Desempenho do inhame (taro) em plantio direto e no consórcio com crotalária, sob manejo orgânico.

Estudaram-se os efeitos do plantio direto em cobertura morta de aveia-preta e do consórcio com Crotalaria juncea, em sistema orgânico de produção de inhame, em ensaio na EE de Nova Friburgo(Pesagro-Rio), região serrana do estado do Rio de Janeiro. Utilizouse o delineamento de blocos ao acaso com quatro repetições, em esquema fatorial 2 x 2, onde os tratamentos corresponderam ao: modo de plantio (direto ou convencional) e modo de cultivo (monocultivo ou consórcio com crotalária). O cultivo consorciado com a leguminosa promoveu maior altura nas plantas do inhame, assim como reduziu a queima de folhas pelos raios solares. A população infestante de ervas espontâneas foi mais efetivamente controlada com a combinação entre consórcio e plantio direto. Nenhum dos tratamentos influenciou a produtividade do inhame, que foi considerada satisfatória, indicando o potencial do manejo orgânico adotado

The Principal Weedy Melastomaceae in Hawaii

Volume: 15Start Page: 301End Page: 30

Giant swamp taro, a little known Asian Pacific food crop

Meeting: International Society for Tropical Root Crops Symposium, 4th, 1-7 Aug. 1976, Cali, COIn IDL-133

Root Development in Aluminous Hawaiian Soils

Roots of Rhodomyrtus tomentosa and Melastoma malabathricum were excavated in three soil series from the bauxitic area of Kauai . Root systems of R. tomentosa and M. malabathricum in Kapaa and Halii soils were very shallow, with tap roots turning laterally at shallow depth and with long lateral roots very close to the soil surface. Deeper tap-root penetration of R. tomentosa and M. malabathricum was observed in the Koolau soil. Lime and phosphorus treatments were added to bauxitic subsoils of the Kapaa and Halii series in pots and Leucaena glauca (1.) was planted in the pots. Tap roots of L. glauca were stimulated by phosphorus treatment, but were restricted in untreated subsoils. Increased root development with phosphorus treatment seemed to be more related to phosphorus supply than to decreased aluminum effects. No evidence of root damage due to aluminum was found. L. glauca: roots were sectioned with a freezing microtome and stained, using hematoxylin without a mordant. Although all staining obtained could not be attributed to aluminum, since other metals can act as mordants for hematoxylin, intensity of staining was assumed to be related to aluminum concentration in the tissues. Cell walls, nuclei, and cytoplasm stained in all tissues, and outer walls of epidermal cells stained very heavily. Staining was more intense in roots from check and P-treated plants than in roots from lime-treated plants

Estimating the number of papaw (Carica papaya) trees required for reliable yield data

Statistics from twice-weekly harvesting of 4, 6 and 10 papaw trees in plots of 2-, 3- and 4-year-old trees in a continuous 4-year crop cycle showed that tree number and its interaction with treatments were not significant

MOLECULAR ANALYSIS OF THE DNA POLYMORPHISM OF WILD BARLEY (HORDEUM-SPONTANEUM) GERMPLASM USING THE POLYMERASE CHAIN-REACTION

Hordeum spontaneum is the progenitor of cultivated barley (H. vulgare) and is an important source of genetic variation for barley breeding programs. The genetic diversity of H. spontaneum in the Australian germplasm collection was investigated using the polymerase chain reaction with random and semi-random primers. This approach was found to be robust in respect of reaction conditions. Genetic dissimilarity values between genotypes were used to produce a phenogram of the relationships among the accessions using the unweighted pair group method with arithmetic mean. The largest divergence was observed among Israeli accessions, whereas the Turkish and Iranian samples clustered as distinct subsets, each apparently related to portion of the Israeli material. The results indicate that the genetic diversity of the wild barleys is broadly correlated with geographic distribution