http://dx.doi.org/10.11594/jtls.13.03.18
How to cite:
Blessya CP, Karyawati AS (2023) Competition Assessment on Various Intercropping Patterns of Bitter Melon (Momordica Research Article
Competition Assessment on Various Intercropping Patterns of Bitter Melon (Momordica charantia L) and Tomato (Solanum lycopersicum L)
Christabel Putik Blessya, Anna Satyana Karyawati*
Agronomy Department, Faculty of Agriculture, Universitas Brawijaya, Malang 65145 East Java
Article history:
Submission December 2022 Revised June 2023
Accepted July 2023
ABSTRACT
Intercropping is the practice of growing two or more crops in close proximity.
Intercropping is useful for obtaining land efficiency, nutrient efficiency, and increasing biodiversity, which is in line with controlling plant-disturbing organisms.
Intercropping can also be done in the rice fields, and it is hoped that the optimization of the use of the rice fields will have a good impact on rice and other crops. The adverse effect that is feared to arise due to the intercropping method is the contamination of substances through horizontal transfer of substances between plants. This study was conducted to determine the effect of competition on bitter melon and tomato intercropping. The study started from January to May 2022 in Sukorejo Village, Gondanglegi District, Malang Regency. The research stages include planting and maintaining commodities, observing growth, and organoleptic testing. The study used a Randomized Block Design (RBD) which was arranged in a non-factorial. The total treatment was 5 treatments which were repeated 4 times.
The results of the research on the competitiveness of tomatoes were superior to bitter melon in a 2-line and 3-row intercropping system. From an economic point of view, intercropping in a 1:1 or 1:2 ratio is feasible because it has an R/C Ratio of more than 1. Bitter melon and tomatoes grown in polyculture with a 3-row alternate cropping pattern in a 1:2 ratio of tomatoes and bitter melon are feasible because has an R/C Ratio of 3.57 and has a more stable price for bitter melon.
Keywords: Aggressivity, Agricultural Economics, Competition Ratio, LER
*Corresponding author:
E-mail: [email protected]
Introduction
Bitter melon (Momordica charantia L.) is an annual vine that belongs to the Cucurbitaceae fam- ily [1–5]. The order of the bitter melon plant is Vi- olales. Bitter melon belongs to the family Cucur- bitaceae and the genus Momordica [6]. Bitter melon plants in the community are usually for functional food and pharmaceutical or medicinal purposes [7–10]. Usually, bitter melon as food is processed by frying, steaming, pickling, or adding to other foods. To reduce the bitter taste, bitter melon is usually boiled first or soaked in salt water before cooking [11–13].
The tomato (Solanum lycopersicum L.) is an annual plant that belongs to the Solanaceae family.
The order of tomato plants is Solanales. Tomato belongs to the genus Solanum, with the species name S. lycopersicum [14]. Tomatoes are widely
consumed as vegetables that are important for nu- tritional adequacy because they contain vitamins, minerals, fiber, protein, essential amino acids, monounsaturated fatty acids, carotenoids, and phytosterols [15–17].
The increasing demand for these two crops and limited agricultural land has encouraged the intensification of cropping patterns. According to [18], from 2015 to 2019, Indonesia's agricultural land decreased to 7.46 million hectares from 8.09 million hectares. Intercropping is recognized as an alternative to sustainable cropping patterns as a solution to limited land. This method is gaining popularity as the most efficient land-use system adopted by farmers when they have only limited access to agricultural inputs [19]. The use of the intercropping system can also be carried out on
rice fields as an effort to use land [20–23].
Rice fields can be used to provide by-products other than rice cultivation [24–27]. Intercropping, either on paddy fields or mainland, is an intensi- fication practice that can be used to increase land productivity [23, 28–30]. As a benefit of increa- sing crop variety, intercropping can minimize crop failure due to the detrimental effects of pest explosions, increase the use of limited resources, increase yield stability and provide higher yields [30–33]. Previous research has been conducted on cucumber and eggplant plants, which belong to the same family as bitter melon and tomatoes. Based on the results of this study, the LER value obtained for the cucumber and eggplant intercropping sys- tem was 1.44, indicating that the intercropping be- tween plants was appropriate and did not result in adverse effects [34]. So, the selection of plant species to be planted side by side is important to note. The selection of combined plant species was based on differences in the shape of the plant crown, different families, and avoiding inter- cropping with plants that produce inhibiting alle- lopathy. The side effect that is feared to arise due to the intercropping method is competition between plants [35]. Therefore, it is important for cropping patterns to be designed appropriately in order to reduce the negative effects of competition between plants in intercropping.
