Variation in harvest index of maize (Zea mays) and common bean (Phaseolus vulgaris) grown in a marginal rainfall area of Kenya

1996 ◽  
Vol 126 (1) ◽  
pp. 1-6 ◽  
Author(s):  
C. J. Pilbeam

SUMMARYMaize (Zea mays L.) and common bean (Phaseolus vulgaris L.) were grown in five seasons, beginning in the long rains 1990 and ending in the short rains 1992, at Kiboko, Kenya under a range of different management conditions (N fertilization, irrigation, population density and intercropping). Seed weight was plotted against total dry weight to determine harvest index for both crops. For bean the intercept of this relationship for each experiment, with one exception, was not significantly different from zero, so that the slopes of the regressions were the harvest indices. Harvest indices for bean varied more between seasons (0·38–00·85) than from the effects of management practices (00·53–0·71). Over all seasons and treatments, the index for bean did not vary systematically with crop weight, and averaged 0·50. By contrast, a similar analysis for maize over all seasons and treatments, showed that the harvest index varied with crop dry weight, approaching an asymptotic value as dry weight increased. The regression intercepts for the different experiments were significantly different from each other, and in three cases differed significantly from zero. Therefore, although the slopes for the different experiments were parallel, they did not always represent the harvest index.

1981 ◽  
Vol 38 (1) ◽  
pp. 309-318
Author(s):  
I. P. Oliveira ◽  
E. Malavolta

Nine cultivars of Phaseolus vulgaris L. were grown in nutrient solution to study the effect of boron on growth and mineral composition. Data obtained in thie study allowed for the following conclusions: (1) high levels of boron affected plant height, root length, dry weight of tops, dry weight of root, and total dry weight; (2) regression analysis was used to point out differential behaviour among cultivars in relation to boron concentration in nutrient solution; (3) the best mineral concentration in the plant tissue was obtained with application of 0,5 ppm of boron in the nutrient solution.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Ivan Luzardo ◽  
Rocio Campos-Vega ◽  
Elvira Gonzalez de Mejia ◽  
Flavia Loarca

Abstract Objectives The aim of this research was to evaluate the anti-inflammatory properties of an oven-baked nixtamalized corn (Zea mays L.)/cooked common bean (Phaseolus vulgaris L.) chip in a model of chronic colitis in vivo. The hypothesis was that the chip consumption would prevent colon barrier disruption and improve enzymatic biomarkers by the modulation of infiltration and adhesion of inflammatory cells. Methods A 70% corn and 30% bean chip (7030C) was evaluated, using dextran sodium sulfate (DSS, 2% v/v) as chemical inductor of colitis. After 1-week of acclimatization, 36 CD-1 male mice (6–8 weeks age) were randomly divided into 5 groups: G1 (negative control, fed with basal diet, BD, and water); G2 (positive control, BD + DSS), G3 (100 g 7030C/kg body weight, BW/day + BD), G4 (200 g 7030C/kg BW + BD) and G5 (300 g 7030C/kg BW + BS). The G2-G5 groups were administered DSS every other week, during 5-weeks.After the mice were euthanized, BW and disease activity index (DAI) were recorded. Liver, colon, and spleen were collected, weighed and analyzed for histology. Colonic myeloperoxidase (MPO)/fecal b-glucuronidase (GLUC) activities were also quantified, as well as fecal/cecal metabolites. The colonic mRNA expression of inflammation-associated genes was conducted using a gene inflammation profiler array. Results DSS increased DAI up to 2 units, BW loss was 10–17%, and induced colon shortening 10–15%. Compared to G2, G4 exhibited significantly (p < 0.05) lower DAI (0.75 ± 0.01), spleen relative weight (0.003 ± 0.0001) and colon weight/length ratio (0.045 ± 0.008). The histological analysis showed that the chip consumption prevented colonic barrier damage. G4 displayed the lowest MPO and GLUC among all DSS-induced groups (0.004 ± 0.0004 mU/mg colon; 0.44 ± 0.01 mmol/min/g feces, respectively), and the lowest seric content of MCP-1 protein. Amid all the quantified metabolites, the chip consumption significantly reduced the fecal/cecal content of acetic acid, while butyric and propionic increased at the end of the study. Inflammation gene expression was modulated by the chip consumption. Conclusions Our results suggest that the consumption of this chip might alleviate chronic colitis symptoms because of a protective effect in the gut barrier function and the modulation of infiltration of inflammatory cells. Funding Sources The funding received by CONACyT, CONCyTEQ-Mexico and NIFA-USDA-HATCH are appreciated.


