• Authors:
    • Zekaite, V.
    • Deveikyte, I.
    • Kadziuliene, Z.
    • Sarunaite, L.
    • Maiksteniene, S.
    • Arlauskiene, A.
    • Cesnuleviciene, R.
  • Source: ZEMDIRBYSTE-AGRICULTURE
  • Volume: 98
  • Issue: 4
  • Year: 2011
  • Summary: Intercropping of cereals and grain legumes is a technology intended to enhance biodiversity in organic agroecosystems, increase and stabilize yields and make better use of plant growth resources. The experiments were designed to investigate the intercrops' yield advantage in different soil, climate and plant competition conditions in organic farming. Field trials were carried out during 2007-2010 at the Lithuanian Institute of Agriculture at three different soil sites: on a loamy Endocalcari-Epihypogleyic Cambisol ( CMg-p-w-can) (Dotnuva), on a clay loam Endocalcari-Endohypogleyic Cambisol ( CMg-n-w-can) (Joniskelis) and on a sandy loam Hapli-Albic Luvisol ( LVe-ha) (Perloja). Pea ( Pisum sativum L. (Partim)) and spring wheat ( Triticum aestivum L. emend. Fiori et Paol.), spring barley ( Hordeum vulgare L.), oat ( Avena sativa L.) and spring triticale (* Triticosecale Wittm.) were sown as intercrops (50:50 - a relative proportion of grain legume and spring cereal seeds) or as a sole crop. The result showed that weather and soil conditions during plant emerge determined the optimal productive density and created a basis for competition between the intercrop components. Spring cereals were dominant due to higher aggressivity index and competition rate compared with peas. Under various soils' conditions the aggressivity of cereals increased with increasing density of pea. In productive soils (Dotnuva, Joniskelis), the highest competitive and suppressive power in the intercrops was exhibited by oats, in low productivity soils (Perloja) - the dominant species varied. Under the conditions of various soils, the production of pea intercrop with oats or barley was directly affected by cereals, while pea intercropped with wheat or triticale by the two components of the intercrop. In terms of grain yield, intercrops ranked as follows: pea/oats > pea/wheat, pea/triticale > pea/barley. In loamy soil (Dotnuva), these regularities were less consistent, therefore the advantages of intercrops' yield over sole crops' yield were negligible when the relative yield total (RYT) was >1.0, except for the pea intercropped with barley. In Joniskelis and Perloja, the relative yield total showed greater and more stable yield advantages of intercrops, except pea intercropped with triticale. The efficiency of intercrops stood out even more vividly in the treatments managed under organic cropping system for a longer period of time.
  • Authors:
    • Shahid, A.
    • Saghir, A.
    • Jamil, M.
    • Zubair, M.
    • Farooq, M.
    • Awais, R.
  • Source: Pakistan Sugar Journal
  • Volume: 26
  • Issue: 2
  • Year: 2011
  • Summary: Sugarcane is a long duration crop and is suitable for intercropping with other short duration crops to maximize the farmer income from the unit area. Thus, this study was designed to find out the possibility of wheat, lentil and gram intercropping with autumn planted sugarcane crop. The study was carried out at National Agricultural Research Centre, Islamabad during 2004-05 cropping season. Sugarcane variety RB-72-454 was used as test crop and planted at 1.2 meter row distance in the first week of September, 2004. Two rows of each wheat, lentil and gram crop were seeded in the month of November in between cane rows. Sugarcane crop was harvested in the month of December, 2005. Lentil and gram were harvested in the month of April while, wheat in May. The results of the study indicted that sugarcane planted alone produced highest cane yield of 130.5 t ha -1, while sugarcane intercropped with wheat produced lowest cane yield of 105.5 t ha -1. The yields of wheat, lentil and gram were 1.18, 0.57 and 0.43 t ha -1, respectively. However, it was observed that intercropping of wheat, lentil and gram with sugarcane decreased cane yield by 19.2, 18.6 and 14.3%, respectively. The maximum economic return of Rs. 156641 ha -1 was noticed when sugarcane was planted without intercropping, whereas, intercropping of sugarcane with wheat resulted in minimum return of Rs. 138889 ha -1. Findings of the study revealed that autumn planting of sugarcane without any intercropping is more profitable than intercropping with cereal and leguminous crops.
