Periphyton on natural substratum in jurumirim reservoir (São Paulo, Brazil): Community biomass and primary productivity

Seasonal variation in the biomass and primary productivity of the periphyton on natural substratum (internodes of Echiiwchloa polystaclya HBK Hitch.) was studied during one year (from August 1993 to July 1994) in a lagoon with permanent connection with a river. We also analysed the relationships between the hydrological regime, climatic conditions and physico-chemical variables of water with the biological compounds of the periphyton. Values of dry mass, ash-free dry mass, chlorophyll a and phaeophytin of periphyton ranged from 0.55±0.24 g m-2 to 7.86±4.93 g m-2; 0.28±0.18 g m-2 to 3.72±2.23 g m-2; 0.57±0.09 mg m-2 to 15.57±4.52 mg m-2; 0.03±0.03 mg m-2 to 4.74±3.46 mg m-2, respectively. The primary productivity of periphytic algae measured by C14 method ranged from 6.45±1.29 mg C m-2 h-1 to 52.88± 7.55 mg C m-2 h-1. The biomass showed a peak in October 1993, February and April 1994. Higher value of primary productivity was recorded in December 1993 and January 1994 and was due to the peculiar light and nutrition conditions during this period. We conclude that biomass and productivity of the community are controlled mainly by hydrological regime (fluctuations of water level). © INTERNATIONAL SCIENTIFIC PUBLICATIONS.

Nutrients foliar content for high productivity cultivars of guava in Brazil

Commonly grown in tropical and sub-tropical regions, guava (Psidium guajava L.) is an important fruit crop of Brazil. It is cultivated on a large scale in São Paulo state, and covers about 6,500 hectares. As a result of the guava selection program developed at FCAV/UNESP, two new cultivars were created: 'Rica' and 'Paluma' with a high productivity, and also with higher nutritional requirement. Leaves analysis has become a powerful tool in mineral-nutrition research with fruit crops, not only to determine response to different nutrients, but also for diagnostic techniques in making fertilizer recommendations and assessing deficiency symptoms. Nutrient composition of the leaves varies depending on the leaf maturity, tree age, variety and nutrient supply. For the interpretation of analytical values, selection of the index tissue is important. The results of experiments conducted in the field during 1989-2000 were studied. The nutritional status was evaluated by annual leaf sampling, carried out at full bloom. Recent fully developed leaves, corresponding to the third pair (with the petiole) were collected, starting at the end of the branch, all around the tree, at a height of 1.5 m from the soil, with a total of 30 leaf pairs per sample. The yield was evaluated by weighing all the fruits in the useful area of each lot. Foliar chemical analysis showed excellent correlation with the fruit production. Through the results it was verified that the maximum yield was associated to the following levels: N = 22-26; P = 1.5-1.9; K = 17-20; Ca = 11-15; Mg = 2.5-3.5; S = 3.0-3.5 g kg -1; B = 20-25; Cu = 10-40; Fe = 50-150; Mn = 180-250; Zn = 25-35 mg kg-1 DW in the leaves of the 'Rica' guava and to N = 20-23; P = 1.4-1.8; K = 14-17; Ca = 7-11; Mg = 3.4-4.0; S = 2.5-3.5 g kg-1; B = 20-25; Cu = 20-40; Fe = 60-90; Mn = 40-80; Zn = 25-35 mg kg-1 DW in the leaves of the 'Paluma' guava.

Net melon cultivars productivity under different cultivation systems, during summer and winter

In order to access the effects of cultivation in soil, sand or a commercial substrate on the productivity of Bonus #2 cultivars, 'Don Carlos' and 'Hy Mark', two experiments were conducted in the greenhouse at FCAV-UNESP, Jaboticabal- SP, Brazil, 21° 15' 22 S, 48° 18'58 W, and altitude of 595 m, from November 1999 to April 2000 (summer), and from July to November 2000 (Winter). For cultivation in soil, chemical nutrients were added, and plants were irrigated with drip irrigation. Fertigation with recirculation of the nutrient solution was used on sand; slabs were used on commercial substrate with the fertigation with non circulating nutrient solution. Bonus #2 cultivar yielded the highest production of marketable fruit, but were later in production, while Hy Mark cultivar had early production but a lower number of fruit per plant. The winter planting yielded higher production of marketable fruit while summer plantings yielded lower number of fruit per plant, but with higher average weigh. The combination between cultivation systems and cultivars yielded higher fruit production in winter.

