Two-way predation between immature stages of the hoverfly Eupeodes corollae and the invasive fall armyworm(Spodoptera frugiperda J. E. Smith)

Since its 2018 invasion of eastern Asia, the fall armyworm Spodoptera frugiperda(Lepidoptera: Noctuidae) has become a key pest in local maize production. Though pesticides have been widely used to mitigate the initial S. frugiperda attack, biological control is receiving ample attention as a desirable, environmentally-sound alternative to chemical control. Hoverflies(Diptera: Syrphidae) are abundant natural enemies in Chinese maize fields and have been observed to consume S. frugiperda larvae. In this study, we use laboratory assays to study the two-way interaction between immature stages of S. frugiperda and the endemic syrphid Eupeodes corollae. To mimic natural conditions, assays were performed in the presence of fresh maize leaves. Those 2 nd or 3 rd instar larvae of E. corollae preyed on 1 st and 2 nd instar S. frugiperda larvae with a Holling type III response, consuming a respective theoretical maximum of 43.48 and 83.33 larvae over a 24-h period. Conversely, once S. frugiperda larvae reached 3 rd instar, they exhibited aggressive behavior and equally preyed on syrphid larvae with a Holling type III response. Those 5 th and 6 th instar larvae of S. frugiperda consumed a respective 16.39–19.23, 6.02–19.61 and 6.76–8.26 of 1 st, 2 nd and 3 rd instar E. corollae larvae per day. Though our results await field-level validation, S. frugiperda agonistic(i.e., defensive) and consumptive behavior towards resident natural enemies such as E. corollae possibly degrades biotic resistance and raises its invasion potential. Our findings shine new light on the interaction between lepidopteran herbivores and their natural enemies, and can help advance the development of conservation biological control and other integrated pest management(IPM) strategies against S. frugiperda in China and abroad.     

Fitness of fall armyworm,Spodoptera frugiperda to three solanaceous vegetables

The fall armyworm(FAW), Spodoptera frugiperda Smith(Lepidoptera: Noctuidae) is an important agricultural pest that invaded China in the middle of December 2018. As a polyphagous pest, FAW is identified as a serious threat to agricultural production and food security in China. Pepper(Capsicum annuum L.), tomato(Solanum lycopersicum Mill.) and eggplant(Solanum melongena L.) are three of dominant solanaceous vegetables of this country. To our knowledge, the effects of these plants on the performances of FAW have not been well studied. In this study we assessed the fitness of this pest to these three plants. Results showed that FAW can complete its life cycle when fed with tomato and pepper, but not on eggplant. The population parameters of FAW fed with maize(Zea mays L.) and the three solanaceous vegetables were compared using the age-stage, two-sex life table method. Developmental duration was significantly different in the larval stage, but not in the pupae stage. FAW fed with pepper had the longest pre-adult period(41.73 d) and the lightest pupal weight(0.1134 g); the survival rate was lower than FAW fed with tomato. Significant differences were observed in the mean fecundity of female, with the highest(943.95 eggs) laid by FAW fed with tomato. FAW had the shortest mean generation time(T), the highest intrinsic rate of increase(r) and finite rate of increase(λ) on maize, and the highest net reproductive rate(R_0) on tomato. Overall, FAW fitness on the three solanaceous vegetables was: tomatopeppereggplant. This study provides the foundation for further assessment of FAW risk to solanaceous vegetables and for establishing corresponding control strategies in China.     

Modelling the Relationship Between Summer Maize NPK Uptake and Yield on the Basis of Soil Fertility Indices

Quantitative estimation of fertilizer requirements can help to increase maize （Zea mays L.） yields and improve the fertilizer use efficiency. The model for the Quantitative Evaluation of the Fertility of Tropical Soils （QUEFTS） was calibrated for maize by use of soil fertility data and fertilizer trials at different sites of the Huang Huai Hai river plain in China. The QUEFTS model accounts for interactions between nitrogen （N）, phosphorus （P） and potassium （K）. It describes the effects of soil characteristics on maize yields in four steps： （1） assessment of the potential supply of N, P and K based on soil chemical data; （2） calculation of the actual uptake of N, P and K, in function of the potential supply as determined in step 1 ; （3） draft the yield ranges as a function of the actual uptake of N, P and K as determined in step 2; （4） calculation of the maize yield based on the three yield ranges established in step 3. Data of field experiments with different fertilization treatments of various regions in China during the years of 1985 to 1995 were used to calibrate the QUEFTS model for summer maize. In step 1 the N, P and K recovered from their amount applied were described by new equations. The minimum and maximum accumulated N, P and K （kg grain kg^-1） in summer maize were determined as （21-64）, （126-384） and （20-90）, respectively. The simulated yields were in good agreement with the observed ones. It was concluded that the calibrated and adjusted QUEFTS model could be useful to improve fertilizer recommendations for maize in the Huang Huai Hai plain of China.     

