Jurnal Agronomi Indonesia (Indonesian Journal of Agronomy)

Evaluation of Wedelia water extract on soybean, purple nutsedge, and billygoat seeds germination

2024-09-06T15:58:30+07:00

Weeds cause significant yield loss in many agriculture crops; thus, management practices are urgently needed to alleviate losses while conserving environmental and human health. This study aimed to evaluate the allelopathic potential of Wedelia leaf and flower extracts on the germination and early growth stage of three plant species. The research was conducted using a completely randomized design experiment with two factors and four replicates. The first factor was extract sources: leaves (S1) and flowers (S2). The second factor was the concentration: control (C0) and extract concentrations of 1% (C1), 5% (C5), and 10% (C10). The extract was tested on three different plant species: soybean (Glycine max), nutsedge (Cyperus rotundus), and billygoat weed (Ageratum conyzoides). Fifty seeds of three different plants were germinated separately in Petri dishes and treated using Wedelia extracts. The allelochemicals in Wedelia leaf and flower extracts inhibited germination and induced abnormal sprouting. Wedelia leaf extract showed the most pronounced inhibitory effects and highest inhibition levels across all measured parameters. Moreover, a clear concentration-response relationship was observed, where increased extract concentration increased the degree of inhibition. These findings contribute to the development of bioherbicides and can help reduce the use of synthetic herbicides for more sustainable agriculture.

Keywords: Ageratum conyzoides, bioherbicide, Cyperus rotundus, Glycine max, weed control

Growth and water-needs analysis of sweet corn and peanuts in different cropping systems

2024-09-02T14:00:02+07:00

Maize and peanuts are important food crops in Indonesia and are generally planted in monoculture and intercropping systems. The water required for monoculture and intercropping is believed to be different. However, comparison analysis of water requirements in monoculture and intercropping is rarely conducted. The research aimed to evaluate the growth and production of sweet corn and peanuts in monoculture and intercropping systems concerning water requirement and crop coefficient. The study was conducted at IPB Experimental Station in Leuwikopo, Bogor, Indonesia from September to December 2022. Sweet corn and peanuts were planted in different cropping systems, i.e., monoculture and intercropping. Water consumption of both cropping systems was evaluated in every growing stage. The experiment used a completely randomized block design and was repeated three times. Results showed that sweet corn growth was not significantly different among cropping systems, but yield from intercropping was lower than monoculture. Intercropped peanuts grew lower than monoculture but did not show any significant difference in yield among cropping systems. Water use efficiency in intercropping was higher than monoculture for both crops, indicating intercropping is a suitable cropping system for limiting soil water availability. The land equivalency ratio was 1.80, concluding that intercropping was more efficient than monoculture in land use by 80%.

Keywords: climate change; crop coefficient; intercropping; land equivalent ratio; water use efficiency

Evaluation of phosphorus fertilizer rate based on Upland Soil Test Kit analysis for tomato fertigation

2024-09-12T09:02:04+07:00

Upland Soil Test Kit (PUTK) is a rapid soil analysis kit that estimates the nutrient availability in soil. From previous studies, tomato plant production showed a good correlation with available phosphorus (P) and potassium (K) analysis using the PUTK. This study aimed to find the optimal P fertilizer rate based on PUTK analysis for tomato fertigation. This experiment was carried out using a randomized complete block design, four replications with a single factor, namely P fertilizer rate comprising 0% X, 50% X, 100% X, 150% X, and 200% X, with X the recommended P fertilizer of PUTK on moderate P availability (175 kg ha¹). The ANOVA showed that P fertilizer did not significantly affect the vegetative growth, production, and fruit quality of tomatoes. It means that PUTK analysis had low accuracy as a basis for determining the optimum P fertilizer rate for tomato fertigation. The low accuracy could be due to PUTK underestimating the status of soil P availability. Mechlich-1 analysis showed that the experimental field had high P availability (44.6 ppm), while PUTK analysis still indicates moderate P availability. This shows that PUTK needs to be developed further, especially quantifying the result to help make informed and accurate decisions.

Keywords: precision farming; precision fertilization; Upland Soil Test Kit; FERADS; sustainable agriculture

Optimizing cultivation system and pest management in different types of rice varieties

2024-09-17T09:12:02+07:00

Improving rice productivity and efficiency is the main goal of cultivation techniques to meet the demand for rice production. The aim of this research was to evaluate the suitability of rice varieties in cultivation systems, namely: organic cultivation + biological pest management (BPM), inorganic cultivation + BPM, and conventional cultivation. Different types of rice varieties, namely New Superior Varieties (NSV: INPARI-30, INPARI-32), New Plant Type (NPT: IPB-3S), and Superior Varieties from West Sumatra (Batang Piaman, Anak Daro), may exhibit differences in agronomic performance across various cultivation systems. This research was conducted at the Sawah Baru Babakan Experimental Farm, IPB University, Dramaga Bogor, using a factorial nested design with 4 replications. The results based on yield per hill and plot showed that Batang Piaman and INPARI-30 varieties were suitable for all organic + BPM, inorganic + BPM, and conventional cultivational systems. The INPARI-32 and IPB-3S varieties were more suitable for conventional cultivation and inorganic + BPM; while the Anak Daro variety was better in organic cultivation + BPM. Utilizing varieties with different characteristics for better yield performance could be considered with obtaining the suitability of the cultivation system, whether organic + BPM, inorganic + BPM, or conventional.

