Effects of Mulch from 14 Multipurpose Tree Species (MPTs) on Early Growth and Nodulation of Cowpea (Vigna unguiculata L.)   总被引：2，自引：0，他引：2  

A. Y. Kamara  I. O. Akobundu  N. Sanginga  S. C. Jutzi 《Journal of Agronomy and Crop Science》1999,182(2):127-134

Leaf extracts and mulch from 14 MPTs were used to study their effects on germination, initial growth and nodulation of cowpea. Aqueous leaf extracts of , , and full concentrations were added to cowpea seeds placed in Petri dishes. In the pot experiment, cowpea was planted in plastic pots filled with 1200 g of soil, and mulch was either surface-applied or incorporated into the substrate at rates equivalent to 5, 10 and 20 tons · ha⁻¹. Leaf extracts from Gliricidia sepium, Senna siamea, Milletia thoningii, Grewia pubescens and Tetrapleura tetraptera reduced cowpea germination significantly at concentrations above 25 % of the full concentration 7 days of incubation. Root length was also strongly reduced by extracts from Gmelina arborea, Senna siamea, Alchornea coordifolia, and Tetrapleura tetraptera. These inhibiting effects were also observed in the pots. Mulch incorporation significantly reduced growth and nodulation of cowpea in the pots. These reductions were more pronounced with the incorporation of mulch from fast decomposing trees such as Leucaena leococephala, Gliricidia sepium and Grewia pubescens. Although Leucaena leucocephala and Gliricidia sepium released much nitrogen, they strongly reduced cowpea growth when incorporated. This may suggest that other reasons than N immobilization caused growth reduction when the plant residues were applied to cowpea.  相似文献   

模拟酸雨对豇豆种子萌发及幼苗生长的影响     

韩春梅 《长江蔬菜》2009,(9):35-36

研究了不同pH值（1．0,2．0,3．0,4．0,5．0和6．5）酸雨对豇豆种子萌发及幼苗生长的影响。研究结果表明,随着pH值的下降,豇豆的发芽率、发芽势、发芽指数、幼苗根长及下胚轴长均呈降低的趋势,均受到不同程度的抑制。当pH值降到最低1．0（酸度最强）时,所有豇豆种子全部发生霉烂现象。  相似文献   

Reproductive Abscission and Yield of Irrigated and Drought Stressed Cowpea     

H. Tewolde    A. K. Dobrenz    D. L. Robinson  V. Marcarian 《Journal of Agronomy and Crop Science》1991,166(3):191-199

Two experiments were conducted under field conditions to evaluate reproductive abscission, seed yield and yield components of three cowpea [Vigna unguiculata (L.) Walp.] genotypes. In the first experiment, level of abscission and yield of two cultivars, California Blackeye Pea No. 5 (CA-5) and Speckle Purple Hull (SPH), and one experimental line (AZ-54) were studied. In the second experiment, effect of drought stress on abscission at three nodal positions, seed yield, and yield components of CA-5 were studied. Abscission in both experiments was determined by counting scars left by dropprd reproductive structures including floral buds, open flowers, and immature pods. Abscission of CA-5 and AZ-54 in the first experiment ranged between 68 and 76 % while that of SPH ranged between 86 and 89 %. CA-5 and AZ-54 retained two to three pods per peduncle, and SPH retained only one mature pod per peduncle. Average seed yields of SPH and AZ-54, respectively, were 45 and 50 % of CA-5. Drought stress in the second experiment did not affect production of floral buds Peduncle^?1 (average of 10) but significantly increased percent reproductive abscission and decreased pod retention of CA-5. Abscission in the bottom two-third nodes increased from 82 % in well-irrigated plants to 93 % in non-irrigated plants. This increase in abscission corresponded to nearly 60 % reduction in pod retention. The number of pods per peduncle in the bottom two-third nodes decreased from 1.9 in well-irrigated plants to only. 77 in non-irrigated plants. The increase in abscission and decrease in pod retention with increasing intensity of drought was greatest in the bottom one-third nodes. Drought stress did not affect abscission and pod retention in the top one-third nodes. Stress also decreased peduncles plant^?1, seeds pod^?1, and dry matter and seed yield plant^?1 but did not affect seed weight and harvest index. The decrease in seed yield was largely due to reductions in pods plant^?1 and seeds pod^?1. The reduction in the number of pods and, therefore, seed yield due to stress was because of reductions in the number of peduncles plant^?1 and increases in reproductive abscission. It is concluded external conditions that increase abscission beyond that of normal occurrence affect seed yield adversely.  相似文献   

