Influence of Chromolaena odorata and Mucuna pruriens fallow duration on weed infestation

Summary Fallow management is a major strategy for weed control and soil fertility restoration in tropical farming systems. From 1995 to 1998, weed infestation was evaluated in plots managed under 0, 1, 2 and 3 year fallow durations of (1) a natural bush fallow dominated by Chromolaena odorata ; (2) a planted Mucuna pruriens fallow; and (3) a modified bush fallow without C. odorata . The study was conducted at the Nigerian Institute for Oil Palm Research (NIFOR), Benin City, Nigeria. The 3 × 4 factorial experiment was set up in a split plot arrangement. The three fallow types were the main plots and the four fallow durations were the subplots. Each year, the subplots were planted to maize ( Zea mays , cv. TZSR-W) as appropriate and harvested 14 weeks after planting for yield comparison. Continuous cropping and the modified natural bush fallow increased weed diversity and biomass. Irrespective of fallow type, weed infestation was more gradual in the first year of cropping after fallow than in subsequent cropping years. Regardless of cropping intensity, C. odorata and M. pruriens fallows promoted broad-leaved weeds, chiefly Ageratum conyzoides , Tridax procumbens and Phyllanthus amarus , whereas the modified bush fallow promoted grasses. Maize grain yield was higher in the C. odorata and M. pruriens fallows than in the modified bush fallow, but the yield difference diminished with cropping intensity.     

Velvetbean (Mucuna spp.) suppresses speargrass (Imperata cylindrica (L.) Raeuschel) and increases maize yield

Speargrass, Imperata cylindrica (L.) Raeuschel, is a serious weed, threatening crop productivity in smallholder farms in West Africa. Since the use of more effective practices such as deep tillage and chemical control is beyond the means of resource-poor farmers who carry out most agricultural activities in this region, low-input alternative technology needs to be developed. Field studies were conducted during the 1993/1994 and 1995/1996 growing seasons to investigate the influence of three velvetbean accessions and two levels of fertilizer on the control of speargrass during the year of cover crop planting and one year later. The velvetbean accessions in 1993 were: Mucuna cochinchinensis and M. pruriens var. utilis. In 1995, M. pruriens var. IRZ was included in the study. M. cochinchinensis in 1993 and M. pruriens var. IRZ in 1995 had the highest ground cover rating early in the growing seasons whereas M. pruriens var. utilis had the lowest ground cover rating in both years. Inorganic fertilizer at30 kg ha- 1 each of N, P and K increased velvetbean ground cover by 2-22%, with M. cochinchinensis (14-22%) and M. pruriens var. IRZ (5-15%) showing the highest response in 1993 and 1995, respectively. M. pruriens var. utilis showed the least response in both years. After one growing season M. pruriens var. utilis, M. cochinchinensis, and M. pruriens var. IRZ reduced speargrass shoot density by 50, 76, and 68%, and shoot dry matter by 72, 92, and 79%, respectively. Fertilizer reduced speargrass growth in velvetbean plots, while the opposite occurred in plots without velvetbean. Velvetbean residue effectively suppressed speargrass until the beginning of the subsequent cropping season. Maize grown 1 year after velvetbean required 50% less weeding than plots without velvetbean. Maize shade reduced speargrass shoot growth by 30-80% but regrowth of the weed occurred 4 weeks before maize harvest. Maize grain yield was higher in plots previously seeded to velvetbean than in plots without velvetbean. Speargrass shoot density and dry matter were negatively correlated with maize grain yield (r =_-0.42 and r =_-0.32, respectively, P < 0.01). Although velvetbean may effectively reduce speargrass during the year of establishment and the subsequent cropping phase it has a limited effect on rhizomes and, as such, does not provide a long term control.     

