Days After Planting Research Articles

Plant emergence and maize (Zea mays L.) yield across multiple farmers’ fields

ContextUneven crop stands result from natural variation in emergence time that is related to soil moisture and temperature, and variation of within-row plant-to-plant distance caused during planting operations. Understanding the effect of the spatial and temporal variation of plant emergence on crop yield can help farmers make improved management decisions about planting. ObjectiveThe objectives of this work were to i) compare the timing of maize plant emergence across and within sub-field yield stability zones, ii) evaluate the impact of delayed emergence on crop yield and yield components by yield stability zone, and iii) compare the effect of spatial and temporal variability of plant emergence on crop yield and yield components. MethodsTen experiments were conducted in farmers’ maize fields in Springport (Michigan, US), Portland (Michigan, US), and Parana (Entre Rios, Argentina). Several years of yield monitored data for each field were used to delimitate yield stability zones (YSZ). Individual plant emergence was recorded daily, across yield stability zones. Emerged plants were tagged and the distance between plants within the row was recorded and used to calculate plant growing space (cm2 plant−1), and to classify them within plant stand as uniform, double or skips. Tagged plants were hand harvested to analyze the individual plant yield, number and weight of grains, and total crop yield. ResultsIndividual plant emergence time ranged from 3 to 31 days after planting (DAP). The variation in timing of plant emergence had a greater impact than the variation of within-row plant spacing on crop yield and yield components. In general, the impact was larger in stable low yield areas. On average, plant yield was reduced by 7 %, grain number by 6 %, and final crop yield by 8.5 % per day of emergence delay after planting. The greater variation in the days of emergence delay when compared to within-row plant spacing variation can be related to the small overall spatial variability within the rows. ConclusionsPlant emergence temporal variability had a higher impact than within-row plant spatial variability on crop yield and its components. The decrease in maize yield caused by the delay in emergence was not statistically related to yield stability zones. However, a trend of a more negative impact of delayed emergence in the low yield stability zones was observed. ImplicationsUnderstanding factors affecting the spatial and temporal plant emergence patterns of crops can help farmers optimize their planting operation and may help them with decisions on using more precise and tailored inputs (such as seed rate and nitrogen fertilizer) on different sub-field yield stability zones. Incorporating emergence data and information into crop models will also help improve yield simulation results.

Growth Manipulation of Slicer Carrots by Foliar-applied Gibberellic Acid in New York

New York, USA, is a regional hub for processing carrot (Daucus carota ssp. sativus) production and Nantes-type cultivars are preferred for slicing. Diameter is critical in carrots for slicing, with roots larger than 1 5/8 inch being rejected. The potential to manipulate carrot root diameter and hence suitability for slicing by foliar-applied gibberellic acid (GA3) was tested in four small plot replicated field trials over 3 years (2020, 2021, and 2022). In the most efficacious treatments, GA3 resulted in a 23.1% to 135.4% increase in foliar biomass at the expense of root weight and diameter. Increases in foliar biomass are beneficial to facilitate top-pulling harvest. Reductions in root diameter from GA3 ranged from 9.5% to 19.6%, and in 2020 and 2022, increased the proportion of roots suitable for slicing. GA3 did not significantly affect root length and number. In two 2021 trials, GA3 increased color intensity quantified by a colorimeter, but this change was not noticeable to the naked eye. The optimal number of GA3 applications was seasonally dependent, ranging from a single application at 107 to 108 days after planting (DAP) in 2021, to two applications at 74 + 92 DAP in 2022. Three GA3 applications per season or late applications (up to 14 days prior to harvest) were not beneficial.

Weed-Hoeing Periods in Cowpea Cultivation under Direct and Conventional Systems.