Material and Methods
The study was conducted from January to May 2022. The study was conducted in Sukorejo Village, Gondanglegi District, Malang Regency (8.15°S, 112.59°E). Gondanglegi District (has an average rainfall of 1,328-1,448 mm per year with an estimated rainfall of 201-300 mm per month [36]. Sukorejo Village is located at an average altitude of 345 meters above sea level with temperatures ranging from 20-35°C [37].
The study only used 1 factor arranged in a Randomized Block Design (RBD). The treatments consisted of 6 cropping patterns as shown in Table 1. Each treatment was repeated 4 times. The observational data will be analyzed descriptively to obtain the value of LER, aggressiveness, competition ratio, economic ratio.
Land Equity Ratio (LER)
LER describes efficiency in land use. This calculation uses the yield component so that it is carried out after the plant is harvested. The formu-
la used is as follows [38]:
LER = (Yab
Yaa) + (Yba Ybb) Description:
Yab: the result of intercropping bitter melon Yes: monoculture bitter melon
Yba: intercropped tomato yield
Ybb: the result of monoculture tomatoes Table 1. Intercrop arrangements
No Description
1. Bitter melon monoculture 2. Tomato monoculture
3. Zigzag Tomato and Bitter melon 4. 1 row Tomato and bitter melon
5. 2 Row Tomato + Bitter melon + Tomato 6. 2 Row Bitter Melon + Tomato + Bitter
melon Aggressivity (A)
The calculation of aggressiveness was used to determine the ability of the two plants to compete in this intercropping system between bitter melon and tomato. The aggressiveness value is known by using the following formula [39, 40].
Aab = ( Yab
Yaa − Zab) − ( Yba Ybb − Zba) Aba = ( Yba
Ybb − Zba) − ( Yab Yaa − Zab) Description:
Yab : the result of intercropping bitter melon Yes : monoculture bitter melon
Yba : intercropped tomato yield
Ybb : the result of monoculture tomatoes Aab : bitter melon's aggressiveness towards
tomatoes
Aba : the aggressiveness of tomatoes to bitter melon
Competition Ratio (CR)
The calculation of the competition ratio or CR is the LER ratio of individual plants in each plant component by taking into account the proportion of plants in the intercropping system. The formula used is as follows according to [40, 41] :
CRa = ( Yab Yaa Yba Ybb
) × (Zba Zab)
CRb = ( Yba Ybb Yab Yaa
) × (Zab Zba)
Description:
Yab : the result of intercropping bitter melon Yes : monoculture bitter melon
Yba : intercropped tomato yield
Ybb : the result of monoculture tomatoes Zab : Bitter melon population ratio to tomatoes Zba : Tomato population ratio to bitter melon CRa : The ratio of bitter melon to tomato
competition
CRb : Tomato to bitter melon competition ratio Results and Discussion
The LER value in all treatments gave an LER value > 1, which means that it is possible to des- cribe bitter melon or tomato plants in an intercrop- ping way. The highest LER value in bitter melon treatment in multiple growers was the ratio of to- matoes and bitter melon 1 : 2, which was 1.9, which indicated that the intercropping system yielded 90% more efficiency than the single crop- ping system [42]. The lowest LER value was in the treatment of bitter melon with the ratio of toma- toes and bitter melon 2:1, which is 1.7 which means that it provides 70% more efficiency than a single cropping pattern.
Aggressivity
The A measures the ability of plants to com- pete in competing for resources in intercropping systems. This value describes the dominance of one plant species in the intercropping system. The results of the research on bitter melon and toma- toes showed that tomato plants were more aggres- sively dominant against bitter melon plants in all treatments except bitter melon polyculture, the ra- tio of tomatoes and bitter melon was 2 : 1. On the other hand, bitter melon plants lost in competition in all treatments except for the polyculture treat- ment with a 2 : 1 ratio of tomato and bitter melon.
The values closest to 0 were in bitter melon and tomatoes were double planted with a zigzag crop- ping pattern, so this cropping pattern was the most suitable to do. The aggressiveness value is pre- sented in Figure 1.
Competition Ratio
The value of the CR indicates the ability of plants to compete in obtaining resources both. The results showed that the competition ratio of tomato plants was higher than that of bitter melon in all treatments except bitter melon with multiple plant- ing at the ratio of tomatoes and bitter melon 1 : 2 with a maximum value of 1.97. The average value of the competition ratio is presented in Figure 2.
