Root Dip Research Articles

Root Dip Treatments for Controlling Blueberry Stem Blight Caused byBotryosphaeria dothideain Container-Grown Nursery Plants

Root Dip Treatments for Controlling Blueberry Stem Blight Caused by<i>Botryosphaeria dothidea</i>in Container-Grown Nursery Plants

Benomyl Root Dips Adversely Affect First-Year Performance of Stored Loblolly Pine Seedlings

Abstract Dipping loblolly pine roots into a clay slurry containing benomyl (1.25% active ingredient) at the time of packing did not improve survival of seedlings stored (near 3°C) for 1 to 4 weeks. In some situations, benomyl decreased out-planting survival. Regardless of lifting date or storage length, benomyl slightly decreased first-year height growth (by 12 to 17%). Although previous research has demonstrated that a benomyl treatment can improve the ability of March-lifted seedlings to withstand prolonged storage, a beneficial response is not yet predictable for loblolly pine seedlings lifted between October and February. South. J. Appl. For. 15(3):133-137.

Auxin-impregnated hygroscopic gel: effects on ponderosa pine and common hackberry seedlings

Greenhouse and field studies were conducted to determine the effects of indole3-butyric acid (IBA) and 2,4-dichlorophenoxyacetic acid (2,4-D) on root development and survival of 3+0 bareroot Pinus ponderosa (Dougl. ex Laws.) and 2+0 bareroot Celtis occidentalis (L) seedlings. In the greenhouse, 100 and 200 ppm. IBA and 10 and 50 ppm 2,4-D were applied to seedlings through a root dip in an auxin hygroscopic gel mix. A randomized complete block analysis of variance indicated that IBA gel treatments increased root volume and root dry weight in hackberry and had no effect on ponderosa pine; 2,4-D gel treatments had detrimental effects on both species. In the field, IBA gel treated ponderosa pine seedlings exhibited improved height and survival relative to the non-treated control seedlings. There was no detectable improvement in survival in the field for hackberry. However, diameter and stem dry weight were lower for hackberry seedlings treated with the gel dip alone.

Evaluation of Oospore Hyperparasites for the Control of Phytophthora Crown Rot of Pepper

AbstractNine isolates of known oospore mycoparasites comprised of six actinomycetes (Actinoplanes missouriensis, A. philippinensis, A. utahensis, Amorphosporangium auranticolor, Ampullariella regularis, Spirillospora albida) and three fungi (Acremonium sp., Humicola fuscoatra, Verticillium chlamydosporium) were tested in the greenhouse for their ability to suppress or delay the onset of crown rot of pepper caused by Phytophthora capsici. Verticillium chlamydosporium applied as a root dip increased the number of healthy plants by more than 100% when peppers were transplanted into soil artificially infested with oospores of Phytophthora capsici, but not when peppers were transplanted into soil naturally infested with P. capsici. The other mycoparasites were ineffective in the greenhouse. All the mycoparasites tested parasitized oospores of P. capsici in vitro.

Square root sign of left ventricular diastolic pressure curve in atrial septal defect.

The square root (dip and plateau) sign was observed in 7 of 21 adult patients with atrial septal defect (ASD). This study evaluated left ventricular (LV) diastolic filling dynamics and hemodynamic findings in 7 patients (Group 1) with, and 14 patients (Group 2) without the square root sign; 10 normal subjects (Group 3) served as controls. No significant differences were observed in LV end-diastolic and end-systolic volumes, ejection fraction, or left to right shunt. In Group 1, 77% of LV filling was completed in the first half of diastole; this percentage was 49% and 53% in Groups 2 and 3, respectively (both p less than 0.01 versus Group 1). Early diastolic filling velocity (at 20% of diastole) in Group 1 was significantly greater, and late diastolic filling velocity (at 80% and 90% of diastole) was reduced in Group 1 compared to those in Groups 2 and 3 (all p less than 0.05). The average values for right and left ventricular end-diastolic pressures were significantly higher in Group 1 (11 +/- 2 and 10 +/- 4 mmHg, p less than 0.05) than Group 2 (7 +/- 2 and 7 +/- 2 mmHg, p less than 0.05). It is suggested that a constrictive pathophysiology due to 4 chambers interaction or right ventricular constraint may play a role in the genesis of the square root sign in ASD.