Productivity of beet and roquette cultivation as a function of time of establishing intercropping

With the aim of evaluating the effect of intercropping on the productivity of beet and roquette crops, a study was conducted in the Section of Vegetable and Aromatic-Medicinal Plants, FCAV-UNESP, Jaboticabal/SP. The treatments consisted of co-cultivations of roquette (Cultivada) and beets (Early Wonder) established at 0, 7, 14 and 21 days after the transplanting of beets, and as monocultures of beets and roquette. The experiments were delineated in a randomized block design. The productivity of beets in monoculture was not superior to that obtained with intercropping with roquette. The production of dry mass of roquette with intercropping was less than that with monoculture and the reduction was more marked with more delayed establishment of co-cultivation. Intercropping established at 0 and 7 days after the transplanting of beets was the most efficient, with indices of efficient use of land of 1.26 and 1.27, respectively.

Productivity of lettuce and radish cultivations as a function of spacing and of time of establishment of intercropping

The experiment was conducted at UNESP, Jaboticabal-SP, during the period of September to November of 2000, with the objective of evaluating the productivity of the cultivation of lettuce and radishes as a function of spacing between plants and of the time of establishment of intercropping. The experimental design was a completely randomized blocks and four replications. The 14 treatments consisted of combinations of spacing between lines (0.30 and 0.40 m), cultivation systems (intercropping and monoculture), and time of sowing of radish seeds to establish intercropping (0, 7 and 14 days after transplant of lettuce). The cultivars of lettuce and radish were, 'Tainá' and 'Crimson Gigante', respectively. A greater yield of commercial radish roots was obtained with intercropping cultivation. The fresh mass of lettuce in monoculture did not differ from that produced with intercropping. These results suggest that intercropping cultivation between these species is advantageous.

Morphologic characterization and evaluation of the productivity of nine rootstocks of rose bush (rosa spp.)

In Brazil, garden and cut rose bushes are propagated through cuttings or grafting. The rootstocks used in most of the traditional areas of cultivation are not identified, being known just by the vulgar name. There is not any information in the literature on the morphologic characteristics, nor about the productivity of different cultivars on the rootstocks available in Brazil. The objective of this work was to characterize and determine productivity of nine rootstocks (Rosa multiflora 'Paulista'; R. multiflora 'Japones'; R. multiflora 'Iowa'; R. multiflora 'Kopmans'; R. indica 'Mayor'; R. indica x multiflora; R. sp. 'Natual Brier'; R. manetti and R. canina 'Inermis') grafted with 'Versilia' and 'Tineke' scions. Morphologic studies were undertaken to characterize branches of adult plants to determine shape and dimensions of the leaf; number of prickles/15 cm of stem; vigor of the stems; incidence of Diplocarpon rosae (blackspot) and coloration of the leaf. The productivity (number of commercial flowers/plant/month) was evaluated for 6 months (October, 2000 to March, 2001), in the city of Andradas, Minas Gerais State, located at 1251 meters above sea level. Since there was significant difference in just two months for both rootstocks, 'Tineke' and 'Versilia', no rootstocks could be considered inadequate. Nonetheless, in general, the rootstocks that showed a better performance with 'Tineke' were, R. multiflora 'Kopmans' and R. manetti and with 'Versilia', R. multiflora 'Kopmans' and Rosa sp. 'Natual Brier'.

Productivity of cherry tomatoes under protected cultivation carried out with different types of pruning and spacing

The aim of the study was to evaluate production and determine the level of total soluble solids for cherry tomatoes, under protected cultivation carried out with different types of spacing and pruning. The experiment was performed according to a randomized block design in a 2×2 factorial scheme, with two types of spacing between plants and two types of pruning, and with five repetitions. The cultivar 'Sindy' (De Ruiter) was utilized. Each experimental parcel contained seven plants, and fruits were collected from the five central plants. The seedlings were produced in Styrofoam trays of 128 cells and transplanted at 33 days after planting using two types of spacing between plants (0.3 and 0.5 m) and 1 m spacing between rows. The plants were grown as single-or double-stem form and staked individually. The parameters evaluated were the number of fruit per plant, fresh weight of fruit and the level of total soluble solids expressed in °Brix. There was no evidence of significant interaction between the treatments. For fresh weight of fruit per plant, there was a significant effect when the plants were grown with a spacing of 1 × 0.5 m, with 4.12 kg per plant, compared to a production of 3.00 kg per plant with a spacing of 1 × 0.3 m. With regard to the number of fruit per plant, a significant difference was seen between the two types of spacing, where a spacing of 1 × 0.3 m yielded a lower number of fruit per plant (188.8), compared to that observed with a spacing of 1 × 0.5 m (238.1). With regard to the two types of pruning, there was a significant effect for only the number of fruit per plant, where the mean number of fruit was 188.4 with one stem and 238.4 with two stems. No significant difference was observed between the treatments for the level of total soluble solids. It is concluded that for the cultivar 'Sindy', under protected cultivation, production is better with a spacing of 0.5 m between plants and the use of two stems per plant.