  • Authors:
    • Escobar-Gutierrez, A.
    • Louarn, G.
    • Barillot, R.
    • Huynh, P.
    • Combes, D.
  • Source: Annals of Botany
  • Volume: 108
  • Issue: 6
  • Year: 2011
  • Summary: Background and Aims: Most studies dealing with light partitioning in intercropping systems have used statistical models based on the turbid medium approach, thus assuming homogeneous canopies. However, these models could not be directly validated although spatial heterogeneities could arise in such canopies. The aim of the present study was to assess the ability of the turbid medium approach to accurately estimate light partitioning within grass-legume mixed canopies. Methods: Three contrasted mixtures of wheat-pea, tall fescue-alfalfa and tall fescue-clover were sown according to various patterns and densities. Three-dimensional plant mock-ups were derived from magnetic digitizations carried out at different stages of development. The benchmarks for light interception efficiency (LIE) estimates were provided by the combination of a light projective model and plant mock-ups, which also provided the inputs of a turbid medium model (SIRASCA), i.e. leaf area index and inclination. SIRASCA was set to gradually account for vertical heterogeneity of the foliage, i.e. the canopy was described as one, two or ten horizontal layers of leaves. Key Results: Mixtures exhibited various and heterogeneous profiles of foliar distribution, leaf inclination and component species height. Nevertheless, most of the LIE was satisfactorily predicted by SIRASCA. Biased estimations were, however, observed for (1) grass species and (2) tall fescue-alfalfa mixtures grown at high density. Most of the discrepancies were due to vertical heterogeneities and were corrected by increasing the vertical description of canopies although, in practice, this would require time-consuming measurements. Conclusions: The turbid medium analogy could be successfully used in a wide range of canopies. However, a more detailed description of the canopy is required for mixtures exhibiting vertical stratifications and inter-/intra-species foliage overlapping. Architectural models remain a relevant tool for studying light partitioning in intercropping systems that exhibit strong vertical heterogeneities. Moreover, these models offer the possibility to integrate the effects of microclimate variations on plant growth.
  • Authors:
    • Bedoussac, L.
    • Justes, E.
  • Source: Field Crops Research
  • Volume: 124
  • Issue: 1
  • Year: 2011
  • Summary: There are many indices available to evaluate the potential advantages of intercrops and species interactions but correct choice of index is crucial in making accurate interpretations. This study compared and evaluated the relevance in understanding intercrop functioning of some well-known indices (aggressivity, AG; cumulative relative efficiency index, REIc; land equivalent ratio, LER) and other potentially useful indices (change in contribution, CC; interspecific and intraspecific interaction index, IE and IA; comparative absolute growth rate, CGR). Data collected from a two-year field experiment in SW France with different fertiliser N levels comparing wheat ( Triticum turgidum L., cv. Nefer) and pea (winter pea, Pisum sativum L., cv. Lucy) grown as sole crops or intercrops in a row substitutive design were used to calculate, compare and evaluate the relevance of the selected indices for understanding intercrop functioning. It was found that AG indices (calculated with or without considering sowing density or actual plant density) did not provide the information generally claimed in the literature (i.e. whether a crop is dominant or dominated). Consequently, their use is clearly unadvisable except when analysed jointly with partial land equivalent ratios. The LER index proved to be clearly relevant, versatile and helpful in illustrating the pattern of competitive outcomes in intercropping experiments, in particular when plotting partial LER values of wheat as a function of those of pea. However, LER cannot identify intraspecific and interspecific interactions. To do so we suggest using the intraspecific and interspecific interaction indices, which can also reveal possible facilitation phenomena and allow description of species change in the contribution index (CC). Interaction dynamics between crops that determine the final balance and the outcome of all competitive interactions occurring between the two crops can be evaluated using the CGR index, which is preferable to REIc, particularly when crops differ greatly in their dry weight. Careful choice of index and interpretation of the results are thus essential in correctly understanding species interactions (globally and dynamically) and intercrop efficiency compared with sole crops. Such indices can help highlight and reveal cereal and legume traits suited to intercropping and also appropriate cropping sequences and management techniques, allowing efficient intercropping. However, the results must always be related to actual data values (yield, dry weight or N accumulated) because the indices used cannot evaluate intrinsically quantitative performance but only the relative performance of intercrops compared with that of sole crops.
