The effect of different harvest times on the quality of red chili seeds for sustainable agriculture

Red chili (Capsicum annuum L.) is one of the most attractive agricultural commodities. To minimize risks in cultivating red chilies, high quality seeds must be used. These seeds are obtained from chili fruit from previous plantings. Chili fruit is harvested several times. This research aims to determine the effect of different harvest times on the quality of red chili seeds for sustainable agriculture. The research was carried out at the Seed Technology Laboratory, Faculty of Agriculture, Universitas Sumatera Utara, Medan. This research used a Non-Factorial Randomized Complete Block Design (RCBD) with seven harvest time treatments, namely harvest in the first week, harvest in the second week, harvest in the third week, harvest in the fourth week, harvest in the fifth week, harvest in the sixth week, and harvest in the seventh week. The parameters observed were the weight of 100 seeds, maximum growth potential, germination test, germination rate and vigor index. The research results show that harvest time has a significant effect on all parameters. Seed harvested in the third and fourth week are the best quality because they have the weight of 100 seeds, maximum growth potential and the highest vigor index and fastest germination rate.


Introduction
Red chili (Capsicum annuum L) is one of the horticultural crops that plays a very important role economically and commercially.The position of red chilies tends to be increasingly important in daily food consumption patterns as cooking spices and can be processed into various chili derivative products such as sauces, dried chilies, chili flour, chili paste, instant chili seasoning, chili chips, candied chili and others.
The demand for red chilies continues to rise every year in line with the increasing population and the growth of industries that require chili as a raw material.This makes red chili a nationally favored vegetable commodity.Red chili is one of the most attractive agricultural commodities.At certain times, their prices can multiply several times over.This makes chili cultivation a unique challenge for farmers.Chili cultivation is quite vulnerable to weather conditions and pest attacks.To minimize all of these risks, there are several stages that need to be prepared for chili cultivation, such as the selection of highquality and superior red chili seeds [1].
To obtain seeds of the highest quality of chilies for sustainable agriculture must be harvested at the right time.If harvested prematurely or before reaching physiological maturity, many seeds may not be fully developed, resulting in low-quality seeds.On the other hand, if harvested after reaching physiological maturity, there may be exposure to adverse weather conditions in the field, leading to a decline in seed quality before harvest [2].Red chili cultivation consists of several stages or phases, starting with the nursery phase, which lasts for approximately 3-4 weeks.The planting phase occurs from day 1 to 6 after planting (DAP), the vegetative phase from day 7 to 25 DAP, the generative phase begins with flowering and fruit set around 25-40 DAP, while the harvesting phase occurs from day 40 to 90 DAP, although this may also be influenced by the type of chili plant [3].Chili fruits are fleshy berries, and the physiological maturity of chili seeds can be indicated by changes in the fruit's flesh color.The color of chili fruit flesh changes from green when it is still young to dark green, brown, and red when it matures [4].Chili fruits are harvested when their color has changed from green to red.Harvesting is done gradually according to the level of ripeness.Harvesting is typically carried out in the morning or afternoon, with a 3-day interval between each harvest [5].
In the village of Lubuk Cuik, red chili farmers harvest their crops sixteen times in one planting period, with a 3-day interval between each harvest.Typically, farmers use red chili from the seventh and eighth harvests as planting material.Based on the above descriptions, a study was conducted to assess the quality of red chili seeds at each harvest time.

Site and research materials
Chili fruit collection was carried out in Lubuk Cuik Village, Lima puluh District, Batu Bara Regency (Sumatera Utara) in April-May 2023.Germination research was carried out at the Seed Technology Laboratory, Faculty of Agriculture, Universitas Sumatera Utara.The materials used in this study include seeds of Local red Chili harvested from Lubuk Cuik Village, Lima Puluh Pesisir district, Batubara, Sumatera Utara, pot trays, hand sprayer, water for irrigation, sand as planting medium, labels for marking each treatment, and other supporting materials.