Influence of Climatic Factors on the Recent Spread of Dubas Bug Ommatissus lybicus （Debergevin） on Date Palm Trees in Some Upper Euphrates Regions of AI-Anbar Province

The dubas bug Ommatissus lybicus （Debergevin） （Homoptera： Tropiduchidae） was almost absent in AI-Anbar Province during the past years, however, field survey conducted in different regions of the province during fall of 2007 indicated the presence of heavy infestation by this pest on date palm trees in some orchards toward the east of Hit city. Infestation was highly influencing in term of affected trees and accumulation of honey dew. Scattered infestations were also recorded in some orchards west of Hit city and near the cities of Haditha, Rawa and AI-Kaim near the Syrian border. However, a sharp decline of dubas population was observed during 2008 and subsequent years as a result of the influence of sever winter in 2008 and the continuous occurrence of dust storms which showed a detrimental effect on moving stages of dubas bug. Data showed that nymphs density reached to about 50 individuals/leaflet recorded during the last week of April and early May of 2008 and was reduced to less than 5 nymphs/leaflet by the end of the third week of May of the same year as a result of the indicated climatic factors. Farther samplings conducted in Spring and Fall seasons of 2009 and 2010 indicated that insects were mainly found on offshoots near the ground with a maximum density reached to 12 individuals/tree. Since the spread of the pest occurred in a discontinuous manner with no correlation to infestations in close by provinces indicating that the arrival or transportation of the pest was happened in a way other than the normal distribution, therefore, dubas bug may not persist in date palm orchards in A1- Anbar Province.     

Efficiency of Different Methods for dsRNA Delivery in Cotton Bollworm （Helicoverpa armigera）

RNAi trigged by dsRNA not only facilitates the development of molecular biology, but also initiates a new way for pest control by silence of fatal genes. However, one of the key limitations in pest control is lack of the convenient and efficient method for dsRNA delivery. In this study, different dsRNA delivery methods at their own optimum conditions were evaluated comparatively for their efficiency with Helicoverpa armigera as test animal. It was found that the popular one- time injection of larvae with dsRNA could reduce the pupation rate by 43.0% and enhance larva mortality by 11.7%. One- time ingestion of dsRNA did not result in any significant effect on phenotype. Continuous ingestion of in vitro synthesized dsRNA by refreshing the bait diet every day caused 40.4% decrease in successful pupation and 10.0% increase in larval mortality, which was similar as one-time injection. The most efficient method was found to be the continuous ingestion of the bacteria containing dsRNA expressed, which reduced the rate of pupation by 68.7% and enhanced the larval mortality by 34.1%. Further analysis found that dsRNA was degraded faster in midgut juice than in hemolymph. However, the cell of bacteria could protect dsRNA and delay the degradation in the midgut juice of H. armigera. These results throw light on the application of dsRNA in pest management with proper ways.     

Liberalization of Staple Crops： Lessons from the Mexican Experience in Maize

In this paper the authors inquire why, after more than 25 years of domestic agricultural reforms in Mexico and 15 years of trade liberalization of maize under the North American Free Trade Agreement （NAFTA）, the domestic production of maize, a non-competitive crop and the major staple in Mexico, has increased. The authors present new empirical evidence showing that, as expected, maize prices in Mexico dropped until 2006 and have experienced a process of convergence with USA prices, and maize imports from the USA have increased. However, despite lower prices, maize production in Mexico has trended upward since 1992, two years before the beginning of NAFTA＇s implementation. Based on the heterogeneity of maize production in Mexico, three possible explanations are proposed to explain this unexpected outcome： government supports to big commercial farmers in the agriculturally rich North of Mexico; the persistence of maize production by subsistence farmers; and to a lesser degree, increasing yields on some irrigated maize farms. We finish the paper by drawing lessons from the experience of Mexico for other Less Developed Countries.     