  • Authors:
    • Gibson, L. R.
    • Singer, J. W.
    • Blaser, B. C.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 4
  • Year: 2011
  • Summary: Interseeding red clover ( Trifolium pratense L.) or alfalfa ( Medicago sativa L.) into winter cereals in the North Central United States can provide forage and a green manure crop. We hypothesized that winter cereal canopy traits such as leaf area index (LAI) and whole plant dry matter (DM) would influence interseeded legume establishment and productivity, yet the effect of canopy traits on resource competition in intercropping systems is not well understood. This study was conducted from 2005 to 2007 to evaluate the impact of diverse cereal canopy traits on the establishment of frost-seeded legume intercrops. In March, red clover and alfalfa were frost-seeded into three winter wheat ( Triticum aestivum L.) and three triticale (X Triticosecale Wittmack) varieties selected for differences in maximum LAI, plant height, and DM. Across three growing seasons, the cereals produced a range of LAI from 2.1 to 6.2 and whole plant harvest DM of 817 to 2029 g m -2. In the 2 yr with legume data, densities were influenced by cereal 1 yr and DM was affected by cereal both years. Alfalfa and red clover densities were similar, yet DM production was 42% higher in red clover 40 d after grain harvest. The presence of a legume intercrop did not affect grain yield, but reduced weed densities and weed DM 40 d after harvest. Producers implementing this intercrop may select cereal varieties based on grain yield, but must be cautious of varieties known to produce above normal LAI values because of the potential to reduce legume productivity.
  • Authors:
    • Montfort, F.
    • Faloya, V.
    • Schlaunich, E.
    • Aubree, N.
    • Breton, D.
  • Source: 4eme Conference Internationale sur les Methodes Alternatives en Protection des Cultures.
  • Year: 2011
  • Summary: To study the interest and the limits of the insertion of various cover crop with biofumigation potential in a crop succession, three trials, one in Aquitaine (40), one in Normandy (50) and one in Rheu (35) were performed on two important soilborne diseases of carrot: cavity-spot due to Pythium sulcatum or the brown rot disease due to Rhizoctonia solani. Intercrop plants were cultivated then crushed and incorporated in the soil one month before carrot crop. In the three trials, the effect of the mustard Brassica juncea on the incidence and the severity of the diseases is studied and compared with bare soil. In the Normandy trial, two other cover crops are also studied: oat and rye crop. In Le Rheu trial, regular observations allow to compare the development of cavity-spot over time after insertion then incorporation of a mustard crop or after a bare soil. The results are presented; the technical feasibility and the impact of method on disease development are discussed.
  • Authors:
    • Ladewig, E.
    • Schulte, M.
    • Schmitz, F.
    • Burcky, K.
    • Buhre, C.
  • Source: Sugar Industry / Zuckerindustrie
  • Volume: 136
  • Issue: 10
  • Year: 2011
  • Summary: Since 1994, data on sugarbeet production in Germany are continuously collected in annual cultivation surveys based on the information from the German sugar factories. Because of the long-term data set, many developments over the last years as well as short-term adaptations could be described. Cereals, particularly winter wheat, are the main pre-crop before sugarbeet (50%), followed by maize. Intercrops have been cultivated on 40% of the sugarbeet area since the beginning of the survey. The use of reduced systems increased in soil cultivation. The soil is covered by intercrops or pre-crop residues on more than 65% of the sugarbeet area. Since 2006, an increase in nitrogen fertilization was observed. Organic fertilizer was applied on 50% of the sugarbeet area. Crop production, from sowing to harvesting is characterized by an increase in technical specialization. The survey is conducted in cooperation with the farmers, or by specialized contractors. The beets are harvested mainly with six-row harvesters and transported increasingly with semi-trailer trucks.
