Glasshouse Assessment Research Articles

Foliar Application of Liquid-Silicate Rock Fertilizer Counteracts the Suppressing Effects of Saline Soils on Soybeans: A Glasshouse Assessment

Developing an alternative method for productive farming on saline soils is necessary because remediating the soils is not feasible on-farm. A foliar application of liquid-silicate rock fertilizer (LSRF) was proposed in response to this need, and its effectiveness was evaluated in a greenhouse. The specific aim of the research was to identify the effects of LSRF on the growth and yield components of soybeans grown on salinized soils. The experiment employed a split plot in a completely randomized design, with the main plot consisting of soil salinity levels (EC), i.e., 0.5, 1.5, and 2.5 dS. m-1 and the sub-plot was the concentration of applied LSRF, i.e., 0, 1, 2, and 3 %, in triplicates. Results reveal an increase in soil EC to 2.5 dS. m-1 slowed down the growth rate and reduced the yield of soybeans by about 20 %. In contrast, applying LSRF at concentrations ranging from 1 to 3% improved soybean growth and yield components while reducing the severity of soil salinity’s effects on the plant. Foliar application of LSRF could be an effective method of reducing the stresses caused by saline environments in soybeans. How to Cite: Joko Priyono, Akhmad Zubaidi, 2023. "Foliar Application of Liquid-Silicate Rock Fertilizer Counteracts the Suppressing Effects of Saline Soils on Soybeans: A Glasshouse Assessment." Journal of Agriculture and Crops, vol. 9, pp. 250-256.

Evaluation and Pre-selection of New Grapevine Genotypes Resistant to Downy and Powdery Mildew, Obtained by Cross-Breeding Programs in Spain.

The need to develop an environmentally friendly, sustainable viticulture model has led to numerous grapevine improvement programmes aiming to increase resistance to downy and powdery mildew. The success of such programmes relies on the availability of protocols that can quantify the resistance/susceptibility of new genotypes, and on the existence of molecular markers of resistance loci that can aid in the selection process. The present work assesses the degree of phenotypic resistance/susceptibility to downy and powdery mildew of 28 new genotypes obtained from crosses between “Monastrell” and “Regent.” Three genotypes showed strong combined resistance, making them good candidates for future crosses with other sources of resistance to these diseases (pyramiding). In general, laboratory and glasshouse assessments of resistance at the phenotype level agreed with the resistance expected from the presence of resistance-associated alleles of simple sequence repeat (SSR) markers for the loci Rpv3 and Ren3 (inherited from “Regent”), confirming their usefulness as indicators of likely resistance to downy and powdery mildew, respectively, particularly so for downy mildew.

Adding Organic Matter Enhanced the Effectiveness of Silicate Rock Fertilizer for Food Crops Grown on Nutritionally Disorder Soils: A Glasshouse Assessment

A glasshouse experiment was carried to identify effects of the application rate of ground silicate rock as a multinutrientfertilizer (SRF) with and without organic matter (OM) on growth and nutrient status of food crops (rice,corn, and soybean). Those crops were grown on 3 different soils in 2 cropping patterns, i.e., rice – soybean and corn– soybean, providing 6 experimental sets. A completely randomized design was applied in each experimental set.The treatment in each set consisted of 3 rates of SRF (5, 10, and 15 g kg-1), those 3 rates + 5 g kg-1 of OM, and acontrol (without adding SRF or OM). The first crops (rice and corn) were grown up to 65 days, while the secondcrop (soybean) was up to 40 days. Results indicated that for crops grown on less fertile soils, the application of SRFonly slightly increased growth of crops, mainly of the 2nd crops, and adding OM greatly increased the growth ofboth the 1st and 2nd crops. In those experimental sets, about 60 – 80% of the variation of crop growth was significantlydetermined by concentration of Cu and several other essential nutrients in crop tissue. In contrast, the growth forcrops grown on more fertile soils was not affected by the application of SRF or/and OM. It was concluded thatadding OM enhanced the effectiveness of SRF as a multi-nutrient fertilizer, and that may be used as an appropriatemulti-nutrient fertilizer or general ameliorant to sustain soil quality and remediate the nutritionally disorder soils.

High‐Energy Milling Improves the Effectiveness of Silicate Rock Fertilizers: A Glasshouse Assessment

The effectiveness of intensively milled gneiss and potassium (K-feldspar) as K fertilizers was evaluated through a glasshouse experiment with ryegrass. Plant were grown on two soil types for 12 months. Results show that the agronomic effectiveness of milled gneiss was nearly as great as potassium sulfate (K2SO4), but milled K‐feldspar was much less effective because of the relatively small extent of dissolution of K‐feldspar in the soil. The positive effects of K‐silicate rock fertilizers (K‐SRFs) included increases in plant biomass, uptake of K and silicon (Si), and soil pH with increasing application rate of the K‐SRFs. The application of K‐SRFs will be most advantageous for amending K‐deficient soils, and high‐energy milling provides a simple method for manufacturing effective multinutrient SRFs.