1994 ◽  
Vol 122 (2) ◽  
pp. 265-273 ◽  
Author(s):  
J. W. White ◽  
R. M. Ochoa ◽  
F. P. Ibarra ◽  
S. P. Singh

SUMMARYTo develop an effective breeding programme for rainfed production of the common bean (Phaseolus vulgaris L.), the inheritance of seed yield under such conditions should be understood, preferably considering the effects of environment to account for site or season specificity. Thus, heritability, expected and realized gain from selection, and combining ability were evaluated for a nine-parent diallel of common bean without reciprocals but including parents, at two locations each in Mexico and Colombia, using the F2 and F3 population bulks. Heritability estimated from regressions of F3 on F2 ranged from 0·09 ± 0·18 (S.E.) to 0·75±0·25 for seed yield, from 0·26±009 to 0·34±009 for days to maturity and from0·57±004 to 0·80±004 for 100-seed weight. Expected gain from selection in the F2 was estimated as a percentage of the population mean, selecting the upper 20% of the populations. Expected gain in seed yield ranged from 1·8 to 8·4% in Mexico and from 6·5 to 28·1% in Colombia. Realized gains in seed yield in the F3 were 0·4–7·4% in Mexico and 2·9–15·7% in Colombia. Realized gain values for days to maturity were < 2·2%, and for 100-seed weight > 13·4%. General combining ability (GCA) mean squares (estimated using Griffing's Method 2, Model 1) were significant (P <0·01) and larger than those for specific combining ability (SCA) for all traits at all locations. The parents from the Mexican highlands tended to have a positive GCA effect for yield in Mexico but negative values in Colombia, whereas parents adapted to mid-elevation tropical environments showed the opposite tendency. However, all significant GCA values of breeding line V8025 were positive in both countries.


1980 ◽  
Vol 30 (2) ◽  
pp. 145-153 ◽  
Author(s):  
G. Contreras ◽  
L. G. Elias ◽  
R. Bressani

1995 ◽  
Vol 124 (1) ◽  
pp. 27-37 ◽  
Author(s):  
E. F. Foster ◽  
A. Pajarito ◽  
J. Acosta-Gallegos

SUMMARYField and glasshouse studies were conducted in Durango, Mexico in 1987 and in East Lansing, Michigan, USA in 1989, respectively, to determine the effects of moisture deficits upon N-use efficiency (NUE), N partitioning and remobilization, and N harvest index (NHI) in edible beans (Phaseolus vulgaris L.). Four indeterminate, semi-prostrate genotypes adapted to the semi-arid high plains of Mexico, Pinto Nacional-1, Durango 222, L1213–2 and Bayo Madero, were used in the field study and Pinto Nacional-1 and Bayo Madero were used in the glasshouse study. A Xerosol Haplic soil was used in the field study and a Spinks loamy sand in the glasshouse study. A moisture deficit was induced by use of temporary rainshelters in the field and curtailment of water in the glasshouse. Plants were sampled periodically and subdivided into leaves, stems, pods and flowers, and roots (in the glasshouse study only) for determination of dry weight and total N content. Water-use efficiency was determined in the glasshouse study. A moderate moisture deficit (drought intensity index 0·41) reduced yield by 41% in comparison with non-stressed yield (from 134·3 down to 79·2 g/m2) and resulted in a greater percentage of seed-N derived from N that had been redistributed from the leaf, indicating that N partitioning was not impaired by this degree of stress. In contrast, N remobilization was greatly reduced by a more severe moisture deficit (drought intensity index 0·92), which resulted in yield losses of 92% (from 2·19 down to 0·17 g/pot). These results suggest that N remobilization may be an important drought adaptation strategy under moderate or intermittent moisture deficits. Severe moisture deficits reduced NHI, harvest index (HI), NUE and water-use efficiency (WUE) when WUE was expressed as seed dry weight per litre water used. Genotypic variability was observed for NHI, HI and NUE.


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