Patterns of interaction between isolates of three pathovars of Pseudomonas syringae and accessions of a range of host and nonhost legume species

Isolates of three pathovars of Pseudomonas syringae were tested against 10 legume species. Some isolates of all pathovars showed cultivar-specific interactions with at least one legume species outside the expected host range. Lablab purpureus and Phaseolus lunatus were found to be hosts to isolates of both P. syringae pv. glycinea and P. syringae pv. phaseolicola, while Lathyrus latifolius was host to isolates of P. syringae pv. pisi and P. syringae pv. glycinea . Lens culinaris showed patterns of interaction with isolates of all three pathovars. Gene models based on mathematical estimates of minimum gene numbers agreed with those previously published for the interactions of P. syringae pv. pisi with Pisum sativum and P. syringae pv. phaseolicola with Phaseolus vulgaris. Two different gene-for-gene models based on five resistance/avirulence gene pairs were proposed to explain observed interactions between Glycine max and P. syringae pv . glycinea . Pathogen isolates which contained no known avirulences defined on their respective host species were found to carry cryptic avirulences recognized by other plant species. Estimates of minimum gene numbers required to explain the interactions of a plant species with all pathogen isolates or to explain the interactions of the isolates of one pathovar with all plant accessions were consistently lower than the sum of the minimum gene numbers required to explain the interactions of each individual component.     

Sympatric ascochyta complex of wild Cicer judaicum and domesticated chickpea

The aim of this study was to isolate, identify and characterize ascochyta blight pathogens from Cicer judaicum , a wild annual Cicer species which grows in Israel and other Mediterranean countries in sympatric distribution with legume crops, and determine their virulence and aggressiveness to other wild and domesticated legumes. Native C. judaicum plants exhibited symptoms resembling ascochyta diseases of grain legume crops. Two distinct pathogens were isolated and identified as Phoma pinodella and Didymella rabiei using morphological and molecular tools; their infectivity was verified using Koch's postulates. The virulence of these pathogens was examined on 13 legume species, of which P. pinodella was virulent to Pisum sativum , P. fulvum , C. judaicum , C. arietinum , C. reticulatum , C. pinnatifidum and C. bijugum . Didymella rabiei infected all these Cicer species, but not the other legume species tested. Aggressiveness of the pathogens was tested on wild and domesticated chickpea and pea. Didymella rabiei isolated from C. judaicum had significantly higher ( P  < 0·001) aggressiveness than P. pinodella from C. judaicum on both wild and domesticated chickpea. Disease severity on the former species ranged from 62·5% to 70% and on the latter from 41% to 56%. Phoma pinodella isolates from C. judaicum were more aggressive on C. arietinum and P. sativum than on C. judaicum and P. fulvum . Results of the current study suggest that C. judaicum may serve as an alternative host to ascochyta pathogens that endanger chickpea and possibly other crops and wild species growing in close proximity.     

Resistance to Striga hermonthica in Wild Accessions of the Primary Gene Pool of Pennisetum glaucum

ABSTRACT Resistance to Striga hermonthica in 274 wild Pennisetum glaucum subsp. monodii and stenostachyum accessions was evaluated at Samanko, Mali in 1997 and 1998, and at Cinzana, Mali and Sadoré, Niger in 1998. Data recorded included number of striga plants per plot at least three times during the season, date of striga emergence, number of Pennisetum plants, Pennisetum anthesis date, and downy mildew incidence (caused by Sclerospora graminicola). Across trials, the average maximum number of striga per host plant ranged from 0.9 to 8.3. Average days to striga emergence ranged from 54 to 68 days across trials, and was negatively correlated (P < 0.01) with maximum striga within trials. Days to Pennisetum flowering ranged from 54 to 74 days across trials. Host flowering was correlated (P 相似文献   

Effects of vegetation cover on recruitment of Ulmus pumila L. in Horqin Sandy Land,northeastern China

Understanding the effects of vegetation cover on seedling survival is helpful for promoting vegetation restoration in environmentally fragile zones. This study was conducted in the desertified, moving sand dunes of Horqin Sandy Land, Inner Mongolia, northeastern China. We hyphothesized that(1) seed density(i.e., number/m2) increases as vegetation cover increases, and(2) there will be more surviving seedlings in locations with higher vegetation covers. Total vegetation cover and initial densities of seeds, germinated seeds and surviving seedlings of Ulmus pumilia were evaluated under various vegetation covers in trying to clarify the effects of vegetation cover on the early stages of the plant life history. In agreement with the first hypothesis, initial seed densities were greater(P<0.05) under higher vegetation covers. The relationship between vegetation cover and initial seed density was represented by a quadratic regression, where a threshold occurred with a vegetation cover of 36%(P<0.05). The higher total vegetation covers, however, did not result in increased densities of germinated seeds(P>0.05), which on average represented 16.7% of initial seed densities. Even more, three months after the study initiation, total vegetation covers were similar(P>0.05) at all positions in the dunes, and they determined a similar number(P>0.05) of surviving seedlings at those positions(i.e. the second hypothesis had to be rejected). The mean number of seed- lings that survived at all positions was only 4.5% of germinated seeds. The number of surviving elm seedlings(0 to 1.7 seedlings/m2) under various vegetations covers(12.2% to 20.8%) at all dune positions by late summer would most likely not contribute to vegetation restoration in the study area.     