Weed coexistence with an agricultural crop can negatively affect its growth, development, and yield. From this perspective, this study aimed to evaluate weed management strategies and their effect on the agronomic parameters of cowpea cultivation in direct (SPD) and conventional (SPC) planting systems. The experiment was set up in a completely randomized block design with a split-plot arrangement with four replications. The plots received a source of variation referring to the planting systems (direct and conventional planting), and the subplots corresponded to ten weed management strategies (manual hoeing 18 days after planting (DAP); at 36 DAP; at 54 DAP; at 18 and 36 DAP; at 18 and 54 DAP; at 18 and 72 DAP; at 36 and 54 DAP; at 36-72 DAP; at 18, 36, and 54 DAP; and a control with no hoeing). Density and dry mass evaluations of the cowpea plants were performed at harvest (72 DAP) by determining the number of pods per plant, pod length, number of grains per pod, 1000-grain mass, and yield. A total of 28 species distributed in 12 botanical families were identified in the two cultivation systems. The family Poaceae showed the highest frequency, with 25% of the species identified. At the end of the assay, treatment 20 had the highest positive influence and provided significant quantitative gains to the complex of traits related to cowpea production (SPD and hoeing at 18, 36, and 54 DAP). UPGMA cluster analysis and canonical discriminant analysis were performed and allowed a better classification of the evaluated treatments. It was observed that the first two canonical variables explained 90.8% of the total variance contained in the original variables. The use of SPD with weeding at 18, 36, and 54 days after planting provides greater weed control and significant quantitative gains for the complex of characteristics related to cowpea production. The results underscore the importance of choosing the correct cropping system and implementing effective weeding practices to optimize weed control and improve crop performance.

Evaluasi efektivitas tanaman repelen dalam pengendalian penggerek batang Apomecyna saltator F. (Coleoptera: Cerambycidae) pada tanaman labu madu dengan pola tanam tumpang sari

Apomecyna saltator Fabricius (Coleoptera: Cerambycidae) merupakan hama tanaman labu madu yang keberadaannya perlu dikendalikan. Namun, informasi mengenai hama ini masih sangat terbatas. Pengendalian dengan penerapan pola tumpang sari memiliki prospek dan perlu dikembangkan untuk pengendalian hama ini sebagai bagian integral dari pengembangan pengendalian hama terpadu A. saltator. Penelitian ini dilakukan untuk mengetahui pengaruh pola tanam tumpang sari tanaman labu madu dengan beberapa tanaman repelan terhadap persentase infestasi, populasi larva/pupa A. saltator, dan produksi labu madu. Penelitian ini dirancang dengan rancangan acak kelompok (RAK) yang terdiri atas 4 perlakuan, yaitu monokultur tanaman labu madu (A); tumpang sari tanaman labu madu dan serai (B); tumpang sari tanaman labu madu dan kunyit (C); tumpang sari tanaman labu madu dan bawang daun (D). Setiap perlakuan diulang sebanyak 6 kali. Hasil menunjukkan bahwa rata-rata persentase infestasi A. saltator sampai 56 hari setelah tanam (HST) untuk semua perlakuan berkisar 72–79,6%. Populasi larva/pupa A. saltator berkisar 107–128 individu/9 tanaman. Produksi labu madu berkisar 21,97–26,75 kg/9 tanaman. Dari hasil penelitian ini disimpulkan bahwa tanaman kunyit, serai, dan bawang daun tidak berpengaruh terhadap persentase infestasi, populasi A. saltator, dan produksi labu madu.

Tannins, flavonoids, and lignin levels of clitoria ternatea L legumes in different levels of urea fertilizer and harvesting age