Research method
This research used a Randomized Complete Block Design (RCBD) non-factorial with the treatment of harvest age, namely: P1 = Harvested in the first week, P2 = Harvested in the second week, P3 = Harvested in the third week, P4 = Harvested in the fourth week, P5 = Harvested in the fifth week, P6 = Harvested in the sixth week, and P7 = Harvested in the seventh week.The research was repeated four times.The number of seeds per pot tray was 50 seeds.The total number of seeds was 1400 seeds.

Research implementation seed preparation
Harvesting is done mechanically using scissors or cutters.Harvesting is carried out according to harvest time in Lubuk Cuik Village.The harvested fruit is collected, first the seeds are split to remove the seeds.The seeds used are seeds that are uniform in size, not attacked by fungi.

Preparation of seed germination media.
The germination medium used is sand with a thickness of ± 5 cm.Before use, the sand is first sifted with a 20-mesh sieve and sterilized by roasting it for ± 30 minutes to remove contamination from fungi and bacteria.Seed germination was carried out in pot trays with 50 planting holes per research unit.

Maintenance.
Watering is carried out in the morning and evening using a hand sprayer until the media becomes moist, maintenance is carried out every day until 21 days after the seeds are planted and research activities are scheduled.

Data Analysis
Data analysis is using analysis of variance and data that significantly affect will be tested using Duncan Multiple Range Test at a significance level of 5%.

Weight of 100 seeds
The difference in harvest time significantly influenced the weight of 100 chili seeds.The highest weight of 100 seeds was observed in the treatment with harvest in the third week (P3) with a value of 0.72 grams, which was significantly different from all other harvest time treatments.Conversely, the lowest weight of 100 seeds was found in the treatment with harvest in the seventh week (P7) with a value of 0.48 grams, also significantly different from all other harvest time treatments (Table 1).
This variation in seed weight can be attributed to the fact that seed weight increases with the age of harvest, reaching its peak at the third-week harvest.During this period, the growth and development of chili plants are at their maximum, allowing for efficient photosynthesis and the production of larger chili fruits.This aligns with the findings of [6], which suggest that the seed formation phase requires a high rate of assimilate production and allocation to the seeds.The rate of photosynthesis for assimilate production is influenced by factors such as light, leaf health, and nutrient availability.
In summary, the timing of chili harvest time significantly affects the weight of chili seeds, with the highest seed weight observed when harvesting in the third week.This information can be valuable for optimizing seed quality and yield in chili cultivation for sustainable agriculture in the context of maintaining biodiversity and the flexibility of biological or genetic resources.

Maximum Growth Potential
The difference in harvest time significantly affects the maximum growth potential at 7 days and 14 days (Table 2).The highest maximum growth potential at 7 days was observed in the third-week harvest treatment (P3) with a value of 94.50%, while the lowest maximum growth potential at 7 days was in the seventh-week harvest treatment (P7) with a value of 49%.The highest maximum growth potential at 14 days was observed in treatments (P2), (P3), and (P4) with a value of 97.50%, and the lowest maximum growth potential at 14 days was in the seventh-week harvest treatment (P7) with a value of 87%.This is because at the third-week harvest, the weight of 100 seeds also showed an increase, indicating a positive correlation, i.e., the seeds had maximum food reserves and sufficient water content for germination.This is in accordance with [7], which states that the larger the food reserves in a seed, the higher the viability of the seed will be.Physiologically mature seeds have a high potential for growth, germination capacity, and strong vigor in their growth.

