Salinity stress effect on ion uptake and yield attributes in rice

The pot experiment was conducted under tropical condition (102012' N latitude and 101042' E longitudes) to evaluate salinity tolerance level of three rice cultivars viz., MR219, Binashail and IR20 during November 2012 to March 2013. Salinity levels were 0.34 (control), 4.2 and 8.8 dS/m. Salinity stress was evaluated in terms of ion uptake in plant straw (leaves & stems) and yield attributes. Sodium ion increased with increasing salinity levels whereas reverse trend was observed in potassium and calcium ions content in straw. However, among the cultivars, MR219 contained less sodium ions in straw. Sodium content was the highest in IR20. The number of effective tillers/hill, number of filled grains/panicle, 1000-grain weight and harvest index decreased with increasing salinity levels whereas reverse trend was observed in case of non-effective tillers/hill and unfilled grains/panicle. MR219 showed the best performance in terms of yield and yield attributes up to 8.8 dS/m soil followed by Binashail. The yield and yield attributes of IR20 drastically decreased with the increase of soil salinity. MR219 was found tolerant, Binashail was moderately tolerant and IR20 was susceptible to imposed moderate salinity

First report of Diaporthe/Phomopsis complex isolates in soybean from Malaysia and their longevity in stored seeds.

Diaporthe/Phomopsis Complex (DPC) can infect soybean seed and reduce its germination in the field and also survive on the seed during storage. Ten soybean seed lots which were stored at 0°C for up to 13 years were used to evaluate the percentage of DPC infection on them and also to identify the DPC isolates. Morphological and molecular methods were used to determine the longevity and frequency of DPC isolates in stored soybeans seeds. Conventional and nested Polymerase Chain Reaction (PCR) was used for amplification of pure cultures and seed lots. The longevity of isolates in storage was found to be <9 years which suggested that Diaporthe/Phomosis sp., can survive up to 9 years in cold storage (0°C). Six isolates of DPC were detected, identified and characterized based on morphological and molecular methods in soybean seeds for the first time in Malaysia. Most of the isolates identified belonged to Phomopsis longicolla and only one isolate identified from Diaporthe Phaseolorum var. sojae. All isolates that were identified using morphological technique were confirmed using molecular method and registered in national center of biotechnology information (NCBI). The result of this study showed that DPC isolates can survive for long time in storage

Dormancy and cardinal temperatures during seed germination of five weedy rice (Oryza spp.) strains

Temperature during seed imbibition has been found to influence germination rate and final percent germination. Seeds of one cultivated variety and five weedy rice strains, collected from different localities in Peninsular Malaysia, were used to determine their degree of dormancy and cardinal temperatures. Meanwhile, standard germination and tetrazolium chloride (TTC) tests were used to evaluate the percentage of seed viability and degree of dormancy. Seed germination test at six different constant temperatures (between 10 and 35oC) was applied to determine the cardinal temperatures estimated by linear regression models, base temperature, Tb, optimum temperature, To, and maximum temperature, Tc. The TTC test was found to be a simple and quick test to determine the degree of seed dormancy among different weedy rice strains, when used together with a standard germination test. Germination rate was found to be related to the degree of dormancy but it had no influence on the range of cardinal temperatures. The Tb among the five weedy rice strains was in the range of 2-7.3oC. The To varied between 28.1 and 37.5oC, with an average of 32.5oC. This temperature (To) was higher than that of the cultivated MR73 variety (24.3oC), whereas the range of Tc was 42.2-43.3oC. The study indicated that the non-dormant cultivated rice seed had lower Tb and To values than the dormant seed of weedy rice

Influence of weeds on seed development, yield components and seed quality in Okra (Abelmoschus esculentus)

The presence of weeds during crop production is known to affect yield. However, changes to yield components, seed development and seed quality are not well documented. The study was conducted to determine the effect of weeds on accumulation of seed dry weight, yield components, and seed quality in okra (Abelmoschus esculentus). Treatments in the field consisted of manual weeding, no weeding or herbicide spraying. Flowers were tagged daily al flowering stage and fruits were harvested at 15, 20, 25, 30, 35 or 40 days after flowering (DAF). Changes in accumulation of seed dry weight, lOO0 seed weight, seed germination and field emergence were evaluated following all harvests. Yield components (fruits plant1 and seeds fruit1) were evaluated at 40 DAF. The presence of weeds did not affect the duration for seeds to reach maximum dry weight, but reduced lOO0 seed weight, fruits plant1 and seeds fruit1. Seeds harvested from manually weeded plats resulted in higher germination and field emergence compared with those from herbicide or no weeding plots. The presence of weeds >= 7.5% coverage) did not affect the time taken to achieve maximum germination and seed quality directly however, weeds directly affected rate of accumulation of seed d,y weight and seed size which subsequently affected germination and field emergence

Oil palm (e. guineensis) seed dormancy type and germination pattern

This study aimed to evaluate seed dormancy type and germination pattern for oil palm seeds. Physical dormancy tests included imbibition of intact, scarified and heat-treated seeds to determine percentage of mass increase over time. Seeds were stored at room temperature for 32 weeks to monitor embryo growth and seed germination. Physiological dormancy was evaluated by pre-soaking the seeds in 150 mg L-1 GA3. Results showed that the seeds were unable to imbibe water. Morphological tests on seeds at room temperature indicated that an embryo length of 3.64 or 3.03 mm was required to initiate germination in tenera × tenera (T × T) and dura × pisifera (D × P) seeds, respectively. Heat treatment accelerated embryo growth, regardless of treatment duration. Application of exogenous GA3 did not significantly increase germination. The seeds recorded higher germination at 30°C compared with room temperature. Oil palm embryo growth potential increases with time to overcome mechanical resistance of the endosperm micropylar region. The embryo growth (length) greater than 13% is required to commence germination. Results indicate that oil palm seeds have a combination of both morphological and physical dormancy