An evaluation of the productivity of mischocyttarus drewseni in a semi-urban environment (Hymenoptera: Polistinae)

The biology and productivity of Myschocytarus drewseni were studied in semi urban conditions at Rio Claro, S P - Brazil. We observed 51 nest foundations, of which 24 (47%) were destroyed or predated, 13 (25.5 %) were abandoned and 14 (27.5%) completed the cycle. The life-span of colonies ranged from 44-427 days with a mean of 216.7 ± 140.6 days, producing 8-390 cells with a mean of 125.7 ± 137.9 cells, and 2-303 adults with a mean of 89.4 ± 110.36 adults. We observed a maximum of 3 utilizations/cell. This showed that the species presents asynchronous foundation and abandoningoccurs throughout the year. Also, the chance of a colony utilizing the same cells two or three times for adult production is highly dependent on the colony size/age, and the relation between them is positive, meaning that there is a greater chance of cell re-utilization in larger/older colonies.

Economic Survey of Latin America and the Caribbean 2006-2007

Includes bibliography

Productividad de la mano de obra y de la tierra en la agricultura latinoamericana = Productivity of labour and land in Latin American agriculture

Incluye Bibliografía

Phytoplankton primary productivity in an urban eutrophic reservoir (São Paulo, Brazil)

The aim of this study was to analyze temporal ..d vertical variation of the biomass and of phytoplankton primary productivity in an urban eutrophic reservoir, in relation to the physical and chemical characteristics of the water. The physical and chemical variables of the water were defined in the limnetic region of the reservoir, at depths of 0.0; 0.5; 1.0; 2.0; 3.0 and 4.0 meters. Three samples were taken to define both the physical and chemical variables, concomitantly with the biomass (chlorophyll-a and phaeophytin) and phytoplankton primary productivity (C-14 method). Based on data obtained on differences in depth of the mixture zone and the euphotic zone, it is hypothesised that, depending on the time of the year, phytoplankton is conditioned by differences in the light and nutrient regimes, which change according to the constant loads of nutrients thrown into the system. The highest concentration of chlorophyll-a in the photic zone of the limnetic region was observed in November 2000 (1,197.3 mg Chl L -1) and the lowest in November 1999 (94.0 mg ChI L -1), whereas the profiles of primary activity of phytoplankton presented the highest rates on the surface of the water column, with values varying from 84.7 (May 2000) to 1,376.7mg C m -3 h -1 (December 2000). Annual primary productivity was calculated at 1,567.0gC m -2y -1, considered euproductive. The primary productivity profiles reported in this study are typical of aquatic eutrophic systems, rich in plankton and with low light penetration. It can be stated that Garças Lake is a system that suffers from anthropogenic impact, through receiving large loads of organic pollution, reflecting on the physical and chemical characteristics of the water and on the high values of biomass and primary phytoplankton activity. © National Institute of Ecology, New Delhi.

Structural reforms, productivity and technological change in Latin America

Includes bibliography

Structural change and productivity growth, 20 years later: old problems, new opportunities

Includes bibliography

Leaf spray fertilization of boron and zinc on productivity and fruit quality of Japanese pear tree

The cultivation of fruit plants from temperate climate in tropical or subtropical regions can be a good income alternative for the producer. However, due to the little existent information about cultivation of those fruit plants, the producers use imported techniques of other producing areas, or even an association of practices used for other fruit plants, pointing out the leaf spray fertilization of micronutrients without appropriate scientific base. In this context, the objective of this study was to verify the effect of the leaf spray fertilization of B and Zn on productivity and fruit quality of Japanese pear tree. The experiment was conducted from 2004 to 2005, in Ilha Solteira, in northwestern São Paulo State-Brazil. The climate is, according to the Köpppen Classification, tropical wet and dry (Aw). The 'Okusankichi' cultivar, grafted on Pyrus communis L. rootstock was used as well as doses of 110 g.ha-1 of B and 250 g.ha-1 of Zn in each application. The treatments were: T1. water, T2. boric acid, T3. zinc sulfate, T4. T2 + T3, T5. boric acid + urea + citric acid + EDTA, T6. zinc sulfate + urea + citric acid + EDTA, T7. T5 + T6, T8. boric acid + urea + citric acid + EDTA + sodium molibdate + sulfur + calcium chloride, T9. zinc sulfate + urea + citric acid + EDTA + Fe sulfate + Mn sulfate + Mg sulfate and, T10. T8+T9. A randomized blocks design was used and the averages were compared by Tukey test. In the first crop the mixture of boric acid with quelating agents were efficient to supply B to the plants and zinc sulfate plus quelating agents were efficient to increase Zn leaf content. However, the productivity and the fruit quality were not influenced by the leaf spray of B and Zn. In the second crop the leaf content of B and Zn and the productivity were not influenced by the leaf spray; the boric acid and the zinc sulfate with or without quelating agents increased the contents of total soluble solids and, the boric acid with or without quelating agents increased the contents of total titratable acidity.

Productivity growth in Latin American manufacturing: what role for international trade intensities?

Includes Bibliography