Dynamic multiline population approach to resistance gene management

ABSTRACT The dynamic multiline population breeding strategy integrates principles from the gene stacking and multiline approaches and allows application of the multiline strategy to cross-pollinated hybrid crops. Experiments were conducted to evaluate the effectiveness of the breeding approach. Backcross derivatives of pearl millet Tift 23DB were developed with rust resistance from 18 Burkina Faso landraces, 3 Pennisetum glaucum subsp. monodii accessions, and 2 elite inbreds (1 from India and 1 from the United States). Four cycles of open pollination were made, the last two in the field in rust epidemics. Cytoplasmic male-sterile (CMS) counterparts of the populations in the A(4) cytoplasm were included and advanced simultaneously with the B population. Hybrids with Tift 383 were produced on CMS cycles 1 (C1) through C4. Frequency of hybrid seedlings with resistance increased with each cycle, and frequencies averaged 18 to 38% in C1 to C4 hybrids, respectively, when inoculated with five single-uredinium isolates of Puccinia substriata var. indica. The hybrid populations and Tifleaf (TL)1 and TL2 were evaluated in three yield trials in 1998 to 1999. Disease-free forage dry matter yields did not differ among hybrids. Across trials, area under the disease progress curve (AUDPC) of TL1 and TL2 averaged 1,307, C1 and C2 averaged 914, and C3 and C4 averaged 604. Final severities of TL1 and TL2 averaged 67%, C1 and C2 averaged 47%, and C3 and C4 averaged 30%. When analyzed by regression analysis, AUDPC was reduced 12.2%, final rust severity was reduced 13.3%, and digestible biomass was increased 4.1% per cycle.     

Weed suppression by cover crops: comparative on‐farm experiments under integrated and organic conservation tillage

Cover crops are increasingly being used for weed suppression and to enhance the sustainability of agro‐ecosystems. However, the suitability of cover crops for weed suppression in integrated and organic conservation tillage systems is still poorly investigated. Therefore, a 2‐year field study at eight sites was conducted to test the weed suppressive potential of six legume‐based cover crops, with the aim to reduce herbicide input or mechanical weed management interventions. In all experiments, cover crops were directly sown after cereals before next year's main crop (grain maize or sunflower). The presence of cover crops caused a 96% to 100% reduction of weed dry matter at the four sites managed under integrated production, while effects were lower at the four sited managed under organic production, ranging from 19% to 87%. Cover crops that covered soil quickly and which produced much dry matter had the best weed suppressive potential. However, their weed suppressing effect was difficult to predict, as it depended on the year of the investigation, experimental site, cover crop species, the speed of soil cover in autumn and the density of the resulting mulch layer in spring. The study demonstrated that cover crops are a useful tool to suppress weeds under integrated and organic conservation tillage practices. Our recommendation for supporting weed management in conservation tillage systems is to use locally adapted cover crops that have rapid establishment, good soil coverage and high dry matter production. However, additional weed management measures are required for reliable weed control under on‐farm conditions.     

羊草、赖草与白草种苗活力及耐旱性的研究

本文对羊草、赖草与白草三种根茎型牧草进行了种子活力和幼苗耐旱性研究。结果表明:三种牧草种子萌发时需水量相对较低,为种子重量的0.4—0.46倍;种子活力与发芽率、发芽指数和活力指数呈正相关关系,白草的种子活力明显高于赖草和羊草;三种牧草幼苗的耐旱性与种子活力和种子萌发最低需水量有关,活力高的种子其幼苗耐旱能力强,萌发时最低需水量低的种子其幼苗耐旱能力强,白草幼苗的耐旱性强于赖草和羊草幼苗的耐旱性。     

Inter-population variabilities in seed mass and germination of Panicum turgidum and Pennisetum divisum in the desert of Kuwait