Glasshouse assessment of clomazone response of US pumpkin cultivars

Glasshouse experiments were conducted to assess differences in clomazone tolerance between US pumpkin cultivars that were first observed when the herbicide was used for weed control in a pumpkin variety evaluation experiment. Two Cucurbita maxima cultivars, Big Max and Mammoth Gold, were highly tolerant and did not exhibit shoot weight reduction at a potting-medium clomazone concentration of 64 mg kg −1 (w/w), four times the clomazone concentration that severely injured and reduced the shoot weight of the less tolerant C. pepo variety , Magic Lantern . A subsequent experiment to assess the response of 67 pumpkin cultivars demonstrated that while most C. maxima cultivars tested were not sensitive to clomazone, the response of C. pepo cultivars varied greatly.

Multiple field and glasshouse assessments increase the reliability of linkage mapping of the Vf source of scab resistance in apple

Apple scab, caused by the fungus Venturia inaequalis (Cke.) Wint., is an important disease in commercial apple production. A mapping population of 155 individuals, derived from a cross between the apple varieties ‘Prima’ (resistant)בFiesta’ (susceptible), was scored for response to the disease in replicated field and glasshouse trials throughout Europe. Twenty data sets were selected and cluster analysis was used to form a consensus score for the population fitting a 1 : 1 segregation ratio of resistance:susceptibility. The progeny were scored with molecular markers. A detailed map covering 54 cM of the ‘Prima’ linkage group containing the Vf gene for scab resistance was constructed using 24 molecular markers linked to the resistance gene. One isoenzyme marker (Pgm-1), six RFLP markers and 17 RAPD markers formed a linkage group with the consensus measure of resistance to scab. Four marker bridges were established with the corresponding ‘Fiesta’ linkage group with additional markers (one isozyme, one RFLP, three RAPD and one AFLP). A low chi-square value indicated a good fit of the marker ordering, which was in close agreement with previously reported linkage positions for some of the markers and Vf. Differences were observed in the ability of different scoring methods to resolve susceptible and resistant classes. The results obtained for the consensus classification of resistance to scab for the population may suggest the presence of virulent inocula at some sites, which could overcome the Vf gene for resistance. The consequences of relying on individual scoring occasions for studying Vf scab resistance are discussed in the context of linkage analysis, conventional breeding selection, and marker-assisted selection.

A glasshouse test for assessing resistance to early blight (Alternaria solani)

Fourteen genotypes of potato were assessed for resistance toAlternaria solani Sor., both in the glasshouse at the Scottish Crop Research Institute in Scotland and in the field in the Negev, Israel. Glasshouse assessments agreed well with field results, identifying the most resistant and susceptible genotypes. The effects on the glasshouse test of plant age, inoculum concentration, and length of time plants were kept damp after inoculation, were examined. The best agreement with field results was shown by plants inoculated at flowering, and the best discrimination between genotypes was achieved by keeping the foliage damp for 24 h after inoculating with a spore suspension containing 2.5×103 spores/ml.

Selection for resistance and tolerance of white clover to root-knot (Meloidogyne hapla) and clover cyst (Heterodera trifolii) nematodes

Abstract Glasshouse assessments of tolerance and resistance were conducted on 18 lines of white clover (Trifolium repens L.) which had been derived by crossing plants selected for improved performance in field soil naturally infested with nematodes. Resistance to the clover cyst nematode (Heterodera trifolii Goffart) was increased over unselected controls but tolerance to this nematode was not reliably assessed because the numbers of nematodes were too low. The selected lines did not show any improved tolerance or resistance to root-knot nematode (Meloidogyne hapla Chitwood) over unselected controls.

An evaluation of water extraction as a soil-testing procedure for phosphorus I. Glasshouse assessment of plant-available phosphorus

A water extraction procedure was evaluated as a soil-testing procedure for phosphorus (P). In a glasshouse experiment using perennial ryegrass, the water extraction procedure was used to predict plant-available P in 20 New Zealand soils varying widely in P status and P retention capacity. Water-extractable P in the 20 soils was highly correlated with plant uptake of P (r = 0.90**). Although plant uptake of P and Olsen-extractable P were equally well correlated (r = 0.90**), relationships between plant uptake of P and Bray1 — and Truog-extractable P, and isotopically exchangeable P were less close. The prediction of plant-available P using water extraction was not improved by inclusion of an estimate of P-buffering capacity (obtained from P retention capacity or the slope of the P desorption isotherm), in contrast to the finding for Olsen-extractable P. Because the interpretation of the results obtained appears to be independent of P-buffering capacity and soil type, the water extraction procedure may have advantages over the other soil-testing procedures for P for soils containing reasonable amounts of water-extractable P.