In general, the factors that affect bitter melon and tomato plants on plant growth are the treat- ment of cropping patterns and the availability of
Figure 1. Aggressivity of bitter melon and tomato
-0.05 -0.16
1.40
-1.48
0.05 0.16
-1.40
1.48
-2.00 -1.50 -1.00 -0.50 0.00 0.50 1.00 1.50 2.00
Zigzag Tomato and Bitter melon
Tomato + bitter melon
Tomato + Bitter melon + Tomato
Bitter Melon+
Tomato + Bitter melon
Agressivity (A)
Bitter Melon Tomato
nutrients, both of which are related to competition between plants. The results showed that plant composition plays an important role in the process of plant growth and development. Competition de- termines how plants can grow and develop, as a provider of nutrients for plants.
The treatment of cropping patterns on bitter melon and tomatoes is considered effective for land use in an effort to increase yields. Based on the land equivalence ratio (LER) in Figure 1, all double cropping patterns between bitter melon and tomatoes showed LER values >1. LER is defined as the ratio of the yield of two intercropped crops and the yield of a single crop at the same manage- ment level [43]. The planting pattern of 2 rows of bitter melon and 1 row of tomatoes got the highest LER value of 1.9, which means 90% more effi- cient than the single cropping pattern. According to [14] it is better to increase the planting density through intercropping or intercropping rather than increasing the density of single plants.
Aggressiveness value (A) determines the com- petitive ability of a plant when planted in inter- cropping with other plants. The aggressiveness value of zero (0) indicates that the component plants are equally competitive. If both plants have the same numerical value, the sign of the dominant species will be positive and the sign of the domi- nant species will be negative [44]. In the treatment of zigzag planting and one row polyculture treat- ment, the ratio of bitter melon and tomato was comparable. Seen in the results of the A value, to- matoes are more dominant in the intercropping
competition in this study. Indicated by a positive sign on all A values in tomatoes, except in the treatment the ratio of tomatoes and bitter melon was 2 : 1.
In composition, the tomato population was higher in the treatment with a 2 : 1 ratio of toma- toes and bitter melon, but tomatoes experienced intraspecific competition. Intraspecific competi- tion means that individuals within a species com- pete for the same resource. So, it is judged that competition within species is stronger than be- tween species. The previous research [45] states that intraspecific competition can be 4 to 5 times stronger. Both of these competitions are density dependent, meaning that the denser the popula- tion, the greater the competition.
The ability of plants to compete is described in the value of the competition ratio in Figure 2. The value of the competition ratio in this study is not related to the aggressiveness value, which should indicate that the higher the aggressiveness value of a plant in the intercropping system, the stronger the plant to compete in obtaining the required re- sources [35]. This highest CR value indicates the competitive ability of tomatoes which is superior to bitter melon. In this study, bitter melon and to- mato plants did not show the same competitive intensity.
The greater competitiveness of tomatoes in the intercropping system with bitter melon may be due to the number of leaves of tomato plants which have a small leaf area per leaf but are denser. In- deed, high-growing bitter melon intercropped with Figure 2. Competition ratio of bitter melon and tomato
0.00 0.50 1.00 1.50 2.00 2.50 3.00
Zigzag Tomato and
Bitter melon Tomato + bitter
melon Tomato + Bitter
melon + Tomato Bitter Melon+
Tomato + Bitter melon
CR Ratio
Bitter Melon Tomato
tomatoes may affect mild interception in tomatoes.
However, tomatoes can still catch light because bitter melon propagates at different vines so it doesn't block the light too much.
Economic analysis
Based on the results of farming analysis in the research of bitter melon and tomatoes, the total ex- penditure (cost/C) and total revenue (revenue/R) were calculated to obtain the results of the R/C Ra- tio, the data from the analysis of farming activities are presented in Figure 3.
The value of the R/C ratio is calculated by di- viding the output received by the input output. In- put costs include land rent, bitter melon and to- mato seeds, equipment rental, stakes, use of pesti- cides, safety ropes, labor and use of organic and inorganic fertilizers. In this study, the input costs and yields of each treatment were different due to differences in the plant population used.
Based on the findings in all intercropping and monoculture treatments, the R/C ratio was greater than 1. It means that cultivation can be said to be profitable or feasible. In accordance with Fadli's statement, (2014) that if the R/C ratio is greater than 1 then the business being run is profitable and can be managed, but if the R/C ratio is less than 1 then the business is run at a loss, cannot be man- aged, and if R/C ratio = 1, then the business is not profitable or not profitable (no loss).