<p class="MDPI17abstract"><strong>Objective: </strong><em>Clitoria ternatea</em> L is a legume that has the potential as animal feed. This study determined to evaluate tannins, flavonoids, and lignin levels in different urea fertilizer applications and harvesting ages.</p><p class="MDPI17abstract"><strong>Methods: </strong>This study used a split-plot design with three replications. The main plots were urea levels (0 kg/ha, 100 kg/ha, and 200 kg/ha), as subplots were harvesting ages (30, 45, and 60 days after planting (DAP)). Fresh weights of <em>Clitoria ternatea</em> L harvested at the ages of 30, 45 and 60 DAP were weighed and recorded. The weighed forage is put in newspapers and dried in a 55°C oven for three days to gain a constant dry weight. The dried samples were then ground using a willey mill with a sieve porosity of 1 mm. Furthermore, the sample is analyzed to determine the content of secondary metabolites. The parameters observed were tannins, flavonoids, and lignin levels. Analysis of variance (ANOVA) was used to analyze Research data, and Duncan's Multiple Range (DMRT) was used to analyze the differences between means.<strong></strong></p><p class="MDPI17abstract"><strong>Results: </strong>The lowest lignin content of <em>Clitoria ternatea</em> L was prodiced in non-urea treatment (20.64± 2.53%), and significantly different compared to various levels of urea fertilization treatment (P<0.05). The highest tannin levels were obtained at 30 DAP harvest age (4.20±0.56%) and significantly different (P<0.05) from tannin levels at 45 and 60 DAP. The lowest flavonoid levels were obtained when the plants were harvested in 60 DAP (0.87±0.05%) and significantly different (P<0.05) compared to 30 and 45 DAP.<strong></strong></p><p><strong>Conclusions: </strong>The increase of urea fertilization level in <em>Clitoria ternatea</em> L only significantly affected lignin levels. The decrease of lignin content value is linear with the increase of harvesting age. In contrary, harvesting age of <em>Clitoria ternatea</em> L showed significant linear effects on tannins and flavonoids value.</p>

The effects of cereal rye cover crop seeding rate, termination timing, and herbicide inputs on weed control and soybean yield

AbstractGrowers have been experimenting with cover crop termination timings to maximize weed suppression and potentially reduce herbicide inputs in soybean [Glycine max (L.) Merr.]. A field study was replicated three times from 2018 through 2021 in South Charleston, OH, to evaluate different management strategies involving a cereal rye (Secale cereale L.) cover crop. The objectives were to determine the effects of cereal rye seeding rate (0, 50, and 100 kg ha−1), management program (preplant, postplant, and delayed), and soybean residual herbicide (flumioxazin + chlorimuron ethyl and no herbicide) on cover crop, weed, and soybean parameters. The preplant program consisted of cereal rye terminated 7 d before planting (DBP) + a postemergence application. The postplant program consisted of cereal rye terminated 7 d after planting (DAP) + a postemergence application. In the delayed program, saflufenacil was applied in April and cereal rye was terminated 21 DAP, and there was no postemergence application. Giant foxtail (Setaria faberi Herrm.) density was reduced by the presence of cereal rye, averaged over other factors, regardless of seeding rate. Cereal rye seeding rate did not affect giant ragweed (Ambrosia trifida L.) density. The delayed management program was generally associated with the lowest weed density, but weed density was often similar in the postplant program. Setaria faberi density was lower in treatments that included a residual herbicide. Residual soybean herbicide use did not affect density of A. trifida. Terminating cereal rye after soybean planting resulted in increased soybean yield in 2019 and reduced yield in 2020, compared with preplant rye termination. These data suggest that adjusting the cereal rye management program may have a greater effect on weed suppression than adjustments to seeding rate. Delaying termination of cereal rye can aid in the suppression of weeds, but a comprehensive herbicide program was necessary to provide adequate (>85%) weed control.