Stem Borer Species Composition on Maize and Two Non-Cereal Hosts in the Forest Zone of Kisangani,DRC

Lepidopteran stem borers are the most damaging pests of maize in Sub-Saharan Africa. Despite the growing importance of maize in the forest zone of Democratic Republic of Congo, no data is available regarding stem borer pest species present and their relative importance. It is thus important to gather information likely to guide future research in this area. This study was undertaken to catalogue stem borer pest species identity and assess their relative infestation levels on maize. Surveys were carried out in wild and cultivated habitats in Kisangani. Five species were collected on maize, i.e., Sesamia calamistis Hampson （1910）, Eldana saccharina Walker （1865）, Busseola fusca Fuller （1901）, Chilo sp. Strand （1913）, and Mussidia nigrivenella Ragonot （1888）. In the wild habitats, Poenoma serrata Hampson, B. fusca and S. calamistis were collected on Pennisetum purpureum whereas Chilo sp. was collected on Panicum maximum. Our results suggest that P. maximum might affect the population dynamics of Chilo sp. whereas P. purpureum is expected not to influence the population dynamics of other stem borers owing to its scarcity in the interior of the forest.     

Effects of temperatures on the development and reproduction of the armyworm,Mythimna roseilinea: Analysis using an age-stage,two-sex life table

The armyworm Mythimna roseilinea(Walker) is a major pest of grain crops in South China. So far little is known about its basic biology and ecology, making prediction of population dynamics difficult. This study examined the relationships of individual development and population growth with temperature based on an age-stage, two-sex life table of M. roseilinea reared on maize in the laboratory at 18, 21, 24, 27 and 30°C. The highest values of net reproductive rate(R_0) and fecundity were observed at 21 and 24°C, respectively. Both the intrinsic rate of increase(r) and finite rate of increase(λ) increased significantly and mean generation time(T) decreased significantly with increasing temperature. M. roseilinea was able to develop, survive and lay eggs at all temperature regimes tested. Development rates of the egg, larval, pupal, as well as the whole pre-oviposition stages had a positive linear relationship with temperature. The calculated development threshold temperatures of egg, larval, pupal, pre-oviposition and total pre-oviposition stages were 13.29, 8.39, 14.35, 7.42, and 12.24°C, respectively, and their effective accumulated temperatures were 63.59, 445.00, 211.11, 89.02, and 698.95 degree-days, respectively. These results provide insight into temperature-based phenology and population ecology of this insect pest and will allow population prediction and management available in the field.     

Expression profiles and functional prediction of ionotropic receptors in Asian corn borer,Ostrinia furnacalis (Lepidoptera: Crambidae)

Genes involved in chemosensation are essential for odorant-mediated insect behaviors. Odorant receptors(ORs) bind and respond to pheromones and plant volatiles, regulating insect behaviors such as mating and host-plant selection, while ionotropic receptors(IRs), which are present at lower levels in insects than ORs, influence ion channels, especially in agricultural pests. Asian corn borer, Ostrinia furnacalis, is the main pest of maize that causes huge economic losses in Asia. Twenty-one Ofur I...     

不同耕作方法条件下玉米抗御低温冷害的研究(英文)

[Objective] Aiming at chilling damage of maize in lowland of western Liaoning, the powerful evidences of resisting chilling damage of maize were provided from tillage method perspective.[Method] The depths of plough layers, sunshine effects in seedling stage, resistances to frost damage, microclimatic effects such as soil moisture, root system in filling stage, growth periods and grain weights of maize planted on ridge and in furrow were comparatively observed. The random arrangement was adopted in comparative observation with 4 replications.[Result] The daily mean ground temperature and effective accumulated temperature of plough layer of maize planted on ridge were relatively high. In addition, the seedling stage and mature stage of maize planted on ridge were in advance, the soil moisture, root growth and seed plumpness of maize planted on ridge were good. [Conclusion] The ridge planting in lowland of western Liaoning could improve in 0-20 cm plough layer where root grew, besides that this method could also improve maize growth and development.     

The influence of potassium to mineral fertilizers on the maize health

Field experiments(2009–2011) were conducted at the Department of Agronomy at Poznań University of Life Sciences on the fields of the Research Institute in Swadzim. We evaluated the health of maize plants of two types, depending on the variations in mineral fertilization. The conducted research recorded the occurrence of pests such as oscinella frit(Oscinella frit L.) and the European corn borer(Pyrausta nubilalis Hbn.). Diseases recorded during the research included two pathoagenes: Fusarium(Fusarium ssp.) and corn smut(Ustilago maydis Corda). It was shown that the meteorological conditions during the maize vegetation had a significant influence on the occurrence of pests. Adding potassium to mineral fertilizers increased the maize resistance to Fusarium. Cultivation of "stay-green" cultivar shall be considered as an element of in-tegrated maize protection. The occurrence of oscinella frit was correlated with the occurrence of Fusarium as well as the occurrence of the European corn borer for both examined cultivars.     