Based on the findings in all intercropping and monoculture treatments, the R/C ratio was greater than 1. It means that cultivation can be said to be profitable or feasible. In accordance with [46]
statement, that if the R/C ratio is greater than 1
then the business being run is profitable and can be managed, but if the R/C ratio is less than 1 then the business is run at a loss, cannot be managed, and if R/C ratio = 1, then the business is not prof- itable or not profitable (no loss).
Meanwhile, monoculture tomatoes, got a lower yield with a value of 1.06 because they used more seeds. Tomato cultivation requires higher costs but the selling price of tomatoes is cheap. So that intercropping with bitter melon in 3 rows with 2 rows of bitter melon and 1 row of tomatoes is better because it has an R/C ratio of 7.13 and is supported by stable bitter melon prices in the mar- ket.
Conclusion
Based on the results of the study, it was shown that intercropping between bitter melon and tomato could be carried out because it had an LER value >1 in all interropping patterns. Based on the competitive analysis of aggressiveness and competition ratio, the competitiveness of tomatoes is greater than that of bitter melon in a 2-row or 3- row intercropping system and competition occurs between individuals within the species. All treatments are feasible because they have an R/C Ratio of more than 1. Alternating treatments of 3 rows with a ratio of tomatoes and bitter melon 1:2 are feasible because they have an R/C Ratio of 7.13 and have a more stable price for bitter melon.
We recommend conducting additional research with a greater emphasis on measuring the concen- trations of useful medicinal compounds and as- sessing the allelopathy effects on other plants.
Figure 3. R/C ratio of bitter melon and tomato
5.38 5.07
7 6.95 6.67
7.13
0 1 2 3 4 5 6 7 8
BG Monoculture
Tomato monoculture
Zigzag Tomato+BG Tomato + BG + Tomato
BG + Tomato + BG
R/C Ratio
References
1. Islam S, Jalaluddin M (2019) Biological functions and sensory attributes of different skin colored bitter melon (Momordica charantia L.) varieties. Am J Food Sci H 5 25–31.
2. Hassan RA, Ali S, Zaheer MS et al. (2022) In-vitro and in-vivo evaluation of different fungicides against leaf blight causing fungus Alternaria cucumerina in bitter gourd. Journal of the Saudi Society of Agricultural Sci-
ences 21 (3): 208–215. DOI:
10.1016/j.jssas.2021.08.005.
3. Rahman M, Kamrunnahar A, Bhuiyan M, Zeba N (2021) Morphological characterization, character association and path analysis of bitter gourd (Momordica charantia L.) genotypes. Plant Cell Biotechnol Mol Biol 22 53–62.
4. Mehta T, Duhan D, Panghal V (2021) Genetic diversity studies for improved horticultural traits in bitter gourd [Momordica charantia L.] genotypes. Vegetable Science 48 (2): 198–202. DOI: 10.61180/vegsci.2021.v48.i2.11.
5. Fan M, Kim E-K, Choi Y-J et al. (2019) The role of Momordica charantia in resisting obesity. International Journal of Environmental Research and Public Health 16 (18): 3251. DOI: 10.3390/ijerph16183251.
6. Upadhyay A, Agrahari P, Singh D (2015) A review on salient pharmacological features of Momordica char- antia. Int J Pharmacol 11 (5): 405–13. DOI:
10.3923/ijp.2015.405.413.
7. Dar AH, Singh A, Khan SA (2020) Bitter Gourd 9. Anti- oxidants in Vegetables and Nuts-Properties and Health Benefits 175.
8. Venkatakrishnan K, Chiu H-F, Wang C-K (2019) Exten- sive review of popular functional foods and nutraceuticals against obesity and its related complications with a spe- cial focus on randomized clinical trials. Food & function 10 (5): 2313–2329. DOI: 10.1039/c9fo00293f.
9. Wang H, Shuai X, Ye S et al. (2022) Recent advances in the development of bitter gourd seed oil: from chemical composition to potential applications. Critical Reviews in Food Science and Nutrition 1–13. DOI:
10.1080/10408398.2022.2081961.
10. Mahmood MS, Rafique A, Younas W, Aslam B (2019) Momordica charantia L. (bitter gourd) as a candidate for the control of bacterial and fungal growth. Pak. J. Agric.
Sci. 56. DOI: 10.21162/PAKJAS/19.7684.