Effect of glufosinate-ammonium, glycophosphate and imazapyr herbicides at two spraying volumes on Imperata cylindrica (L.) Raeuschel

Imperata cylindrica (L.) Raeuschel is a problematic weed of the tropical region which causes significant losses in cultivated and non-cultivated areas, and is difficult to control. A field study was conducted to evaluate the effectiveness of glufosinate-ammonium, glyphosate and imazapyr herbicides on a stand of the weed in the field. The herbicide treatments were applied at their recommended field rates (glufosinate-ammonium at 3 kg a.i. ha-1; glyphosate at 1.65 kg a.e. ha-1; imazapyr at 0.75 kg a.e. ha-1), at two spray volumes of 400 and 800 L ha-1. Visual observation on foliage kill was related to the tiller number/unit area and mass production of the green foliage and fresh rhizomes, and the short-term plant succession pattern was also evaluated. Spray volumes of 400 and 800 L ha-1 did not influence the effectiveness of the herbicides on the weeds, however, significant kill (>80% kill) of the foliage was observed for each herbicide when compared with the control. Glufosinate-ammonium caused fast kill (within 1 week after treatment (wat)) of I. cylindrica foliage, but plant regeneration was faster (within 10 wat) than treatments with glyphosate or imazapyr which killed both the foliage and rhizomes (within 3 and 13 wat, respectively), resulting in longer control period and minimal regrowth of the weed. Regeneration of other plant species was much less in imazapyr treatment compared with those of the glyphosate or glufosinate-ammonium. Plants regenerated were mostly of the broadleaf species

Foliar application of chitosan improved morpho-physiological attributes and yield in summer tomato (Solanum lycopersicum)

Chitosan acts as an elicitor in many plant species. It not only activates the immune system of plants, but also increases the crop yields. A study was planned to investigate the effect of foliar application of chitosan on morphological, growth and reproductive characters and its consequence on fruit yield of summer tomato. The experiment comprised five levels of chitosan concentrations viz., 0 (control), 25, 50, 75 and 100 mg L-1. The chitosan was sprayed two times, 25 and 35 days after transplanting. Foliar application of chitosan at early growth stages increased plant height, number of branches and leaf area plant-1 and nitrate reductase activity in leaves, resulting increased total dry mass plant-1 and absolute growth rate. Reproductive parameters (number of effective flower clusters and flowers plant-1, and reproductive efficiency) also increased in chitosan applied plants and thereby increased the prime yield component, number of fruits plant-1 of summer tomato. The higher fruit yield was recorded in 50 and 75 mg L-1 of chitosan in summer tomato with being the highest in 75 mg L-1 (35.61 t ha-1). Therefore, foliar application of chitosan at 75 mg L-1 may be used at early growth stage for getting maximum fruit yield of summer tomato under sub-tropical condition

Selection of a high yielding soybean variety: Binasoybean-1

Collected 201 soybean [Glycine max (L.) Merrill] germplasm were evaluated for selection of desirable germplasm for registration as variety and/or for future utilization as breeding materials. Among the germplasm, nine were selected on the basis of better field performance considering their seed yield, morphological characters and yield attributes. Results showed that BAU-S/80 produced higher number of pods/plant and its yield was 2516 kg/ha as against 2142 and 2108 kg/ha of the two control varieties, Sohag and BARISoybean-5, respectively. Yield trials of BAU-S/80 were carried out in both rabi and kharif seasons during the period from 2007 to 2010 in selected locations under soybean growing areas of Bangladesh and found to be suitable for cultivation in the farmers' field. BAU-S/80 was found to be moderately resistant to soybean yellow mosaic virus and collar rot diseases, and also showed lower insect infestation than control varieties. On the basis of superior performance of BAU-S/80, Bangladesh Institute of Nuclear Agriculture (BINA) applied for registration to the National Seed Board NSB of Bangladesh. Consequently, the NSB of Bangladesh registered BAU-S/80 as Binasoybean-1 in 2011 for commercial cultivation in Bangladesh

Inherent variability in growth and development of two ecotypes of sesame plant (Sesamum sp.) in Malaysia

Differences in the growth and development of sesame ecotypes growing sporadically as uncultivated plant in dissimilar agro-ecological and habitat conditions of Serdang and Port Dickson of Malaysia have not been studied. The purpose of the study was to compare the inherent variations in growth parameters and degree of relationships between the two ecotypes over time. The quantitative growth parameters of the plants’ height, leaf number per plant, total leaf area, fresh and dry weight of leaves, fresh and dry weight of roots were measured at 2, 4, 8 and 12 weeks after planting under the same growing conditions. Results indicated that the two ecotypes manifested almost similar growth patterns and the variations on growth parameters between the ecotypes were statistically insignificant. Regression analysis showed that all the growth parameters increased exponentially over time, and the growth parameters were positively correlated between the ecotypes. Thus, this study suggested that a high homology in the growth patterns between the two sesame ecotype could exist when grown under the same growing conditions, although both have adapted to different habitat conditions