• Authors:
    • Hamilton, G.
    • Bickerton, M.
  • Source: Environmental Entomology
  • Volume: 41
  • Issue: 3
  • Year: 2012
  • Summary: Bell pepper plots intercropped with flowering plants were measured for improving biological control provided by natural enemies of the European corn borer [ Ostrinia nubilalis (Hubner)]. The intercropped plants Dill, Anethum graveolens L.; coriander, Coriandrum sativum L.; and buckwheat, Fagopyrum escuelentum Moench; were established on the edge of two pepper plots and compared with nonintercropped control plots. Predation by the three species Orius insidiosus Say; Coleomegilla maculata DeGeer; and Chrysoperla, sp. Stephens, was monitored by installing O. nubilalis egg masses on sentinel plants in 2008, 2009, and 2010. To assess negative impacts of alternative prey on O. nubilalis egg predation, green peach aphid, Myzus persicae (Sulzer) populations were monitored via whole-plant counts in 2009 and 2010. Myzus persicae densities on pepper plants peaked in June or July and then declined rapidly. Predation on O. nubilalis eggs increased rapidly after aphid populations declined. Aphid populations were reduced in two out of three field-seasons in intercropped plots. Seasonal predation by O. insidiosus was significantly higher in the intercropped system four out of five field-seasons and one field season by C. maculata. Results indicate that biocontrol of O. nubilalis can be improved by intercropping with flowering plants, although this capacity may depend on the abundance of alternative prey.
  • Authors:
    • Shi, X.
    • Luan, C.
    • Sui, P.
    • Chen, Y.
  • Source: Journal of Integrative Agriculture
  • Volume: 11
  • Issue: 6
  • Year: 2012
  • Summary: Weed control is one of the major constraint factors in crop production around the world. Field experiments were conducted during 2008-2009 under intercropping systems involving alfalfa ( Medicago sativa L.), sweet potato ( Ipomoea batatas [L.] Lam.), peanut ( Arachis hypogaea L.), and sunflower ( Helianthus annuus L.) in maize ( Zea mays L.) without any weeds control methods taken. The results demonstrate that maize||sunflower is most effective on weed suppression and that it also has a more competitively inhibitory effect on Xanthium compared with the other patterns by evaluating the Xanthium density and dry weight under different intercropping systems with maize. Maize||peanut, maize||alfalfa and maize||sweet potato intercrops have no apparent inhibitory effect on weeds. To further investigate the effect of maize||sunflower on weed control, indoor pot experiments were conducted by determining the effect of extractions on germination rate (GR), root vigor, MDA (malondialdehyde), SOD (superoxide dismutase) and POD (peroxidase) content of Xanthium. The results better prove that maize||sunflower extractions have more significant inhibitory effect on GR and young root vigor of Xanthium than maize monocrop extractions.
  • Authors:
    • Lithourgidis, A.
    • Vlachostergios, D.
    • Dordas, C.
  • Source: Crop & Pasture Science
  • Volume: 63
  • Issue: 1
  • Year: 2012
  • Summary: Pea ( Pisum arvense L.) is an important legume in many areas of the world, which is used for forage and grain production and could be used in intercropping systems. Intercropping of pea with oat ( Avena sativa L.) and barley ( Hordeum vulgare L.), in two seeding ratios 60:40 and 80:20, was compared with pea and two cereal monocrops for two growing seasons (2008-10), at the Aristotle University of Thessaloniki, Greece. The effect of the intercropping systems was determined on growth rate, plant height, chlorophyll content, DM, and N yield. Also, several competition and economic indices were used to evaluate the intercropping systems, such as land equivalent ratio (LER), relative crowding coefficient (K), aggressivity (A), competitive ratio (CR), actual yield loss (AYL), system productivity index (SPI), monetary advantage index (MAI), and intercropping advantage (IA). Growth rate of pea and cereals was lower by an average of 39 and 64%, respectively, in the intercrops than in the monocrops. DM yield was the highest in barley monocrop (13.00 Mg ha -1) followed by P 80O 20 intercrop (11.73 Mg ha -1). Pea monocrop, and P 80O 20 and P 80B 20 intercrops showed the highest crude protein (CP) concentration (137, 132 and 130 g kg -1 DM, respectively), whereas P 80O 20 intercrop also produced the highest CP yield (1552 kg ha -1). The LER, K, and AYL values (average 1.09, 1.75 and 0.29, respectively), were greater for both pea-oat intercrops compared with the pea-barley intercrops (average 0.98, 0.92 and 0.06, respectively), indicating that in these systems there was an advantage of intercropping for exploiting the resources of the environment. The A, CR, and partial AYL values in all intercrops were greater for oat and barley than pea, which indicated that cereals were more competitive partners than pea. The highest MAI, IA, and SPI values were recorded for P 80O 20 followed by P 60O 40 intercrops indicating that these intercropping systems were the most profitable. The results from this study showed that both pea-oat intercrops were more productive with high CP yield, and also they showed the best land-use efficiency.