11. Iliev P, Ilieva I, Staci C (2021) Evaluation of the different genotype of Bitter Gourd in the Republic of Moldova. Ro manian Journal of Horticulture 2 41. DOI:
10.51258/RJH.2021.05.
12. Kumar D, Kumar S, Shekhar C (2020) Role of Bitter gourd (Momordica charantia L.) in human health strengthening and regulate different diseases. Journal of Pharmacognosy and Phytochemistry 9 (5): 895–899.
13. Gayathry K, John JA (2022) A comprehensive review on bitter gourd (Momordica charantia L.) as a gold mine of functional bioactive components for therapeutic foods.
Food Production, Processing and Nutrition 4 (1): 1–14.
14. Sandhu RK, Boyd NS, Zotarelli L et al. (2021) Effect of planting density on the yield and growth of intercropped tomatoes and peppers in Florida. HortScience 56 (2):
286–290. DOI: 10.21273/HORTSCI15567-20.
15. Aksoy HM, Kaya Y, Ozturk M et al. (2017) Pseudomonas putida–Induced response in phenolic profile of tomato seedlings (Solanum lycopersicum L.) infected by Clavi- bacter michiganensis subsp. michiganensis. Biological
Control 105 6–12. DOI: 10.1016/j.biocon- trol.2016.11.001.
16. Ali MY, Sina AAI, Khandker SS et al. (2020) Nutritional composition and bioactive compounds in tomatoes and their impact on human health and disease: A review.
Foods 10 (1): 45. DOI: 10.3390/foods10010045.
17. Yilmaz K, Faten A-R, ARVAS YE, DURMUŞ M (2018) Domates Bi̇tki̇si̇ Ve in Vi̇tro Mi̇kro Çoğaltimi (Tomato Plant and Its In Vitro Micropropagation). Journal of En- gineering Technology and Applied Sciences 3 (1): 57–73.
DOI: 10.30931/jetas.418758.
18. Pertanian K (2019) Statistik lahan pertanian tahun 2014- 2018. Jkt. Pus. Data Dan Sist. Inf. Pertan. Sekr. Jenderal- Kementeri. Pertan.
19. Wang Z-G, Jin X, Bao X-G et al. (2014) Intercropping enhances productivity and maintains the most soil fertility properties relative to sole cropping. PloS one 9 (12):
e113984. DOI: 10.1371/journal.pone.0113984.
20. Mulyono D, Hilman Y, Sastro Y, Setiani R (2019) Vari- ous cropping patterns of chili and shallot crops as land intensification program in some production centers. IOP Publishing. p 012082. DOI 10.1088/1755- 1315/399/1/012082.
21. Arianti F, Minarsih S, Nurwahyuni E (2021) Optimizing dry land through the implementation of maize and rice multiple cropping system in Pemalang Regency. IOP Publishing. p 012070. DOI 10.1088/1755- 1315/648/1/012070.
22. Purba S, Slamet B, Rauf A (2021) Land use directions based on the level of land conversion vulnerability in the Padang Watersheds, North Sumatera. IOP Publishing. p 012005.
23. Shah TM, Tasawwar S, Bhat MA, Otterpohl R (2021) In- tercropping in rice farming under the system of rice inten- sification—An agroecological strategy for weed control, better yield, increased returns, and social–ecological sus- tainability. Agronomy 11 (5): 1010. DOI: 10.3390/agron- omy11051010.
24. Taşeva G, Sabirkulova T, Kidiraliyeva B et al. Kirgizistan çeltik üretimine genel bir bakiş. Frontiers in Life Sciences and Related Technologies 3 (2): 86–94. DOI:
10.51753/flsrt.1122101.
25. Song Y, Lee S-H, Woo JH, Lee K-W (2023) Forage yield, nutritional value, soil chemical composition, and soil mi- crobial abundance under maize–legume intercropping systems in a paddy field. Journal of Crop Science and Bi- otechnology 26 (3): 285–300.
26. Hei Z, Xiang H, Zhang J et al. (2021) Rice intercropping with water mimosa (Neptunia oleracea Lour.) can facili- tate soil N utilization and alleviate apparent N loss. Agri- culture, Ecosystems & Environment 313 107378. DOI:
10.1016/j.agee.2021.107378.
27. Wangiyana W, Farida N, Ngawit I (2021) Effect of pea- nut intercropping and mycorrhiza in increasing yield of sweet corn yield. IOP Publishing. p 012068. DOI:
10.1088/1755-1315/648/1/012068.