Understanding variability in seed germination among populations is essential for planning an effective germplasm collection for restoration and conservation purposes.The knowledge of germination and dormancy patterns among populations of desert grasses is crucial for determining the potential of the species and populations to be used for restoration and conservation as well as forage production.Variability in seed germination of Panicum turgidum Forssk and Pennisetum divisum(Gmel.)Henr.in the desert of Kuwait was evaluated in different populations in May 2017.Experiment of seed germination(25 seeds and 4 replicates)was conducted for each population at night/day temperatures of 15℃/20℃and 20℃/30℃under the following light condition:continuous darkness or 12 h/12 h light/dark.Results showed that seed masses of both species strongly varied according to their seed provenances,and both species produced heavier seeds in population with a higher soil electrical conductivity.Seed germination percentage considerably varied between two species,and the variation in P.turgidum was greater(17%–49%)than that of P.divisum(72%–93%).Germination percentage in P.turgidum was greater at high temperature(20℃/30℃)than at low temperature(15℃/20℃).However,temperature regimes had no effect on germination percentage of P.divisum seeds.Mean germination time of both species exhibited significant inter-population variability.This result is especially relevant to assure the selection of the best population of each species and the regeneration success of the species.Besides this,inter-population variability also provides valuable information for enhancing our understanding of the mechanisms that regulate seed germination and how they might be related to seed provenance.     

Inactivation of Macrophomina phaseolina Propagules during Composting and Effect of Composts on Dry Root Rot Severity and on Seed Yield of Clusterbean

Survival of a heat-tolerant pathogen Macrophomina phaseolina, causing dry root rot of clusterbean, was studied by incorporation and retrieval of infected residue samples at various stages of the composting process of pearl millet (Pennisetum glaucum) and clusterbean (Cyamopsis tetragonoloba) residues. During the heating phase, temperatures varied from 48–51°C at 30cm and 60–62°C at 60cm depth in compost pits. Reduction in survival of M. phaseolina propagules (13–23%) was significantly higher in the residues enriched with 4% urea-N and kept at 60cm compared to 2% urea-N and at 30cm. However, a heat phase (48–62°C) was not enough to completely eradicate M. phaseolina propagules from infected residues. Further reductions (54–61%) in survived propagules were achieved by sub-lethal temperatures (48–53°C) when moistened compost materials were exposed to heat during summer days. Beneficial effects of composts were ascertained on dry root rot intensity, seed yield of clusterbean and densities of M. phaseolina, Nitrosomonas and antagonists in soil. In a two-year field study, all the composts significantly reduced plant mortality due to dry root rot and increased the yield of clusterbean. The highest disease suppression and yield promotion were recorded in soil amended with pearl millet compost and cauliflower leaf residue compost, respectively. Soil amendment with compost also lead to a significant reduced density of M. phaseolina and an increased density of antagonistic actinomycetes, lytic bacteria and Nitrosomonas. Among composts, greater potential of cauliflower compost in enhancing population of antagonists in soil was discernible.     

Importance of the proportion of grassy weeds within legume crops in the perpetuation of Gaeumannomyces graminis var. tritici

Various grass species susceptible to infection by Gaeumannomyces graminis var. tritici were mixed-sown into a legume crop in order to assess their influence on density of inoculum and take-all disease in a subsequent crop of wheat.
In a pot experiment take-all inoculum increased ( P < 0.001) in all treatments containing a proportion (from 20 to 100%, in increments of 20%) of grass in subterranean clover. In a plot trial, most severe take-all occurred in the 20% legume/80% grass stands and least in the 100% legume and 80% legume/20% grass stands. Total grain weight was highest ( P <0.1) after the 100% legume stands. There was no difference in severity of take-all after pure stands of medic, subterranean clover and lupin, but there was more severe take-all after the grass-infested medic stands than after those of subterranean clover ( P < 0.1) or lupin ( P < 0.05). No significant differences ( P > 0.1) in yield occurred in wheat following any of the legumes or mixed stands.     

The biology of African feather grass (Pennisetum macrourum Trin.) in Tasmania, I. Seedling establishment

Seedling establishment of Pennisetum macrourum was studied in a series of glasshouse and field experiments. Maximum germination of 88% occurred at a constant temperature of 30C. In the glasshouse, highest seedling establishment was obtained from seeds buried 1 cm deep; it was less than 25% from seeds sown on the soil surface. Dormancy was induced in seeds buried 8 cm deep but only 6.4% remained viable after 6 months. Few viable seeds of P. macrourum were found in the soil and only one seedling was observed to establish in the field over a 20 month period. Up to 98% of seedlings transplanted into the field established successfully. The results suggest that reproduction by seed would not be a major problem in the control of P. macrourum.     