Germination Test
The difference in harvest time significantly affects the percentage of normal germination, abnormal germination, and dead germination (Table 3).The highest percentage of normal germination wasfound in the fourth-week harvest treatment (P4) with a value of 97.50%, which was not significantly different from all other treatments except for the seventh-week harvest (P7), which had the lowest value of 85.50%.The fourth-week harvest treatment appears to be the best time for germination.This is supported by [8], which states that seeds harvested at the right time have optimal food reserves, which support germination.
The highest percentage of abnormal germination was observed in the second-week harvest treatment (P2) with a value of 6.50%, significantly different from all other harvest time treatments.The lowest percentage of abnormal germination was found in the fourth-week harvest treatment (P4) with a value of 0%.This is likely because in the second-week harvest treatment, the seeds were not fully matured.According to Ashworth [9], seeds harvested before or after physiological maturity may not achieve optimal growth and production, possibly due to the seeds not being fully mature (in the case of harvesting before physiological maturity) or entering a phase of senescence (in the case of harvesting after physiological maturity).
The highest percentage of dead germination was observed in the seventh-week harvest treatment (P7) witha value of 13.0%, not significantly different from the fifth and sixth-week harvests (P5 and P6), but significantly different from the first to fourth-week harvests (P1 -P4).The lowest percentage of dead germination was found in treatments (P2), (P3), and (P4) with a value of 2.50%.Seeds produced from fruits harvested in the seventh week (the last week) may have experienced nutrient deficiencies, leading to a decrease in seed germination capacity.

Germination Rate
The difference in harvest time significantly influences the germination rate of the seeds (Table 4).The fastest germination rate was observed in the third-week harvest treatment (P3) with values of 5.05 days and 5.18 days.The slowest germination rate was found in the seventh-week harvest treatment (P7) with values of 7 days and 7.64 days (Table 4).This is expected because seeds harvested at that time have reached full maturity, which can enhance their viability and germination vigor.According to [10], factors affecting seed germination include factors within the seed itself, such as seed maturity level and seed size.In this study, the chili fruits used were physiologically mature, and in the third-week harvest, they had the highest weight of 100 seeds.This indicates a positive correlation, where larger food reserves in the seed lead to increased seed viability.Physiologically mature seeds have a high potential for growth, germination capacity, and strong germination vigor.

Vigor Index
The difference in harvest time significantly influences the seed vigor index.The highest vigor index was observed in the third-week harvest treatment (P3) with values of 9.60 and 9.76.The lowestvigor index was found in the seventh-week harvest treatment (P7) with values of 3.50 and 5.77 (Table 5).The treatment at the third-week harvest exhibited the highest vigor, and this is directly proportional to the germination rate and 100-seed weight.A rapid germination rate and high 100-seed weight contribute to high seed vigor.This aligns with [11], where seeds with a high weight will also have high vigor because ofthe efficient utilization of food reserves inside the seed.Seeds with high vigor can efficiently form and transport raw materials to the embryo axis rapidly.

Conclusion
Based on the conducted research, it can be concluded that the optimal harvesting time is in the third and fourth weeks.Harvesting in the third and fourth weeks yields the highest seed quality as it provides the best results, maximum growth potential, germination capacity, and the highest seed vigor, as well as a rapid germination rate.The information regarding the best harvest time is very useful in sustainable agriculture related to maintaining genetic resources.

Table 1 .
The weight of 100 chili seeds for each harvest age treatment Note: Numbers followed by different letters are significantly different based on Duncan's Multiple Range Test at the α level 5%

Table 2 .
Maximum growth potential in each treatment at harvest time Note: Numbers followed by different letters are significantly different based on Duncan's Multiple Range Test at the α level 5%

Table 3 .
Percentage of normal, abnormal, and dead germination in each harvest time

Table 4 .
Germination rate in each harvest time treatment Note: Numbers followed by different letters in the same column indicate statistically significant differences based on Duncan's Multiple Range Test at the α level 5%.

Table 5 .
Seed vigor index in each harvest time treatment Note: Numbers followed by different letters in the same column indicate statistically significant differences based on Duncan's Multiple Range Test at the α level 5%.
[1] Alfian A 2018 Decision Support System for Determining Land Feasibility in Red Chili Cultivation Using the Simple Additive Weighting (SAW) Method Universitas Nusantara PGRI Kediri