Control of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in greenhouse tomato crops using the mating disruption technique

The effectiveness of mating disruption to control the tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), in greenhouse tomato crops was evaluated in four trials carried out in winter–spring and summer–winter growing seasons in Southwestern Sardinia (Italy). Pheromone dispensers loaded with 60 mg of the natural blend of the major and minor sex pheromone component (rate 90 : 10) were applied in disrupted greenhouses at a rate of 1000/ha (60 g of active ingredient/ha). Male captures in monitoring pheromone traps, percentage of tomato plants infested by T. absoluta and damage on leaves and fruits were monitored weekly and compared in disrupted and untreated (control) greenhouses. In greenhouses disrupted with 1000 dispensers/ha, a reduction of 93–97% in male trap captures was observed, compared with control. Leaf damage was significantly lower in greenhouses disrupted with 1000 dispensers/ha than in control ones, with a reduction of infestation throughout the growing season ranging from 57% to 85%. Pheromone dispensers applied at the density of 1000/ha significantly reduced the percentage of damaged fruits by 62–89%. In control greenhouses, the highest damage on leaves and fruits was generally observed in edge plants, while leaf and fruit infestation was uniformly distributed in pheromone‐treated greenhouses, indicating an even distribution of the pheromone cloud inside the greenhouse. Mating disruption showed to be an efficient strategy to control in greenhouse the tomato leafminer and can be included in the overall tomato integrated pest management programs.     

Entomopathogenic fungi (Hypocreales) for control of potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae) in an area endemic for zebra chip disease of potato

Potato psyllid, Bactericera cockerelli, is a serious pest of potato and other solanaceous vegetables in the United States, Mexico, Central America, and New Zealand and is responsible for transmission of Candidatus Liberibacter solanacearum which causes a disease known as “zebra chip” (ZC). Entomopathogenic fungi could provide a viable component for an integrated pest management strategy for control of B. cockerelli and other potato pest insects. Three field trials of commercial formulations of Metarhizium anisopliae (F 52®, Novozymes Biologicals) and Isaria fumosorosea (Pfr 97®, Certis USA) and abamectin (Agri-Mek®, Syngenta, USA) were conducted in Weslaco, Texas. Rates are expressed in quantity of product delivered in 375–470 l of water/ha. F 52 applied at 0.51, 1.1, and 2.2 l/ha and Agri-Mek applied at 584 ml/ha produced reductions of B. cockerelli eggs and nymphs of 45%, 59%, 67%, and 63%, respectively. Only Agri-Mek significantly reduced plant damage. Pfr 97 at 1.1 kg/ha with and without 1% Trilogy® (neem oil, Certis, USA), and Agri-Mek at 584 ml/ha resulted in psyllid reductions of 78%, 76%, and 84%, respectively. Significantly decreased plant damage and ZC symptoms were observed for all treatments. Tuber yields for Pfr plus Trilogy and Agri-Mek were significantly higher than the control. F 52 applied at 1.1 and 2.2 l/ha and Pfr 97 at 1.1 and 2.2 kg/ha produced 62%, 62%, 66%, and 65% reduction, respectively. Tuber yield for both rates of Pfr and the high rate of F 52 were significantly higher than the control. All fungal treatments significantly reduced plant damage and ZC symptoms.     

Efficacy of crude neem seed kernel oil (NSKO) in controlling the tree locust (Anacridium melanorhodon melanorhodon Walker), a serious pest of the gum arabic producing tree (Acacia senegal L. Willd.) in the Sudan

The present study was carried out at Al Semih (western Sudan) (13° 14′ N: 30° 27′ E: Alt. 550 m). The area is part of the gum arabic belt which is heavily populated with farmers who practice shifting cultivation and/or agroforestry where Acacia senegal L. Willd (the main gum arabic producing tree) is dominant. The tree locust (Anacridium melanorhodon melanorhodon Walker (Orthoptera, Acrididae) is a serious pest of A. senegal. Farmers practice agroforestry within the gum belt where they cultivate their crops e.g. millet, groundnut, sesame and sorghum between A. senegal trees. Gum Arabic is an important source of revenue for farmers. Chemical pesticides have been used to control the tree locust. Although the gum belt (where A. senegal grows) is heavily populated, pesticides are used to control the tree locust in the area. The present study was undertaken with the objective of using alternative environmentally safe pesticides. Several doses of neem seed kernel crude oil (NSKO) were tested against the 4^th, 5^th, 6^th instars and the mature tree locust (A. melanorhodon melanorhodon) in a completely randomized block design. Experiments were carried out in cages placed on part of the gum arabic belt. NSKO at high doses (5 and 10% v/v) significantly reduced feeding, moulting and ovipositing of the tree locust and significantly increased the mortality of all developmental stages tested. However, low doses of NSKO had no significant effect on the tree locust.     