A Comparative Analysis of B Chromosomes and Genetic Diversity in Maize （Zea mays L.） Landraces from Southwest China

The number of B chromosomes （Bs） in 54 maize landraces from Southwest China was tested by means of cytological observations. Nine landraces with Bs were observed. A map, showing the geographic distribution of the landraces with Bs, was plotted. It was found that southeastern Sichuan Province in China was the main distribution area of the landraces with Bs in Southwest China. In order to obtain information on relationships between Bs and genetic variation, genetic diversity both among and within 11 landraces was evaluated. For each SSR marker, the number of alleles ranged from 3 to 12 with an average of 7.86, which revealed a high level of genetic diversity among maize landraces in Southwest China. Based on SSRs data, higher genetic variation was found in the landraces with 2B, and the genetic distance between the landraces with and without Bs was higher. The results together with the principal component analysis （PCA） supported the hypothesis that maize landraces in Southwest China were first introduced to the middle part of southwest Sichuan, China. At the same time, the effect of Bs on genetic variation was discussed.     

Suitability of the DNDC model to simulate yield production and nitrogen uptake for maize and soybean intercropping in the North China Plain

Intercropping is an important agronomic practice. However, assessment of intercropping systems using field experiments is often limited by time and cost. In this study, the suitability of using the DeNitrification DeComposition(DNDC) model to simulate intercropping of maize(Zea mays L.) and soybean(Glycine max L.) and its aftereffect on the succeeding wheat(Triticum aestivum L.) crop was tested in the North China Plain. First, the model was calibrated and corroborated to simulate crop yield and nitrogen(N) uptake based on a field experiment with a typical double cropping system. With a wheat crop in winter, the experiment included five treatments in summer: maize monoculture, soybean monoculture, intercropping of maize and soybean with no N topdressing to maize(N0), intercropping of maize and soybean with 75 kg N ha~(–1) topdressing to maize(N75), and intercropping of maize and soybean with 180 kg N ha~(–1) topdressing to maize(N180). All treatments had 45 kg N ha~(–1) as basal fertilizer. After calibration and corroboration, DNDC was used to simulate long-term(1955 to 2012) treatment effects on yield. Results showed that DNDC could stringently capture the yield and N uptake of the intercropping system under all N management scenarios, though it tended to underestimate wheat yield and N uptake under N0 and N75. Long-term simulation results showed that N75 led to the highest maize and soybean yields per unit planting area among all treatments, increasing maize yield by 59% and soybean yield by 24%, resulting in a land utilization rate 42% higher than monoculture. The results suggest a high potential to promote soybean production by intercropping soybean with maize in the North China Plain, which will help to meet the large national demand for soybean.     

Maize-rice cropping systems in Bangladesh： Status and research needs

Maize-rice cropping systems are expanding in Bangladesh. Hybrid maize has increasing demand and value, particularly for poultry feed, while rice remains the traditional dominant starch staple food. Bangladesh maize yields （with average farm yields around 5.7 t·ha^-1） are among the highest found in Asia. Cool winter （Rabi） season maize followed by T. Aman （monsoon） rice is the major cropping system; however it is now becoming diversified with many other crops including potato. Financially, hybrid maize is far more profitable than boro （irrigated） rice, wheat, or most other competing winter season Rabi crops. Although maize is relatively problem-free in Bangladesh, some constraints are intensifying with increased concern over input supply and soil-related environmental sustainability. An array of new technologies for sustainable intensive maize production systems is emerging in Bangladesh and some are being promoted and adopted. Continued sustainability of hybrid maize production in Bangladesh depends on optimization of planting time, quality seed of appropriate hybrids, balanced use of nutrient inputs along with soil fertility conservation and other management, for which further research would be high priority.     