New corn resistant lines to stalk rot disease (Dickeya zeae) in Indonesia

Abstract. Suriani, Patandjengi B, Muis A, Junaid M, Mirsam H, Azrai M, Efendi R, Sebayang A. 2023. New corn resistant lines to stalk rot disease (Dickeya zeae) in Indonesia. Biodiveritas 24: 3190-3200. Stalk rot disease caused by Dickeya zeae is one of the important diseases of corn in Indonesia. Host resistance cultivars are an effective and sustainable control measure of the disease. Therefore, the present study aimed to evaluate the resistance of 15 S1 hybrid maize lines to stalk rot disease. The research was conducted in two seasons (DS and WS) using a randomized block design with 3 replications. The D. zeae suspension with 108cfu/mL concentration was inoculated into the plant test 45 Days After Planting (DAP). Disease incidence and severity were observed during the two seasons. The results showed that all tested lines were infected with stalk rot disease but had various resistance reactions. Disease incidence and severity in the dry season were higher than in the rainy season. In the rainy season all test lines followed the 3 models of disease development, but in the dry season, all lines followed the monomolecular model. Further analysis showed that 3 lines of hybrid maize had the lowest AUDPC value with a protection index of more than 50% in two growing seasons. Stalk lignin content had negative correlation with a disease incidence of -0.60877, so it can be used as a parameter of plant resistance to disease. Tested lines that show resistance to the disease could potentially be useful as new varieties of maize.

Growth performances of maize (Zea mays L.) intercropping with soybean (Glycine max (L.) Merrill.) in the legowo row system applied with bokashi plus fertilizer on marginal soils

The research aims to determine the growth response of maize intercropped with soybeans in a legowo row system with bokashi plus fertilizer on marginal land. It was carried out in Lamaeo Village, from May to August 2021, utilizing a randomized block design with a single factor and the dose of bokashi plus fertilizer, consisting of four levels, namely 0, 3, 6, and 9 t ha-1. Every therapy was replicated in four periods to obtain a total of 16 experimental plots. The legowo row system involved four rows of soybeans spaced 30 cm x 30 cm, with rows of corn spaced 120 cm x 40 cm. Plant height (cm), the number of leaves (strands), stem diameter (cm), leaf area (cm2), leaf area index (LAI), net assimilation rate, and relative growth rate were variables observed at 14, 28, 42, and 56 days after planting (DAP). The results of the research showed that bokashi plus fertilizer had a positive impact on the performance of corn intercropped with soybeans in the legowo row system on marginal land. The best outcome in terms of plant height, the number of leaves, stem diameter and leaf site were observed at 14, 28, 42, and 56 DAP, as well as leaf area index, net assimilation rate, and relative growth rate. The highest yields of corn and soybeans were obtained at a dose of 9 t ha-1, which amounted to 6.3 and 2.1 t ha-1, respectively, indicating better response on organic fertilizer.

Anthocyanin Content and Antioxidant Activity of Red Chrysanthemum (Chrysanthemum morifolium Ramat.) at Different Flower Ages

Chrysanthemum sp. is a floricultural plant of the Asteraceae family with high economic value. The anthocyanin pigment in red chrysanthemum acts as an antioxidant, the content of which can be influenced by genetic factors such as the physiological age of the flower. This study aimed to determine the effect of flower age on anthocyanin content and antioxidant activity in red chrysanthemum plants. The age of red chrysanthemum used was 115 Days After Planting (DAP) (early bloom stage), 120 DAP (half-bloom stage), 125 DAP (blooming stage), and 134 DAP (wilted flower). The anthocyanin content was analysed using spectrophotometric methods. Antioxidant activity was determined by the DPPH method and then the absorbance was measured using a UV-Vis spectrophotometer. The results showed that the highest anthocyanin content was obtained at the age of 134 DAP at 3.56 mg/g, followed by the age of 115 DAP at 2.40 mg/g, then at 125 DAP at 1.95 mg/g and the lowest at 120 DAP at 1, 69 mg/g. The highest antioxidant activity was shown in chrysanthemum flowers aged 115 DAP which had an IC50 value of 288.85 g/ml. The research shows that wilted chrysanthemum flowers still contain anthocyanins so it can be used in various industrial fields such as chrysanthemum tea and additives for soap.

