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

Abstract

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

Marginal superiority of maize: an indicator for density tolerance under high plant density

“…This indicated that, in the studied modern maize cultivars, marginal superiority existed in no more than the outermost three border rows under high plant density and yield level, which was consistent with previous finding 31 . Moreover, the magnitude of marginal superiority was found to be different between different cultivars which was also consistent with previous studies 32 , 33 . However, a previous study on rice showed that only one border row had marginal superiority 33 ; this difference in number of rows with marginal superiority might be due to that different species may have different magnitude of marginal superiority and may be attributed to the difference in stem height.…”

Edge-biased distributions of insects. A review

“…Edge-biased crop development has been observed and reported for almost 100 years in winter wheat fields, where wheat rows along the borders showed higher yields than those in the center (Arny 1922). Over the years, rice (Wang et al 2013), maize and climbing beans (Davis et al 2008;Tiegu et al 2012), wheat (Wu and Li 2002;Bulinski and Niemczyk 2015), millets, Sudan grass (Drapala and Johnson 1961), soybean (Teng et al 2008), cotton (Luckett et al 1992), rapeseed (Buliński and Niemczyk 2010), carrots, cabbages, and onions (Peach et al 2000) have been shown to display edge-biased distribution of growth. In rice, the increase in yield of border rows compared to central portions of fields or plots ranged from 63 to 68% (Bulinski and Niemczyk 2015).…”

Genetic Evaluation and Correlation Analysis Among Various Quantitative Traits in Maize Single-Cross Hybrids Under Diverse Environments

“…Each hybrid was planted in a one-row plot, 4m long, with an inter-row spacing of 0.75 m and an intra-row spacing of 0.25 m. Two seeds were sown per each planting station, and later thinned to one plant per station at three weeks after crop emergence (WACE), in order to obtain a plant density of approximately 53 333 plants ha -1 . To eliminate variation due to border effects, commercial maize hybrids of similar vigor were used as borders (Davis et al, 1981). The hybrids were subjected to four different types of management regimes: optimal, managed drought, low nitrogen stress (Low N) and managed heat stress conditions.…”