass root length of cagaita plants. Deficit extension had negative effects on its growth and development. There was a statistical difference between mother plants, with mother plant 2 being more resistant to drought. The application of a severe or longer water deficit affected shoot growth and reduced the appearance of new leaves. The stress caused by water deficiency allowed an increase in root functional characteristics, supporting the hypothesis that plants under adverse conditions focus on higher biomass production and convert a higher amount of dry matter into the roots. Leaf area did not show to be a functional characteristic, explaining the stress effects in E. dysenterica DC plants. [ABSTRACT FROM AUTHOR]

Pot capacity (PC) is a direct method of determining field capacity (FC) for experiments with plantings in pots. The objective of this study was to evaluate different laboratory methods to determine field capacity and compare them with the pot capacity method. The experimental design was completely randomized (CRD), with nine treatments (methods of obtaining FC) and four replications, totaling 36 experimental plots. The mean values of moisture contents in the FC of the nine methods were compared, being eight empirically obtained and one directly in the greenhouse, defined as a control treatment (PC). The relative accuracy (RA) for all treatments was determined in relation to the control treatment. The estimation of the upper limit of available water in the soil varies depending on the method, and a decreasing order of moisture levels can be observed at FC: FC-Lab4pts > FC-Labip > FC-Lab8pts > PC > FC-Lab6pts > FC-6KPa > FC-LabSWRC > FC-10KPa > FC-33KPa. The treatment FC-Lab6pts has the relative accuracy closest to 100% and can be a practical alternative to PC. The use of 4, 6, 8 or 10 points for modeling the SWRC does not interfere with the quality of the FC estimated by the Dexter inflection point method, which is much more efficient for experiments of this nature. The use of potentials -10 kPa and -33 kPa is not adequate to estimate FC in tests with pots in a greenhouse. [ABSTRACT FROM AUTHOR]

Knowing the behavior of a growing and productive species in a given regions, subject-specific management, is basic to the development of new production technologies. This study aimed to evaluate the characteristics of the vegetative growth, yield and fruit quality of Pérola cultivar pineapple for different irrigation depths. The work was developed in the Universidade Vale do Rio Doce, in the city of Governador Valadares, MG. The experiment was carried out in randomized blocks design with three replications, being the experimental plots disposed in perpendicular strips to a sprinklers line, following the land slope. Different irrigation depths composed the treatments: L1 = 0, L2 = 81, L3 = 203, L4 = 348, L5 = 452 and L6 = 543 mm per season. The following characteristics were evaluated: number of slips, crop productivity, fruit biomass, crown biomass, fresh and dry leaf biomass A, B, C and D, fresh and dry stem biomass, fruit length without crown, crown length, fruit diameter, stem base diameter and fruit content total soluble solids. From the obtained results, it can be concluded that there was increment in the effect of irrigation depths over the crop yield, fruit mass, fruit length, and crown length of pineapple, number of seedlings in peduncle, mass of leaves, dry mass of leaves and mass of stem. Keywords: Ananas comosus L., 'Pérola', pineapple, management. [ABSTRACT FROM AUTHOR]

In order to study the effect of nitrogen (N) and potassium (K) rates on the growth and nutrient accumulation of shoot shoots (Malpighia emarginata DC), an experiment was carried out under greenhouse conditions at Federal University of São João Del Rei-UFSJ in Sete Lagoas, MG, using seedlings from the cutting process. A 4 x 4 factorial scheme was used in a randomized complete block design with three replications and three plants per plot. The factors consisted of four doses of N (0, 200, 400 and 600 mg dm-3) and four doses of K (0, 100, 200 and 300 mg dm-3). At 110 days after transplanting, the seedlings were evaluated for root length, root diameter, stem number, leaf number and Dickson Quality Index, and were then harvested, oven dried at 65 °C to obtain the material dry matter of the aerial part, root and total, being crushed for the determination of the concentration of nutrients. The accumulated amounts of N, P, K, Ca, Mg, S, B, Cu, Zn, Fe and Mn in the shoot dry matter were determined. The isolated doses of N and K influenced the growth variables and increased the accumulated amounts of P, K and Zn, the accumulated amounts of the other nutrients being affected only by N. The accumulation of nutrients in the seedlings followed the decreasing order N> Ca> Mg> P> S> K> Mn> B> Zn> Fe. [ABSTRACT FROM AUTHOR]

The cv. Bordô grapevine (Vitis labrusca L.) is characterized by rusticity and greater resistance to fungal diseases, good adaptability to climatic changes and good aptitude for the production of juices and wines. However, many of these characteristics can also be influenced by the rootstock. Thus, this work aimed to evaluate the effect of diurnal and rootstock variation on the photosynthetic capacity and stomatal conductance of Bordô vine. The experiment was carried out in a randomized complete block design, in a factorial arrangement with time subdivided plots, the IAC 572, IAC 766 and 1103 Paulsen rootstocks were used in the period from 08:00 to 16:00 h with intervals of 2 h in 2 evaluation periods, the months of April and May, using three replicates and four plants per experimental unit. The rate of liquid photosynthesis (Pn), leaf stomatal conductance (gs), vapor pressure deficit and photosynthesis were evaluated. The rootstocks IAC 572 Jales, IAC 766 Campinas and 1103 Paulsen, did not alter the net photosynthesis rate and leaf stomatal conductance of cv. Bordô, in both periods evaluation. The period of greatest photosynthetic rate and higher stomatal conductance of leaves is given in the morning. However, both decreases as the air temperature and vapor pressure deficit increase, as well as the reduction of the relative humidity of the air. The best time interval for evaluating the net photosynthesis rate for cv. Bordô is between 9 h and 11 h, since the conditions in this time frame are more suitable for photosynthesis. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ceres is the property of Revista Ceres and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)