A laboratory evaluation of the palatability of legumes to the field slug,Deroceras reticulatum Müller

Slugs are major pests of many crops, including winter wheat, in temperate climates, yet current methods of control are often unreliable. The aim of this study is to investigate the potential for common legume species to act as an alternative source of food, or trap crop, for the most damaging agricultural pest species, the grey field slug, Deroceras reticulatum Müller, thereby reducing damage to the wheat crop. A series of three controlled-environment experiments were designed to assess this aim. Individual slugs were fed leaves of one of ten legume species together with winter wheat leaves for a 72-h period. A clear hierarchy of acceptability was shown, with red clover, lucerne, lupin and white clover showing significantly higher Acceptability Indices than the other six species tested. Red clover produced the greatest reduction in mean wheat consumption (78%) from day 1 to day 3. When species were fed individually, red clover was consumed in significantly greater quantities than any of the other treatments: 40% more than white clover and 56% more than wheat. Furthermore, when fed with red clover the amount of wheat consumed was some 50% less than when the latter was fed alone. The results indicate that legumes vary greatly in their acceptability to D. reticulatum and it is essential that a legume with a high Acceptability Index is chosen, which results in the least amount of wheat consumed.     

Identification and origin of races of Pseudomonas syringae pv. phaseolicola from Africa and other bean growing areas

Isolates of Pseudomonas syringae pv. phaseolicola from Africa and other bean growing areas were categorized into nine races on the basis of their reactions to eight differential cultivars following artificial inoculation. Eight hundred and ninety-three isolates representing 303 disease occurrences were initially identified as P.s. pv. phaseolicola by their pathogenicity to bean, cultural and serological characteristics and phage sensitivity. These tests also served to distinguish P.s. pv. phaseolicola from the closely related pathovars P.s . pv. glycinea and P.s. pv. syringae . Detailed race determinations were carried out on 175 selected isolates of p.s. pv. phaseolicola representative of the different geographical regions and hosts in which the pathogen was found and nine races were identified. A number of races (1,2,5,6 and 7) were distributed worldwide with race 6 predominant. Other races were found mainly in Africa; races 3 and 4 in East/Central Africa and races 8 and 9 in Southern Africa. Most isolates were obtained from the major host, Phaseolus vulgaris . Alternative natural hosts included 10 legume species representative of seven different genera ( Cajanus cajan, Desmodium sp., Lablab purpureus, Macroptilium atropurpureum, Neonotonia wightii, Phaseolus acutifolius, P. coccineus, P. lunatus, Vigna angularis and V. radiata ). Of these, Desmodium sp. constitutes a new host record.     

Relation between cropping frequency of peas and other legumes and foot and root rot in peas

The relation between the frequency of legume crops in a rotation and the root rot severity in pea was examined in a field survey. Additionally, greenhouse experiments were performed with soil samples from legume rotation trials or from farmers' fields. The frequency of pea crops in current rotations proved to be much less than the recommended value of one in six years. The correlation between pea root rot and the number of years that pea or other legumes were not grown on the field under consideration (called crop interval) was weak. Root rot severity correlated better with the frequency of peas or legumes in general over a period of 18 years, but the frequency still explained only a minor fraction of the variation in disease index. Some experimental data pointed to the occurrence of a highly specific pathogen microflora with continuous cropping of only one legume species, but this phenomenon probably does not occur in farmers' fields. In field samples, root disease index for pea correlated well with that for field bean. The survival of resting structures of pathogens such asAphanomyces euteiches probably explains why the frequency of legume cropping has a higher impact than crop interval on root disease incidence. Pea-free periods and legume frequencies have a poor predictive value for crop management purposes.     