淡绿色豇豆新品种东方玉龙的选育     

周云德  贾志明  王永莉 《长江蔬菜》2012,(10):12-14

为丰富江苏豇豆品种,以嫩荚淡绿色,生长势旺盛,商品性佳为目标,以种质X为母本,种质J为父本,有性杂交后经6代系统选育出东方玉龙豇豆,于2010-2011年进行品比试验、生产试验,以扬豇40为对照。试验结果表明,东方玉龙生长势旺,耐热性强,嫩荚淡绿色,色泽佳,肉质紧实,耐贮运,每667 m2产量为1 523.8 kg,比对照增产9.2%,春夏均可栽培。  相似文献   

Effects of fertilizer timing and placement on grain yield and leaf nutrients of sole‐crop cowpeas (V. unguiculata) in Sierra Leone     

《Communications in Soil Science and Plant Analysis》2012,43(8):645-665

Abstract

Effects of fertilizer timing and placement on the grain yield and leaf nutrients of uninoculated sole‐crop cowpeas in two experiments during the minor cropping season on Njala upland soil of Sierra Leone were studied. Timing and placement and their interaction had no significant effects on grain yield. Placement affected highly significantly lamina Mg, Cu and Co and significantly lamina N and Ca. Placement and timing x placement interaction affected highly significantly petiole N and petiole P respectively. Timing affected highly significantly petiole N, which decreased as fertilizer application was delayed. The spectrum of nutrient distribution in both lamina and petiole was decidedly different. Multiple regression studies indicated that variability in only petiole Mg, Cu and Co significantly contributed to grain yield variability. By the introduction of 15 nutrients (6 lamina and 9 petiole) after examining the linear regression coefficients into a composite multiple regression study, lamina Ca, petiole Fe and petiole Co were selected as significant contributors to grain yield variability with marked improvement in R². Removal of the effects of the correlated variables produced significances in the effects of fertilizer placement and timing x placement interaction on grain yields.  相似文献   

Phosphorus uptake by cowpea plants from sparingly available or soluble sources as affected by nitrogen form and arbuscular‐mycorrhiza‐fungal inoculation     

Benard Ngwene  Eckhard George  Winfried Claussen  Elke Neumann 《植物养料与土壤学杂志》2010,173(3):353-359

In most plant species, nutrient uptake is facilitated upon root association with symbiotic arbuscular mycorrhizal (AM) fungi. The aim of the present experiment was to test how the form in which nitrogen (N) is supplied to the growth medium affects substrate pH, AM development, and contribution of the symbiosis to phosphorus (P) uptake from sparingly available or soluble resources. Cowpea (Vigna unguiculata L. Walp) plants inoculated or noninoculated with AM fungi (Glomus sp.) were grown in pots with a sand substrate supplied with nutrient solution. The nutrient solution was prepared either with a high or a low concentration of soluble P, and NO ‐N : NH ‐N ratios of 9:1 or 5:5. The substrate supplied with low‐P nutrient solution was either or not additionally amended with ground rock phosphate. Despite a high level of root colonization, AM fungi used in the present study did not appear to increase plant availability of rock phosphate. It cannot be excluded that the ability of AM root systems to acquire P from sparingly available resources differs depending on the plant and fungal genotypes or environmental conditions. The absence from the growth substrate of P‐solubilizing microorganisms able to associate with AM mycelia might also have been a reason for this observation in our study. Increased supply of NH relative to NO improved plant P availability from rock phosphate, but also had a negative effect on the extent of AM‐fungal root colonization, irrespective of the plant P‐nutritional status. Whether increasing levels of NH can also negatively affect the functioning of the AM symbiosis in terms of plant element uptake, pathogen protection or soil‐structure stabilization deserves further investigation.  相似文献   