Exploration of Whitefly (Bemisia tabaci) (Homoptera: Aleyrodidae) on Tomato (Solanum lycopersicum Mill) in Kedisan Village, Kintamani District, Bangli Regency

The main pest of tomato plants is the whitefly Bemisia tabaci (Homoptera: Aleyrodidae). This study aims to determine the symptoms of attack, population size and percentage of attack by B. tabaci on tomato plants in Kedisan Village, Kintamani District, Bangli Regency, Bali. The research was conducted from January to March 2023 in Kedisan Village, Kintamani District, Bangli Regency. This research was carried out using a direct survey method with direct observation in the field. Sampling was carried out by purposive sampling using the diagonal sampling method with 10 sample points and 3 plant clusters were taken at each sampling point so that a total of 30 plant families were observed. The variables observed were attack symptoms, population size and percentage of B. tabaci attack on tomato plants. The data obtained were analyzed and presented in the form of tables and graphs. The results showed that B. tabaci was found on tomato plants in the farmers fields in Kedisan village. Symptoms of B. tabaci attack on tomato plants are necrotic spots and chlorosis on leaves, which are caused by damage to leaf cells and tissues due to attack by nymphs and adult insects. Pests began to be found at 14 DAP (Day after Planting) with an average of 0.37 individuals/plant and the highest population was found at 63 DAP with an average of 1.63 individuals/plant on tomato plants. The results of the analysis show that the high percentage of attacks occurred at 63 DAP of 93.33%. In general, the high number of pest populations affects the high pest attacks as evidenced by the high percentage of B. tabaci attacks.

Fenologi Fase Pembungaan dan Perbuahan serta Produksi Polen pada Tanaman Kacang Panjang Kultivar Sabrina

Yardlong beans (Vigna unguiculata subsp. sesquipedalis (L.) Verdc.) is a vegetable source of vitamins and minerals which are quite widely cultivated in Indonesia. Phenology study the phases that occur in a plant that is provides benefits in agriculture, but information on the phenology of legumes crops in Indonesia is still scarce. This study aims to observe the reproductive phenology and pollen production of the yardlong bean cultivar Sabrina. A phenological study was carried on 7 plants to obtain information on the timing and duration of the reproductive period, inflorescence and fruiting phases, peak flowering time, and flower biology. Pollen production was observed in 5 samples of flowers. Pollen microscopic preparations were made using the acetolysis method. The results showed that the flowering and fruiting phases took 21-29 days; including flower initiation phase 7-10 days, small bud phase 1day, large bud phase 1 day, anthesis phase 1-2 days, and fruit development phase 11-15 days. Flower initiation occurred 36 days after planting (DAP), and flower blooming occurred 49 DAP. The peak of flowering occurred at 56-62 DAP. The flowers of the Sabrina cultivar have purplish-white corollas, producing about 276±23.58 pollen/anther.

Effect of zinc and boron on the performance of rainy season local potato variety “Sete” (Solanum tuberosum L.) at Rukumkot, Rukum East, Nepal

A field experiment was carried out at Rukumkot, Rukum East, Nepal during the rainy season of 2021 to study the effect of boron and zinc on vegetative growth and yield parameters of the local “Sete” variety of potato. The experiment was laid out in a randomized complete block design (RCBD) with 4 replications, and 7 treatments i.e., control, boron @2kg/ha soil application, zinc @4.5kg/ha soil application, boron @2kg/ha + zinc @4.5kg/ha soil application, 0.1% boron spray, 0.1% zinc spray and 0.1% boron+ 0.1% zinc spray. The highest tuber yield per hill and productivity was reported in boron @2kg/ha + zinc @4.5kg/ha soil application i.e., 2888.52 grams and 27.51 ton/ha, respectively. A similar result was shown by zinc @4.5kg/ha soil application. Plant height (26.33cm, 46.57cm), number of branches (4.85, 12.02) and number of leaves per plant (30.05, 73.70) were significantly high in boron @2kg/ha + zinc @4.5kg/ha soil application at both 45 DAP (days after planting) and 60DAP. Soil application of only boron, only zinc and boron + zinc increased the total yield of tubers by 10.23%, 24.66% and 25.66%, respectively over the control. The foliar application of only boron, only zinc and boron + zinc increased the total yield of tubers by 4.22%, 2.07% and 12.37%, respectively over the control. Hence, research suggested combined soil application of zinc and boron at the rate of 4.5kg/ha and 2kg/ha, respectively over the foliar cum solitary application of micronutrients for increasing number of medium and large sized tubers and get an overall high yield of potato.