Effects of density and sowing pattern on weed suppression and grain yield in three varieties of maize under high weed pressure

We tested the hypothesis that improved weed suppression by maize can be achieved through increased crop density and spatial uniformity. Field experiments on three varieties of maize sown at three densities (5, 7 and 10.5 seeds m^?2) and in two spatial patterns (grid pattern and rows) under very high weed pressure from Brachiaria brizantha were performed in 2012 and 2013. We measured weed biomass 1 month after sowing and at harvest, and grain yield at harvest. Density, variety and sowing pattern all had strong and significant effects on both weed biomass and yield. On average, weed biomass was reduced (by 72% in the first year and 58% in the second year), and grain yield was increased (by 48% and 44%) at the highest density in the grid pattern compared with standard sowing practices (medium density, row pattern). There was a significant density × variety interaction, which is evidence for genetic differences in the response of the varieties to density in characteristics that influence weed suppression. The variety that suppressed weeds best at high density had the lowest variation in the angle of insertion of the oldest living leaf at harvest (leaf 6), supporting the hypothesis that reduced phenotypic plasticity may be advantageous for weed suppression under high density and spatial uniformity. Increased density and uniformity can contribute to weed management in maize in many cases, potentially reducing the need for herbicides or mechanical weed control.     

Reaction of genotypes from several species of grain and forage legumes to infection with a French pea isolate of the oomycete <Emphasis Type="Italic">Aphanomyces euteiches</Emphasis>

The susceptibility/resistance to Aphanomyces euteiches of various genotypes (cultivars and breeding lines) of several grain legume species was assessed in controlled conditions. A total of 279 genotypes from the major grain legumes grown in temperate climates (faba bean, chickpea, lentil, lupin and common vetch) and three other legumes frequently cultivated in France (French bean, clover and alfalfa) were screened with one pea-infecting isolate from France. Four different categories of susceptibility/resistance were identified among the legume species/cultivars tested with the pea A. euteiches isolate: (1) susceptible legume species (lentil, alfalfa, French bean) among which low levels of partial resistance was observed; (2) legume species including susceptible genotypes and genotypes with high levels of resistance (common vetch, faba bean and clover), (3) species with a very high level of resistance (chickpea) and (4) species displaying no symptoms (lupin). It is therefore important to consider pathogen-species and pathogen-genotype interactions when defining the host specificity of A. euteiches and considering the possible role of different legume species in increasing or decreasing the soil inoculum potential.     

Growth of bell pepper plants (Capsicum annuum) affected by coloured covers

While a plant utilizes the full spectrum of visible light, some colours of light have more important applications than others. The aim of this study was to evaluate the responses of bell pepper plants grown under coloured covers. Bell pepper plants (Capsicum annuum) were grown hydroponically in a greenhouse in Tunja, Colombia, under different light quality regimes that were obtained with polypropylene films (yellow, green, blue, transparent, red, and a control without a plastic film cover). Conventional growth indices were calculated or measured as response variables. All of the evaluated parameters were influenced in a different ways by the colour of the covers, e.g. the leaf area was higher under the green and blue covers. The highest water uptake was found in the plants grown under the blue film. Plants under the yellow cover presented higher water use efficiency than the other treatments. The chlorophyll content index was higher under the blue, green and transparent covers. Based on these results, a coloured cover that favors most of the growth indices of plants cannot be selected; however, according to the needs of growers, the supplemental light quality can be used to achieve a specific effect.     

Combining biocontrol agents to reduce the variability of biological control

ABSTRACT Two biocontrol agents, a yeast (Pichia guilermondii) and a bacterium (Bacillus mycoides), were tested separately and together for suppression of Botrytis cinerea on strawberry leaves. The aims of the research were to determine whether the use of their combination would broaden the environmental conditions under which biological control is effective, and to test the hypothesis that it would reduce the variability of control efficacy under diverse conditions. Applied separately, the biocontrol agents significantly inhibited spore germination, lesion formation, and lesion development at most temperatures, relative humidities, and spray-timing combinations (temperatures: 10, 15, 20, 23, 25, and 30 degrees C; relative humidities: 78, 85, 96, and 100%; and spray-timings: 0, 4, and 7 days before inoculation). However, control efficacy was highly variable, and under certain combinations it was not adequate. Control efficacy achieved by the biocontrol agents applied separately ranged between 38 and 98% (mean 74%) and the coefficient of variation ranged from 9.7 to 75%. The mixture of Bacillus mycoides and Pichia guilermondii suppressed Botrytis cinerea effectively (80 to 99.8% control) under all conditions, and the coefficients of variation were as low as 0.4 to 9% in all cases. Thus, application of both biocontrol agents resulted in better suppression of Botrytis cinerea, and also reduced the variability of disease control. Application of more than one biocontrol agent is suggested as a reliable means of reducing the variability and increasing the reliability of biological control.