Phytophthora Root and Stem Rot of Apple Rootstocks from Stool Beds

(...)Field applications of fosetyl-Al and metalaxyl to apple rootstocks reduced disease severity in the field, reduced lesions on excised stem pieces inoculated with P. cactorum and reduced disease development on apparently healthy rootstocks while in cold storage for 3-9 mo. Short-duration root dipping of healthy or mildly infected rootstocks before cold storage in high concentrations of benalaxyl, etridiazol, fosetyl-Al, or metalaxyl reduced disease, but the degree of reduction varied. Fosetyl-Al and metalaxyl consistently produced the best results. None of the materials were phytotoxic

Genetic Analysis of Brown Stem Rot Resistance in Soybean

Genetic resistance of soybean [Glycine max (L.) Merr.] to Phialophora gregata (Allington and Chamberlain) W. Gains, the cause of brown stem rot (BSR), can reduce yield losses in northern USA and Canadian production regions. Although two major dominant genes have been identified, additional sources of resistance may provide higher levels of resistance and/or more stable resistance over environments. The objectives of this study were to: (i) determine the pattern of inheritance of the BSR resistance found in PI 437970 and (ii) study allelic relationships of resistance genes in PI 437970 with Rbs 1, and Rbs 2. Evaluations were conducted using a root dip inoculation method in the field and greenhouse. The F2 and F3 plants were classified as resistant or susceptible based on mean parental reactions. Segregating generations of the cross PI 437970 ✕ ‘Pioneer Variety P9271’ revealed a single dominant gene conditioning BSR resistance. Crosses of PI 437970 with L78‐4094 ( Rbs 1 and PI 437833 ( Rbs 2) each demonstrated duplicate dominant epistasis indicating a third distinct gene designated Rbs3.

First-year Shoot Development and Carbohydrate Distribution in Fall-and Spring-planted Apple Trees

Abstract Fall- and spring-planted spur ‘Delicious’ trees were monitored for first-year spur and shoot development and major carbohydrate levels in 1986 and 1987. Fall planting resulted in significantly greater shoot extension growth and lower tendency to become spurbound than spring planting during both years for two strains of spur ‘Delicious’. Higher starch reserves were found following the growing season after fall planting than after spring planting. A root dip of 10,000 mg a.i. IBA/liter before spring planting in 1987 did not affect any of the characteristics measured. Chemical name used: lH-indole-3-butyric acid (IBA).

Bare Root Dip Treatment of Tomato Transplants with Paecilomyces lilacinus for the Control of Meloidogyne incognita

Results on the evaluation of bare root dip treatment of tomato seedlings in a spore suspension of Paecilomycis lilacinus for the control of Meloidogyne incognita is reported in this paper.

Inhibitory Effects of Two Organocarbamates Nematocides on Growth and Yield of Capsicum annuum, NP 46A, and Their Reversion by Gibberellic Acid

Summary Results have shown that two nematocides aldicarb and carbofuran at all the concentrations were inhibitory to the plant growth as well as for seed germination in Capsicum annuum. But the extent of toxicity was very low when applied as bare root dip treatment at lower concentrations (1-2 · 106ppm). Results on the effect od GA3 alone showed that 100ppm of GA3 was the optimum concentration for plant growth and seed germination. A combination of 100ppm of GA3 with graded concentrations (1-10 · 106 ppm) of aldicarb and carbofuran could reverse the inhibitory effects of both the nematocides on chilli plant. However, higher dosages of nematocides were able to nullify the stimulatory effect of GA3. An analysis of residual nematocides in plants after treating with graded concentration of nematocides indicated a linear increase in the amount of toxic residues as the concentration of nematocides was increased. But application of an optimum concentration of GA3 (100 ppm) along with graded concentration of nematocide (1-10 · 106 ppm) could significantly reduce the level of toxic residues in plants. thus, the results showed an antagonistic nature of GA3 against nematocide toxicity which might base upon its property to prevent the accumulation of toxic residues of nematocides in plants.

Monogenic resistance in tomato to Fusarium oxysporum f. sp. lycopersici race 3

Resistance to fusarium wilt, incited by Fusarium oxysporum (Schlecht.) f. sp. lycopersici (Sacc.) Snyder & Hansen race 3 in tomato (Lycopersicon esculentum Mill.) was discovered in LA 716, a L. pennellii accession. A resistant BC1F3 breeding line, E427, was developed from LA 716. E427 was crossed with the susceptible cv. Suncoast and F1, BCP1, BCP2 (to Fla 7155, a susceptible parent) F2, F3, and BCP2S1 seeds were obtained. Segregation for resistance following root dip inoculation over three experiments indicated a single dominant gene controlled resistance. Five of the 12 BCP1S1's segregated more susceptible plants, whereas one of the 12 segregated more resistant plants than expected (P<0.05). Three of 23 F3 lines segregated more susceptible plants than expected while 1 of the 23 had more resistant plants than expected (P<0.05). Segregation in all other lines fit expected ratios. Five of the 23 F3's were homozygous resistant which was an acceptable fit to expectations (P=0.1−0.5). The gene symbol I 3 is proposed for resistance to race 3 of the wilt pathogen. Deviations from expected ratios in data reported here and for other breeding lines indicate an effect of modifier genes and/or incomplete penetrance. Plant age at inoculation and seed dormancy did not affect results.