喷雾方式及喷液量对吡蚜酮和啶虫脒在棉田的沉积分布及棉蚜防治效果的影响

为探明防治棉田棉蚜Aphis gossypii (Glover)的最佳喷雾方式及喷液量, 提高棉田的农药利用率, 作者于2011-2012年在山东省棉花苗期和成株期分别使用背负式手动喷雾器和背负式机动弥雾机以常规大容量和低容量喷雾, 比较杀虫剂25%吡蚜酮可湿性粉剂和3%啶虫脒乳油的喷雾雾滴在棉花田的沉积分布及棉蚜防治效果。结果表明： 在棉花苗期, 3%啶虫脒乳油用量450 mL/ha时, 使用机动弥雾机以75, 150和225 L/ha喷液量喷雾, 药剂在地面的流失率分别为24.4%, 28.9%和26.7%; 使用手动喷雾器以300, 450和600 L/ha喷液量喷雾, 杀虫剂在地面的流失率分别为35.6%, 37.8%和46.7%; 啶虫脒不同喷雾处理对棉蚜的防效无显著性差异（P>0.05）。在棉花成株期, 25%吡蚜酮可湿性粉剂用量为300 g/ha时, 使用手动喷雾器以600 L/ha喷液量喷雾, 药剂地面流失率为13.3%; 使用机动弥雾机以喷液量150 L/ha喷雾时, 药剂地面流失率为3.3%; 25%吡蚜酮可湿性粉剂用量减少至225 g/ha, 使用机动弥雾机以喷液量150和300 L/ha喷雾, 对棉蚜的防效与吡蚜酮用量300 g/ha、 使用手动喷雾器在喷液量600 L/ha条件下喷雾相比没有显著差异（P>0.05）。使用机动弥雾机喷雾可以减少田间用药量和喷液量, 降低药液的流失率, 减轻对环境的污染。     

Effects of fertilization on the nutrient distribution of aboveground components ofAbies balsamea (L.) Mill

Summary The following fertilizer treatments were applied to a 20-year-old aspen-birch-sprucefir stand in southeastern Maine: N at 448 kg/ha, P at 112 kg/ha, N and P applied as above in addition to 1751 kg/ha Ca and 27 kg/ha Mg. Five years after treatment, foliar concentrations of N, P and Ca for understory blasam fir exhibited significant increases in response to fertilization with those nutrients. Mean five-year height growth, adjusted for pretreatment differences, increased 36 percent in response to fertilization with N alone and in combination with P and lime.     

Role of thiourea in improving productivity of wheat (Triticum aestivum L.)

The role of thiourea (TU), a sulfhydryl compound, was assessed in wheat via soil and foliar treatments. Results showed that at 30 days after flowering, soil-applied TU treatments did not influence dry matter accumulation or its distribution in leaves, stems, and ears, but foliar-applied treatments brought about significant effects varying with the timing of spray. At harvest, however, soil-applied treatment of 10 kg/ha TU increased the number of ears, grains/ear, weight/grain, biological yield (total above ground biomass), grain yield, and harvest index. Grain yield increased by 17.3% over control. Soil-applied 20 kg/ha TU increased the grain yield by 1.6% over control. Foliar applied treatment of 0.5 kg/ha TU at tillering increased the number of ears, grains/ear, weight/grain, biological yield, grain yield, and harvest index. Grain yield increased by 15.2% over control. Foliar spray of 0.5 kg/ha TU at flowering tended to improve only weight/grain, but biological yield and grain yield increased significantly. Grain yield increased by 6.6% over control. TU spray at both tillering and flowering increased the number of ears, grains/ear, weight/grain, biological yield, grain yield, and harvest index. Grain yield increased by 23.9% over control, and when compared with spray at tillering there was a significant increase of 7.5%. Thus, two foliar sprays of thiourea, at tillering and at flowering, at 1 kg/ha can be recommended for improving wheat productivity.Abbreviations TU thiourea - DMA dry matter accumulation - DMD dry matter distribution     