  • Authors:
    • Bohm, H.
    • Gronle, A.
  • Source: Julius-Kühn-Archiv
  • Volume: 1
  • Issue: 434
  • Year: 2012
  • Summary: The reduction of soil tillage depth is of special interest in organic farming. However, shallow ploughing often results in higher weed abundances in comparison to deep ploughing. Thus, the objective of this study was to evaluate whether the high weed suppressive ability of spring and winter pea-cereal intercrops can compensate for the higher weed growth in shallow ploughing compared to deep ploughing in organic farming. Peas and cereals were grown as sole crops and intercrops under shallow and deep ploughing in experiments on a sandy loam soil in Northern Germany in 2009, 2010 and 2011. Semi-leafless spring peas-oats, semi-leafless winter peas-triticale and regular-leaf type winter peas-triticale intercrops were examined. At harvest, weed shoot biomass in semi-leafless spring and winter pea sole crops under deep ploughing were slightly higher than those of the corresponding intercrops under shallow ploughing. Whereas weed shoot biomass in semi-leafless winter peas-triticale intercrops under deep ploughing was comparable to shallow ploughing, the cultivation of spring peas-oats intercrops under shallow ploughing led to a significantly higher weed growth than did deep ploughing. The regular-leaf type winter pea grown as a sole crop, or an intercrop with triticale, showed a higher weed suppressive ability than the semi-leafless peas. The tillage system had no significant influence on the weed infestation of sole and intercropped regular-leaf type winter peas. Semi-leafless spring peas-oats and winter peas-triticale intercrops could compensate for weed infestation differences under shallow ploughing compared to the corresponding pea sole crops under deep ploughing. Due to the high weed suppressive ability of regular-leaf type winter peas, shallow ploughing and deep ploughing, as well as sole cropping and intercropping, led to comparable weed infestation.
  • Authors:
    • Chimbizi, A.
    • Chimphero, L.
    • Mwale, C.
    • Mhango, W.
    • Kambauwa, G.
    • Kabambe, V.
    • Ngwira, A.
    • Mapfumo, P.
  • Source: African Journal of Agricultural Research
  • Volume: 7
  • Issue: 6
  • Year: 2012
  • Summary: Maize ( Zea mays L.) is a major staple food in Malawi. However, low soil fertility resulting from low and inappropriate use of fertilizer practices, continuous monocropping and inappropriate crop residues management coupled with limited resources and droughts keep yields low. This had led to a quest for sustainable solutions such as maize-legume intercropping or rotation including more efficient use of crop residues in smallholder farming systems. Innovation platforms (IP) built around learning centres (LC) located on smallholder farmers' fields in target locations were used as an approach to disseminate integrated soil fertility management (ISFM) technologies and build capacity of farmers, extension staff and other stakeholders. Rotating maize with either groundnut or groundnut intercropped with pigeonpea increased maize grain yield (3678 and 3071 kg ha -1 respectively) compared to sole maize (2260 kg ha -1). These preliminary findings were linked to farmer assessment of technologies where farmers participating in the LCs expressed strong interest in the maize legume rotation technologies. Associated farmer field days outlined constraints underlying technology choice, information that is not usually considered in conjunction with on-farm experimentation. Although, the legumes were highly productive, farmers expressed worries about legume seed availability, disease incidences, weeds infestations and livestock damage. Participating farmers commonly manage residues by burning. Promotion and experimentation with more efficient use of legume residues have shown short-term positive impacts in efforts to promote scaling-out of best fit legume technologies. This study reports the value of multi-stakeholder partnering in scaling-out and evaluation of best fit legume technologies and adoption constraints.
