• Authors:
    • Fuller, M. P.
    • Al-swedi, F.
    • Al-Issawi, M.
    • Rihan, H. Z.
  • Source: Scientia Horticulturae
  • Volume: 141
  • Year: 2012
  • Summary: The effects of using PPM (plant preservative mixture) (Apollo Scientific Limited, UK) on the growth of cauliflower microshoots were determined. A negative correlation was found between the concentration of PPM in the liquid medium and the number of microshoots developed: the greater the concentration, the lower microshoot number. The stage of the culture process most suitable for the introduction of PPM was also investigated. While the use of PPM with blending medium (S23: 4.4 g L-1 MS + 30 g L-1 sucrose) did not control the later contamination in the culture medium, the use of 0.5 mL L-1 of PPM with culture medium (S23 supplemented with 2 mg L-1 (9.29 mu M) of kinetin + 1 mg L-1 (4.9 mu M) of IBA (indole butyric acid)) was found to be effective in controlling contamination and keeping the growth capacity of microshoots. Cauliflower microshoots were encapsulated in sodium alginate as artificial seeds. Artificial seeds conversion rate and viability assessed as fresh weights of plantlets produced were evaluated in different culture substrates (compost, perlite, sand and vermiculite). The effects of PPM concentrations used with S23 irrigation solutions were also evaluated. This study showed the effectiveness of using PPM in controlling the contamination and the necessity for determination the correct concentration and the correct stage for the use of this material in order to obtain optimum results. (C) 2012 Elsevier B.V. All rights reserved.
  • Authors:
    • Yahuza, I.
  • Source: International Journal of Biosciences (IJB)
  • Volume: 2
  • Issue: 6
  • Year: 2012
  • Summary: Five experiments agronomically managed differently investigated yield-density relationships in wheat/faba bean (bean) intercropping system. For the wheat sole crop, seed yield (SY) ranged from 102 g/m 2 to 734 g/m 2. Intercropping reduced wheat SY but this did not always depend on wheat seed rate (wsr). Standard intra-specific and/or inter-specific yield-density equations derived from the literature and others modified here were used to quantify the SYs (as was applicable). For the majority of the experiments wheat SYs, whether sole cropped or intercropped responded asymptotically as wsr increased. The maximum bean sole crop SY was 392 g/m 2: bean SY declined as wsr increased. The total intercrop (wheat+bean) SY response to wsr was asymptotic in at least two of the experiments, following similar pattern as the wheat. Although, for the mean effects of intercropping the total intercrop SYs was substantial in three experiments; the total intercrop did not produce significantly greater SY than the wheat sole crop as wsr increased. Moreover, maximum wheat sole crop and wheat intercrop SYs were significantly greater under the organically-managed experiment than the conventional-managed one, even though they were both established in the same cropping year. Similarly, as regards wheat SYs, comparisons of spring-sown with the winter-sown crops established in the same cropping year indicate that the former performed better than the latter. Nevertheless, for most of the experiments investigated here, this research indicates that 100-wheat seeds/m 2 or lower may be appropriate to intercrop with bean at 30 to 40-bean seeds/m 2 to reduce competition and improve productivity.