Silicon-mediated resistance of sugarcane to Eldana saccharina Walker (Lepidoptera: Pyralidae): effects of silicon source and cultivar

Abstract:  The effects of four silicon sources – a USA calcium silicate, a local (South African) calcium silicate, Slagment^® and fly ash – on the resistance of sugarcane cultivars (two resistant and two susceptible) to Eldana saccharina Walker (Lepidoptera: Pyralidae) were studied in a potted sugarcane trial. Silicon sources were applied at 5000 or 10 000 kg/ha for the calcium silicates and Slagment; fly ash was applied at 15 000 or 30 000 kg/ha. The greatest increase in plant silicon content (particularly in stalks) was recorded for plants treated with local calcium silicate. Silicon uptake did not vary significantly between the susceptible and resistant cultivars, although the resistant cultivars had inherently higher silicon content than the susceptible ones. Treatment with silicon significantly reduced borer damage and borer performance at the higher treatment level. In general, borer damage and performance decreased with increasing rates of applied silicon and both variables were inversely related with per cent stalk silicon. On average, the higher silicon rate reduced damage by 34% in the susceptible cultivars and by 26% in the resistant cultivars, supporting the argument that susceptible cultivars benefit more from silicon treatments than resistant ones. We propose that calcium silicate amendments could be employed in the integrated, area-wide management of E. saccharina and in the management of soil acidity, both of which are widespread problems in the South African sugar industry.     

Effects of aerial spray volume, coverage, and abamectin on Scirtothrips perseae (Thysanoptera: Thripidae).

Helicopter applications using abamectin in different spray volumes were made against Scirtothrips perseae Nakahara in Ventura County, CA. On small (2.2 m tall) trees, spray coverage on water-sensitive papers was 24-48% and 43-97% for 468 and 935 liter/ha volume treatments, respectively. On large (6.2-8.1 m tall) trees, spray coverage was lower and quite variable, from 1 to 28% and 10 to 70% for 468 and 935 liter/ha treatments, respectively. On small trees, 468, 701, and 935 liter/ha with a high abamectin rate (26 g [AI]/ha) were equally effective against larvae from 13 to 27 d after treatment (DAT). On medium (4.2 m tall) trees, 468 and 935 liter/ha with the high rate were equally effective from 23 to 113 DAT. On large (6.5-8.1 m tall) trees, 468 and 935 liter/ha with a low abamectin rate (13 g [AI]/ha) were ineffective in three tests. In a fourth large (6.8 m tall) tree test, 468 and 935 liter/ha with the high rate were effective at 3 and 37 DAT. In a fifth large (6.2 m tall) tree test, 468-1,403 liter/ha with the high and 935 liter/ha with the low rate were equally effective 2-22 DAT. After all effective treatments, thrips numbers were lower than in controls for 1-3 mo. However, stable and highest reductions in populations were sometimes delayed until 20-23 DAT even when coverage was high. The variability in spray coverage on the lower levels of large trees and the delayed effect may explain inconsistencies in the reporting of or in actual aerial application results.     

Optimization of water and nitrogen application to menthol mint (Mentha arvensis L.) through sugarcane trash mulch in a sandy loam soil of semi-arid subtropical climate

Studies were carried out to optimize the use of water and nutrients by the crop with three moisture regimes [0.9, 1.2 and 1.5 irrigation water:cumulative pan evaporation (IW:CPE) ratios], two variables of organic mulch (control and sugarcane trash at 7 t/ha) and three levels of nitrogen (0, 100 and 200 kg/ha). Soil moisture regimes maintained at 1.2 IW:CPE ratio significantly increased the crop growth and herb and essential oil yields as compared with that of 0.9 IW:CPE ratio. The increase in herb yield due to 1.5 and 1.2 IW:CPE ratios was recorded to be 28.5% and 19%, respectively, over the irrigation given at 0.9 IW:CPE ratio, with the corresponding increase in essential oil yield to the extent of 23.5% and 15.5%. Interaction effect of moisture regimes and nitrogen rates indicated that increasing levels of irrigation at the highest level of N (200 kg/ha) improved essential oil yield of the crop. Application of N at 200 kg/ha in the mulched plots significantly enhanced the N uptake by the crop and essential oil yield over the control and 100 kg N/ha applied in the mulched/or unmulched plots and 200 kg N/ha applied in the unmulched plots. Application of organic mulch and nitrogen at 200 kg/ha improved the water use efficiency (WUE) in menthol mint crop. Higher moisture regimes maintained up to 1.2 IW:CPE ratio increased the WUE. The quality of essential oil in terms of its major constituent, menthol, improved slightly with 1.2 IW:CPE ratio as compared to 0.9 and 1.5 IW:CPE ratios at first and second harvests of the crop. It is recommended that menthol mint crop could be grown profitably by providing 16 irrigations, that is 80 cm water (based on 1.2 IW:CPE ratio) and nitrogen at 200 kg/ha in the sugarcane trash mulched plots, which could give a highest benefit:cost ratio from menthol mint cropping.     