Production of disease free seed potato tuber through optimization of planting and haulm pulling time

The time for planting and haulm pulling is very crucial for production of quality of seed potato tuber. Thus, the different planting times i.e., 15th October, 4th November, 24th November, and 14th December, and haulm pulling (HP) at 68, 75, 82, and 89 days after planting (DAP) were evaluated to find out the suitable planting time and haulm pulling time for disease-free potato seed production. This study was conducted in the research field of the Plant Pathology Department, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during 2016-2017. The maximum seed potato tuber yield (23.9 ton/ha) was recorded from 4th November planting time with haulm pulling at 82 days after planting. The findings also exhibited that the minimum disease infestation was observed in the same treatment combinations which enhanced the maximum photosynthesis and growth for the plants resulting in higher seed potato yield. Farmers of subtropical regions would be benefitted if they practice these methods. Bangladesh J. Agri. 2023, 48(1): 19-39

Responses of Worowo [Senecio biafrae (Oliv. & Hiern.) S. Moore] to Composts enriched with Organic Nitrogen Sources

Worowo (Senecio biafrae) is a semi-wild, indigenous and nutritious vegetable. Demand for worowo vegetable is increasing due to its nutritional values, thus necessitating its domestication for increased production. However, there is limited information on soil fertility requirements of worowo and the use of inorganic fertilizers could be expensive and detrimental to environment. Composts, on the other hand are environment-friendly and effective, but their use is constrained by low nitrogen contents, thereby necessitating enrichment with various nitrogen sources. Responses of worowo to organically enriched composts were therefore investigated. Composted Cattle Dung+Sawdust (CDS) and Poultry Droppings+Sawdust (PDS), at 1:1 (w/w) were enriched to 60 g N/ kg with meals from dried bone-BnM, blood-BM, hoof-HM, and horn-HnM, neem-NM and Tithonia leaves-TM. Compost treatments obtained were: CDS and PDS (no enrichment added), CDSBnM, CDSBM, CDSHM, CDSHnM, CDSNM and CDSTM; PDSBnM, PDSBM, PDSHM, PDSHnM, PDSNM and PDSTM. Worowo was raised in pots with CDS, PDS and 60 g N/kg enriched composts at 30 t/ha and control (soil alone), compared with 60 kg N/ha NPK 15-15-15 in a completely randomized design with three replicates. Data generated from the growth indices and edible Shoot Yield (ESY) of worowo (t/ ha), which were measured at 60, 120 and 180 Days After Planting (DAP) were analyzed using ANOVA at α0.05. ¬¬¬¬¬¬The ESY (t/ha) of 60 g N/kg CDSNM (54.93) was significantly higher than NPK (36.53) and others but similar to CDS (50.93) while pots treated with PDS were lowest (8.00). The CDSDNM at 60 g N/kg applied at 30 t/ha could hence be adopted for worowo production.

Pengaruh kombinasi pupuk NPK dan ekstrak kecambah kacang hijau terhadap pertumbuhan dan hasil tanaman kubis bunga (Brassica oleraceae var. Botrytis L.)

