José Antonio Moura e Silva

Grapevine root distribution in drip and microsprinkler irrigation

ABSTRACT: Grape ( Vitis vinifera L.) yield and its quality are dependent of the status of the root system.Root distribution information is also valuable for soil and water management. An analysis of methods toevaluate the root distribution of grapevines for both, drip and microsprinkler irrigation in a Typic Acrustoxis presented for the table grape cv. Italia grafted on the rootstock IAC-313, in northeastern Brazil. Measuredroot parameters using the monolith method were root dry weight (D w ) and root length density (L v ), while rootarea (A p ) was estimated using the soil profile method in combination with digital image analysis. For bothirrigation systems, roots were present to the 1 m soil depth and extended laterally to 1 m distance from thetrunk, but grapevines irrigated by microsprinkler showed greater root presence as the distance from the trunkincreased. Values of A p were reasonably well correlated to D w and L v . However, correlation values werehigher when fractional root distribution was used. The soil profile method in combination with image analysistechniques, allows proper grapevine root distribution evaluation.Key words:

Guidelines for irrigation scheduling of banana crop in São Francisco Valley, Brazil . II - Water consumption, crop coefficient, and physiologycal behavior

The water consumption and the crop coefficient of the banana cv. Pacovan were estimated in Petrolina County, northeastern Brazil, in order to establish guidelines to irrigation water management. Evaluations were carried out since planting in January 1999 to the 3rd harvest in September 2001 on a microsprinkler irrigated orchard, with plants spaced in a 3 x 3 m grid. Average daily water consumption was 3.9, 4.0, and 3.3 mm in the 1st, 2nd and 3rd growing seasons, respectively. Crop coefficient values increased from 0.7 (vegetative growth) to 1.1 (flowering). Even with high soil water availability, transpiration was reduced due to high evaporative demand.

Guidelines for irrigation scheduling of banana crop in São Francisco Valley, Brazil. I - Root distribution and activity

In order to establish guidelines for irrigation water management of banana cv. Pacovan (AAB group, Prata sub-group) in Petrolina County, northeastern Brazil, the root distribution and activity were measured on an irrigated plantation, in a medium texture soil, with plants spaced in a 3 x 3 m grid. Root distribution was evaluated by the soil profile method aided by digital image analysis, while root activity was indirectly determined by the changing of soil water content and by the direction of soil water flux. Data were collected since planting in January 1999 to the 3rd harvest in September 2001. Effective rooting depth increased from 0.4 m at 91 days after planting (dap), to 0.6 m at 370, 510, and 903 dap, while water absorption by roots was predominantly in the top 0,6 m.

Guidelines for irrigation scheduling of peach palm for heart-of-palm production in the São Francisco Valley, Brazil

O consumo de agua, o coeficiente de cultura e a profundidade efetiva de raizes da pupunha cultivada em um Vertissolo foram estimados do plantio ate a quinta colheita de palmito, durante dois anos e tres meses, em Juazeiro-BA. As plantas foram irrigadas por microaspersao sob dois tratamentos, irrigacao total (IT) e irrigacao reduzida (IR), sendo a quantidade de agua aplicada em IR correspondente a 75% daquela em IT. O consumo de agua e o coeficiente de cultura aumentaram consideravelmente ate a primeira colheita (7,3 mm dia-1 e 1,2, respectivamente, no tratamento IT) no decimo terceiro mes apos o plantio, devido ao crescimento continuo das plantas. Posteriormente, como os cortes foram realizados a cada tres ou quatro meses, os valores de consumo de agua e coeficiente de cultura apresentaram variacoes devido a reducao do numero de plantas por area. A profundidade efetiva das raizes foi de 40 cm aos 12 meses (antes da primeira colheita) e permaneceu a mesma aos 24 meses apos o plantio (apos a quarta colheita). Nao houve diferenca significativa entre a producao de palmito de ambos os tratamentos de irrigacao.

Distribuição radicular de cultivares de aspargo em áreas irrigadas de Petrolina - PE

In 1997 the root distribution of two asparagus cultivars (New Jersey 220 and UC 157 F1) irrigated by sprinkler was evaluated in coarse textured soils in experimental and commercial areas at Petrolina county, in the semi-arid region of northeastern Brazil, to obtain useful information for soil and water management. Both the monolith and the soil profile aided by digital image analysis methods were used to evaluate it. In the experimental area, a greater concentration of root dry weight, root area and length in the soil profile and root length density were found up to 04 m depth for both cultivars, while in commercial area the root area and length of cv. New Jersey 220 were concentrated until 0,6 m depth. Roots reached 1 m depth in both areas. In experimental area, dry weight, area and length in the soil profile and the length density of the roots showed greater presence up to the distance of 0.6 m from the plant row. Most of the roots (88% for cv. New Jersey 220 and 82.2% for cv. UC 157 F1) were found with diameter greater than 2 mm and less than or equal to 5 mm, while root diameter estimated by image analysis varied from 2.4 to 2.6 mm (cv. New Jersey 220) and from 2.4 to 3.6 mm (cv. UC 157 F1). Data of both methods of root distribution analysis and diameter estimation showed similarity.