Field-Cage Studies of Beauveria bassiana (Hyphomycetes: Moniliaceae) for the Suppression of Adult Western Corn Rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae)

The efficacy of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin, was tested as a control agent for adult western corn rootworm, Diabrotica virgifera virgifera LeConte, in walk-in field cages. Suspensions of B. bassiana conidia were applied to corn plants in cages into which laboratory-reared beetles had been released. Beetles were collected at 3 and 5 days post-application and evaluated in the laboratory for mortality. Mortality was 10, 29 and 50%, at rate equivalents of 7 X 10 12 , 2 X 10 13 (two applications), and 5 X 10 13 conidia/ ha, respectively. There was no significant difference in mortality of beetles collected at 3 days compared with 5 days post-application. Mortality due to B. bassiana was 24% when beetles were released into field cages 24 h post-application (5 X 10 13 conidia/ha) compared with 50% when beetles were present during the application. Beetle mortality declined significantly with increasing time from application in feeding assays carried out with leaf samples removed from plants at 0, 12, 24 and 72 h post-application. Mortality of beetles collected from treated plants within cages and maintained in the laboratory was found to overestimate the population decline by 10% when compared with beetle estimates from treated plants within field cages.     

Effects of aerial spray volume, coverage, and sabadilla on Scirtothrips perseae (Thysanoptera: Thripidae).

Helicopter applications using sabadilla (27-57 g [AI]/ha and 11.1-23.7 kg/ha sugar bait) in different volumes of water were made on avocado against Scirtothrips perseae Nakahara in Ventura County, CA. On small (2.8 m tall) trees, volumes of 374 and 795 liter/ha resulted in 3-18% and 19-43% spray coverage, respectively, on water-sensitive papers. On large (6.9-8.4 m tall) trees, these volumes resulted in only 1-3% and 6-11% coverage, respectively. On small trees, sabadilla in 374 liter/ha significantly reduced numbers of larvae 3 and 6 d after treatment (DAT). In contrast, on large trees, 374 liter/ha did not reduce larval numbers and was less effective than 561-1,964 liter/ha from 3-11 DAT. However, volumes of 1,543 and 1,964 liter/ha did not increase efficacy compared with 1,169 liter/ha. The results indicate that large trees require sabadilla in higher spray volumes for control of S. perseae, making applications on large trees more costly. The extra costs may not result in larval control beyond 11 d, making it especially critical to properly time applications on large trees.     

Bean leaf beetle (Coleoptera: Chrysomelidae) management for reduction of bean pod mottle virus

Bean pod mottle virus (BPMV) is a management concern for soybean, Glycine max (L.), producers in the North Central states because it can cause yield loss and reduce seed quality by induction of seed coat mottling. The main vector of BPMV is the bean leaf beetle, Cerotoma trifurcata (Forster). An experiment was conducted in 2000 and 2001 at two locations in northwestern and central Iowa to test three insecticide treatments for suppression of bean leaf beetles, and subsequently, BPMV. Treatments of insecticide applications with lambda-cyhalothrin were 1) a single early-season application (23 g [AI] /ha) (2.5 oz/acre) at the VE-VC soybean developmental stage; 2) two early-season applications, the first the same as treatment 1 and a second at the same rate 9-13 d later; 3) a single early-season application the same as treatment 1, followed by a mid-season application (28 g [AI] /ha (3.2 oz/acre) at approximately R2 (flowering, near 15 July); and 4) an unsprayed control. Application of lambda-cyhalothrin after soybean emergence and again as first-generation bean leaf beetles emerged in northwestern Iowa in 2000 (treatment 3) significantly reduced beetle densities through mid-season, BPMV field incidence by 31.5%, and seed coat mottling by 31.2%, compared with the unsprayed control. Similar effects were measured at the same location when insecticide was applied twice at early season (treatment 2). Yield was 453.7 kg/ha (6.74 bu/acre) greater in treatment 2 and 525.20 kg/ha (7.80 bu/acre) greater in treatment 3 than in the unsprayed control at the northwestern site in 2000. At both locations in 2001 fewer treatment effects were observed, which was likely related to lower beetle populations in that year. Early-season insecticide sprays targeted at overwintered beetles on VC-VE reduced the initial population of vector insects and may have contributed to a lower first-generation population because of reduced overwintered beetle oviposition. In 1 year at one location there was a benefit to an additional mid-season insecticide spray, although effectiveness of spraying at this time could vary based on the magnitude of the vector population.     