Effect of Seedling Root Dip and Main Field Treatment on Hirschmanniella mucronata and Rice Yield

Effect of Seedling Root Dip and Main Field Treatment on Hirschmanniella mucronata and Rice Yield

Inheritance of Resistance to Two Races of Fusarium Wilt in Three Cowpea Cultivars1

Fusarium wilt [caused by Fusarium oxysporum f. sp. tracheiphilum (E.F. Sm.) Snyder and Hansen] is a serious disease of cowpea [Vigna unguiculata (L.) Walp.] in California. The objectives of this study were to determine the inheritance of resistance to F. oxysporum f. sp. tracheiphilum races 2 and 3 in ‘California Blackeye Number Five’ (CB5), ‘California Blackeye Number Three’ (CB3), and line 7964, and to determine if the genes for resistance to each race were independent of each other. Cultivar CB5 is susceptible and CB3 and 7964 are resistant to races 2 and 3. The F1, BC1, F2, F3, and F5 progenies were evaluated for resistance to each race using a seedling root dip inoculation procedure. Some F1 and F2 progenies were also evaluated for resistance using a tray inoculation procedure. A single dominant race 3 resistance gene was identified in CB3 and a single dominant race 2 resistance gene was identified in 7964. The F3 family reaction to both races suggested that the race 3 gene in CB3 also conferred incompletely dominant resistance to race 2, and the race 2 gene in 7964 also conferred incompletely dominant resistance to race 3. The reaction of F5 lines to both races did not support this hypothesis. It was concluded that CB3 also possessed a single incompletely dominant gene for race 2 resistance and that 7964 also possessed a single incompletely dominant gene for race 3 resistance.

Use of insecticides as bare‐root dip treatments for the control of the root‐knot nematode,Meloidogyne incognitaon brinjal(Solanum melongenaL.)

Abstract Bare‐root dip of brinjal seedlings with BPMC, carbosulfan, chlorpyriphos, dimethoate and phosphamidon at 500 and 1000 ppm for 30 min exposure significantly increased plant growth and reduced host infestation as well as multiplication of Meloidogyne incognita. Root dipping in carbosulfan and phosphamidon at 1000 ppm level gave good protection against M. incognita and was found to be the best treatment. The efficacy of different chemicals in controlling the nematode was in the order of carbosulfan, phosphamidon, chlorpyriphos, BPMC and dimethoate.

STUDIES ON THE SOURCES AND METHODS OF APPLICATION OF ZINC TO LOWLAND RICE

Field experiments were conducted to study the effect of different sources and methods of application of zinc () to rice in two Zn deficient rice fields of Wetlands, Tamil Nadu Agricultural University, Coimbatore. The results revealed that soil application of six percent Zn-DAP enhanced the grain yield significantly over no Zn control. Four, five and six per cent Zn-DAP recorded higher yield over soll application of ZnSO, @ 25 kg/ha, foliar application of ZnSO, 0.5 per cent. sprayed on 50 and 45 days after planting and seed- fing root dipping in two per cent ZnO suspension.

Inheritance of Resistance to Phytophthora Root Rot in Highbush Blueberry

Abstract Young highbush blueberry seedlings (Vaccinium corymbosum L.) from 26 crosses of a partial diallel were inoculated with Phytophthora cinnamomi Rands by dipping the roots into a mycelial slurry. The seedlings were grown 90 days in sand in the greenhouse and rated for resistance to root rot damage. Of the 2412 inoculated seedlings, 214 (8.9%) were resistant. The 2 parental clones that produced the largest percentage of resistant seedlings were US 141 and G-164; within their progenies, each produced an average of 18% resistant seedlings. Mean squares for general (GCA) and specific combining ability (SCA) were significant at the 1% and 5% levels, respectively. The mean square estimate for GCA was about 5 times higher than that for SCA, While both additive and nonadditive effects are important, rapid improvement can be made by phenotypic selection. Resistance to P. cinnamomi in blueberry progenies studied appears to be partially recessive and quantitatively inherited. Inoculation of young seedlings by root dipping in a mycelial slurry of P. cinnamomi and growing the seedlings in sand provided rapid identification of resistant plants.