Influence of Calcium Silicate on Growth, Physiological Parameters and Mineral Nutrition in Two Legume Species Under Salt Stress     

B. Murillo-Amador  S. Yamada  T. Yamaguchi  E. Rueda-Puente  N. Ávila-Serrano  J. L. García-Hernández  R. López-Aguilar  E. Troyo-Diéguez  A. Nieto-Garibay 《Journal of Agronomy and Crop Science》2007,193(6):413-421

Cowpea and kidney bean plants were grown in a hydroponic system, and the effect of calcium silicate supplied to the nutrient solution under salt stress was investigated. The plants were subjected to four different treatments: (1) nutrient solution alone (C), (2) nutrient solution + 40 mmol l⁻¹ NaCl (NaCl), (3) nutrient solution + 40 mmol l⁻¹ NaCl + 0.5 mmol l⁻¹ CaSiO₃ (NaCl + Si₁) and (4) nutrient solution + 40 mmol l⁻¹ NaCl+1 mmol l⁻¹ CaSiO₃ (NaCl + Si₂). The results showed that, in both species, salinity reduced all growth variables but silicate supplementation however partly overcame this growth reduction. Addition of silicate in NaCl‐stressed plants maintained membrane permeability. Net photosynthesis, chlorophyll content, stomatal conductance and transpiration were higher in plants under control treatment, and the inclusion of silicate in the nutrient solution resulted in a slight increase in these plant parameters. Intercellular CO₂ was slightly higher in plants under silicate treatment than in plants under control or NaCl treatment. Calcium concentration in shoots and roots in both species was slightly higher in the treatments where silicate was added. Potassium concentration for salt treatment was reduced in shoot and root of both species in the absence of silicate. Sodium and chloride concentration in shoots and roots in both species were slightly higher in the presence of NaCl and were slightly reduced in the plants under silicate treatments. The results suggest that, in hydroponically grown plants, the inclusion of silicate in the nutrient solution is beneficial because it improves growth, physiological parameters and may contribute to a more balanced nutrition by enhancing nutrient uptake under NaCl‐stressed conditions. Added calcium silicate may ameliorate the parameters affected by high salinity, may reduce sodium and chloride, and can slightly increase calcium and potassium concentrations in shoots and roots of salt‐stressed cowpea and kidney bean.  相似文献   

Evaluation of Pedigree and Single Seed Descent Selection Methods for Cultivar Development in Cowpea (Vigna unguiculata L. Walp)     

I. O. Obisesan 《Plant Breeding》1992,108(2):162-168

Three crosses of cowpea (Vigna unguiculata [L.] Walp) were used to assess the effectiveness of two selection procedures in cowpea. The selection procedures were pedigree selection (PD) and single seed descent selection (SSD). Lines developed through each procedure were yield tested and selected at F₆ and F₇ for PD and SSD, respectively. The selected lines for both procedures were compared at F₈ for grain yield per plant (YLD), number of pods per plant (NPO), and pod development period (PDP), in two locations. Lines developed through both procedures differed more in their population means than in the performance of their top 10% or highest yielding lines. There was no consistent relationship between magnitude of genetic variability and percentage of superior lines obtained from each procedure. Both procedures have been effective in producing superior genotypes for yield and number of pods. The PD method produced superior transgressive segregants in two out of the three crosses for PDP. SSD allowed a more rapid generation than PD.  相似文献   

Segregation Pattern of Decumbent, Climbing and Bushy Growth Habits in Vigna unguiculata (L.) Walp.     

M. I. Uguru  J. O. Uzo 《Plant Breeding》1991,107(2):173-176

F₁ and F₂ data from crosses of cowpea accessions with three different growth forms showed that the inheritance of growth habit is governed by two allelic pairs, AA and BB. The genetic ratio obtained implicated a modifier gene interaction in which the genotype A-B- has the decumbent growth habit; the genotype aaB- has the climbing and aabb has the bushy habit. While the decumbent growth habit was dominant and epistatic over the climbing habit, the decumbent and the climbing growth forms were each monogenically dominant over the bushy habit.  相似文献   

Subject Index     

《Journal of Agronomy and Crop Science》2002,188(6):no-no

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