This study aims to determine the effect of the combination of NPK fertilizer and bean sprout extract (BSE) on the growth and yield of cauliflower plants and to determine the right dose of the combination of NPK fertilizer and bean sprout extract, so as to provide maximum results on the growth and yield of cauliflower plants in the lowlands. The experiment was carried out in Pusakanagara District, Subang Regency, West Java Province. With an altitude of 15 m above sea level, the air temperature ranges from 270C–300C. The experiment was carried out from October to December 2022. The study used an experimental method and a randomized block design with four treatments and six replications. The treatment consisted of P0: 5 g NPK (as control), P1: 5 g NPK + 75 g/L, P2: 5 g NPK + 100 g/L, P3: 5 g NPK + 125 g/L. The results showed that all treatments of a combination of NPK fertilizer and bean sprout extract had a significant effect on plant height (14 and 28 days after planting(DAP)), number of leaves (14, 28, and 35 DAP), leaf diameter (14 and 35 DAP), flower weight and flower diameter. For the P3 treatment, the combination dose of 5 g of NPK fertilizer and 125 g/l of bean sprout extract had a significant effect and showed the highest yield on plant height, number of leaves, and the highest weight of cauliflower, namely 379.25 g/plant. It can be concluded that the administration of bean sprout extract (BSE) was proven to increase the growth and yield of cauliflower varieties PM 126F. Doses of bean sprout extract fertilizer up to 125 mg/L of water are considered quite effective in efforts to increase the growth and yield of flower cabbage variety PM 126F.

Response of peanut (Arachis hypogaea L.) to sublethal rates of dicamba plus glyphosate at different growth stages

AbstractThe widespread adoption of dicamba‐resistant crops has increased the applications of newer dicamba formulations for weed control. However, there is a concern for potential off‐target injury and yield reduction to peanuts (Arachis hypogea L.) planted in close proximity to dicamba‐resistant crops. Field experiments were conducted in the summer of 2019 and 2020 to evaluate peanut response to reduced rates (1/512X, 1/128X, 1/32X, and 1/8X the label rate, 564 + 1280 g ae ha−1) of dicamba plus glyphosate (XtendiMax plus Roundup PowerMax) at 25, 50, and 75 days after planting (DAP) which corresponds to vegetative, flowering, and pod development stages, respectively. Peanut exposure to dicamba plus glyphosate at 25 DAP resulted in 1.6–2.3 times greater injury and 3.4–8.5 times greater height and canopy width reductions compared to 50 and 75 DAP exposures. Peanuts suffered greater yield reduction (18%–19%) when exposed to dicamba plus glyphosate at 25 and 75 DAP than at 50 DAP (10%). Regression analysis indicated a significant linear response for peanut injury (except at 8 weeks after treatment), canopy width reduction, and yield reduction with an increasing rate of dicamba plus glyphosate. Dicamba plus glyphosate at 1/512X rate resulted in a 3% peanut yield reduction, whereas a 41% yield reduction was observed at 1/8X rate. Correlation analysis, with Pearson's rho values ranging from 0.81 to 0.86, showed that peanut injury can be a useful predictor for estimating yield reduction. Therefore, extreme care must be taken to prevent drift occurrence or spray‐tank contamination when applying dicamba plus glyphosate on XtendFlex crops near peanut fields.

Respon Pertumbuhan Jagung Lokal Pulut dan Siropu Gorontalo Terhadap Cekaman Kekeringan

In Indonesia, maize has a number of growth constraints and one of which is climate factor. The objective of this research was to determine the growth response of local maize variety. This research was conducted by applying a factorial Randomized Block Design (RBD) with two factors. The first factor is variety (V): pulut, siropu and jakaring (comparison) while the second factor is drought treatment (K) which comprises three treatments including control, drought for 45-55 days after planting (DAP), and drought for 55-65 DAP. In this case, all treatments are repeated three times. The research revealed that the growth of maize indicate different responses towards variety as shown by parameters of plant height, soil moisture content, cob diameter, cob length, cob weight with husks, cob weight without husks, dry weight of root, and number of cob row. Meanwhile the drought stress does not indicate significant response towards growth of maize the drought-tolerant variety of maize with parameter of number of cob raw is siropu local maize.Key words: staple food; local corn; drought stress; growth.Â

Comparative Transcriptome Analysis Reveals the Effect of Lignin on Storage Roots Formation in Two Sweetpotato (Ipomoea batatas (L.) Lam.) Cultivars.

