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The pH, exchange and potential acidity were determined in soil samples taken at depths of 0-30 cm and 30-60 cm, under Pinus elliottii(19, 14 and 19 years old), Pinus patula (19 years old), Pinus taeda (19 years old) and under native "cerrado" vegetation at an adjacent área. The samples were collected in a Dark-red Latossol in Assis City, São Paulo State, Brazil. The effects of Pinus cover were an increase in soil acidity (pH, exchange and potential acidity). No differences were found among soil under Pinus stands, neither of different ages nor of different species.

Em condições de campo, borbulhas de laranja 'Pera' foram enxertadas sobre porta-enxertos de limão 'Cravo'. As alturas de enxertia utilizadas foram 5, 10, 20 e 40 cm acima do colo dos porta - enxertos nas exposições norte, sul, leste e oeste. Utilizou-se como método de forçamento do enxerto, o corte parcial do porta-enxerto pouco acima da enxertia com envergamento (pique). As alturas e as exposições de enxertia não afetaram o pegamento dos enxertos. Ovigor das mudas não foi afetado pelas exposições de enxertia, mas foi pelas alturas. As alturas de 5 e 10 cm promoveram maior desenvolvimento e maior diâmetro da haste principal do enxerto.

The objective of this work is to determlne elements for utilization of quantitative analysis on plant growth, which is a valuable complement of experimental analysis in crop science, mainly plant productivity research.

Estudou-se a influência do ácido 2-cloroetilfosfônico, aplicado em cultura de fumo (Niaotiana tabacum L.) cultivar "Goianinho", em condições de campo, visando uniformizar e antecipar a colheita das folhas. Aplicou-se o produto comercial Ethrel (240 g/l de i.a), nas dosagens de 2,4, 6 e 8 litros/ha, quando nas folhas apre sentavam, na maior parte da planta o crescimento máximo. Após 6 dias do tratamento, foram as folhas colhidas, contadas e pesadas. Os resultados obtidos mostraram que o regulador vegetal utilizado promoveu um amadurecimento mais precoce, antecipando e uniformizando a colheita das folhas de fumo, independentemente das concentrações utilizadas, que não diferiram entre si.

No presente trabalho são apresentados a análise dos dados obtidos, através da mensuração de elementos xilemáticos , nos diferentes anéis de crescimento de um disco de madeira, formado ao nível do DAP de uma planta adulta de Eucalyptus teretícornis Smith. Pela observação dos dados obtidos, verifica-se o maior crescimento em comprimento das fibras e dos elementos do vaso ocorrem ao nível do 9°anel de crescimento, portanto, o Eucalyptus tereticornis Smith na região sul do Brasil tem o lenho adulto aproximadamente aos 9 anos de idade.

One kg of dry cocoa beans contains, in grams: N--33.4; P-2.1; K-8.1; Mg-1 .9; S-0.9; in mg: B-12; Cu-16; Fe-80; Mn-28; Mo-0.04; Zn-47. The partially decomposed hulls left in the field showed the following composition on the dry matter basis: N-2.20%; P-0.05; K-2.40; Ca--0.51; Mg-0.32; S-0.12; B-16 ppm; Cu-16; Fe-368; Mn-56; M0-0.06 and Zn-93. Leaves (third from the apex of freshly matured flushing) collected in a high yielding plantation (2.6 t dry beans/ha) showed the following mineral composition: N-1.98%; P-0;17; K-2.20; Ca-0.73; Mg-0.29; S-0.19; B-25 ppm; Cu-14, Fe-87; Mn-134; MO-0.16; Zn-96.

The essay insered in a global study about the spacing and nitrogen rate effects on the competitive relationship between weeds and upland rice crop. The treatments were located in a factorial desing 2x2x3 , when the variables were: two weed managment conditions - weeded and not weeded during all rice cycle - two row spacing - 0.40 and 0.60, e three nitrogen rate - 2.4 , 2.8 and 7.2 g de N/m of row. The essay was installed on Latossolo Vermelho Escuro sandy phase soil. Two valuations were realized: the first in the crop tillerinq and the second in the crop flowering. In the tillering phase the most important weed were Digitaria horizontalis and Indigofera hirsuta. The first weed showed higher contents of K, Mg, Fe and Mn and lower contents of N and Ca than the legumonosous weed. In comparison with the weeds, the rice contents of N, P, Fe, Mn and Zn were higher, the contents of Ca and Mg were lower. The K and Cu rice contents were lower than in D.horizontal in and higher than in l.hirsuta. In the flowering phase, the rice showed higher contents of P, Cu, Mn and Zn and lower contents of N, K, Ca, Mg and Fe, than the weed community. The row spacing and nitrogen rate effects showed different aspects, in according with the nutrient, weed especie and valuation period. In general, the weed effects were more drastics on the 0.60 m row spacing.