Effects of Water Stress on the Protective Enzyme Activities and Lipid Peroxidation in Roots and Leaves of Summer Maize

A systematic study was conducted to determine the effects of water stress on the activities of protective enzymes and lipid peroxidation in maize. The results showed that, under water stress, the activities of superoxide dismutase （SOD）, catalase （CAT）, and peroxidase （POD） in leaves and roots increased sharply at prophase and metaphase growth stages, such as, male tetrad stage, but then declined towards the physiological maturity. The protective enzyme activities in roots were lower than those in leaves. The content of malondialdehyde （MDA） increased according to the severity of water stress. The content of MDA in roots was lower than that in leaves. The activities of protective enzymes and lipid peroxidation in roots were positively related to that in leaves with most of the correlation coefficients being significant. The content of soluble proteins in roots and leaves decreased with increasing drought stress. The ear characteristics deteriorated and the economic yields of maize decreased significantly under water stress. The main factors that caused reduction of yields were the decrease in the number of ear kernels and 100-kernel weight.     

Effect of four crop straws on transformation of organic matter during sewage sludge composting

A 45-d laboratory experiment was conducted to compare the effect of four crop straws on the transformations of organic matter(OM) during composting of sewage sludge. The four crop straws included rape straw, wheat straw, maize straw and rice straw. The following parameters such as temperature, OM, humic-like substances(HS), fulvic-like acids(FA) and humic-like acids(HA) were determined. The degradation of OM and the formation of HS and HA could be described well by the first-order kinetic model, while the FA content fluctuated during composting. T he maximal degradation rates of OM in the compost piles added with rape straw, wheat straw, maize straw and rice straw were 34.7, 46.9, 54.7 and 52.8%, respectively, and the final contents of HS were 118, 128, 141 and 134 g kg~(–1), respectively, while the humification indices were higher in the compost piles added with maize straw and wheat straw than in those with rice straw and rape straw. The results indicate that a higher hemicellulose content and a lower C/N ratio in crop straw can result in a higher rate of OM degradation and higher contents of HS, while a higher content of lignin can lead to a higher polymerization degree of humic substances in compost piles. The final compost piles added with maize straw has the highest contents of OM, total nitrogen and humus substance as well as the highest values of polymerization degree, while compost piles with rape straw have the highest potassium content and those with rice straw have the highest pH values.     

Response of Cytochrome P450 Expression to Maize Volatiles in Helicoverpa armigera (Hner)

The 7-ethoxycoumarin O-deethylase (ECOD) activities of cytochrome P450s and differential expression of six cytochrome P450 genes induced by the volatiles from both damaged and undamaged maize plants were investigated in the cotton bollworm, Helicoverpa armigera (Hner). The ECOD activity changed with time of exposure to maize volatiles. At 36 h after cotton bollworm larvae exposure to maize volatiles, the ECOD activities in cotton bollworm damaged and artificially damaged groups were 2.36 and 4.53 times higher than the control group respectively. The relative expression levels of CYP4S1, CYP6B2 and CYP6B7 in the cotton bollworm were significantly increased in artificially damaged plant group, which was 2.93, 5.09 and 10.66 times higher than that in the control group, respectively. The expression levels of CYP6B2, CYP6B6, CYP9A12, and CYP9A14 were much lower in the larvae exposure to volatiles from both healthy and pest damaged maize seedlings than in the control group at 12 h after larvae exposure to maize volatiles. For the cotton bollworm damaged maize group, the expression of CYP4S1 and CYP9A14 increased.     

Wheat,maize and sunflower cropping systems selectively influence bacteria community structure and diversity in their and succeeding crop's rhizosphere

Wheat and maize are increasingly used as alternative crops to sunflower monocultures that dominate the Hetao Irrigation District in China.Shifts from sunflower monocultures to alternate cropping systems may have significant effects on belowground microbial communities which control nutrient cycling and influence plant productivity.In this research,rhizosphere bacterial communities were compared among sunflower,wheat and maize cropping systems by 454 pyrosequencing.These cropping systems included 2 years wheat(cultivar Yongliang 4) and maize(cultivar Sidan 19) monoculture,more than 20 years sunflower(cultivar 5009) monoculture,and wheat-sunflower and maize-sunflower rotation.In addition,we investigated rhizosphere bacterial communities of healthy and diseased plants at maturity to determine the relationship between plant health and rotation effect.The results revealed taxonomic information about the overall bacterial community.And significant differences in bacterial community structure were detected among these cropping systems.Eight of the most abundant groups including Proteobacteria,Bacteroidetes,Acidobacteria,Gemmatimonadetes,Chloroflexi,Actinobacteria,Planctomycetes and Firmicutes accounted for more than 85%of the sequences in each treatment.The wheat-wheat rhizosphere had the highest proportion of Acidobacteria,Bacteroidetes and the lowest proportion of unclassified bacteria.Wheat-sunflower cropping system showed more abundant Acidobacteria than maize-sunflower and sunflower monoculture,exhibiting some influences of wheat on the succeeding crop.Maize-maize rhizosphere had the highest proportion of γ-Proteobacteria,Pseudomonadales and the lowest proportion of Acidobacteria.Sunflower rotation with wheat and maize could increase the relative abundance of the Acidobacteria while decrease the relative abundance of the unclassified phyla,as was similar with the health plants.This suggests some positive impacts of rotation with wheat and maize on the bacterial communities within a single field.These results demonstrate that different crop rotation systems can have significant effects on rhizosphere microbiomes that potentially alter plant productivities in agricultural systems.     