Sweet potato (Ipomoea batatas (L.) Lam.) is one of the most important crops with high storage roots yield. The formation and expansion rate of storage root (SR) plays a crucial role in the production of sweet potato. Lignin affects the SR formation; however, the molecular mechanisms of lignin in SR development have been lacking. To reveal the problem, we performed transcriptome sequencing of SR harvested at 32, 46, and 67 days after planting (DAP) to analyze two sweet potato lines, Jishu25 and Jishu29, in which SR expansion of Jishu29 was early and had a higher yield. A total of 52,137 transcripts and 21,148 unigenes were obtained after corrected with Hiseq2500 sequencing. Through the comparative analysis, 9577 unigenes were found to be differently expressed in the different stages in two cultivars. In addition, phenotypic analysis of two cultivars, combined with analysis of GO, KEGG, and WGCNA showed the regulation of lignin synthesis and related transcription factors play a crucial role in the early expansion of SR. The four key genes swbp1, swpa7, IbERF061, and IbERF109 were proved as potential candidates for regulating lignin synthesis and SR expansion in sweet potato. The data from this study provides new insights into the molecular mechanisms underlying the impact of lignin synthesis on the formation and expansion of SR in sweet potatoes and proposes several candidate genes that may affect sweet potato yield.

Atributos químicos de um argissolo cultivado com cana-de-açúcar após aplicação de doses elevadas de vinhaça

ABSTRACT The use of high doses of vinasse in sugarcane crop can cause modifications in the chemical characteristics of the soil. The aim of this study was to evaluate the effect of the application of high doses of vinasse on the chemical characteristics of an Ultisol cultivated with sugarcane for 210 days. The treatments used were doses equivalent to 0 (D0), 150 (D150), 300 (D300), 600 (D600) and 1200 (D1200) m3 ha-1 of vinasse plus a control treatment with mineral fertilization. The experimental design was completely randomized with six treatments and six repetitions. Exchangeable potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na) contents, organic matter, cation exchange capacity, sodium adsorption ratio, exchangeable sodium percentage, electrical conductivity and pH were analyzed at 90, 120, 150 and 210 days after planting (DAP), in addition to microbial basal respiration at 210 days at depths of 0-0.20 and 0.20-0.40 m. Soil pH increased with the use of vinasse within the proper range for sugarcane, varying from 6.2 to 6.4. The highest K and Na contents were found at D600 and D1200; the highest K and Na availability occurred at 120 DAP and 150 DAP, respectively, indicating competition between these nutrients for exchange sites. Organic matter content was proportionally high according to the vinasse dose applied. D600 and D1200 doses increased Na content in the soil, with greater magnitude at the 0-0.20 m depth.

Radiosensitivity of Two Local Chili Varieties to Gamma Rays

Genetic variation is needed for developing new superior varieties in plant breeding. Genetic variation of chili plants could be increased by inducing mutation with gamma rays irradiation. The aim of this study was to determine radiosensitivity of two local varieties of chili pepper by calculating the lethal dose values at LD20 and LD50. Chili pepper (Capsicum frutescens L.) seeds of local varieties origin from Tulungagung and Ponorogo were irradiated with cobalt-60 gamma rays at doses of: 0; 100; 200; 300; 400; 500; 600; 700; 800; 900; 1000 Gray (Gy); each as many as 50 seeds per dose of radiation. The irradiated chili seeds were grown in small polybags containing 1:1 mixture of soil and compost. Germination parameters of chili seeds was observed 30 days after planting (DAT) to determine lethal dose of 20 (LD20) and lethal dose of 50 (LD50). The results showed that increasing doses of gamma rays caused greater damage to chili seeds therefore the seeds were not able to germinate. Local Tulungagung Variety had LD20 and LD50 of 147.62 Gy and 409.52 Gy; and the Local Ponorogo variety had LD20 and LD50 of 90.3 Gray and 453.7 Gray. Local Tulungagung Variety was more sensitive to gamma rays than Local Ponorogo Variety. LD20 and LD50 can be used to get a lot of genetic variation and obtaining the positive mutants. Keywords: Irradiation, Genetic variation, Lethal dose, Mutation