The Distribution of Leaf Area and Light Intensity Within Wheat Crops Differing in Row Direction, Row Spacing and Rate of Sowing; A Contribution to the Study of Undersowing Pasture With Cereals

Santhirasegaram, K.; Black, J. N.

doi:10.1111/j.1365-2494.1968.tb00544.x

Cited by 11 publications

(6 citation statements)

References 5 publications

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“…However, it is probable that a i m head border should be sufficient for the majority of trials but there may occasionally still be a slight over-estimation of the land equivalent ratio (LER) owing to entry of light from the paths. Orientation of the rows, on the other hand, does not seem to be important, although for the associated bean rows oriented east-west planting in hill-plots might possibly result in more favourable penetration of light to the bean (Santhirasegarem and Black, 1968).…”

Section: Discussionmentioning

confidence: 89%

Border Effects and Optimum Plot Sizes for Climbing Beans (phaseolus vulgaris) and Maize in Association and Monoculture

1981

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Minimal competition was observed between adjacent plots of climbing bean varieties and maize in association, but there was a large head border effect which was not uniform among varieties. Head borders of 1 m at each end of the plot are recommended and a net plot size of 11 m 2 with 3 replications for climbing bean varieties associated with maize was found to be adequate to detect significant differences in yield of beans of 24% of the mean. For climbing beans in monoculture a somewhat smaller plot (8 m 2 ) would achieve the same level of precision. Larger plot sizes in general were needed for maize comparisons, especially in association.In Latin America up to 60% of the maize and 80% of the beans are produced in various associated cropping systems (Francis, 1978). Climbing beans need some kind of support and whilst they are found grown on stakes as pole beans in some areas of tropical America, they are more typically grown in mixed cropping with maize. The most commonly found systems are either simultaneous planting of the two crops in hill plots, or relay cropping in which the beans are planted some time between flowering and physiological maturity of the maize. These cropping systems were traditional in Latin America well before the Spanish conquest and are currently found mainly in highland areas, often on steep slopes, where the advantages of reduced soil erosion, enhanced competition with weeds and the greater stability (reliability) of production inherent in multiple cropping systems are essential for survival (Rappaport, 1971).The objective, then, of this study was to contribute some basic information on field plot design for research into associated cropping, given that appropriate improved varieties and technology need to be developed specifically for multiple cropping if traditional small farmers in upland areas are to benefit. Results for the equivalent monocultures of beans and maize were obtained as a basis for comparison. A similar study was carried out previously for bush beans in monoculture (Amezquitaetal., 1977;Munoz et'al., 1977). MATERIALS AND METHODSThree field experiments were carried out on the CIAT farm, Palmira, in 1977 and1978 with the object of quantifying the effects of plot borders and harvested plot sizes. Palmira is a tropical location (3° 31' N, altitude 1001 m) with a mean temperature of 24°C and 1000 mm of rain per year distributed

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Section: Discussionmentioning

confidence: 89%

Border Effects and Optimum Plot Sizes for Climbing Beans (phaseolus vulgaris) and Maize in Association and Monoculture

1981

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“…As examples, Weber (1965, 1966) and Williams et al (1965a) found that when cover is scant, production is directly related to the fraction of light intercepted. With annual crops, it usually takes a very long time for even a densely sown crop to achieve as much as 75% interception (Santhirasegaram and Black, 1968).…”

Section: Community Organization a Density Of The Vegetative Covermentioning

confidence: 99%

Productivity and the Morphology of Crop Stands: Patterns With Leaves

Loomis

Williams

2015

Physiological Aspects of Crop Yield

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“…In a row crop of wheat (Santhirasegaram and Black 1968) 75% of the leaf area is confined in a belt 9 cm wide on both sides from the row centre, symmetrically to either side in the eastern and northern direction of rows; in the eastern row direction the leaf area of the southern side of the row exceeds that of the northern side of the row considerably.…”

Section: Horizontal Distribution Of Phytomass and Phytoareamentioning

confidence: 99%

“…According to Santhirasegaram and Black (1968) the general shape of the curve of uL(z) in a wheat stand is little affected by the rate of sowing, spacing and row direction. …”

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confidence: 99%