Leaves, systems and branches from trees of one year up to four years were collected from a plantation located at the BONAL S/A in Rio Branco, AC, Brazil the soilunder the plantation is classified as Red-yellow Latossol. Samples of the leguminous (Pueraria phaseoloides) and liter were also collected in order to estimate the total amounts of nutrients extracted and the cycling of the nutrients in the system. The results obtained showed that: - The dry matter produced (3,185 kg/ha) by the leguminous at 48 months is much greater than that produced by the rubber trees (2,787 kg/ha) at the same age. - The dry matter produced by the liter (5,912 kg/ /ha) is also greater than that produced by the rubber trees . - The total amount of nutrients content in the leguminous at 48 .months is estimate in 164 kg/ha in the rubber trees is approximate in 57 kg/ha. - The total amount of nutrients content in the mulch covering the soil at 48 months is estimate in 196 kg/ha. From the total amounts of nutrients extracted from the soil by the rubber trees and the leguminous at 48 months the following porcentage in nutrients return to the soil: K-21.7%; P-37.3%; S-51.2%; Zn-51.8%; Mg-54.4%; B-54.7%; Ca-56.4%; Cu-57-5%; N-58.5%; Mn-74.5% and Fe--90.7%.

Neste trabalho buscou-se identificar as plântulas de cinco taxa do gênero Brassica: B.napus, var. olei fera (colza), B.oleracea var. botrytis (couve-flor), B.oleracea var. capitata (repolho), B.oleroeca var. italica (brócolo) e B. pekinensis (couve-chinesa). Foram elaboradas chaves para adistinção das plântulas nos estágios cotiledonar, da primeira folha e da terceira - quarta folha e feitas as descrições. Foi possível a distinção das taxa por características corno: forma dos cotilédones e pilosidade, forma, bordo, cerosidade e nervação foliar.

Within the range of 15 to 240 minutes it was found that absorption increased in a linear fashion.By varying the external concentration of H2PO-4 from 10-7M to 10-2 M a dual pattern uptake was observed: a high affinity macnamism with a Km= 6.17 x 10-6M and a second one with low affinity (Km= 1.64 x 10-2M) . Absorption was raised when the external concentration of Mg ions varied from 10-6 to 10-4When supplied in the range of 10-6 to 10-2M the chloride salis of K and Ca rediced the absorption, the effect being traced to the CI ion. Zincsulfate (10-8to 10-4M) had no effect on phosphate absorption.

With purpose to study the influence of the detaching of spermoderm and position of seeds on germination and later growth of seedlings of Caesalpinia echinata Lam., an experiment was carried out in greenhouse of Didactic Vegetable Garden, Botany Department, ESALQ. It was installed two plots with 450 seeds each one, being one plot with and the other wi thout spermoderm. It was verified that seeds with spermoderm showed 76% germination, while seeds without spermoderm the germination was zero. It was observed the following parameters: length of future principal root (CR),distance between coll urn to insertion of cotyledonous leaves (DCFC), distance between cotyledonous leaves to insertion of definitive first leaf (DFCIFD), length and width of other definitive leaves. It was verified that position of seeds do not affected germination, but to character DCFD of growth seedling it was detected significance at 5% level, also for length of the first two definitive leaves.

Experiment was carried out to evaluate the effect of girdling the stem before taking the cutting, the previous position of the cutting In the stem, and the treatment of the cuttings with IBA plus KOH solution, on rooting of stem cuttings of Hevea brasiliensis. Stem cuttings were taken from three stem positions (base, median, and apical regions) from 12 months old plants. Girdling treatment was done 30 days before takingcutting using a'copper wire. This treatment did not affect rooting. IBA treatment was done using a 200 ppm IBA solution plus KOH, by immerging the base of the cuttings on it by 12 hours. This treatment caused phytotoxic symptons on cutting bases. It was observed a significant difference on the rooting of the cutting according to the cutting origin from the stem. The best rooting was obtained on cuttings taken from the base of the stem. Callus formation was more evident on girdling cuttings and median cuttings of rubber plant.

The objective of the present work was to study the effect of Triacontanol and Agrostemmin on rice seeds by evalluating germination, coleoptile and seedling root growing, under laboratory conditions. The Petri dishes received 10 ml of solution (ether and benzene) for Triacontanol treatments and distilled water for the Agrostemmin treatments. Results showed that the treatments does not present significant effects in relation to germination percent but a statistically significant effect with respect to seedling root growing was observed.