Qualitative and quantitative assessments of the reaction of lucerne plants to verticillium wilt

Abstract A glasshouse assessment of reaction of lucerne (Medicaga sativa L.) plants to infection (wilt score) with Verticillium albo-atrum Reinke et Berthold was influenced by the particular combination of fungus isolate and host cultivar. Within any particular cultivar an increase in wilt score was associated with increased depression of growth when plants were inoculated with strongly pathogenic isolates but not with weakly or moderately pathogenic isolates. For plants inoculated with a strongly pathogenic isolate, growth of symptomless or slightly affected plants was reduced to as little as 26% of that of uninoculated plants with a cultivar of low resistance such as ‘Rere’ and to between 77 and 93% for plants of ‘Vertus’ which has good resistance to wilt. Scoring plant reaction on the basis of visual symptoms, for the purpose of screening for resistance, was generally as good as using quantitative growth assessments and offered the advantages of speed and leaving the plants intact. Factors which must b...

Sources of Alternaria carthami inoculum in safflower

Spread of the disease Alternaria leaf blight (Alternaria carthami) from infected safflower seed and stubble was studied at Biloela in central Queensland to determine the importance ofthese inoculum sources in the initiation of epidemics. Seed infection levels of 20-55% resulted in 1.4-2.0% emerged diseased seedlings in the field. Levels of 1.0% seed infection have previously caused severe disease outbreaks in commercial crops. Visual appraisal of seed health correlated highly with laboratory, glasshouse and field assessments of diseased seedlings. Glasshouse assessment of emerged diseased seedlings gave the best indication of expected disease incidence in the field. Seed germination in the laboratory correlated poorly with emergence in the glasshouse and the field. Incidence of A. carthami on seedlings following soil incorporation of diseased stubble in November 1977 diminished from 28% in May 1978 to 0% in September 1980. Burning of diseased stubble in November 1977 failed to eliminate the disease, but reduced the number of emerged disease seedlings by 66% in May 1978. Dusting of healthy seed with a fungicide increased total emergence, but it did not control the spread of the fungus from the infected stubble as emergence of diseased seedlings was also increased.

Development of Methods for Screening Grapevines for Resistance to Infection by Downy Mildew. I. Dual Culturein vitro

The responses of grapevine varieties and hybrids, with a range of field disease resistance, to infection by downy mildew (<i>Plasmopara viticola</i>) were studied <i>in vitro</i>. Dual cultures of host and pathogen were established for Chambourcin, JS 23-416, Verdelet, Muscat St. Vallier, Cabernet Sauvignon, and Sultana by inoculating sterile rooted shoot cultures with a contaminant-free fungal spore isolate. It was demonstrated that resistance to downy mildew was expressed <i>in vitro</i>, and a scale of infection, based on foliar symptom development 10 days after inoculation, was described to rank the varieties. It can be summarized as I - discrete necrotic spots; II - extensive necrotic lesions; or III - extensive sporulation. The order of ranking of the varieties correlated with field and glasshouse assessments, although due to the high efficiency of <i>in vitro</i> inoculation and infection, symptom expression was more severe than in the field. These results were verified using full siblings of JS 23-416 x Sultana and Chambourcin x (Merlot x Sultana) differing in resistance to downy mildew. This report demonstrates that the dual culture technique can be used as a reproducible screening procedure, independent of season, to select for host resistance to an obligate parasite.

Studies on some neutral red duplex soils (Dr 2.12) in north-eastern Queensland. 2. Glasshouse assessment of plant nutrient status

Glasshouse experiments using the subtractive technique were conducted on 15 neutral red duplex soils from north-eastern Queensland. On two of the soils factorial experiments were conducted to obtain information on nutrient interactions. The legumes Phaseolus lathyroides and Stylosanthes humilis were used as test plants. All soils were deficient in phosphorus, sulphur, and molybdenum, although the magnitude of the various deficiencies often differed between soils. Yields of plants were well correlated with phosphorus extracted from the soils by 0.01 N.H,SO, and by 0.5 M. Na HCO3. Soil tests used were unsatisfactory indices of sulphur deficiency. A possible zinc deficiency was indicated.

Studies on some solodic soils in north-eastern Queensland. 2. Glasshouse assessment of plant nutrient status

Glasshouse experiments using the subtractive technique were undertaken to assess the nutrient status of a number of solodic soils in north-eastern Queensland. On two of the soils factorial experiments were conducted to obtain more information on nutrient interactions. The legumes, Phaseolus /athyroides and Stylosanthes humilis, were used as test plants. Omission of phosphorus severely depressed yield on all soils. This deficiency was usually corrected by applications of superphosphate equivalent to 670 lb an acre. Omission of sulphur and molybdenum also depressed yields in all except one soil. Soil potassium values were low on several soils and the omission of potassium from these gave lower yields. In the factorial experiments the lime, sulphur, and molybdenum main effects and interactions were generally significant. Lime appeared to be having the dual effect of enhancing the availability from the soil of both sulphur and molybdenum. There was some evidence of slight zinc deficiency on several soils and further investigation is required on this aspect.