  • Authors:
    • Subramanian, S.
    • Meyhofer, R.
    • Nyasani, J.
    • Poehling, H.
  • Source: Entomologia Experimentalis et Applicata
  • Volume: 142
  • Issue: 3
  • Year: 2012
  • Summary: The study aimed at determining thrips species composition and thrips population density on French bean planted as a sole crop and as an intercrop with either sunflower, Irish potato, or baby corn, in various combinations. Field experiments were conducted in two seasons to examine: (1) thrips population development and thrips species composition over time, (2) effect of intercrops on thrips population density and natural enemies, and (3) effect of intercrops on French bean yield. The experiments were conducted at the Kenya Agricultural Research Institute, Embu, Kenya in a randomized complete block design with four replicates. The thrips population on French beans increased with time. It showed a peak at the flowering stage then started declining when the crops were nearing senescence. French beans hosted four thrips species, Megalurothrips sjostedti (Trybom), Frankliniella schultzei (Trybom), Frankliniella occidentalis (Pergande), and Hydatothrips aldolfifriderici (Karny) (all Thysanoptera: Thripidae) in order of decreasing abundance. The main thrips species on Irish potato and sunflower was F. schultzei. Baby corn hosted only Frankliniella williamsi (Hood) and Thrips pusillus (Bagnall). A monocrop of French bean hosted more thrips than a French bean intercrop mix. Thrips natural enemies such as Orius spp. and Ceranisus spp. were recorded in all crop plants but in especially high numbers on French bean and baby corn, respectively. Plots with French bean alone had about 1.4 times higher yields compared to intercropped plots of French bean with sunflower and French bean with baby corn. However, the percentage of pods that could get rejected on the market due to thrips damage was highest on plots with French bean alone (68 and 63%) and lowest on plots with French bean and baby corn (35 and 37%) in the first and second seasons, respectively. This study showed that a complex of thrips is found in the field and its composition varies with crop stage and species. Intercropping French bean with other crops compromises on French bean yield but reduces damage to the French bean pods, thereby enhancing marketable yield.
  • Authors:
    • Afolayan, S.
    • Olorunmaiye, P.
  • Source: Notulae Scientia Biologicae
  • Volume: 4
  • Issue: 1
  • Year: 2012
  • Summary: A preliminary study was carried out to evaluate the performances of eight crops in the intercrop of citrus with arable crops at the National Horticultural Research Institute (NIHORT) Ibadan, Nigeria. Eight arable crops: maize, cucumber, sweet potato, Corchorus olitorius, large green, grain amaranth, Mucuna pruriens var. utilis, and groundnut were intercropped with young citrus trees in the early planting season of 2010 with sole citrus as control. The experiment was laid out in a completely randomized block design with three replicates. Data were collected on weed flora, weed density and weed dry weight. Results showed that the relative frequencies of weeds in all the plots were less than 4% at both 6 and 9 WAP. Gomphrena celosoides, Oldenlandia corymbosa and Tridax procumbens were most preponderant in appearing in all the plots. Tridax procumbens had a consistent relative frequency (2.34%) in all the plots except in citrus/maize plot (0.78%) at 9 WAP. Significantly lower broadleaf weed densities were obtained in citrus/sweet potato, citrus/large green, control plot and citrus/cucumber (28.67, 45.00, 50.00 and 76.33 m -2 respectively) than in citrus/groundnut plot (143.00 m -2). Similarly, significantly lower grass weed densities were produced in citrus/ Mucuna and citrus/sweet potato (0.33 m -2 each) plots than the control plot (11.33 m -2). Whereas citrus/ Corchorus plot produced significantly lower broadleaf weed dry weight (37.59 g m -2) than citrus/ Mucuna plot (126.47 g m -2) at 3 WAP, citrus/large green plot (16.15 g m -2) and citrus/groundnut plot (123.25 g m -2) followed the same trend at 6 WAP. Sedges dry weights were less than 7 g m -2 in all the plots compared with control plot.