Efficacy of Selected Nonvolatile Nematicides on Control of Ditylenchus destructor in Iris

Greenhouse and field tests established that fenamiphos at 6.7 and 13.4 kg ai/ha applied in a 30-cm band directly on iris bulbs at planting effectively controlled Ditylenchus destructor. Aldicarb at rates of 5.6 to 11.2 kg ai/ha was less effective. Carbofuran, fensulfothion, and oxamyl at 6.7 to 13.4 kg ai/ha were ineffective. When applied on the bulbs, fenamiphos (granular or liquid) reduced nematode infection from 31 to 0.6% as determined by visual inspection of bulbs at harvest. Populations of D. destructor were reduced from 5.7 nematodes/g of fresh weight of bulb tissue to 0.04, 0.05, and 0.14 with applications of 13.4, 6.7, and 3.3 kg ai/ha fenamiphos, respectively. The most effective treatment was fenamiphos (granular or liquid) applied in a 30-cm band directly on the bulbs at time of planting.     

Effect of different fertilizers on the germination and growth of velvetleaf (Abutilon theohrasti Medic.)

Velvetleaf (Abutilon theophrasti Medic.) is one of the most important and invasive weed species in Hungary and also in Europe. Its dangerousness derives from its germination biology characteristics and its strong competitive and allelopathic ability. In wide line space crops such as corn, sunflower and soybean it may reduce the yield significantly, According to some authors, this yield reducing ability is lower with bigger nutrient supplies. Our experiment was carried in Keszthely, Hungary (46 degrees 45'35.53"; 17 degrees 14'26.9") at the Institute of Plant Protection, Georgikon Faculty, University of Pannonia in 2009 and 2010. We studied the separate and combined effect of different fertilizers on the germination and growth of velvetleaf in greenhouse pot experiments. The applied fertilizers were Linzer NAC (27% N) in doses of 200 kg N ha(-1) (2,325 g Linzer NAC/pot), Patent Káli (30% K2O) in 100 kg K2O ha(-1) (1,05g Patent Káli/pot) and DC Szuperfoszfát (20.5% P2O5) in 100 kg P2O5 ha(-1) (1,05g DC Szuperfoszfát/pot). Our study was carried out in 1.5-litre pots with Ramman brown-forest soil in four replications, with 25 seeds of velvetleaf per pots. Five velvetleaf plants were removed four and six weeks after planting from the pots and the lenght, the fresh- and the air dried weight and the leaf area of the plants was measured. The data were analyzed by ANOVA. We observed that nitrogen which was applied alone or with other nutrients can reduce the germination and growth of Abutilon with 200kg N ha(-1) doses. Potassium and phosphorus stimulate germination and growth. The biggest stimulating effect was produced by potassium when it was applied alone.     

Evaluation of the pear ester kairomone as a formulation additive for the granulovirus of codling moth (Lepidoptera: Tortricidae) in pome fruit