  • Authors:
    • Bandyopadhyay, P.
    • Nath, R.
    • Jena, S.
    • Dutta, S. K.
    • Dutta, A.
    • Chakraborty, P. K.
  • Source: Journal of Crop and Weed
  • Volume: 7
  • Issue: 1
  • Year: 2011
  • Summary: Temperature is an important weather parameter affecting the growth and development of the crop. The growing degree days (GDD) indicate the thermal index required for the onset of phenophases in crop. A two-year (2008-09 and 2009-10) field experiment was conducted at the B.C.K.V Instructional Farm to investigate the effect of GDD on leaf growth rate (LGR), crop growth rate (CGR) and leaf area indices (LAI) of wheat and mustard grown under sole (T 1 and T 2) and intercrop situations, [2 wheat:6 mustard (T 3), 4 wheat:4 mustard (T 4) and 6 wheat:2 mustard (T 5)]. The experiment was laid out in a RBD design with 6 replications having a plot size of 50 m 2. The experimental soil has pH of 6.92, organic carbon 0.63%, total N 0.06%, available P 2O 5 18.47 kg/ha and available K 2O 127.22 kg/ha. The experimental site is under tropical humid climate. From the results, leaf growth rate, crop growth rate and leaf area index were found to be polynomial function of GDD. The results also suggested that the effect of GDD on different growth indices of wheat and mustard were strongly expressed in 4 wheat:4 mustard row ratios which might be adopted in the Gangetic Plains of New Alluvial zone of West Bengal.
  • Authors:
    • Eskandari, H.
  • Source: African Journal of Biotechnology
  • Volume: 10
  • Issue: 77
  • Year: 2011
  • Summary: Wheat ( Triticum aestivum) and bean ( Vicia faba L.) sole crops and their mixture in three planting pattern (M 1: alternate-row intercrop, M 2: within-row intercrop, M 3: mixed intercrop) were used to investigate the amount of resource consumption in terms of photosynthetically active radiation (PAR) interception, water and nutrient uptake. The experiment was carried out as randomized complete block design with four replications. The results show that intercropping systems had a significant effect on environmental resources consumption, where intercropping systems had more light interception and water, and nutrient uptake compared to sole crops, suggesting the complementarity effect of intercropping components in resources consumption. The ability of wheat and bean was different in intercropping systems in absorbing nutrients because of their differences in root morphology and cation exchange capacity. Regarding weed suppressions, intercrops were more effective than wheat sole crops, which were related to lower availability of environmental resources for weeds in intercropping systems.
  • Authors:
    • Emeran, A. A.
    • Shtaya, M. J. Y.
    • Fernandez-Aparicio, M.
    • Allagui, M. B.
    • Kharrat, M.
    • Rubiales, D.
  • Source: Crop Protection
  • Volume: 30
  • Issue: 8
  • Year: 2011
  • Summary: Chocolate spot incited by Botrytis fabae is a serious faba bean disease of worldwide distribution. The increasing interest in sustainable tools for disease control, together with the lack of sufficient levels of genetic resistance triggered our interest in the use of intercropping as a tool for the management of this disease. The effect of intercropping on chocolate spot severity was studied in field experiments performed in Egypt, the Palestinian Territories, Spain and Tunisia, in which a susceptible faba bean cultivar was grown as a monocrop or with two mixed species intercrops of either barley, oat, triticale, wheat, pea or common vetch, or with three mixed species intercrops of wheat and berseem clover. Chocolate spot was significantly reduced when faba bean was intercropped with cereals, but not when intercropped with legumes. Suppressive effects can be ascribed to a combination of host biomass reduction, altered microclimate and physical barriers to spore dispersal.