Amylose contents of cereals; influence of household processing on the amylose contents of these foods

Amylose is a food starch found in cereals, legumes and root vegetables. Keeping in view the importance of amylose for various food industries as well as its importance on domestic level, the current study was conducted to analyze the amylose content of common cereals e. g rice （sela, coarse and basmati）, maize yellow, Kisan and Azam varieties and wheat （Tatara, Fakhr-e-sarhad and Bakhtawar-92） varieties as well as quantifying the influence of cooking/boiling procedures on the amylose contents of cereals. The maximum amylose content were observed for wheat variety Tatara （24.28%） followed by Bakhtawar-92 （22.74%） and Fakhr-e-sarhad （19.77%）. Among maize and rice varieties studied, Kisan and course rice were rich in amylose content with values of 27.19 and 30.48% respectively. The chapti of Tatra wheat were scored highest for appearance （7.6）, flavor （7.5）, texture （7.6） and overall acceptability （7.55）. The roti of Kisan and Azam varieties got maximum appearance score of 7.6 as compared to 7.4 for maize yellow variety. Basmati rice was scored highest regarding appearance （8.4）, flavor （8.6）, texture （8.6） and overall acceptability （8.53. The moisture content ranged from 10.61 （Azam） to 8.01% （wheat variety Fakhr-e-sarhad）. Cooking reduced the amylose content of wheat bread from （19.77%-24.28%） to （15.47%-15.94%） with cooking time of 5 min, maize bread from （21.48%-27.19%） to （19.53 %-25.85%） with maximum cooking time of 10 min and boiled rice from （24.90%-30.48%） to （24.18%-30.19%） with cooking time ranging from 12 to 20 min. It can be inferred from these studies that the reduction in amylose content were more in chapti/roti preparation of wheat and maize varieties as compared to boiling of rice varieties and that significant varietals differences exist in amylose content of the uncooked samples.     

Regulation of Foliar Application DCPTA on Growth and Development of Maize Seedling Leaves in Heilongjiang Province

DCPTA （2-diethylaminoethyl-3, 4-dichlorophenylether） is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to study the effects of foliar applied DCPTA. The plant pots were placed in a completely randomized design with three replicates. The maize seedlings were treated with 0 mg·L-1 （control）, 20 mg·L-1 and 40 mg·L-1 DCPTA solution. The effects of DCPTA on the photosynthetic characteristics （photosynthesis, stomata conductance, intercellular CO2, and transpiration rate）, related physiological characteristics （contents of soluble sugar and starch）, chlorophyll fluorescence parameters （Fo, Fro, Fv/Fm, Fv/Fo, qP, and qN） and the weight of dry matter in maize seedling were studied. The results showed that DCPTA enhanced photosynthesis of maize seedling. In general, photosynthetic rate in leaves was significantly promoted through spraying DCPTA solution, and 40 rag＂ L~ DCPTA was found to be the best concentration for maize. The relationship between stomata conductance and transpiration rate in maize leaves could be described as linear. With regard to the chlorophyll fluorescence parameters, our fmdings showed that 40 mg·L-1 DCPTA in maize seedling caused an increase in Fm, Fv/Fm, Fm/Fo, qP and a decrease in Fo and qN at some time points checked. It is suggested that DCPTA increased photosynthetic rate by raising both the content of chlorophyll and activities of PSII and the contents of sugar and starch. Compared with the control, the treated maize seedling caused an increase in plant height, root length, shoot dry mass, root dry mass, or the total （root plus shoot） dry mass.