Keywords: Chemical pest control; conventional cultivation; organic cultivation; integrated pest management

Growth of cocoa seedlings (Theobroma cacao L.) in application of cow manure compost and density of Bacillus subtilis bacteria

2024-09-12T12:43:47+07:00

Cocoa rejuvenation is important to maintain high productivity. The rejuvenation mainly uses seedlings; thus providing high-quality seedlings is important. This research aimed to determine the effect of various doses of cow manure compost and the density of Bacillus subtilis bacteria on the growth of cocoa seedlings. The research was implemented at the Teaching Farm, Faculty of Agriculture, Hasanuddin University, Makassar City, from 2021 to 2022. The experiment was arranged in a split-plot design with three replications. The main plot was the dose of cow manure (without compost, 1.25 kg per polybag, and 2.5 kg per polybag). The subplot was the density of Bacillus subtilis (without bacteria, 10⁴ CFU.mL^-1, 10⁸ CFU.mL^-1, and 10¹² CFU.mL^-1). The results showed an interaction between the dose of cow manure 2.5 kg per polybag and the bacterial density 10¹² CFU.mL^-1 on chlorophyll a (347.91 mol.m^-2), chlorophyll b (158.33 mol.m^-2), total chlorophyll (444.57 mol.m^-2), and leaf area of cocoa seedlings (813.96 cm²). A compost dose of 2.5 kg per polybag showed the best results for plant height (8.98 cm).

Keywords: bacteria density; bivariate correlation; chlorophyll content; manure dose; organic fertilizer

Growth and nitrogen uptake modeling in composite and hybrid corn varieties

2024-09-18T13:52:47+07:00

Corn is a strategic commodity in Indonesia's agricultural and economic development. The problem of corn production can be overcome with proper usage of nitrogen fertilization. Dynamic modeling can be used as a tool to solve this problem. This study aimed to develop a dynamic model for the growth and nitrogen uptake of composite and hybrid corn varieties. Stages in the model construction: (1) identifying system components, (2) model construction, (3) simulation, and (4) validation. The growth model is a construction of the plant's ecophysiological response to solar radiation and temperature in photosynthesis. A growth model in composite and hybrid corn varieties with simulated dry weight as output has been constructed validly. The model input components, such as light use efficiency, extinction coefficient, specific leaf area, and carbohydrate partition coefficient varied at each development phase for each variance. The actual total dry weight on the Pioneer 27 variety was 6,406 kg ha^-1 with a simulated total dry weight was 6,228 kg ha^-1, and the actual total dry weight on the Bisma variety was 5,127 kg ha^-1 with a simulated total dry weight was 4,864 kg ha^-1. The level of validity of the Pioneer 27 variety growth model reached 83.5% and the Bisma variety reached 80%.

Keywords: Bisma; dry weight; growth model; nitrogen uptake; Pioneer 27; simulation; validation

Land use efficiency of sweet corn intercropping with different cowpea planting dates

2024-09-20T14:31:21+07:00

Cultivation of cowpea and sweet corn can optimize land use through an intercropping system, however, the planting date on intercropping is rarely evaluated. The research aimed to evaluate land use efficiency in sweet corn intercropping of different planting dates of cowpea. This research was conducted from January to May 2024 in Bocek Village, Malang, East Java. The study used a randomized complete block design with a single factor consisting of 7 levels, i.e., monoculture sweet corn, and sweet corn intercropping with different cowpea planting dates (0, 7, 14, 21, 28, and 35 days after sweet corn planting (DAP). Plant growth, yield, land equivalent ratio (LER), and area time equivalent ratio (ATER) were evaluated. The results showed that the intercropping sweet corn and cowpea planted at 21 DAP produced a higher yield than other planting dates. The highest LER of 1.96 and ATER of 1.93 was achieved in the sweet corn with cowpea planted at 21 DAP, indicating the highest land use efficiency occurred at the planting date of cowpea 21 days after planting sweet corn.

Keywords: ATER; cropping system; LER; planting time; Vigna unguiculata; Zea mays

Leaf growth pattern and morphology of Sauropus androgynus (L.) Merr. in tropical lowland

2024-09-18T14:10:10+07:00

Chikurmanis or katuk (Sauropus androgynus (L.) Merr.) is a traditional leafy vegetable that is consumed widely in Indonesia. The leaf is rich in vitamins, minerals, nutrients, and dietary fiber. The study aimed to investigate the leaf growth pattern and morphological characteristics of the chikurmanis cultivated in the tropical lowland ecosystem. The research was conducted on local farmland in Marga Sakti Sebelat, Bengkulu, Indonesia on December 2023 by survey method. The results showed that the leaf of chikurmanis grew in the daytime and continued to grow at nighttime as indicated in midrib length, leaf width, and foliole number. It is likely that nighttime growth become predominant in chikurmanis. The plant was a type of shrub with complete organs of stem, branch, root, flower, and leaf. The leaf was arranged as a compound leaf with many folioles in opposite positions. Midrib length (M) x leaf width (W) with a zero intercept of linear regression was the most reliable predictor of leaf area with the formula Y = 0.4964MxW (R²= 0.9677).

Keywords: chikurmanis plant; katuk; leaf area estimation; morphological trait; traditional leafy vegetable