Toxicological investigations against rice green leafhopper,Nephotettix virescens(Distant)

Abstract Among nineteen granular formulations evaluated against green leafhopper, thiocyclam hydrogen oxalate, fensulfo‐thion, carbofuran, BPMC, MIPC and monocrotophos possessed good persistent toxicity while thiocyclam hydrogen oxalate, MIPC and BPMC exhibited a better knockdown effect. Of the twenty three spray formulations, phosalone, isofenphos, chlorfenvinphos, triazophos, monocrotophos, carbaryl and MIPC were better for persistent toxicity whereas monocrotophos, malathion, chlorfenvinphos, UC 54229 and phosphamidon showed considerable knockdown effect. Carbosulfan was the best insecticide for seedling root dip treatment and it was also effective in combination with chlorpyriphos. Granular formulations of thiocyclam hydrogen oxalate act on green leafhopper by volatalization from surface of the soil and translocation in the plant system. Utilization of these insecticides in integrated insecticide application methodology has been suggested.

Tolerance of Some Garden Flowers to Selected Preemergence Herbicides

Alachlor G and EC, chloropropham G, and napropamide G at 4.4 and 8.8 kg/ha and trifluralin G at 4.4 kg/ha were applied to chysanthemum, aster and portulaca and all materials except trifluralin to gladiolus after field planting. Weed population and plant quality data were taken twice during the growing season. Alachlor G or EC provided the best weed control followed by napropamide. Control by trifluralin was acceptable but weed suppression by chloropropham was not. Alachlor, napropamide, chloropropham and trifluralin cause no significant injury to portulaca, aster or gladiolus. All formulations of alachlor produced significant damage to the chrysanthemum while napropamide, chloropropham and trifuralin were safe. A wide variety of annual flowers are grown for seasonal color in commercial and residential landscapes and for cut flower production. Weed competition in such plantings causes a serious reduction in growth (Newman and Binning, 1974) and detracts from the aesthetics of the planting and overall landscape. Handweeding is a major maintenance cost for such plantings. Ahrens (1974) reported hoeing costs in chrysanthemum fields to be over $1000/ha. The cost for present day operations has increased dramatically due to inflation and is compounded by the varied sizes and shapes associated with annual beds as opposed to field rows. The diversity of species used for outdoor annual and perennial gardens serve to further complicate chemical weed control. Several trials conducted in the past have found species tolerance to herbicides highly variable (Newman and Binning, 1974; Bing, 1982, 1983a). Four species of flowers of particular interest in landscapes include: chrysanthemum (Chrysanthemum x morifolium Ramat.); gladiolus (Gladiolus x hortulanus Baily); aster (Callistephus chinesis (L.) Nees); and portulaca Journal Article 83-190-J, Kansas State University Agricultural Experiment Station. This content downloaded from 207.46.13.148 on Sun, 11 Sep 2016 04:33:42 UTC All use subject to http://about.jstor.org/terms VOLUME 88, NUMBERS 3-4 147 (Portulaca grandiflora Hook). Chrysanthemums are planted for a fall color display and are field-grown for retail sales. A large number of cultivars have been selected and named. Gladioli are grown commercially as cut flowers from corms (Bing, 1979) and as landscape annuals. Asters are also grown for cut flowers and as annual bedding plants. Portulaca is a low growing landscape annual tolerant of dry, hot conditions. Chrysanthemum has been shown to be tolerant of DCPA, diphenamid, trifluralin, chloropropham, and napropamide (Bing, 1982). DCPA, dephenamid, trifluralin, EPTC and chloramben are currently recommended for use with this species (Smith, 1982). Ahrens (1974) reported injury to chrysanthemum from emulsifiable concentrate formulation of alachlor (4.4 kg/ha) and a slight reduction in growth and later flowering due to granular application to the cultivar 'Chapel Bell'. Root dips of activated carbon were not totally effective in protecting chrysanthemums from alachlor. No injury occurred when 2.2 kg/ha alachlor was applied to field planted rooted cuttings, however, 4.4 kg/ha caused moderate leaf curl in two established cultivars and stunted field plant rooted cuttings (Ahrens, 1973). Granular alachlor (4.4 kg/ha) did not injure seven cultivars when applied in August. Currently recommended herbicides for gladiolus include trifluralin, bensulide and DCPA (Smith, 1982). Napropamide (Wilfret and Burgis, 1977; Bing, 1979) and oxyflurofen caused leaf burn and greatly reduced corm production (Bing, 1979). Talbert et al. (1979, 1980) reported increasing injury to gladiolus with increasing rates of napropamide but found no injury for alachlor. Bing (1977) reported injury to cormels by alachlor at higher

Seedling Root Dip Treatments to Control Gall Midge (GM)

Seedling Root Dip Treatments to Control Gall Midge (GM)

Inoculation Methods for Evaluating Verticillium Wilt Resistance in Strawberry Germplasm

Abstract Four methods of inoculation with Verticillium were tested for effectiveness in infecting strawberry plants grown in a greenhouse bench. The most severe and early symptoms were produced with a macerated mycelium root dip inoculum. Effect of inoculum aggressiveness on the extrapolation of plant resistance information is discussed.