  • Authors:
    • Jana, J.
    • Partha, C.
  • Source: Crop Research (Hisar)
  • Volume: 43
  • Issue: 1/2/3
  • Year: 2012
  • Summary: A field experiment was conducted at the Instructional Farm of UBKV during rabi seasons of 2008 and 2009 to assess the influence of intercropping on nutrient uptake and quality parameter estimation in potato. The treatments were:T 1-Sole potato (control), T 2-Sole mustard, T 3-Potato+mustard at 1:1 row ratio, T 4-Potato+mustard at 2:1 row ratio, T 5-Potato+mustard at 3:1 row ratio, T 6- Potato+mustard at 4:1 row ratio and T 7-Potato+mustard at 5:1 row ratio and were laid out in randomized block design (RBD) with four replications. The results showed that significantly maximum residual nitrogen per hectare was obtained in sole mustard plots (178.32 kg). Experimental results also revealed that among different treatment combinations, maximum phosphorus content of soil after harvesting was obtained from sole potato plots (30.09 kg/ha) closely followed by sole mustard plots (29.34 kg). Lowest phosphorus content of soil after harvesting was obtained from potato and mustard grown in 2:1 ratio plots (24.87 kg/ha). Maximum potassium content (159.93 kg/ha) in soil after harvesting of potato and mustard was recorded in sole mustard plots. No significant differences were found for quality parameters due to intercropping.
  • Authors:
    • Lu, Y.
    • Zeng, L.
    • Liang, G.
    • Tian, Y.
  • Source: Acta Phytophylacica Sinica
  • Volume: 39
  • Issue: 1
  • Year: 2012
  • Summary: In order to confirm the effect of pest control using intercropping with different crops, investigation was conducted to study the population dynamics of insect pests of maize and their natural enemies in the habitat of sweet corn monoculture or intercropping with other crops (mung bean, kidney bean, sweet potato or peanut) by the method of eyeballing. Damage by Asian corn borer (ACB), Ostrinia furnacalis (Guenee) between different habitats was also be analyzed and discussed. Results indicated that the amounts of two predator groups, spiders and ladybirds, increased in sweet corn intercropping habitats significantly. Individual number of spiders in the fields when sweet corn intercropped with mung bean and number of ladybirds in habitat of sweet corn intercropped with sweet potato were over 21% and 83% respectively more than that in sweet corn monoculture. The number of Trichogramma ostriniae Pang et Chen showed no significant difference between different habitats, with the parasitic rates of ACB eggs were over 86%. No significant differences was observed in number of ACB eggs, Spodoptera litura (Fabricius) or Rhopalosiphum maidis Fitch between sweet corn monoculture and intercropping habitats. However, the ACB damage rate in sweet corn intercropping habitats was less than that in sweet corn monoculture at harvest, with the least in sweet corn intercropped with mung bean habitat, in which the number of holes and larvae was decreased by 55.72% and 76. 70% respectively. Study suggested that sweet corn intercropping with other crops could be beneficial to conservation of natural enemies and control of insect pests in some extents.
  • Authors:
    • Khairy, A. I. H.
    • Idris, A. E.
    • Ibrahim, Y. M.
  • Source: Advances in Environmental Biology
  • Volume: 6
  • Issue: 1
  • Year: 2012
  • Summary: The evaluation of Rhodes grass ( Chloris gayana Kunth) as intercropped with alfalfa ( Medicago sativa L.) was assessed under different intercropping ratios at Shambat, Sudan. A completely randomized block design with three replications was used. Different Rhodes grass growth characters and the yield characters of the intercropping were measured. The significance of intercropping was resulted in plant height and leaf area of Rhodes grass. The fresh yield of intercropping was also higher and significant than monocropping ratios. Thus, the experiment showed the positive effect of Alfalfa on Rhodes grass characters when they intercropped with each others. The highest yield of intercropping ratios than monocropping and the superior of treatment D (50% Rhodes grass+50% Alfalfa) over other treatments used in the study was evident.