O efeito do extrato aquoso de três plantas daninhas, Cynodon dactylon (l.)Pers., Cyperus rotundus l. e Sorghum halepense (l.) Pers. sobre a germinação e o crescimento de plântulas de arroz (Oryza salina L. cv. IAC-165) foi estudado, com a finalidade de investigar a sensibilidade do arroz aos efeitos alelopáticos dessas plantas. Foram utilizados, na preparação dos extratos, raizes de Cynodon daclylon, tubérculos de Cyperus rolundus: e riomas de Sorglun halepense, os quais foram homoneizados em solução aquosa, submetidos a filtração e centrifugação. O sobrenadante foi aplicado no substrato de germinação das sementes, verificando-se, aos sete dias após a se meadura, que apenas os extratos de Cy-nodon daetylon e Sorghum halepense afetaram a porcentagem de germinação das sementes de arroz. Entretanto, o crescimento da radícula e da parte aérea das plântulas foi prejudicado pelos três extratos testados, sendo o efeito mais drástico causado pelo extrato de Cyperus, retundus.

No summary/description provided

The relative analitical absorption data of the macro and micronutrients, in the dry matter of common bean, cropped in soil of an Oxisol and an Alfisol, confined in 3,8 liter pots, were analised in relation to the comportamentaltendency due to the compaction levels of the soils, and further compared to the disponible absolute values. It could be verified a general tendency in increase the accumulation of Mg, Ca and Fe, and decrease of K by the shoots, and increase of the extraction of Mg, Ca and K, and of decrease of N by the roots. It could be observed a differential behavior between the relative and absolute data, principally of the roots, occurring inclusive an inversion of the general tendency of K, Ca and Fe. With the finality to compare the behavior between the different nutrients, the relative data seem to be the more apropriate ones, when all essential nutrients are considered.

Two common bean cultivars were grown on soil samples of an Oxisol (LR) and Alfisol (PVp), with and without fertilizer, subjected to 3 levels of compaction, and confined in 3,8 liter pots. The objective was to observe the diferential behavior of a bean cultivar considered tolerant and another sensible to the Al and the low P level in the soil. The harvested data permit to verify that the tolerant cultivar presents a greater root and a smaler shoot development (in weight), with the tendency to a preferential accumulation of P, K, Mg, Zn and Fe by the roots and of Ca and Mg by the top, independent of soil type, fertility and compaction level. Besides this presents a greater sensibility to compaction on substract with a higher fertility level, when considered the accumulation of dry matter of the shoot.

Soil samples of the A and B2 horizons of an Oxisol (LR) and.an Alfisol (PVp) were subjected to compaction, to offer resistance to cone penetrograph penetration of 0 - 8,8 - 17,6 kg/cm2. The soil samples were cultivated with common bean, cultivar Rico Pardo 896, during 67 days, In 3,8 liter pots in geenhouse, with the soil water content between the tension levels of 100 to 300 mbars. It could be verified, considering the different soil samples, that the dry matter production seems to correlate better with the efective aeration porosity. So it seems to be the better indicator for the plant dry matter production tendency in different soils, with different compaction degrees. The parameters soil bulk density, saturated hydraulic conductivity an mechanical resistance to penetro-graph did not seem good general indicators.

Soil samples of an orthic Haplacrox (LR) and an ochrultic Typustalf (PVp) were used In this experiments, including the A and B2 horizon, subject to compaction. They were confined in 3,8 1 pots, and incubated during 80 days (cultivated with beans during 67 days), with a soil water tension between 100 to 300 mbars. The physical determinations showed an increase of the soil bulk density, and a decrease of the total porosity and the saturated hydraulic conductivity. The micropores and bloqued pores increased in LR an decreased in PVp. The soil samples of the LR-B2 were less susceptible to changes due compaction, while of the PVp-B2 were the most susceptible, followed by those of the LR-A1 and the PVp-Ap. The chemical data showed tendencies of increase of the carbon level in the A horizon without fertilizer, and decrease with fertilizer, on LR and PVp with compaction increase. They also showed decrease of the available P and increase of the exchangeable Al with fertilizer, and reduction of the exchangeable Mg without and with fertilizer in the A horizon of both soils, as the compaction was increased.

Corms of 2nd cycle, type jumbo with 84 g/unity and type 1 with 35 g/unity were compared. It was verified that: type jumbo had better profit in the production of: weight of corms, number of corms, lenght of stipe, lenght of spike and stipe of better quality. The type number 1 showed better profit for weight of corms planted by weight of corms and cormels harvest.