28. Li X-F, Wang Z-G, Bao X-G et al. (2021) Long-term in- creased grain yield and soil fertility from intercropping.
Nature Sustainability 4 (11): 943–950. DOI:
10.1038/s41893-021-00767-7.
29. Curtright AJ, Tiemann LK (2021) Intercropping increases soil extracellular enzyme activity: a meta-analysis. Agri- culture, Ecosystems & Environment 319 107489. DOI:
10.1016/j.agee.2021.107489.
30. Stoop WA, Adam A, Kassam A (2009) Comparing rice production systems: A challenge for agronomic research and for the dissemination of knowledge-intensive farming practices. Agricultural Water Management 96 (11):
1491–1501. DOI: 10.1016/j.agwat.2009.06.022.
31. Glaze-Corcoran S, Hashemi M, Sadeghpour A et al.
(2020) Understanding intercropping to improve agricul- tural resiliency and environmental sustainability. Ad- vances in agronomy 162 199–256. DOI:
10.1016/bs.agron.2020.02.004.
32. Maitra S, Shankar T, Banerjee P (2020) Potential and ad- vantages of maize-legume intercropping system. Maize-
Production and Use 1–14. DOI:
10.5772/intechopen.91722.
33. Bitew Y, Abera M (2019) Conservation agriculture based annual intercropping system for sustainable crop produc- tion: A review. Indian Journal of Ecology 46 (2): 235–
249.
34. Sultana S, Roy R, Das B et al. (2020) Vegetable-Based Multitier Cropping System: A Model for Higher Income for the Farmers in Old Alluvial Soils of West Bengal. Ad- vances in Research 21 (6): 30–34. DOI:
10.9734/air/2020/v21i630212.
35. Doubi BTS, Kouassi KI, Kouakou KL et al. (2016) Exist- ing competitive indices in the intercropping system of Manihot esculenta Crantz and Lagenaria siceraria (Mo- lina) Standley. Journal of Plant Interactions 11 (1): 178–
185. DOI: 10.1080/17429145.2016.1266042.
36. Anwar N, Hariyono ID (2020) Pengaruh Perubahan Iklim Terhadap Produktivitas Tanaman Padi (Oryza sativa L.) Di Kab. Malang.
37. Nugroho F, Hananto S (2015) Penerapan metode SOM untuk klustering pelanggan (BPSAB&S) Sumber Maron, Desa Karangsuko, Kecamatan Pagelaran, Malang.
38. Beets WC (2019) Multiple cropping and tropical farming systems. CRC Press.
39. Gitari HI, Nyawade SO, Kamau S et al. (2020) Revisiting intercropping indices with respect to potato-legume inter- cropping systems. Field Crops Research 258: 107957.
DOI: 10.1016/j.fcr.2020.107957.
40. Palaniappan S (2006) Cropping Systems in the Tropics (Principles and Management). New Age International.
41. Wei W, Liu T, Shen L et al. (2022) Effect of Maize (Zeal mays) and Soybean (Glycine max) Intercropping on Yield and Root Development in Xinjiang, China. Agri- culture 12 (7): 996. DOI: 10.3390/agriculture12070996.
42. Andersen MK (2005) Competition and complementarity in annual intercrops-the role of plant available nutrients.
43. Susanti SA, E Fuskhah S (2014) Pertumbuhan dan Nisbah Kesetaraan Lahan (NKL) Koro Pedang (Canavalia Ensi- formis) dalam tumpangsari dengan jagung (Zea Mays).
AGROMEDIA Berk. Ilm. Ilmu-Ilmu Pertan. 32. DOI:
10.47728/ag.v32i2.92.
44. Ceunfin S, Prajitno D, Suryanto P, Putra ETS (2017) Penilaian kompetisi dan keuntungan hasil tumpangsari ja- gung kedelai di bawah tegakan kayu putih. Savana Cendana 2 (01): 1–3. DOI: 10.32938/sc.v2i01.76.
45. Adler PB, Smull D, Beard KH et al. (2018) Competition and coexistence in plant communities: intraspecific com- petition is stronger than interspecific competition. Ecol- ogy letters 21 (9): 1319–1329. DOI: 10.1111/ele.13098.
46. Fadli S (2014) Analisis Pendapatan dan Kelayakan Usahatani Tomat di Kelurahan Boyaoge Kecamatan Tatanga Kota Palu. Agroland J. Ilmu-Ilmu Pertan. 21.
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