(E,Z) -2,4-decadienoate (pear ester) is a larval kairomone for the codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae). Orchard studies were conducted in 2005 and 2006 in apple, Malus domestica Borkhausen, and pear, Pyrus communis L., to evaluate a 5% active ingredient (AI), microencapsulated formulation of pear ester (PE-MEC) as an insecticidal additive for the codling moth granulovirus (CpGV). Although CpGV applied at 5-15-d intervals at commercial rates (2.2 X 10(12)-10(13) granules per ha) killed the majority (82-94%) of larvae found inside infested fruit, it did not eliminate significant damage, i.e., 30-92% fruit injury at harvest versus 51-82% in controls. PE-MEC treatments had significant but inconsistent results in our tests. In apple (mixed cultivars), PE-MEC (3.7-4.7 g [AI] /ha) plus CpGV reduced the percentage of fruit injured during the second but not the first larval generation, compared with CpGV alone, but there no was no additional population reduction (live larvae collected from infested fruit and tree bands). In 'Bartlett' pear, PE-MEC (3.7 g [AI] /ha) plus CpGV significantly increased larval mortality and reduced deep fruit entries at harvest over CpGV alone in 2006, but similar improvements were not observed in 2005 when a lower rate (1.5 g [AI] /ha) was tested. Surprisingly, compared with untreated controls, the PE-MEC formulation alone also reduced fruit injury (mid-season in Bartlett) and larval survivorship inside infested fruit at harvest (2006 apple tests and both years in Bartlett). Although pear ester seems amenable as a kairomonal adjuvant for use with insecticides, our inconsistent data with CpGV in apple and pear suggest practical improvements in formulation and application strategies (e.g., to optimize and maintain attractive release rates) are needed.     

Field studies on halo-blight of beans (Pseudomonas phaseolicola) and its control by foliar sprays

In 1968 when conditions were favourable for the spread of infection (rainfall 243 mm June-August), halo-blight of beans initiated from 0.38% primary infection produced 33.8% infected pods but in 1969 (rainfall 112 mm June -August+38 mm irrigation water), a similar level of primary infection resulted in only 3.2% infected pods. In both years plant and pod infection were reduced by approximately 90% by sprays of streptomycin sulphate or copper oxychloride (0.1% a.i. 60 gal/acre (675 l/ha)) applied every 10 days from seedling emergence to flowering time.     

Management of Root-knot Nematodes by Phenamiphos Applied through an Irrigation Simulator with Various Amounts of Water

Phenamiphos (6.7 kg a.i./ha) was applied via an irrigation simulator to squash at planting (AP) and 2 weeks after planting (PP), and to corn AP and 1 week PP to manage root-knot nematodes (Meloidogyne incognita). The nematicide was applied with 0.25, 0.64, 1.27, and 1.91 cm surface water/ ha to a Lakeland sand in which the soil moisture was at or near field capacity. Based on efficacy and crop response, no additional benefits resulted when phenamiphos was applied in volumes of water greater than 0.25 crn/ha. The cost of applying each 0.25 cm of water over a hectare is approximately $1.08, or a 92% reduction in nematicide application cost over conventional methods ($13.50/ha). Low root-gall indices and high yields from squash and corn indicate more effective nematode management when phenamiphos was applied AP rather than PP. Results from this method of applying phenamiphos suggest that certain nematicides could be used as salvage alternatives when nematodes are detected in crops soon after planting. For multiple-pest management, nematicides, other compatible biocides, and fertilizers could be applied simultaneously with sprinkler irrigation.     

Effect of nitrogen application on flowering and yield of eggplant (Solanum melongena L.)

Effect of nitrogen application on number of flowers per plant, number of different types of flowers per plant, length of style, number of fruits per plant and fruit yield/ha of eggplant was investigated under controlled greenhouse conditions. Nitrogen was supplied at 50, 75, 100, 125, 150, 175 and 200 kg N/ha with one control (no nitrogen) treatment. Nitrogen supplied at 200 kg N/ha gave best results and significantly produced the highest number of flowers per plant, fruits per plant and yield (32.24 ton/ha) over control plants. Nitrogen failed to influence style length and type of flowers i.e. long, medium, pseudo-short and short styled flowers. Nitrogen application at 150 and 175 kg N/ha showed comparable results with nitrogen applied at 200 kg N/ha.     

Effectiveness of late copper and streptomycin sprays for the control of halo-blight of beans (Pseudomonas phaseolicola)

Two sprays of copper oxychloride or streptomycin sulphate (0–1 % a.i., 675 1/ha) applied to dwarf beans at first flowering and at pod set reduced pod infection by c. 70%. When applied as single sprays at pod set, copper was more effective than streptomycin and reduced pod infection by 50%. Although a copper spray at pod set increased the proportion of pods suitable for processing, more effective control was obtained with a regular spray programme, commencing at the seedling stage.